U.S. patent application number 12/431551 was filed with the patent office on 2010-04-08 for enhancement of surface-active solid-phase heterogeneous catalysts.
This patent application is currently assigned to CCMI Corporation. Invention is credited to Mitchell A. Cotter.
Application Number | 20100087695 12/431551 |
Document ID | / |
Family ID | 37614108 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100087695 |
Kind Code |
A1 |
Cotter; Mitchell A. |
April 8, 2010 |
ENHANCEMENT OF SURFACE-ACTIVE SOLID-PHASE HETEROGENEOUS
CATALYSTS
Abstract
Surface-active solid-phase catalyst activity may be
substantially improved by creating deliberate repetitive
surface-to-surface contact between portions of the active surfaces
of catalyst objects. While they are immersed in reactant material
such contact between portions of the active surfaces of catalyst
objects can substantially activate the surfaces of many
heterogeneous catalysts. Examples are given of such action
employing a multitude of predetermined shapes, supported catalyst
structures, etc. agitated or otherwise brought into contact to
produce numerous surface collisions. One embodiment employs a gear
pump mechanism with catalytically active-surfaced gear teeth to
create the repetitive transient contacting action during pumping of
a flow of reactant. The invention is applicable to many other forms
for creating transient catalytic surface contacting action.
Optionally catalytic output of such systems may be significantly
further improved by employing radiant energy or vibration.
Inventors: |
Cotter; Mitchell A.;
(Raleigh, NC) |
Correspondence
Address: |
WOLF GREENFIELD & SACKS, P.C.
600 ATLANTIC AVENUE
BOSTON
MA
02210-2206
US
|
Assignee: |
CCMI Corporation
Spring Valley
NY
|
Family ID: |
37614108 |
Appl. No.: |
12/431551 |
Filed: |
April 28, 2009 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11499851 |
Aug 3, 2006 |
|
|
|
12431551 |
|
|
|
|
60705656 |
Aug 3, 2005 |
|
|
|
Current U.S.
Class: |
585/700 ;
422/211; 502/100 |
Current CPC
Class: |
B01J 19/26 20130101;
B01J 2219/30234 20130101; B01J 8/02 20130101; B01J 35/023 20130101;
B01J 23/44 20130101; B01J 37/0225 20130101; Y10T 428/16 20150115;
F04C 2/084 20130101; B01J 2208/00672 20130101; F04C 13/00 20130101;
B01J 15/005 20130101; B01J 10/007 20130101; B01J 8/24 20130101;
B01J 2219/30416 20130101; B01J 12/007 20130101; B01J 2219/30296
20130101; B01J 19/30 20130101; B01J 19/18 20130101; B01J 2219/30408
20130101; B01J 8/222 20130101; B01J 19/1812 20130101; B01J 35/026
20130101; B01J 19/20 20130101; B01J 16/005 20130101; B01J
2219/30475 20130101; F04C 2/18 20130101; B01J 14/005 20130101; B01J
8/22 20130101; B01J 8/0095 20130101; F04C 2/10 20130101; B01J
2219/30246 20130101 |
Class at
Publication: |
585/700 ;
502/100; 422/211 |
International
Class: |
B01J 21/04 20060101
B01J021/04; B01J 8/02 20060101 B01J008/02; C07C 2/84 20060101
C07C002/84 |
Claims
1. A catalytic reactor system, comprising: at least two catalytic
objects, each object having at least one surface complementary in
shape and/or contour to at least one surface on another of the
catalytic objects such that a projected contact area between two of
the catalytic objects is capable of being greater than 1% of a
catalytically active total external contact surface area of the two
contacting catalytic objects; and a contact-inducing device
configured and arranged to repeatedly bring complementary surfaces
of the at least two catalytic objects into contact with each other
such that the a projected contact area between two of the
contacting catalytic objects is on average greater than 1% of the
catalytically active total external contact surface area of the two
contacting catalytic objects.
2. The catalytic reactor system as in claim 1, comprising at least
two catalytic objects each object having at least one surface
complementary in shape and/or contour to at least one surface on
each other of the catalytic objects such that a projected contact
area between any two of the catalytic objects is capable of being
greater than 1% of a catalytically active total external contact
surface area of the two contacting catalytic objects.
3.-7. (canceled)
8. The catalyst reactor system as in claim 1, wherein the catalytic
objects are essentially non-porous.
9.-15. (canceled)
16. The catalyst reactor system as claim 1, further comprising a
reactor comprising an inlet configured to allow a reactant to flow
into the reactor and an outlet configured to allow a product to
flow out of the reactor, wherein the catalytic objects are
contained within the reactor such that the catalytic objects are
exposed to the reactant.
17. (canceled)
18. (canceled)
19. A method for performing a reaction catalyzed by a heterogeneous
catalyst, comprising acts of: exposing at least two objects each
object having at least one surface complementary in shape and/or
contour to at least one surface on another of the objects, at least
one of which objects is a catalytic object having a surface that is
catalytically active, to an environment comprising a selected
reactant, creating repeated contact between the objects such that a
projected contact area between complementary surfaces of two
contacting objects is on average greater than 1% of a catalytically
active total external contact surface area of the two contacting
objects, allowing the predetermined reactant to undergo a chemical
reaction at the at least one catalytically active surface to
produced a product.
20.-26. (canceled)
27. A catalytic object, comprising an external surface comprising a
plurality of mosaic patches/facets wherein at least one mosaic
patch/facet meets an adjacent facet at an edge to form a
predetermined three-dimensional shape, wherein at least one mosaic
patch/facet comprises a catalytically active material.
28.-32. (canceled)
33. The catalytic object of claim 27, wherein the predetermined
three-dimensional shape is essentially a truncated icosahedron.
34.-38. (canceled)
39. A catalytic reactor system, comprising a mechanical apparatus
constructed and arranged to intermittently create contact between a
catalytically active surface of a catalyst object and a contact
surface of a second object, such that a projected contact area on
average between the two objects is greater than 1% of the total
external contact surface area of the two contacting objects.
40.-44. (canceled)
45. A method for producing catalytic action upon at least one
reactant material, comprising: providing at least two catalytic
objects, wherein the catalytic objects each comprise a
catalytically active material on at least a portion of an external
surface, exposing the catalytic objects to an environment
comprising the reactant material, producing motion of the catalyst
objects sufficient to cause repeated frequent transient surface to
surface impacting contact events between external surface areas of
the catalyst objects using a contact-inducing device, the contact
events each having on average a projected contact area larger than
1% of the average total projected contact surface area of the
catalyst objects coming into contact during the contact event, and
transforming at least some reactant material into a product
chemically different from the reactant material.
46.-63. (canceled)
64. The method according to claim 45, wherein a shape of the
catalytic objects is substantially the same as a truncated
icosahedron having rounded edges joining adjacent essentially
planar mosaic patches/facets, wherein the width of a rounded edge,
defining a minimum distance separating adjacent essentially planar
mosaic patches/facets, does not exceed about 2% of the nominal
overall diameter of the truncated icosahedron.
65. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 11/499,851, entitled ENHANCEMENT OF SURFACE-ACTIVE SOLID-PHASE
HETEROGENEOUS CATALYSTS, filed on Aug. 3, 2006, which is herein
incorporated by reference. U.S. application Ser. No. 11/499,851
claims priority under 35 U.S.C. .sctn. 119(e) to U.S. Provisional
Application Ser. No. 60/705,656, filed Aug. 3, 2005, the contents
of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present disclosure describes heterogeneous catalysts and
catalyst reactor systems and related methods, which employ
surface-active solid-phase catalyst materials acting on reactant
matter.
BACKGROUND OF THE INVENTION
[0003] Catalyst materials promote chemical reactions but do not
themselves enter into the output product nor are they consumed by
the reaction. "Heterogeneous catalysis" refers to a catalytic
process in which the physical states of the catalyst and reactant
(material involved in the chemical reaction) are different. This is
distinguished from "homogeneous catalysis", where the reactant and
the catalyst have the same physical state and, as a result form
solutions or miscible mixtures (liquid/liquid; gas/gas). For
example, the physical state of heterogeneous catalyst material may
typically be solid-phase (e.g., a metal or ceramic) while the
reactants may be gases and/or liquids. Therefore, the "surfaces" of
a solid catalyst material that may contact a reactant play a
significant role in catalysis.
[0004] However, with advancing knowledge of the nature of "states
of matter" many conventional theoretical models of solid, liquid or
gas may be poorly suited to describe the range of states of matter.
A "surface" displays far more complexity than an oversimplified
image of a visual plane used in many conventional models to
describe it. The theoretical model of a sharp boundary as
characteristic of a surface may be misleading for understanding
certain catalytic surface activity. Instead, a surface of a solid
may be viewed as a zone or transition region where close spaced
atomic groups inside the solid taper off as the view looks toward
the edge of the surface zone. Inside, the solid components are
closely bound but at the surface such bonding is disturbed.
[0005] For more than a century, countless specific examples of
catalysts have been cataloged, developed and applied. The many
known reactions presently form the foundation of most of the
world's chemical industry. Recognition of catalytic effects began
at the dawn of the 19.sup.th century. In the early 20.sup.th
century, many large industrial scale reactions began utilizing
important industrial processes using heterogeneous catalysts.
Notable examples are the Haber-Bosch ammonia synthesis (fertilizers
for world agriculture), the Fischer-Tropsch hydrocarbon synthesis
(oil, gasoline and hydrocarbon materials), and the synthesis of
plastic materials, resulting in a vast polymer chemical industry.
Catalytic processes in the chemical industries of the world
currently have enormous commercial significance. A large fraction
of all chemical production is catalyst based. Some approaches to
fundamental theories of catalysis exist, such as the Density
Functional Theory, which involves mathematical approximation of
some quantum-mechanical factors representing chemical bonding.
Nevertheless, development of products and processes remain largely
based on pragmatic experimental approaches. Consequently, the field
of heterogeneous catalysis is replete with "recipes" for producing
various kinds of catalysts utilizing a wide variety of materials
and constructions. In fact, catalysts are often known by the
molecular species of their reactions rather than by their mode of
action or even by their construction. Three typical examples of
recent US Patents involving catalysts are: U.S. Pat. No. 6,821,922
to Tacke et al "Supported Catalyst For The Production Of Vinyl
Acetate Monomer"; U.S. Pat. No. 6,852,669 to Voit et al
"Hydrogenation Catalyst"; and U.S. Pat. No. 6,867,166 to Yang et al
"Selective Adsorption Of Alkenes Using Supported Metal Compounds".
A product descriptive brochure from the Johnson Matthey Company, a
major supplier of catalyst materials, is similarly functionally
descriptive for each of a group of Palladium based products the
company offers for carbon-carbon bonding. (See brochure available
on the Internet at www.amcpmc.com/pdfs/producttype/45.pdf). In
short, the chemist's understanding of the foundational fundamentals
of catalyst art progresses but as yet is incomplete.
[0006] Heterogeneous catalysts having a spherical particle shape
have often been employed as catalysts and catalyst substrates. Such
interest has typically been in pursuit of large apparent surface
area for contact with reactant, with some added concern for thermal
properties such as heat transfer in exothermic reactions. For
example, U.S. Pat. No. 6,747,180 to Ostgard et al, "Metal Catalyst"
describes the forming of hollow metallic spheres of 0.5 mm to 20 mm
diameter. Its focus appears to be reduction of the amount of
expensive metal unavailable in the sphere's interior to the
catalytic surface of the desired spherically shaped particles.
[0007] U.S. Pat. No. 5,237,019 to Weiland et al, describes small
spherical particles of from 0.01 to 30 mm diameter composed of
organosiloxane materials containing platinum group metals. The
particles are specified to have a bulk density below that of water
while allowing a wide range of surface area to be obtained from
varied particle size. Obtaining large surface area this way appears
a major objective. Emphasis is also placed on the character of the
catalyst metal dispersed in of such compositions.
[0008] U.S. Pat. 6,518,220 to Walsdorff et al, describes "Shaped
Catalysts" of a hollow cylindrical or annular form of a
catalytically active material. Improved selectivity of the
preferred shape as well as reduced pressure drop are the disclosed
objectives of the design.
[0009] In several U.S. Patents to Wang et al (U.S. Pat. Nos.
4,804,796, 4,701,436 and 4,576,926), hollow spheres are disclosed
that are formed in various ways to enable the effective density of
such spheres to be made to allow such to float in a medium of
choice. An object of these patents is to improve the dispersion of
such catalyst in the selected reactant medium.
[0010] U.S. Pat. No. 3,966,644 to Gustafson, titled "Shaped
Catalyst Particles" describes a longitudinally symmetric trilobe
shaped alumina composite catalyst particle having a narrow range of
sizes and specific porosity characteristics claimed useful for
hydrocarbon conversions of petroleum residuum. The shape is
discussed in terms of its void ratio and flow properties, improved
activity, claimed longer duration of effective operating time and,
superior crush resistance.
[0011] U.S. Patent Application US 2005/0130837 by Hoek et al,
titled "Shaped Catalyst Particles For Hydrocarbon Synthesis"
describes a trilobular extruded shaped catalyst form, having a void
ratio in excess of 50%, well in excess of the 43% or so of other
trilobal designs. Flow rates appear to be a principal concern of
these applicants.
[0012] U.S. Pat. No. 4,293,445 to Shimizu et al "Method For
Production of Molded Product Containing Titanium Oxide" discloses
the addition a small proportion of barium for improving the
strength of the ceramic catalyst product.
[0013] A focus of conventional improvements in the catalyst art has
been to maximize the surface area of catalyst material exposed to
the reactant. This has been accomplished via various means: in one
way through creation of powdery and porous materials; in another
through high surface area geometries; in another through the use of
chemical processes acting on the catalyst's surface to "activate"
or "refresh" it.
[0014] Certain investigators outside the field of chemistry and
catalysis have observed what they believed to be detrimental
effects of surface-surface contact in the context of electrical
switches and relays. Such phenomena were studied in a series of
papers coming from The Bell Laboratories in the early 1950s (See,
The Bell System Technical Journal, May 1958 pp 738-776, "Organic
Deposits on Precious Metal Contacts" By H. W. Hermance & T. F.
Egan). The Bell Labs workers' motivation for the study came from
examining the intermittent failure of telephone exchange switching
relays caused by accumulation of organic deposits formed on their
contacts.
[0015] Surprisingly this problem was exacerbated when efforts were
made to hermetically seal a very large number of switching relays
employed in a telephone exchange of that era. The sealing effort
initially seemed desirable to protect the contacts from dust and
airborne contaminants. However, small amounts of organic vapor
inside the sealed relays (coming from magnet wire, insulation, and
other organic material of their fabrication) were not eliminated
and deposited on the contacts sealed inside. The resulting problems
were severe because the "open" circuit caused by a deposit would
soon disappear, making it difficult to locate. The Bell researchers
devised non-current carrying relay-contact-operating mechanisms to
evaluate various kinds of contact material and environments. The
signal circuits that appeared most vulnerable carried essentially
no current through the relay contacts and operated only with very
small signal voltages. Such "dry circuit" operation could provide
no arcing actions that might clean contacts. The Bell Labs
researchers discovered that the carefully chosen corrosion
resistant group 10 (platinum group) contact metals were very prone
to forming the disturbing organic deposits they named "contact
polymers."
[0016] While much effort has been directed to increasing catalysts'
effective surface area as determined by gas adsorption tests, the
resulting increase in surface complexity and porosity has also led
to detrimental reactant trapping and retarded movement of reaction
materials. Accordingly, improved heterogeneous catalysts, catalyst
systems and catalytic reaction methods are still needed.
SUMMARY OF THE INVENTION
[0017] The present invention involves, in certain embodiments,
utilization of repeated catalyst-to-catalyst surface contact to
excite catalytic activity of the contacting surfaces. Previous
research has shown such contacting can produce surface defects and
rearrangement of constituent atoms on contacting surfaces. The
applicability and utility of this phenomena appears to be
previously unrecognized and unapplied in the field of catalysis. As
discussed below, such surface-to-surface contact may be utilized to
enhance catalytic activity.
[0018] The present invention provides catalytic reactor systems
comprising at least two catalytic objects each object having at
least one surface complementary in shape and/or contour to at least
one surface on another of the catalytic objects such that a
projected contact area between two of the catalytic objects is
capable of being greater than 1% of a total catalytically active
external contact surface area of the two contacting catalytic
objects, and a contact-inducing device configured and arranged to
repeatedly bring complementary surfaces of the at least two
catalytic objects into contact with each other such that the a
projected contact area between two of the contacting catalytic
objects is on average greater than 1% of the catalytically active
total external contact surface area of the two contacting catalytic
objects.
[0019] In one embodiment, the catalytic reactor system comprises at
least two catalytic objects each object having at least one surface
complementary in shape and/or contour to at least one surface on
each other of the catalytic objects such that a projected contact
area between any two of the catalytic objects is capable of being
greater than 1% of a catalytically active total external contact
surface area of the two contacting catalytic objects. In another
embodiment, each of the two catalytic objects comprises at least
one essentially planar surface such that an essentially planar
surface of a first catalytic object is capable of contacting an
essentially planar surface of a second catalytic object.
[0020] Catalytic objects of the present invention may comprise a
catalytically active material comprising a metal or metal alloy.
Catalytic objects of the present invention may further comprise a
support material coated with a catalytically active material. In
one embodiment, the support material is a ceramic. In another
embodiment, the at least two catalytic objects comprise discrete
particles or pellets. In another embodiment, the catalytic objects
are essentially non-porous.
[0021] In one embodiment, the catalyst reactor system comprises an
industrial scale slurry bubble column reactor and the
contact-inducing device comprises a device configured to generate
fluid flow capable of suspending and/or agitating the discrete
particles or pellets. In one embodiment, the catalyst reactor
system comprises an industrial scale continuously stirred tank
reactor wherein the contact-inducing device comprises a stirring
device. In some embodiments, the contact-inducing device comprises
a mechanical apparatus comprising or to which is attached at least
one of the catalytic objects.
[0022] In one embodiment, the catalyst objects are discrete
particles or pellets having a shape that is essentially a truncated
icosahedron. In another embodiment, at least one of the catalytic
objects has a shape that is essentially a cylinder. In another
embodiment, a cross-section of the cylinder perpendicular to its
longitudinal axis has a perimeter that is polygonal. In another
embodiment, at least one of the catalytic objects is configured as
a gear having a plurality of gear teeth.
[0023] In certain embodiments, the catalyst reactor system further
comprises a reactor comprising an inlet configured to allow a
reactant to flow into the reactor and an outlet configured to allow
a product to flow out of the reactor, wherein the catalytic objects
are contained within the reactor such that the catalytic objects
are exposed to the reactant.
[0024] Another aspect of the present invention provides a method
for performing a reaction catalyzed by a heterogeneous catalyst,
comprising acts of: exposing at least two objects each object
having at least one surface complementary in shape and/or contour
to at least one surface on another of the objects, at least one of
which objects is a catalytic object having a surface that is
catalytically active, to an environment comprising a selected
reactant; creating repeated contact between the objects such that a
projected contact area between complementary surfaces of two
contacting objects is on average greater than 1% of a catalytically
active total external contact surface area of the two contacting
objects; and allowing the predetermined reactant to undergo a
chemical reaction at the at least one catalytically active surface
to produced a desired product.
[0025] In one embodiment, each of the objects is a catalytic object
having a surface that is catalytically active. In another
embodiment, each of the catalytic objects comprises at least one
essentially planar surface having an area comprising at least about
1% of the catalytically active external surface area of the
object.
[0026] In some embodiments, the catalyst objects are immersed in
the environment. In one embodiment, the environment is a solution
comprising the predetermined reactant. In another embodiment, the
environment is a gas comprising the predetermined reactant.
[0027] In some embodiments, the contact is recurring and transient.
In some embodiments, the contact causes at least a portion of an
external catalytically active surface area of the catalytic object
to become regenerated.
[0028] The present invention also relates to catalytic objects
comprising an external surface comprising a plurality of mosaic
patches/facets wherein at least one mosaic patch/facet meets an
adjacent facet at an edge to form a predetermined three-dimensional
shape, wherein at least one mosaic patch/facet comprises a
catalytically active material.
[0029] In one embodiment, an individual mosaic patch/facet has a
surface area greater than 1% of the total external surface area of
the catalytic object. In another embodiment, each mosaic
patch/facet comprises a catalytically active material. In some
embodiments, at least one mosaic patch/facet is essentially planar.
In some embodiments, each mosaic patch/facet is essentially
planar.
[0030] In one embodiment, the catalytically active material
comprises a metal or metal alloy.
[0031] In one embodiment, the predetermined three-dimensional shape
is essentially a truncated icosahedron. In another embodiment, the
predetermined three-dimensional shape is essentially a cylinder. In
another embodiment, the predetermined three-dimensional shape is
essentially in the form of gear teeth on a gear.
[0032] In some embodiments, the edge where two adjacent mosaic
patches/facets meet is rounded.
[0033] Some embodiments of the catalyst object further comprise a
support material coated with the catalytically active material. In
one embodiment, the support material is a ceramic.
[0034] The present invention also relates to catalytic reactor
systems comprising a mechanical apparatus constructed and arranged
to intermittently create contact between a catalytically active
surface of a catalyst object and a contact surface of a second
object, such that a projected contact area on average between the
two objects is greater than 1% of the total external contact
surface area of the two contacting objects. In one embodiment, the
contact surface of the second object is a catalytically active
surface. In some embodiments, the mechanical apparatus comprises a
motor. In some embodiments, the mechanical apparatus comprises a
gear pump device. In some embodiments, the mechanical mechanism
comprises a series of gear pump devices.
[0035] The present invention also provides methods for producing
catalytic action upon at least one reactant material, comprising:
providing at least two catalytic objects, wherein the catalyst
objects each comprise a catalytically active material on at least a
portion of an external surface; exposing the catalytic objects to
an environment comprising the reactant material; producing motion
of the catalyst objects sufficient to cause repeated frequent
transient surface to surface impacting contact events between
external surface areas of the catalyst objects using a
contact-inducing device, the contact events each having on average
a projected contact area larger than 1% of the average total
projected contact surface area of the catalyst objects coming into
contact during the contact event; and transforming at least some
reactant material into a desired product chemically different from
the reactant material.
[0036] In one embodiment, the repeated frequent transient surface
to surface impacting contact events progressively occur such that
essentially all the catalytically active external surface of the
catalyst objects comes into contact during the method. In another
embodiment, the motion averages distribution of the contact events
over essentially all the catalytically active exterior surfaces of
all the objects.
[0037] In one embodiment, the motion averages distribution of the
contact events over a majority of the catalytically active exterior
surfaces of the objects. In another embodiment, the motion averages
distribution of the contact events over limited portions of the
external surfaces of the objects comprising the catalytically
active surfaces.
[0038] In one embodiment, the catalytically active external surface
of at least a portion of at least one catalyst object is segregated
into mosaic patches/facets, each mosaic patch/facet having an
exterior surface area that is substantially less than the total
catalytically active external surface area of the at least one
catalyst object. In one embodiment, a first mosaic patch/facet of
the catalyst object which is segregated into mosaic patches/facets
has a composition of surface material different from a second
mosaic patch/facet on the same catalyst object. In another
embodiment, a first mosaic patch/facet of a first catalyst object
which is segregated into mosaic patches/facets has composition of
surface material different from a second mosaic patch/facet on a
second catalyst object which is segregated into mosaic
patches/facets.
[0039] In one embodiment, the aspect ratio of at least one
catalytic object is less than about 1.05. In another embodiment,
the aspect ratios of each of the catalytic objects is between about
1.25 and about 1.05. In another embodiment, the aspect ratio of at
least one of the catalytic object is between 1.25 and 2.00. In
another embodiment, the aspect ratio of at least one of the
catalytic objects is between about 2.00 and about 3.00. In another
embodiment, the aspect ratio of at least one of the catalytic
object is greater than about 3.00.
[0040] In one embodiment, all the catalytic objects have
essentially the same shape and size.
[0041] In one embodiment, all the catalytic objects have
essentially the same shape but differ by more than 5% from at least
one other catalytic object in size.
[0042] In certain embodiments, the external surface of the
catalytic objects comprise mosaic patches/facets, and wherein at
least a first and a second catalytic objects have different
polyhedral shapes from each other. In a particular embodiment, the
first catalytic object differs by more than about 5% in size from
the second catalytic object.
[0043] In some embodiments, the external surface of the first
catalytic object comprises a first number of mosaic patches/facets
while the external surface of the second catalytic object comprises
a second number of facets. In a particular embodiment, the first
catalytic object differs by more than about 5% in size from the
second catalytic object.
[0044] In one embodiment, a shape of the catalytic objects is
substantially the same as a truncated icosahedron having rounded
edges joining adjacent essentially planar mosaic patches/facets,
wherein the width of a rounded edge, defining a minimum distance
separating adjacent essentially planar mosaic patches/facets, does
not exceed about 2% of the nominal overall diameter of the
truncated icosahedron.
[0045] In one embodiment, the sizes of corresponding dimensions of
any two catalyst objects are within 5% of each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] The accompanying drawings are schematic and are not intended
to be drawn to scale. In the figures, each identical, or
substantially similar component that is illustrated in various
figures is typically represented by a single numeral or notation.
For purposes of clarity, not every component is labeled in every
figure, nor is every component of each embodiment of the invention
shown where illustration is not necessary to allow those of
ordinary skill in the art to understand the invention. In the
drawings:
[0047] FIG. 1 (prior art) is a plot representing the change of
state occurring when two components A and B link chemically with
some possible changes in energy occurring;
[0048] FIG. 2 shows a perspective view of a Truncated
Icosahedron;
[0049] FIG. 3 shows a perspective view of a geometrically ideal
Truncated Icosahedron;
[0050] FIGS. 4A and 4B show a view of all thirty-two faces of a
Truncated Icosahedron laid flat and adjoining (FIG. 4B) showing
relationship of faces;
[0051] FIG. 5 shows the shape of softened TICO facet edges of a
Truncated Icosahedron (e.g. as shown in FIG. 2 or FIG. 3);
[0052] FIG. 6 shows a cross-sectional view of a tilted Truncated
Icosahedron TICO facet plane, intersecting the mold parting face
(parting line);
[0053] FIG. 7 shows an exploded and internal view of basic gear
pump mechanism comprising a gear having gear teeth comprising a
catalytically active material according to one embodiment of the
invention;
[0054] FIGS. 8A and 8B show a nine-sided cylindrically symmetric
catalyst substrate pellet according to one embodiment of the
invention;
[0055] FIG. 9 illustrates a geometric hecatohedron;
[0056] FIGS. 10A and 10B show a dome design for nine-sided
cylindrical catalyst pellet ends;
[0057] FIG. 11 shows a cross-sectional view of a star roller
catalytic object in a cylindrical reactor chamber according to an
embodiment of the invention;
[0058] FIGS. 12A-12C show a cross-sectional view (FIG. 12A) and top
views (FIGS. 12B and 12C) of an anvil/striker catalytic object
reactor test apparatus according to an embodiment of the
invention;
[0059] FIG. 13 shows an anvil/striker catalytic reactor test
apparatus according to one embodiment of the invention;
[0060] FIGS. 14A-14C show various views of an anvil portion of the
anvil/striker catalytic reactor apparatus of FIG. 13;
[0061] FIGS. 14D-14E show close-up views of the anvil apparatus of
FIGS. 14A-14C;
[0062] FIGS. 15A-15B show views of a striker and striker suspension
portion of the anvil/striker catalytic reactor test apparatus of
FIG. 13;
[0063] FIG. 16 shows a process flow diagram of a catalytic reactor
and analytical system including the anvil/striker catalytic reactor
test apparatus of FIG. 13 used for performing Examples 6-15;
[0064] FIGS. 17A-C show a PIN link air-bearing assembly the
anvil/striker catalytic reactor test apparatus of FIG. 13 of;
[0065] FIG. 18 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, at 70.degree. C.;
[0066] FIG. 19 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, at 150.degree. C.;
[0067] FIG. 20 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is lowered from
71.degree. C. to 31.degree. C.;
[0068] FIG. 21 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is raised from
60.degree. C. to 80.degree. C.;
[0069] FIG. 22 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is raised from
30.degree. C. to 92.degree. C.;
[0070] FIG. 23 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is raised from
100.degree. C. to 200.degree. C.;
[0071] FIG. 24 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is lowered from
85.degree. C. to 40.degree. C.;
[0072] FIG. 25 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is raised from
24.degree. C. to 130.degree. C.; and
[0073] FIG. 26 is a graph showing the mass numbers and abundance of
species in the product gas for (a) an "unstruck" portion of a Pd
anvil and (b) a "struck" portion of a Pd anvil, sampled at various
times during a test run of the anvil/striker catalytic reactor test
apparatus of FIG. 13, wherein the temperature is lowered from
100.degree. C. to 65.degree. C.
DETAILED DESCRIPTION
Definitions
[0074] As used herein, "contact" in the context of catalytic
objects or other solid phase surfaces refers to an intimate
meeting, on an atomic basis, of at least some surface material
substance of each of two, generally solid-phase, different meeting
bodies. Such contact may transfer material between the meeting
bodies and/or at least reposition some material on one or both
bodies.
[0075] This disclosure brings new specific meaning to the word
"contact." Typically, the term "contact" in the catalyst arts
generally is used only in the context of bringing some reactant
together with some solid (often a catalyst) upon which some
reaction follows.
[0076] The present invention introduces a broad range of inventive
embodiments of a potent, fundamental surface-active catalyst
enhancement involving defined and very specific kinds of
contact.
[0077] "Solid-phase" refers to matter in the solid-state, i.e., in
solid association substantially maintaining its inter-atomic
configuration; neither liquid nor gas.
[0078] "Catalyst object" or "catalytic object" refers to a discrete
physical, substantially solid-phase object having an external
surface possessing some catalytic properties when present in some
specified environment designated for its use.
[0079] "External surface" or "exterior surface" of an object refers
to all boundary points between the material substance of a
generally solid-phase object and all surrounding points in space
that touch the object but do not coincide with any material that
remains joined to the object.
[0080] "Surface zone" of a generally solid-phase object refers to a
region relative to its external surface, influencing the object's
catalytic activity, which extends from at least several microns
interior to that surface to least several microns exterior to it,
understanding that such boundaries are somewhat diffuse.
[0081] "Surface-active catalyst" refers to the majority of
catalytic action of such a physical catalyst object occurring
within or upon a surface zone of such catalyst object.
[0082] "Contact event" or "contacting event" refers to the
occurrence of an individual contact for at least some finite period
of time that may be only of extremely brief duration.
[0083] "Separation event" refers to the parting of an existing
contact of at least a minimum separation distance of two microns
and, for a finite period of time greater than one microsecond.
[0084] "Open time" refers to the time elapsed from a separation
event to the next occurring contact of either separated contact
surface.
[0085] "Contact condition" refers to contact occurring in one or
many instances during a defined time period.
[0086] "Average contact duty cycle" refers to the ratio of average
closed time to the average time between recurrences of contact for
any defined particular contact condition, or for a defined set of
contact events.
[0087] "Impacting contact event" refers to the occurrence of a
contact event that produces an effect on more than one atom of at
least one of the contacting objects either transferring atom(s)
between meeting surfaces, or at least two atoms becoming
repositioned in at least one catalyst object's surface.
[0088] "Projected contact area" refers to the maximum possible area
of contact during a contact event, defined as the area included
within the coincident boundaries of contact between the two
contacting surfaces as if completely merged into one another. Such
a projected contact area is therefore typically larger than the
actual area of all minute material-to-material physical contact
occurring within that area.
[0089] "Total external contact surface" refers to the sum of all
possible different projected contact areas of a defined pair of
contacting objects, such as surface-active catalyst objects, or of
a defined set of such objects.
[0090] "TICO" is an aphorism for a catalyst substrate form that has
a shape modified slightly from a classical truncated
icosahedron.
[0091] The present invention relates in certain aspects to catalyst
reactor systems configured for creating contact between surfaces,
for example catalytically active surfaces, of catalyst objects
(e.g., solid-phase heterogeneous catalysts) and methods for
fabrication and use of such catalysts and catalyst reactor systems.
The present invention may comprise recurring transient catalyst
surface interactions. The present invention also relates, in
certain embodiments, to new geometries for catalysts, e.g.
particulate and/or pelleted catalysts (e.g. as illustrated in FIGS.
2-6 and 8-10), and to novel movement and deployment of
catalytically active surfaces to optimize the amount and frequency
of surface-to-surface contacting action. In some cases, a
substantial majority of the active surface area of the catalyst
objects may be employed. Catalysts and catalytic methods of the
present invention may increase catalytic productivity and may also
increase the transport of the heterogeneous reacting materials,
e.g. gases, liquids, slurries, and/or supercritical fluids, through
the catalyst surface zones, relative to other known catalysts and
catalytic methods.
[0092] In one embodiment, the present invention relates to
catalytic reactor systems comprising at least two catalytic objects
having complementary surfaces such that a projected contact area
between the two catalytic objects is on average greater than 1%,
2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or more of the catalytically
active total contact surface area of the catalytic objects, and a
contact-inducing device configured and arranged to bring the at
least two catalytic objects into contact with each other. As used
herein, "complementary surfaces" may refer to the surfaces of any
two objects (e.g., catalytic objects), or portions thereof, having
a shape, surface topography, and other characteristics that allow a
projected contact area defining intimate contact between the two
surfaces to be substantially coextensive with the entirety of the
external areas of the surfaces or portions. Examples of
complementary surfaces include two essentially planar surfaces; an
essentially conical projection and an essentially conical indent
(for same-sized cones); an essentially hemispherical bump and an
essentially hemispherical indent (for same-sized hemispheres); etc.
In one embodiment, a catalyst reactor system of the present
invention comprises catalytic objects each comprising at least one
essentially planar surface such that the essentially planar surface
of a first catalytic object is capable of contacting an essentially
planar surface of a second catalytic object. The catalytic object
may comprise a catalytically active material over at least a
portion or over essentially the entirety of its external surface.
In certain embodiments, the catalytic object may comprise a support
material at least partially coated by a catalytically active
material.
[0093] As used herein, a "contact-inducing device" refers to any
apparatus capable of bringing the catalyst objects into repeated
contact with each other. In some embodiments, the contact-inducing
device may be an agitation system of a reactor in which the
catalytic objects are placed, such as a slurry flow generating
apparatus of an industrial scale slurry bubble column reactor or an
impeller of an industrial scale continuously stirred tank reactor,
for example. In certain embodiments, the contact-inducing device is
a mechanical motor-driven apparatus which is configured to
physically position the surfaces of at least two catalyst objects
in contact with each other. In certain embodiments, a catalytic
reactor system may comprise a mechanical mechanism for placing at
least two catalyst objects in contact, such that a projected
contact area between the two catalytic objects is greater on
average than about 1% of the catalytically active total external
contact surface area of the catalytic objects. In certain such
cases, the mechanical mechanism may be a gear pump, a series of
gear pumps, or the like, and the catalyst objects may be in the
form of rotatable gears, or teeth thereof, or rollers which are
arranged to be in contact with each other and/or other surfaces.
FIG. 7 shows an exploded and internal view of basic gear pump
mechanism, while FIG. 11 illustrates a catalytic roller
assembly.
[0094] Catalyst or catalytic objects of the present invention may
comprise a plurality of facets, or equivalently "mosaic patches,"
wherein at least one facet meets an adjacent facet at an edge to
form a three-dimensional shape, wherein at least one facet
comprises a catalytically active material. In some cases, an
individual facet has a surface area greater than 1% of the total
external surface area of the catalytic object. In some embodiments,
a facet, or portions thereof, may comprise a catalytically active
material. The edges where the facets meet may be essentially
straight edges or edges which may be altered (e.g., rounded). The
facets may have surfaces that are essentially planar or non-planar.
It is advantageous if the surface contours of facets of catalyst
objects to be brought into contact are complementary, as defined
above. Faceted catalytic objects may comprise, in certain
embodiments, particulate or pelleted forms having, in certain
embodiments, particle sizes typical of those known in the art for
particulate catalysts. For example, particle sizes may be in the
range of 0.1 mm-25 mm, more typically from 1 mm-10 mm These
catalytic objects may be particularly well suited for use in
industrial scale reactors, such as slurry bubble column reactors,
fluidized bed reactors, continuously stirred tank reactor.
[0095] The shape of the catalyst objects may vary upon a particular
application, as described in further detail below. Examples of
potentially suitable shapes include, but are not limited to,
polyhedrons, such as a truncated icosahedron, cylinders, gears
(e.g., gear having gear teeth), etc.
[0096] The present invention also describes methods for performing
reactions catalyzed by a heterogeneous catalyst. Such methods may
comprises acts of exposing at least two catalytic objects, at least
one of which has surfaces that are catalytically active, to a
defined environment comprising a selected reactant; creating
contact between the catalyst objects such that a projected contact
area between the two catalytic objects is greater on average than
1% of the catalytically active total external contact surface area
of the catalytic objects; and allowing the selected reactant to
undergo a chemical reaction at a catalytically active surface to
produce a desired product. In certain embodiments, the catalyst
objects are immersed in and surrounded by the environment, which
may be a solution or pure material in liquid or gas form comprising
the predetermined reactant, for example. In certain embodiments,
methods of the present invention comprise contacting the catalyst
objects in a recurring and transient manner In some cases, this may
result in enhanced performance of the catalyst (e.g, higher
yields).
[0097] In certain cases, the recurring and transient contact
between catalytic objects may advantageously alter at least a
portion of the surface area of the catalytic objects, which may
affect or enhance catalytic behavior. In one embodiment, a first
catalytic object which is initially catalytically active may
contact a second catalytic object which is not initially
catalytically active, such that the contact causes the second
catalytic object to become catalytically active. In another
embodiment, the contact may enhance the catalytic behavior of a
catalyst object. In one embodiment, the contact may allow the
surface of the catalyst objects to become regenerated or
"refreshed," enhancing catalytic behavior.
[0098] With advancing knowledge of the nature of "states of matter"
conventional ideas of solid, liquid or, gas may no longer be
sufficient to describe the range of states of matter. It may be
advantageous to consider heterogeneous catalyst behavior in the
context of knowing that such state differences may be somewhat
"fuzzy." A "surface" typically displays far more complexity than
the oversimplified image of a visual plane often used to describe
it. Many surfaces may become quite active catalytically under
appropriate conditions. The conventional model of a sharp boundary
at a surface may be misleading for understanding catalytic
activity. Fundamentally, a surface of a solid may be viewed as a
zone or transition region where closely spaced atomic groups inside
the solid taper off as the view looks toward the edge of the
surface zone. Inside, the solid components are closely bound but at
the surface such bonding may be disturbed.
[0099] The term "surface" in much of the conventional catalyst art
has been applied in a way that does not reflect a full appreciation
of the nature of a surface at its active, small-atomic-scale
dimensions. By contrast, certain of the observations of the present
invention may be consistent with a concept of catalyst "surface"
wherein, atoms in the interior of a catalyst material, well below
the nominal "surface" region--the nearest neighbors somewhat below
the "surface"--may also significantly influence its "surface"
properties. Atoms distributed over larger distances that cover many
atom spaces produce long-range processes that also may play an
important role. Thus, as described herein, a "surface" is much more
a zone than a position.
[0100] Known quantum mechanical results support the contention that
simply by having surfaces or materials come very close to each
other (a few microns or less), forces may arise and virtual
particles may come into being. For example, the Casimir effects
(Casimir, H. G. B. "On the attraction between two perfectly
conducting plates," Proc. Kon. Ned. Akad. van Weten. 1948, Vol. 51,
No. 7, pp. 793-796) may naturally occur in the very small scale of
the surface zone of catalysts. Casimir effects, though operating in
the tiny surface zone domain of catalysis, have typically not been
given attention in the field of catalysts.
[0101] In the context of the present invention, without being tied
to any particular physical phenomena, theory or explanation, it is
plausible that the inventive catalytic enhancement due to the
contacting of solid phase catalytic surfaces may be due, at least
in part, to the phenomenon that as two surfaces approach each
other, some quantum uncertainty may influence not only the
materials but also the "space" separating the two surface regions.
This may be especially true where the two approaching surface
regions have similar atoms; in such a case, the uncertainty may
dictate that some of one "surface" may be found in the other's
"surface." This virtual "tunneling" fuzziness may be only a part of
the extraordinarily active zone as two surfaces are brought into
proximity
[0102] Brunauer, Emmett and Teller (BET) measurement is a common
surface property test used in describing various materials for
catalysts. It is a test of wherein the adsorption of a gas is
measured on the surface of a material. This approach has been based
on a theory of Langmuir regarding the processes of gas adsorption
at a surface. A controlled amount of an inert gas under pressure is
applied under pressure to the test material. The gas is measured as
it is removed by a heating desorption process. BET measurement may
be expressed as square meters (of equivalent surface) per gram of
material under test. Though the theory of a BET measurement
involves many assumptions, the method has become a common
specification for catalysts. The conventional thinking behind such
a measurement was--the more surface area the better. Conventional
belief that all catalytic action is surface controlled, suggests
more is always better. Recently, however, more studied analysis has
shown this to be not necessarily the case (e.g., see U.S. Pat. No.
6,831,037).
[0103] Material surfaces, even when considered relatively smooth,
may be relatively rough on the atomic scale. Examples have been
visualized with recently developed surface scanning techniques
showing many surface peaks and valleys, terraces, and voids, all
present in a typically rather uneven way. Another significant
aspect of the atomic features of the surface zone is the sizable
reach of various forces and influences. In the surface zone, things
may not be as sharply defined as the scan images seem to represent.
Features often shown atom by atom on a scale of an atom every few
millimeters may not convey the lengthy reach of interactions
leaping many atoms distance.
[0104] Not only is such minute space believed to be significant,
also minute time may play an important role. Things may happen not
only over a tiny range in space of such atom dimensions but in a
time of only a few hundred femtoseconds (10.sup.-15 second).
Therefore, consideration of the extremely small time intervals in
which the short-range catalytic molecular actions actually occur
may be advantageous in developing improved catalytic processes.
Consideration should be given to the very great disparity between
the femtoseconds actions of chemical bonding and the much longer
time taken by reaction materials to move in and out of the surface
zone. Thermal molecular velocities are of the order of hundreds to
thousands of meters per second. Thus even a moderate sized molecule
may only be in the neighborhood of atomic bonding distance of a
hundred or so picometers (10.sup.-12 meter) for a few hundred
femtoseconds. However because of inter-colliding of reactant
molecules, the path to and from a surface may be quite indirect and
circuitous. Thus the transport of reaction material may often be
the limiting factor rather than the time it takes to form a
chemical bond. Thus in designing catalyst materials and systems, it
may be important to take into account how components of a reaction
may get into reaction range and how they may get away. An important
concern then arises concerning how much time it takes for a
catalyzed molecule to leave the environment once catalyzed in the
surface zone. Catalytic activity may possibly have more to do with
the ensnaring of materials than with overly simplistic ideas
focusing only on the amount of reactive surface area. Catalyzed and
reactant materials caught in tortuous interstices that restrain and
delay the entering and leaving of materials may have more to do
with production rate results than BET measured surface area alone.
Even where a gaseous reactant is involved, BET measurements for
much the same reason may not necessarily have a dominant impact on
the effective reaction rate. Consequently, a large surface area
built of a dense forest of porosity may also become an inhibitor of
material movement. The cohesiveness (sticking together) of like
materials may further impair movement. The landscape of a surface
may therefore be one of the contributors to the often very large
apparent surface area measured by the gas adsorption test methods.
Though past evaluations of some catalyst activity seemed to
correlate performance with effective adsorption area, the
correlation was often poor. Large BET values can be obtained
through increased pores and surface asperities roughening the
landscape. If carried too far the forest of surface asperities may
have a reverse influence on the catalyst production rate by
stalling material transport. Therefore, in certain embodiments of
the present invention, the catalytic materials are non-porous or
have a relatively low surface porosity.
[0105] Heterogeneous solid-phase surface catalysts may in certain
instances re-configure or assemble some molecular species of
reactants into desired products. Such catalyst actions may take
place within very short distances proximate to some surfaces. Some
catalysts act, at least in part, by breaking apart particular
molecular bonds. Others may produce new bond linkages, for example
forming polymers from monomer "building block" molecules. The very
short time in which such molecular reactions take place may be an
important aspect of all such catalyst behavior. In the atomic scale
region of surface activity, such events may occur over extremely
short periods of time. Such short time behavior appears to not be
appreciated in conventional catalyst research and design. Whether
new bonds are created or existing ones are modified by a catalyst,
each such step may be a discrete transition occurring in extremely
short time--e.g., in the femtosecond domain. The quantized change
of energy in such an action may increase or decrease the total
energy of the components. The quantized nature of such a transition
may substantially limit the applicability of conventional concepts
of mechanical resonant energy exchange or storage. (Q is a symbol
generally used to represent the ratio of resonant energy stored per
cycle to energy lost per cycle). Ideas of a "Q" associated with
such state transitions may fail because the changes are not
continuous ones. A discrete transition may be better represented in
the form of a state diagram, as shown in FIG. 1, in which the
vertical direction represents flow of time. Two molecules, one A
and one B, (coming from below the wavy line), can interact (the
wavy line) through an exchange of a quantum of energy, producing
the linked molecule A+B and a quantum of energy (or phonon) into or
out of the state as shown at the right of the wavy line. This
schematic is presented, not as a complete theory, but merely a
graphic clarifying events that may occur in the very brief time of
such a reaction. That reaction may be either exothermic (energy
released) or endothermic (energy absorbed). The time required for
the transition (the wavy line) may be extremely short. In fact it
may not be possible to say that the transitioning of entrance
states into exit states requires any amount of time whatever. This
is an example of the quantum fuzziness issue. The virtue of such a
simple diagram lies in representing purely the state differences
and the feature changes accompanying the event.
[0106] Much of the conventional theoretical treatment of surfaces
and catalytic activity by statistically modeling large numbers of
elements, which motivates much of the conventional approaches to
catalyst design and research, may fall short by not adequately
considering individual interactions and their brevity. Many known
theoretical and empirical approaches to catalyst chemistry have
dealt in a thermodynamic statistical way only with overall
averages.
[0107] Other surface complexities can also play an important role
in catalyst activity. Even regular "continuous" metal films that
may display nearly atom-by-atom ordered proximity are rarely smooth
on an atomic level. Very pure, nearly perfect semiconductor-crystal
materials can approach such an almost atomically perfect surface.
It is instructive to consider that even a nearly perfect surface
layer may have "defect" properties at its "surface" simply because
of the absence of nearest neighbors in the space above its top
layer of atoms. Surfaces may differ from their interior or bulk due
to discontinuities that may be inherently a property of a "surface"
(boundary). If such a semiconductor crystal material were "doped"
to be of N-type in its interior (electron rich), its surface may
still show some P-type properties (hole rich) because of the
missing electron field on the "empty" side of the boundary. Doping
of a semiconductor material often may be done with just a minute
fraction of atoms (for an N-type silicon, about one in 10,000 atoms
of phosphorous). Notably this illustrates some of the extent to
which long-range properties (many atom-spaced distances) may
contribute to behavior of a surface. Even atoms within a "solid"
array can have a substantial influence on its "surface," arising
from constituent material and organization within interior and
neighboring surface regions. A certain amount of drift of atoms
within such an array may be constantly taking place though the
average of the array (shape) may appear unchanged. On the very
short distance and short time scale these movements may have
influence on opportunities for various reactions to occur.
Temperature of the materials may also have influence and may work
to raise or lower a particular result as different reactions
compete at differing rate, some rising or falling as a result of
the balance at a particular temperature.
[0108] It has been observed that freshly "cleaved" surfaces
obtained by breaking a brittle solid in an ultra-high vacuum have
high catalytic activity compared to similar surfaces that are not
freshly cleaved. Such ruptured naked surfaces are not yet covered
by adsorbed material and can exhibit short-range features known to
"hunger" for companions. Such is the exceptionally active nature of
a nascent surface. It is believed, in the context of the present
invention, that surface-to-surface contact effects may create
surface defects creating similar enhanced catalytic activity as for
freshly cleaved surfaces. In context of the present invention, the
landscape of contacting catalyst surfaces may be changed by each
fresh separation following each contact. Again, without being tied
to any particular theory or explanation, it is believed that such
changes may produce a new crop of surface defects with each
separation accounting, at least in part, to the enhanced catalytic
activity and performance achievable with certain embodiments of the
present invention. Much conventional research and development in
the area of heterogeneous catalysis intensely pursued large values
of measured surface gas-adsorption area. This may have encouraged
the development of counterproductive surface complexity that
opposes catalytic product output. The typical conventional
approaches to catalyst formulation emphasizing particular
empirically derived "recipes" of materials provide little direction
for variation or improvement of the catalytic chemical objective of
the catalyst. Consequently, much past development was the result of
documenting painstaking experimental work and historical operating
experience using established catalyst systems or modest variations
thereof. Further improvement in catalyst productivity requires
attention to directly improving catalyst activity and to increasing
transport of material through surface zones. The present invention,
in certain embodiments, provides materials and methods for
accomplishing such improvements.
[0109] This present invention is not limited to any particular
catalyst recipe or use for any particular reactant input/product
output nor is it specifically limited in its use to any particular
reaction scheme. Examples of catalytic procedures that may be
suitable for use in the invention include, but are not limited to,
cracking (e.g., steam cracking, fluid catalytic cracking,
hydrocracking, thermal cracking, and the like), catalytic
reforming, acetoxylation, alkylation, ammonolysis, carbonylation,
Fischer-Tropsch synthesis, alkane production, pyridine production,
dehydration (e.g., dehydration of alcohols), dehydrochlorination,
dehydrogenation, epoxidation, hydration, hydrochlorination,
hydrogenation, hydrogenolysis, isomerization, oxidation, reduction,
oxychlorination, petroleum refining, and production of synthesis
gas and/or products of synthesis gas. Examples of catalysts and/or
catalyst materials that may be utilized in the invention include,
but are not limited to, nickel such as Raney Ni or Urushibara Ni,
vanadium(V) oxide, platinum, palladium, rhodium, ruthenium,
alumina, silica, platinum rhodium palladium catalysts,
Zielger-Natta catalyst, Grubbs' catalyst, Lindlar's catalyst,
Wilkinson's catalyst, Crabtree's catalyst, catalyst supported on
carbon, alumina, or other materials, derivatives thereof,
combinations thereof, and the like. Other catalysts and catalytic
procedures that may be employed in accordance with the present
invention are described in Rase, H. F., Handbook of Commercial
Catalysts, 1.sup.st Ed., CRC Press, 2000, which is incorporated
herein by reference.
[0110] In fact, the systems, materials, and methods disclosed
herein may potentially be utilized in the context of essentially
any solid-phase heterogeneous catalyst composition for any
appropriate catalytic reaction scheme. Such compositions and
reactions are extremely well known in the art. The disclosed
invention may generally apply to essentially any catalyst employing
surface-active solid-phase catalyst materials acting on
heterogeneous reactant matter. It is generally applicable to the
field of heterogeneous catalysis with surface-active solid-phase
catalysts broadly as defined within this disclosure and by the
appended claims.
[0111] At least two different types of phenomena may influence the
output rates of a catalyst: First, phenomena acting catalytically
upon the desired chemical bonds in the surface zones; second,
phenomena acting to affect transport of surrounding material, to
and from, the surface zones.
[0112] Enhanced clearing of trapped surface zone material may be
provided by the surface-contacting action of the present invention,
which may improve catalytic activity. In certain embodiments, more
surface clearing may be achieved by adding radiant energy to the
active catalyst surface zones to yield even further improvement in
catalyst output results. This radiant energy can aid the lagging
movement of materials to and from the surface zones.
[0113] As discussed above surface contact may be more complex than
previously appreciated in the field of catalysis. Even slight
surface contact may produce significant surface changes and
defects. Some embodiments, of the present invention employ
deliberate recurring transient physical contact between solid-phase
catalyst surfaces to enhance the catalyst's action upon the target
reactant materials.
[0114] Certain embodiments of the present invention involve new
catalyst surface geometries designed to facilitate and increase the
projected contact area of surface-to-surface contact events.
Catalyst reactor systems and/or catalytic objects of certain
embodiments of the present invention are configured to produce
frequent surface-to-surface contact between catalyst objects,
using, in certain embodiments, inventive catalyst shapes and/or
catalyst movement in, for example, catalytic reactors of the
invention. In certain embodiments, catalyst objects used are
designed to provide large contact area (e.g., projected contact
area) between a catalytically active surface and another surface,
which also may be catalytically active, which may be the same or
different in composition, and which may have surfaces that are
complementary in shape and topography facilitating large areas of
intimate contact. Such shapes differ greatly from those typically
used in conventional catalytic processes, which are typically
spheroids or include similar curved, non-complementary surface
shapes. Contact between spheres, especially hard spheres, and other
similar small radius-of-curvature items, provides only extremely
limited contact area. Typical contact between hard spheres will
typically be very much less than one five-thousandth of the
individual object's surface area. Under the conditions typically
found in prior art, spherically shaped catalyst objects coming into
contact with one another produce insignificant contact area in
contrast to the catalytic object shapes provided according to
certain embodiments of the present invention described in more
detail below. In contrast, certain catalyst objects of the present
invention, e.g. catalyst particles or pellets, may comprise a
plurality of facets (e.g., essentially planar facets) or mosaic
patches on the external surface. In some embodiments, two such
catalytic objects coming into contact with each other may be shaped
to have complementary surfaces such that, for a given contact
event, a projected contact area between the two catalytic objects
is (on average over a large number of contacts) greater than 1% of
the catalytically active total external contact surface area of the
catalytic objects. Examples of shapes provided according to the
present invention include, but are not limited to, a variety of
polyhedrons, such as an icosahedron, truncated icosahedron (TICO),
cylinder having a polygonal perimetric shape, gear teeth of a gear,
and the like. Those of ordinary skill in the art will readily
envision a wide variety of other suitable shapes, each of which is
included within the scope of the invention as defined by the
appended claims. The inventive catalytic reaction systems may
further include a contact-inducing device which is configured and
arranged to bring catalytic objects into contact with each other in
the presence of a selected reactant environment to produce a
desired reaction product. In certain embodiments, the catalytic
object(s) may be contained in a reactor comprising an inlet for
introducing a reactant to the reactor and an outlet through which
passes from the reactor a product stream. The reactors of the
invention may take many forms that facilitate the creation of
repetitive contact between catalyst objects therein. For example,
convention designs, or modifications thereof, comprising
continuously stirred tank reactors (CSTRs), fluidized bed reactors,
slurry bubble column reactors, etc. may be employed. In addition,
in certain embodiments the invention also provides new reactor
designs employing, in certain cases, mechanical apparatuses for
creating repeating contact between catalyst objects (e.g., see
description of gear pump and roller reactor designs below). In some
embodiments, the catalyst object is formed of a catalytically
active material. In some embodiments, the catalyst object comprises
an inert support material (e.g., a ceramic) coated on at least a
portion of its surface with a catalytically active material.
[0115] In certain embodiments, the shape of the catalyst surface
provide broad areas of contact, e.g. as with complementary shapes.
This provides catalyst object geometries that are very different
from typical prior art catalysts and, accordingly, to inventive
systems that employ such catalysts. With discrete independent
catalyst objects, certain inventive catalytic reactor systems may
also cause the objects to move about such that the catalyst objects
frequently collide in a fashion that they make substantial surface
contact with one another in the reactant medium utilized. This can
be achieved by placing the catalyst objects in certain
environments, such as gaseous, liquid or mixed media, and providing
a contact-inducing device (e.g., a device for agitating the
environment). Such agitation has been employed in three-phase
reactors such as slurry bubble column reactors, in continuously
stirred tank reactors, and a variety of other configurations.
However, conventional catalytic reactors that have agitation do not
provide the enhanced contact conditions of the present invention
because typical prior art catalyst object designs do not possess
the surface-to-surface contact enhancing properties of certain
embodiments of the present invention.
[0116] In some embodiments, catalyst objects of the present
invention may be used in combination with a contact-inducing device
capable of providing agitation or motion to an environment
comprising the catalyst objects and a reactant. For example, the
many essentially flat facets of a polyhedron shape, such as the
TICO shape described below, may readily engage in repetitive
contact events action when a reactant volume densely filled with
such objects is agitated or stirred in a reactor. These inventive
shaped supported catalysts when used in sufficient quantity to
provide a high density-of-fill may produce with moderate agitation
the desired numerous and frequent recurring contacting between
their many faces (which may be essentially flat or of complementary
contour). Continuously stirred tank reactors (CSTRs) known in the
art can be an appropriate apparatus for such a process use. In
addition to CSTRs, widely employed Slurry Bubble Column Reactor
systems that utilize bubbling gas to agitate for example a
Fischer-Tropsch type of hydrocarbon synthesis reaction may also be
used in conjunction with catalysts of the present invention, such
as a TICO type catalyst. In certain embodiments, especially those
employing a large number of agitated catalyst objects in the form
of particle-like objects, it may be desirable to avoid a
three-dimensionally shaped catalyst object that is symmetric in a
manner that permits aggregation (e.g., "lock-up") when many
catalyst objects are close packed. For example, this may occur with
cubic block-shaped objects upon agitation. In certain embodiments,
catalyst object forms are provided that allow the desired frequent
surface-to-surface contact event but minimize tendency to aggregate
in a locking fashion. Inventive asymmetries are exemplified in the
several examples given below; however, there are many other
geometric possibilities meeting this need that will occur to those
skilled in the art.
[0117] In certain embodiments, a mechanical actuator, mechanism or
apparatus to which at least one catalytic object is attached or
mechanically interconnected may be employed to place at least two
catalyst objects (or one catalyst object and a non-catalytic
object) into contact, such that a projected contact area between
the two objects is greater on average than about 1% of the
catalytically active total external contact surface area of the
catalytic object(s). For example, systems in which meshing gear
teeth, which include a surface comprising a catalytically active
material, contact a reactant may be used (e.g. see FIG. 7). There
are many presently known forms of gear pumps that may serve such
function by positioning the catalytically active gear teeth in an
interdigitated fashion and rotating the gears, creating contact
between surfaces of the gear teeth. Additionally, an inlet and
outlet may be included in the catalyst reactor system such that
reactant material may be circulated over the catalyst objects, for
example at least in part due to convection created by the moving
gears.
[0118] Other embodiments of the present invention may additionally
employ cylindrical reaction chambers or pipes comprising an
interior surface which may be made catalytically active. When
brought into contact with other object(s), such as other catalytic
object(s) of a similar composition, in a suitable reactant
environment, contact events of the other contacting object(s) with
the catalytically active interior external surface of the reaction
chamber may produce the desired contact conditions to promote
enhanced catalytic behavior. Systems of this kind may be readily
applied to circulate fluids, gases and such thus combining desired
fluid moving functions with intended catalytic processes.
[0119] A exemplary configuration for utilizing shaped contacting
catalytic surfaces employing gear teeth having catalytically active
surfaces on the teeth id shown in FIG. 7.
[0120] Such gears naturally operate producing rapid transient
effective surface-to-surface contact on each engaging tooth
surface. Gear pump devices are known having specially shaped
contacting teeth suitable for fluid pumping. Many forms of
commercial gear pumps exist. Such a mechanism combines surface
contacting functions with fluid pumping functions often useful for
many catalyst processes. Such catalytic gear pump-like systems have
uniquely effective uses considering their natural high-pressure
capability along with large flow rate capabilities under even
extreme temperature conditions. By having a desired catalytically
active surface material on the engaging gear pump teeth, the
conditions for the subject system can be achieved in a variety of
otherwise difficult conditions. Well established processes may be
used for depositing catalytic materials on such gear tooth
surfaces.
[0121] Another configuration of this type employs multiple
individual gear pumps. These may be used inside a reactor to
produce mixing and agitation of the reactant materials within it.
Such devices often utilize the action of two or more gears rotating
together so that fluid is swept into the merging teeth and exits on
the parting teeth side of such an arrangement. There are many forms
of this kind of device known in the art. Some employ multiple
gears, some planetary systems. Teeth of varied forms can be used in
such systems.
[0122] It may be desirable for the engagement of such teeth to
develop the largest contact area and travel over each tooth face
that is coated with the appropriate catalyst material. The pressure
between the teeth may also be maintained by an appropriate force
generating motor or other mechanism for exerting just enough force
to insure significant engaging contact over the fullest extent of
tooth surface possible.
[0123] Another configuration for such a gear pump system may be a
serial arrangement of fluid travel from one gear pump to a next one
seriatim to create an extensive surface coverage by a circulated
fluid reactant.
[0124] Another property which may be convenient for catalyst
processes is the ability of such pumps to operate in very
high-pressure conditions. This type of pump can either generate
such pressures or operate the engaging gears without any housing
containment simply inside a controlled reactant chamber
environment. The gear engaging system may be configured and
operated to develop sufficient total surface-active contact area
and, to run high enough gear speeds to optimize contacting action
so as to obtain the desired output of reacted product. The tooth
shape may be any one of the well-known types designed for angled or
helical or other geometries that increase the available contact
area on each tooth engagement.
[0125] The patent literature shows many examples of pump designs
potentially adaptable to the applications described. For example,
two such pump structures are described in US patents are: U.S. Pat.
Nos. 5,660,531 and 6,518,684.
[0126] Another embodiment of the present invention may involve a
catalytic reactor system comprising catalyst objects configured in
the shape of a roller bearing arranged to create the multiple
contacting and separating action modality of certain aspects of the
present invention (see FIG. 11). The roller bearing surfaces may be
coated with a catalytically active material. Structures of this
type can be immersed within a reactant medium within a reactor or
in a flow stream of such a reactor. This type of embodiment with
appropriately designed materials may also facilitate use with a
very wide range of temperature and/or pressure.
[0127] FIG. 11 illustrates an embodiment of an inventive catalytic
reactor system 70 that need not employ catalyst pellets or
particles but rather uses the containment vessel, with an inner
surface 72, and a mechanism that also provides agitation and
stirring action of catalytic objects. Cylindrical reactor 70
includes a series of spring loaded rollers 74, which are coated
with a catalytically active material, arranged on a carrier 76
which is rotated about a central shaft 78. Reactor 70 may further
comprise inlets and outlets, not pictured, to allow for the
circulation of reactant material within the reactor vessel. The
rollers 74 and/or the internal surface 72 of the reactor
containment vessel that they contact and press on may be coated
with a desired catalytically active surface material. Carrier 76
rotates the rollers 74 to make interrupted contacting events on
particular areas of the catalytic surfaces of rollers 74 and/or
surface 72. The rotation also provides a way of agitating and
stirring the contents (e.g., reactant material). Such a vessel can
be either batch or continuous flow operated. The particular
geometry illustrated is but one case of many possible
configurations as would be appreciated by those skilled in the art.
This inventive structure can be constructed in essentially any size
deemed appropriate for the objectives selected. Cylindrical
containment vessels also advantageously lend themselves to extremes
of operating pressure and temperature. Magnetic coupling can be
used to generate rotation of carrier 76 in a sealed systems.
[0128] In another embodiment, gear pump systems like those
discussed above can optionally be combined with a system as
illustrated in FIG. 11 for pressure and flow advantages. The
flexibility of the inventive catalytic reactor systems illustrate
the many possibilities for performing several different kinds of
these reactions on a feedstock stream by coupling varied reactor
configurations. This can be done serially or as a branching network
thus lending itself to many flexible integrated industrial process
configurations within the scope of the invention.
[0129] Certain embodiments of the invention comprise the use of an
anvil/striker catalytic reactor apparatus, which in certain
embodiments may be sized and configured to be particularly well
suited for smaller-scale analytical testing, experimentation,
process/materials optimization, and comparative testing
applications. Two such embodiments are shown in FIGS. 12 and 13,
respectively, which, as explained in more detail below and as shown
in the Examples 6-15, may be especially useful as a pilot-scale
testing and analysis devices.
[0130] FIG. 12A provides a cross-sectional view of an exemplary
embodiment of an anvil/striker catalytic reactor apparatus 80. FIG.
12B shows a top-view illustration of the striker apparatus, while
FIG. 12C shows a top-view illustration of the anvil apparatus. As
shown in FIG. 12B, a striker contact 84 is positioned on a bottom
side of striker leaf 98, and an eddy-current sail 92 is positioned
on a top side of striker leaf 98. Striker leaf 98 is held in an
elevated position by striker base 94. As shown in FIG. 12C, anvil
apparatus 80 includes an anvil base 90 and an anvil carrier plate
88 positioned on a portion of the anvil base 90 such that the anvil
carrier plate 88 has a top surface essentially flush with the
surface of the anvil base 90. The anvil carrier plate may be
aligned with pins 89. An anvil contact 86 is positioned on a
portion of the anvil carrier plate 88. In the anvil/striker
apparatus 80, striker apparatus 98 is positioned on top of the
anvil apparatus such that anvil base 94 contacts a portion of anvil
base 90. Also, striker leaf 98 is positioned above the anvil
apparatus such that striker contact 84 is positioned directly above
anvil contact 86.
[0131] The anvil contact 86 and striker contact 84 may be soldered
to the anvil carrier plate 89 and the striker leaf 98,
respectively. The solder may preferably be a high temperature
gold/silicon type such as those used in semiconductor structures. A
thin foil (<0.002'') of such solder may fuse each of these metal
parts in a reducing atmosphere furnace. One or both of anvil
contact 86 and striker contact 84 may comprise a catalytic
material. This type of assembly preserves the flatness and parallel
form of the parts. The design allows repeated tests with different
catalysts to maintain identical operating behavior.
[0132] In this configuration, striker contact 84 is capable of
contacting anvil contact 86 by movement of striker leaf 98. Screw
96 may be used to control the force with which striker contact 84
contacts anvil contact 86. In the illustrative embodiment, the
anvil contact 86 has a larger surface area than the striker contact
84. For example, the anvil contact may have a surface dimension of
5 mm.times.5 mm, while the striker contact may have a surface
dimension of 2 mm.times.2 mm
[0133] The anvil contact 86 and/or striker contact 84 may be coated
with a catalytically active material, as described above. The
striker contact 84 may be brought into contact with the anvil
contact 86 such that a catalyzed product is formed on the area of
contact (e.g., the surface area of the striker contact and the
"struck" portion of the anvil contact).
[0134] The excess or "un-struck" area of the anvil contact (for
example, a 1.5 mm wide frame having 21 mm.sup.2 of anvil surface)
is exposed to the same environment, however will show substantially
less catalyzed product on its surface than on the 2.times.2
"struck" area (4 mm.sup.2).
[0135] Various catalyst materials, reactant materials, operating
temperatures and pressures, etc., can be tested with the present
system.
[0136] Referring to FIG. 13, a second exemplary embodiment of an
anvil/striker catalytic reactor apparatus 100 containing an
anvil/striker assembly within an enclosure 140 is illustrated. An
embodiment of this apparatus is described in much greater detail
below in Example 6 and is described here only briefly. Striker
assembly 120 is positioned relative to anvil assembly 110 such that
the striker can come into controllable and repeated contact with
the anvil. The striker assembly 120 may be connected to an
electromagnetic drive system, e.g. inductive coil driven linear
actuator 130, which can measure and control the positioning and
movement of the striker and the applied force during contact
events. In the illustrated embodiment, a gas bearing 132 used
provide a very low friction passage through enclosure 140 of push
rod 131, which drives the striker 300 (FIG. 15) A set of inlets 142
can introduce reactant material, such as reactant gas, into
apparatus 100, and a set of outlets 144 can be used to evacuate the
reactant gas from apparatus 100. In certain embodiments, each of
the three illustrated reactant inlets 142 and product outlets 144
can be in fluid communication with different portions of the
catalytically active surface area of the anvil 200 (FIG. 14) of the
anvil assembly 110 (e.g. struck and unstruck portions of the anvil
in the illustrated example).
[0137] The techniques of present invention are not believed to be
limited in their utility to particular catalyst materials or
catalyzed reactions and may be applied to a wide range of
surface-active catalysts and reactions able to be catalyzed by
these catalysts. Essentially the entire known catalog of
surface-active catalysts may potentially be benefit by application
of the surface-to-surface contacting systems and configurations of
certain embodiments of the present invention. Catalyst materials
other than metals, such as oxides or ceramics, may be able to
benefit from effective contact events within the context of the
present invention. Those of ordinary skill in the arts of
heterogeneous catalysis, using no more than the knowledge and
resources available to those skilled in this art, given the
teaching and guidance provided in the context of the present
invention, will be able, without undue experimentation and burden,
to select appropriate catalytic materials for a particular desired
reaction and to fabricate such catalytic materials into the
catalyst objects and catalytic reactor systems of the present
invention. Those of ordinary skill in the art will be able to
perform screening rests and routine testing and optimization, e.g.
such tests may performed in a similar fashion as the procedures
described below in the Examples 6-15, to select appropriate or
optimal conditions for implementing the inventive techniques
involving creating and/or enhancing surface contact of catalytic
objects and to confirm that the inventive techniques yield
increased catalytic activity in their chosen system.
[0138] In some embodiments, catalyst reactor systems of the present
invention may comprise a catalytically active material that forms a
catalytic object or that is present on at least a portion of the
surface of the catalyst object. Catalytically active materials are
known in the art, and can be chosen to suit a particular
application. In certain embodiments, combinations of metals such as
alloys or other metallic mixtures can provide advantages for
specific catalytic activity. For example, combinations, in which
the different components have different valence or oxidation
properties may produce more active sites for catalysis upon contact
with like surfaces. In selecting metal atoms for such combinations,
elements from adjacent periodic table columns may be chosen. For
example, a transition metal from a certain column on the periodic
table may be alloyed with a transition metal from an adjacent
column, such as a preceding column or a following column Examples
of such combinations may include elements from at least two of
columns 9, 10, and 11 of the periodic table. For example, a
transition metal from group 10 (e.g., nickel, palladium, platinum)
may be alloyed with a small amount (e.g., 0.05 wt %, 0.10 wt %,
0.25 wt %, 0.50 wt %. 0.75 wt %, 1.0 wt %, 5.0 wt%, 10 wt%) of a
transition metal from adjacent column 9 (e.g, cobalt, rhodium,
iridium, etc.) In a specific embodiment, palladium metal may be
alloyed with 0.25 wt % iridium.
[0139] Inventive systems employing the enhanced catalyst contacting
techniques and configurations described above may be useful in
ameliorating the often problematic, "regeneration" and refreshing
operations common with industrial catalytic operations.
Surface-to-surface contact may act, at least in part, as a form of
continuous regeneration or re-activation. In addition to
significant improvement in catalytic action the present invention
may, in certain embodiments, enable increased selectivity for
resultant products by permitting a greater range of operating
parameters to be utilized. The present invention may make possible
utilization of conditions not previously effective or practical in
conventional systems.
[0140] Many configurations are possible within the context of the
present invention. Presented below are examples which should be
considered non-limiting cases of a very large scope of possible
applications and configurations within the scope of the present
invention. Others will occur to those skilled in the arts;
therefore only the appended claims should define the limits of the
inventive subject matter.
[0141] In another embodiment, the catalyst reactor system may be
operated at supercritical conditions (of temperature and pressure)
to obtain a desired molecular species for catalytic reaction. This
can be done in a more or less continuous fashion or because of the
severity of such thermodynamically active conditions it may be done
transiently in a repetitive manner to lessen the burden of such
extreme conditions on materials and equipment.
[0142] Other embodiments of the present invention may improve the
transport and release of catalyzed material and reactant to, from,
and/or in the surface zone. Though the system's contacting action
itself may also facilitate significant benefit in material
transport, such effect may be further enhanced in certain
embodiments by application of radiant energy. The exciting action
of radiant energy incident on the catalyst (for example, sonic,
ultra-sonic, photonic, particle and/or electromagnetic energy) may
improve the movement of material to, from, and/or through the
surface zone. As indicated above, the entrainment of materials in
the surface zone from micro cavities or cohesion can be a retarding
process with a time factor many times that required by the actual
catalytic transformation.
[0143] Catalyst objects of the present invention may, in certain
embodiments, be configured as particles or pellets that have
geometries including multiple projected contact areas and/or
facets/mosaic patches, each having an external surface area
typically 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10% or more of the
total active external surface area of an individual catalyst
object. The principle of the subject system may be realized in a
wide variety of sizes, shapes and configurations, which may be
chosen for a particular application, that provide significant
projected contact area greater than 1% of the total external active
surface area of an individual catalyst object. One illustrative
shape is the cylindrically symmetric catalyst object with nine
longitudinal flat facets along its long axis surface shown in FIGS.
8 and 10. Other shapes will suggest themselves to those skilled in
the arts when considering the possibilities for application of the
principles of the subject invention. Differing desired conditions
of use and economic factors also affect such choices.
[0144] The catalyst objects may be a solid catalyst material, a
layered construction, a hollowed structure, or the like. For
example, nickel metal often used in catalysts might be used in a
solid form, its shape conforming in principle to the multifaceted
construction of certain embodiments of the present invention. Many
configurations for such action are conceivable within the scope of
the present invention.
[0145] For certain applications of the present invention small
specially shaped catalyst objects may be desirable. Supported
catalyst objects may be utilized for reasons of freedom in shaping
the objects and for economy of manufacture. For example, ceramic
materials may be utilized for supported catalyst substrates.
Stability, high temperature endurance and chemically inert
qualities may make ceramics suitable for a wide range of process
conditions. As discussed previously the present invention provides
inventive catalyst geometries. In order to form such geometries,
effective methods for molding shapes more complex and precise than
can readily be achieved with extrusion methods common for
fabrication of ceramic materials may be advantageously employed.
Use of such a molding process may be advantageous for achieving the
degree of shape asymmetries discussed above as being useful to
avoid locking behavior of catalyst objects whose shapes interlock
too easily when densely filling the reaction space.
[0146] In certain embodiments, materials that can be produced in
powdered form can be mixed with thermally moldable plastics and
formed into a desired shape using known powder injection molding
(PIM) techniques. These methods have been developed to allow the
very productive and economical technologies of plastic molding to
be realized for the fabrication of metal and ceramic parts. When
ceramic powders are used, such methods are sometimes called ceramic
injection molding (CIM). Among such technologies CIM processes
employing alumina ceramic may be particularly useful for forming
catalyst substrates. Such methods may be utilized for the
fabrication of many catalyst objects within the scope of the
present invention. Materials for performing such methods are
available from BASF AG of Ludwigshafen, Germany, who also publish
guides and handbooks describing fabrication methods (see Piotter,
et al., Sadhana, Vol. 28, Parts 1 & 2, February/April 2003,
299-306).
[0147] Some references describing conventional catalyst processes
employing supported conventional ceramic catalyst carriers have
reported significant wear from abrasion caused by agitation.
Conventionally, concerns have been directed to minimizing effects
of mechanical wear of the ceramic substrates they employed. The
approach generally taken was through manipulation of the
composition and processing of the ceramic. The generally recognized
phenomenon of such wear has been dubbed "attrition" of the
catalyst. Wear particle detritus common from such behavior have
been given a special name--"fines." Such fines particles not only
clog filters and interfere with process machinery but that wear may
also result in reduced catalytic activity. Current ceramic
technology has employed additives to a pure aluminum oxide ceramic
very often used for catalyst support substrate material. Titania
(titanium oxide powder) with other material added to it (for
example barium in a lesser proportion) has been blended in to
improve resistance to attrition. Durable fully sintered pure
alumina molded parts produced by the CIM process described may be
adequate for many uses but wear factors should be considered for
each specific process in selecting substrate shape, materials and
processing conditions. To improve abrasion resistance an alumina
material (e.g., AO-F alumina available from BASF) may be blended
with one to five percent titania powder with the optional addition
of one percent or less of barium to neutralize any sulfate content
affecting abrasion performance.
[0148] The function and advantage of these and other embodiments of
the present invention may be more fully understood from the
examples below. The following examples, while illustrative of
certain embodiments of the invention, do not exemplify the full
scope of the invention.
EXAMPLES
Prophetic Example 1
Manufacture of a Catalyst Object
[0149] Catalyst objects are made using moldable alumina powder
material sold under the trade name Catamold.RTM. type AO-F
available from BASF AG of Ludwigshafen, Germany and their
distributors in other countries. The AO-F material is made of a
99.8% purity aluminum oxide that is compounded as a finely divided
powder blended with about 20% polyacetal plastic material. This
enables it to be handled and molded like a plastic using existing
screw plasticizing molding equipment. Even complex shapes are
possible with such techniques. The full process as described below
exists as a commercial operation used routinely to produce ceramic
molded parts. The parts as first molded by such a process actually
are not yet fully ceramic, requiring two processing steps beyond
the plastic molding step to become hardened durable ceramic shapes.
Because of the amount of plastic material added to make possible
the plastic molding process, as-molded parts are designed to be for
example 20 percent larger than desired for the finished part. The
particular polyacetal plastic chosen for the added material enables
such molded parts ("green" parts) to be chemically treated to
eliminate all the added plastic. This is done in a process the
first step of which gradually raises the room temperature parts (at
a rate of 3.degree. C. per minute) until stable at 270.degree. C.
In that heated environment the green parts are then exposed to
nitric acid vapor for about one hour. This process, called
"debinding," rapidly converts to a gas all the plastic in the
molded part. Thus debound, devoid of the polyacetal, somewhat
porous but firmly and precisely shaped, the now "brown" parts are
in the second step directly carried into a sintering operation. The
temperature is gradually increased at 3.degree. C. per minute
during the next 71/2-hour period arriving at the full sintering
temperature of 1610.degree. C. After remaining there for about an
hour the parts are slightly more rapidly cooled at 5.degree. C. per
minute to 400.degree. C. then further slowly cooled at 3.degree. C.
per minute to 50.degree. C. or room temperature. The now fully
hardened solid shaped parts can be handled, ready for any further
steps.
[0150] This sintering cycle accomplishes several purposes: 1) it
precisely shrinks the parts to the designed size; 2) it fuses the
part into a non-porous precisely shaped solid ceramic such that; 3)
the resulting surfaces then become hard and glassy-smooth. For
beneficial control and economy, the entire debinding and sintering
operation cycle can be done in one continuous automated "pusher"
type tunnel furnace system. The surfaces of parts so sintered
emerge from processing well-suited for coating with any of a
variety of catalytically active materials desired, for example,
palladium or platinum metals or combinations as described above.
The foregoing methods can be utilized as the fabrication technique
for the supported catalyst object examples given below. Economic
advantage and shape possibilities using this CIM molding and
sintering process make it potentially valuable for application for
forming the catalytic objects of the present invention.
Prophetic Example 2
Manufacture of a Supported Catalyst Shape
[0151] This example illustrates manufacture of one selected shape
for a moderate sized supported catalyst object about 3 mm in
diameter that has multiple advantages over a sphere.
[0152] The shape of the catalyst object is essentially a truncated
icosahedron 10, as shown in FIG. 3, a variant of a soccer ball
shape, having thirty-two essentially flat planar faces, twenty of
which are hexagonal faces 12 and twelve of which are pentagonal
faces 14. (The Euclidian ideal geometric form of truncated
icosahedron 10 is shown in FIG. 2.) The catalyst object has general
spherical symmetry yet provides relatively increased projected
contact area when compared to a sphere, as each of the thirty-two
projected contact areas may be greater in surface area than a few
percent of the object's total external surface area. The total
surface area of this particular polyhedral shape is over forty
eight percent larger than a sphere of the same nominal
diameter.
[0153] FIG. 4A shows another view of a truncated icosahedron, while
FIG. 4B shows a view of all thirty-two faces of the truncated
icosahedron laid flat and adjoining showing the relationship of the
faces.
[0154] To synthesize a catalyst in the shape of a truncated
icosahedron, a ceramic supported catalyst substrate having the
desired shape is formed by the CIM methods described in Example 1
above. The ceramic substrate is then coated with selected catalyst
material. For reasons of durability and ease of fabrication the
shape is modified in several ways from its ideal soccer ball shape.
This modified shape hereafter is called a TICO. First, the sixty
edges of the facets are rounded or "softened." As shown in FIG. 5,
facets 22 and 24 meet at edge 20, which is slightly rounded to
eliminate the sharp edge giving rounded smooth facet-edges having a
radius of curvature 26 of about 0.08 mm.
[0155] Also, in embodiments where the catalyst object is
synthesized using a mold, the facet angle at the part-line of a
mold may be less than 90.degree. to aid in release of the catalyst
object from the mold. FIG. 6 shows a catalyst object 30 having a
facet 38 adjacent to a mid-plane parting-line 36 of a mold 32. Line
34 illustrates a 90.degree. angle at mold part-line 36. The facet
38 may preferably be slightly tilted so these adjoining faces make
an angle slightly less than 90.degree., with respect to the plane
of the parting-line. (The parting line is the open face of the mold
for such parts.) This facilitates the molded parts being more
easily released from the mold cavity thus avoiding a part too large
to leave the mold cavity. The half cavity mold opening for such
parts can be slightly larger than the part to enable it to release
easily from the mold.
[0156] In the present example, catalyst particles are fabricated
such that each such truncated icosahedron has thirty-two
essentially planar facets. These facets increase available
projected contact area--a strategy in stark contrast to minimizing
projected contact area, as in a sphere. The substantial difference
in projected contact area complements the relative increase in
possible contact events possible with an agitated multitude of such
faceted TICO-shaped catalyst objects packed within a reactor.
[0157] The resulting numerous frequent contact conditions are
observed to produce a relatively increased amount of catalysis for
a selected reactant. TICO-shaped supported catalyst carriers of the
present example are molded using the process described above in
Example 1 and coated according to needs. Many methods exist that
are familiar to those skilled in the arts for deposition of
materials on substrates that can be used to deposit desired metals,
oxides or other catalytic materials on TICO surfaces. The
techniques can be selected from varied processes ranging from
liquid deposition to vacuum evaporation. In the present example;
cobalt metal-coated TICO is used in a Fischer-Tropsch reaction with
appropriate synthesis gases in either slurry bubble column reactor
(SBCR) or a continuously stirred tank reactor (CSTR). Thermal
toughness of the TICO construction of the present example lends
itself to such a highly exothermic process.
Prophetic Example 3
Manufacture of a Nine Sided Cylindrical Catalyst Pellet
[0158] FIG. 8 illustrates another inventive form of a catalytic
object and system comprising a catalyst pellet that employs a
nine-sided cylindrical shape 40. FIG. 8A illustrates a side view
along the length of the cylindrical pellet, while FIG. 8B
illustrates a transverse cross-sectional view. The methods
described above in Example 1 for CIM molding are used to make this
inventive shape. The unusual number and asymmetric arrangement of
the essentially planar facets 48 lends itself to good mixing and
surface-to-surface contact with minimal locking effects.
[0159] In FIG. 8, an illustrative embodiment of the cylindrical
pellet is shown. Cylindrical pellet 40 has an overall length 42,
with the essentially planar facets having a length 44. A domed end
of the pellet has a length 46. The nominal diameter of cylindrical
pellet 40 is shown by 52. In this particular example embodiment,
the cylindrical pellet is 11.5 mm long, with nine, essentially
planar facets each having a length of 7.5 mm. The length of the
dome end is 1.95 mm. The diameter 52 of the cylindrical pellet is
5.65 mm. Edges 50 are rounded as described above in Example 2.
[0160] The size illustrated is arbitrary as the concept is broadly
applicable to wide range of possible sizes and alternative numbers
of facets. The use of other solid materials will also occur to
those skilled in the arts. The size of the present example in FIG.
8 has about three times the contacting area of the illustrated and
previously described TICO shape having a 3 mm diameter. The larger
contact area of a facet of cylinder 40 can be essentially flat and
smooth to be fully effective in contact events. The maximum
projected contact area of this shape is more than 8 percent of the
total external surface area of the particle. This factor for the
above-described TICO shape may be typically from just over 2
percent for the smaller facet to just over 3 percent for the larger
facet. The FIG. 8 shape may be readily molded using the previously
described CIM process or many other possible known molding
techniques. The domed ends, as shown in FIG. 10, may minimize
attrition of such parts in use such as could occur from simple
squared-off end geometry. FIG. 10A illustrates a cross-sectional
view along side of the length of the cylindrical pellet, while FIG.
10B illustrates a side view down the length of the cylindrical
pellet. The dome design allows for a smooth transition from the
domed end to the body of the cylindrical pellet, which comprises
essentially planar facets. The diameter 60 is the maximum diameter
of the body of the cylindrical pellet, while the diameter 62 of
hemispherical dome is relatively smaller, allowing for a smooth
transition from the body to the domed end.
Prophetic Example 4
Manufacture of a Hecatohedron Catalyst Pellet
[0161] The hecatohedron shape of the catalytic object illustrated
in FIG. 9 comprises a relatively diametrical symmetry that requires
less modification to make the molded object more easily release
from a mold cavity. The external surface area of each facet is
smaller than the TICO object for a given nominal diameter because
the shape approaches more closely that of a sphere. Nonetheless the
large number of essentially flat facet surfaces yields projected
contact areas considerably larger than with for a spheres of the
same diameter. The smaller facets enable the shape to be relatively
easily fabricated with a desirable level of flatness and fine
surface finish. This "HECA" catalyst shape is readily moldable with
the CIM process discussed above. The irregular facet shapes can
moderate the locking tendencies of spherical symmetry.
Example 5
Catalytic Enhancement by Surface-to-Surface Contact
[0162] In order to observe the contacting effect on the catalytic
activity of palladium metal, and alloys thereof, an experimental
catalytic anvil-striker contacting apparatus similar to that
illustrated in FIG. 12 and described previously was fabricated in
the following manner:
[0163] Two reed elements were obtained from a reed relay capsule of
approximately 1/4 inch diameter. A portion of the surface of each
reed element was abraded away, and small samples of palladium metal
were soldered to the stripped down reed pieces. A 3 mm.times.3 mm
(approximately) palladium sample was soldered to one reed, while a
4 mm.times.4 mm (approximately) palladium was soldered to the other
reed. An external magnetic field was applied to control movement of
the reed pieces, so as to bring the palladium samples into contact
with each other. Thus, the modified reed elements functioned to
provide a simple contact opening means. The modified reeds were set
up to be normally closed with a contact force of 6 grams as read by
a 0 to 15 grams dial type spring dynamometer used to set relay
spring force. The reed pieces were mounted to microscope glass
slide as a base using litharge cement. The upper reed was contacted
by the lower reed and bent until 6 grams force just opened the
contact as determined by an ohmmeter.
[0164] The slide assembly was placed in a 1 inch inside diameter
Pyrex glass tube for exposure to the reactants (methane gas). The
volume of the interior of the tube was approximately 75 ml. The
ends of the tube were closed with a single-hole silicone rubber
stopper on each end. Methane gas was flowed through the Pyrex tube
at a rate of 5 to 10 ml per minute. An external wire coil
surrounding the tube was driven by a power amplifier from a
function generator to provide the magnetic opening force for the
assembly. The palladium contacts on the reeds were brought into
contact at a rate of about five times per second, over a time
period between several hours to as much as one day. Significant
organic deposits were found on the contacts. The longer period
showed more deposits. Gas chromatography showed that the molecular
weight of the deposits was more than 20,000 in polystyrene
equivalent. The palladium used was varied between pure palladium, a
palladium-ruthenium alloy comprising 10% ruthenium, and a
palladium-silver alloy comprising 10% silver. The deposits appeared
thick and tacky.
Working Examples 6-14
Striker/Anvil Catalytic Reactor Test (SAT) Apparatus and its Use to
Observe Enhancement of Catalyzed Reactions by Catalyst Object
Contact
The SAT Apparatus
[0165] An SAT apparatus as pictured in FIG. 13 and described above
was designed to permit evaluation of contact effect with a variety
of solid catalyst materials operating in a structure that provides
a closed space reaction volume through which carrier and reactant
gases may be flowed.
[0166] The SAT apparatus incorporates an electronic digitally
controlled electro-magnetic driven mechanical system to produce
repeated precise contact force between two pieces of catalyst
materials (e.g., striker and anvil) in a precisely parallel meeting
manner
[0167] A large (30''.times.60'') heavy duty welded steel cart with
8-inch pneumatic tires (not pictured) was used to support the total
weight of the SAT apparatus (i.e., more than 700 pounds), as well
as a battery back-up power supply (not illustrated), a
line-regulator-conditioner (not illustrated), gas flow piping and
controls (see, e.g. FIG. 16), a digital-computer controlled
electronic digital drive control system (not illustrated), and a
computer with 20'' LCD monitor (not illustrated). The cart also
supports gas flow valves, piping and flow monitoring Rotameters
(see FIG. 16). An Agilent Mass Sensitive Detector (Model 5879) 502
is positioned adjacent to the cart and connected to the SAT system
100 via a selector valve 504 and piping within a heated enclosure
(not illustrated) attached to the cart. Gas cylinders (not
illustrated) supplying the feed gases are connected to the gas
control panel 507 on the cart through piping from a cylinder
storage area close to the cart
[0168] The catalyst materials are provided in the SAT apparatus via
a removable striker post and a removable anvil carrier insert, such
that the catalyst materials may be easily changed. Small pieces of
catalyst material are brazed to the replaceable striker post and
anvil insert so that the manner in which the two catalyst materials
contact one another is constant over various samples. The anvil and
striker catalyst materials are 1/2 mm thick of mill rolled stock
fabricated to be flat and parallel to within 30 micro-inches and
formed as strips either 3 mm wide or 5 mm wide. The strips have a
smooth bright surface finish typically better than 0.5-micron
roughness. The 3.times.3 mm striker and 5.times.12 mm anvil were
cut from the strips with a fine 8/0 jewelers saw and the cut edges
filed to remove any "flash."
[0169] FIGS. 14A-G show various views of anvil assembly 110 of SAT
100. Anvil 200, which is brazed to anvil insert 201 (FIG. 14B), is
positioned between inlet port 230 and outlet port 220 such that,
when reactant gas is fed from inlet port 230 to outlet port 220,
the reactant gas flows across the width of anvil 200 and contacts
anvil 200. FIG. 14D show a close-up view of inlet port 230 and
outlet port 220. Inlet port 230 comprises inlets 232, 234, and 236,
through which reactant material may be introduced. Inlet port 230
further comprise nozzles 276, 278 and 280, which introduce the
reactant material to the surface of anvil 200. Nozzles 276, 278 and
280 are arranged such that the nozzle openings are positioned just
above the surface of anvil 200 and about 1/2 mm from the edge of
anvil 200. Nozzles 276, 278 and 280 are angled downward about 3
degrees from parallel with the plane of the anvil surface to ensure
that the reactant gas contacts anvil 200. Nozzles 276, 278 and 280
are shaped (e.g., substantially rectangularly shaped) such that,
when the reactant gas is introduced to anvil 200, the reactant gas
has laminar flow. The bottom edges of nozzles 276, 278 and 280 are
precisely located 1/4 mm above the top surface of the anvil insert
201. Similarly, outlet port 220 comprises complementary nozzles
270, 272 and 274, through which the reactant/product gas can exit
after contacting anvil 200. Nozzles 270, 272 and 274 are also
arranged such that the nozzle openings are positioned just above
the surface of anvil 200 and about 1/2 mm from the edge of anvil
200, and the bottom edges of nozzles 270, 272 and 274 are precisely
located 1/4 mm above the top surface of the anvil insert 201.
Outlets 222, 224 and 226 are connected to gas outlets 144 (see FIG.
13) to evacuate the reactant/product gas from the SAT apparatus 100
and to feed the streams to the Mass Spectrometer analysis system
(Agilent 5879 MSD). Resistor 202 (e.g., a 1000 mW resistor)
eliminates static charge. Ceramic components 290 and 294 insulate
the anvil 200 from current, and dowels 292 and 293 guide the
positioning of anvil 200 (FIG. 14G).
[0170] A particularly advantageous feature of the SAT apparatus
allows various portions of anvil 200 to be studied simultaneously.
FIG. 14E shows a top view of a portion of anvil assembly 110,
wherein dividers or "fences" 240 and 242 are positioned across the
width of and in contact with anvil 200 to define portions 210, 212
and 214 of anvil 200, and to prevent crossover of reactant/product
gas from one portion to another portion during operation. Dividers
240 and 242 may be held in place, for example, by slots or grooves
in inlet port 230 and outlet port 220. In some cases, the dividers
240 and 242 may be made of glass, or any other material which may
physically isolate portions 210, 212 and 214 from one another. In
the present example embodiment, thin Borosilicate (6 mil thick)
glass "fences" that are 5.5 mm high and 18.3 mm long were used.
Reactant gas was introduced in a direction 250 via inlets 232, 234
and 236, such that reactant gas exiting outlet 276 only contacts
portion 210 of anvil 200, reactant gas exiting outlet 278 only
contacts portion 212 of anvil 200, and reactant gas exiting outlet
280 contacts only portion 214 of anvil 200. This arrangement may be
advantageous in that the different portions of anvil 200 may be
comparatively evaluated under the same reactant conditions to
determine the relative enhancement in catalytic activity portion
212 when contacted by a second catalytic material.
[0171] In some cases, the dividers 240 and 242 are not necessary,
as the laminar flow of reactant gas can be controlled, for example,
by controlling inlet and outlet flow rates, such that there is
substantially no crossover of reactant gas from one portion to
another.
[0172] In this example, reactant gas flowed in a direction 250 from
inlet port 230 to outlet port 220. It should be understood that, in
other embodiments, reactant gas may flow in a direction opposite to
direction 250 (e.g., from port 220 to port 230).
[0173] Anvil 200 was configured to have a larger surface area
(5.times.12 mm) than the second catalytic surface (i.e. the
catalytic surface of striker 300 (3.times.3 mm) and was arranged
such that the striker contacted only portion 212 of the anvil 200
during operation. In other words, portion 212 of anvil 200 was
contacted by a second catalytic surface (i.e., the striker 300) in
the presence of reactant gas, while portions 210 and 214 of anvil
200 were not placed in contact with a second catalytic surface in
the presence of the same reactant gas. Portions 210, 212 and 214
were then separated evaluated for the catalytic activity that
occurred at each individual portion. Anvil assembly 110 thus
possesses an arrangement and geometry that provides for
differential comparison of the "struck" (e.g., portion 212) and
"unstruck" (e.g., portions 210, 214) areas of anvil 200 while
exposing all areas essentially identical conditions. Differences in
catalytic activity between "struck" and "unstruck" areas of anvil
200 may then, with allowance for the clearance times of
reactant/product in the piping runs and suitable correction for any
differences in total catalyst surface are owing to the intermittent
presence of the additional area of the striker in zone 212, be
attributed solely to the contacting effects of, for example, the
striker on the anvil.
[0174] FIGS. 15A-C show various views of striker assembly 120,
which is positioned directly over anvil assembly 110 in SAT
apparatus 100.
[0175] As shown in FIG. 15A, striker post 300 is connected to an
assembly comprising foil suspension strips 320 and 322, foil frame
310, and connector rod 330. Connector rod 330 is further connected
to actuator 130, as shown in FIG. 13, which controls movement of
striker post 300 via the actuating foil mechanism, wherein foil
strips 320 and 322 oscillate as directed by actuator 130. Foil
frame 310 is 18 mm thick and is precisely ground flat and parallel
to allow proper clamping of foil suspension strips 320 and 322.
Foil suspension strips 320 and 322 and foil frame 310 are made of
X-750 material, and each have a different thickness to ensure that
their resonant frequencies differ significantly. For example, foil
suspension strip 322 is 0.001'' thick and foil suspension strip 320
is 0.002'' thick. Clamp assembly 340 and 342 are constructed to
have smooth surfaces in order to uniformly distribute force across
foil suspension strips 320 and 322 and to solidly anchor foil
suspension strips 320 and 322, which are tensioned in a setup
fixture to 11 grams force. Spacer 341 is finished to have a smooth
surface such that it contacts foil strip 320 uniformly, and screws
343 are self-leveling. Actuator 130 directs oscillation of foil
suspension strips 320 and 322 via connector rod 330 such that
striker post 300 moves in a direction 350 toward the anvil 200.
Foil frame 310 may be moved vertically via rotational mount
360.
[0176] FIG. 15C shows a close-up view of striker post 300 and
striker 301, which was attached via brazing to a bottom surface of
striker post 300 such that striker 301 can contact anvil 200. The
striker post 300 and the anvil insert 201 were fabricated of a 316L
stainless steel, providing very flat and smooth surfaces to which
the catalyst material was brazed. The mating surfaces of these
carrier parts were tinned in a like manner, removing any excess
solder with solder-wick. The catalyst pieces (i.e., anvil 200,
striker 301) were then easily fused to the carrier parts with a
minimal amount of solder, by fusing the two pre-tinned parts in the
presence of a very small amount of a rosin flux. The 316L parts
were tinned with 221C tin-silver solder using a hydrochloric
acid-based flux sold by Lucas-Milhaupt for stainless steel work
(Handy Flux Type TEC). A thin (0.003'' thick) ribbon of this SnAg
eutectic alloy solder was provided by Lucas-Milhaupt. These tinning
and fusing operations were carried out using an electrical
temperature controlled laboratory hot-plate. The fluxes used were
thoroughly removed after each soldering operation and followed with
a pure water wash and acetone rinse before use.
[0177] As described above, striker 301 is a small plate of
catalytic material (e.g. a 3.times.3 mm plate of Pd in this
example) attached to a bottom surface of striker post 300, such
that striker 301 contacts anvil 200 when striker post 300 is
lowered in the direction 350 (FIG. 15A). The removable striker post
300 is fabricated from 316L material, is 0.250'' diameter and has a
precisely placed notch 347 near the top end which engages two
spring loaded ball dent screws 349 that position striker post 300
within the striker assembly 120. As shown in FIGS. 15B-C, striker
post 300 also comprises a 1/16'' dowel pin 302 and is drawn against
a V-groove 353 in the bottom of foil clamp plate 303 to maintain
proper alignment of striker 301.
[0178] In the example embodiment, the striker 301 contacts the
anvil 200 only at portion 212 of the anvil 200, and does not
contact portions 210 or 214 of anvil 200. As shown in the
experimental runs described more fully below, the portion of anvil
200 which is contacted by striker 300 (i.e., portion 212), in the
presence of reactant gas, exhibited enhanced catalytic activity
relative to portions 210 and 214. In some cases, catalytic activity
may be increased by over 50%, over 75% or over 90%, relative to the
unstruck portions 210 and 214.
[0179] The catalyst materials were attached to striker post 300 and
anvil insert 201 by a special brazing technique employing a
eutectic solder. Eutectic solders have a specific temperature at
which they melt and immediately become fluid (i.e., they do not
display a softening range as they are heated). This property allows
the brazing of a flat catalyst material to a flat carrier metal
such that the capillary action of the fluid solder ensures precise
parallel mating of the surfaces. A variety of alloys exist within a
workable temperature range. In some cases, a particular proportion
of gold and silicon can be eutectic at a relatively high
temperature. The alloy selected for experiments described herein
was pure tin with 3.5% silver, which melts at precisely 221.degree.
C. The catalyst material strips were tinned only on the mating side
with this eutectic solder. After tinning, the tinned layer of the
solder was minimized by scavenging the tinned surface with
"solder-wick," which is a very fine copper braid about 3 mm wide,
coated with a "rosin" type solder flux. The scavenging of the
solder was carried to the point where the solder film is bright,
smooth, thin and shows no small lumps or high points. After
tinning, the striker 301 was attached to striker post 300 and the
anvil 200 was attached to anvil insert 201 via brazing.
[0180] A four-port Valco (VICI) selector valve 504, was used to
sample, sequentially each of the three anvil areas and the input
gas stream from portions 210, 212, and 214. This type of selector
valve vents the non-selected, un-sampled ports to a vacuum dump
line thereby maintaining flow through the sampled port and
unselected lines keeping the flow current for when a sample is
selected.
[0181] Inlet port 230 and outlet port 220 were connected to their
corresponding feed or Valco ports through 1/16 inch 316L Stainless
Steel tubing commonly used in chromatography equipment and sold by
Valco as T100C40 as cleaned internally electro-polished and sealed
in one meter lengths. These tubes were bent by hand to shape them
to position so that each set of three rear openings that connect a
nozzle block firmly seat each tube into its shouldered 1/16 inch
opening thereby smoothly connecting the 0.040'' (1 mm) internal
tube diameter to the nozzle path. Each nozzle was wire EDM machined
into the nozzle block 230, 220 providing a smooth laminar flow
transition from the round 1 mm ID to the 1.0.times.3.1 mm wide
nozzle slot. Lateral movement of the EDM wire was used to shape the
smooth transition from round to the broad nozzle aperture.
[0182] The use of EDM machining (e.g., machining of high Nickel
alloy materials) often produces residual products due to the spark
erosion of the metal, leaving a "white layer". Such "white layers"
may form when typical cleaning operations are performed or
aggressive chemistries are used, which may cause the apparatus to
malfunction. In order for mechanical and chemical tolerance to be
preserved, precision surfaces should be brought to size in bright
metal cleanliness. Accordingly, many components of the SAT system
100 were manufactured from a single one-inch thick plate of X-750
High Nickel alloy material, which is chemically resistant. The Ni
alloy was annealed in vacuum at 1800.degree. F. and quenched slowly
in argon to develop desired properties for this application. X-750
is prone to work harden during machining, especially due to
precipitation hardening within a 1000 to 1300.degree. F.
temperature range. Thus, cutting speeds and feeds were carefully
managed to avoid work hardening. Cobalt cutters at moderate cutting
speed were used. After substantial machining of pre-annealed
material a subsequent anneal cycle was performed to preserve
properties and provide stability. In some cases, two or three
anneal cycles are preferred. In some cases, X-750 High Nickel alloy
material is fully annealed before beginning any machining
operations, and the "white layer" of the mill product is removed to
a depth of 0.015-0.025 inches.
[0183] The SAT enclosure 140 was heated in a controlled manner by
five cartridge heaters (not pictured) embedded in a 3/4 inch thick
Aluminum Heat Transfer Plate (not illustrated) intimately attached
by twelve 1/4-20 18-8 Stainless Steel screws (not illustrated) to
the bottom of the base 141 of enclosure 140. This enabled tests to
be conducted at elevated temperatures up to 200.degree. C. or
higher in some cases. Both mating faces of these two parts were
surface-ground flat to better than 3/10,000 inch flatness with
surface finish roughness less than 50 micro-inch. The surfaces were
very thinly coated before assembly with a finely powdered Boron
Nitride lubricant sold by Omega engineering as HTRC compound. The
two parts were repeatedly slid against each other moving an inch or
so to evenly distribute the compound to insure that all of the
surface is wetted with the compound by reducing the sliding stroke
gradually to just a millimeter or so. The 1/4-20 screws were Pan
headed with thin stainless washers and stainless Bellville spring
washers to allow for thermal expansion while maintaining the
desired clamping force. They were seated in counter-bored recesses
(0.585'' D) in the bottom of the Heat Transfer Plate and the
clearance hole for the 1/4-20 screws were over sized at
0.280''.
[0184] Several thermocouples (not pictured) provide readout of the
temperature of the anvil during operation. These and other
thermocouples were used as sensors to control a PID temperature
controller (not pictured) that powered five 1/4-inch diameter 250
Watt cartridge heaters (not pictured) (available from Omega
Engineering as CIR-1042/120V) embedded evenly across the mid-line
of the Heat Transfer Plate. These cartridges were also coated with
the HTRC thermal compound to fully couple the heat to the plate.
The mounting holes for the 1/4 inch diameter heaters provides 10 to
12 thousandth inch clearance before the compound is applied as the
heaters are inserted. The PID controller operates a
"zero-switching" solid-state relay that minimizes electrical noise
production that might interfere with the electronic control system
and data logging computer (not pictured) that are part of the
overall SAT system. To provide compressive stability and low heat
transfer to the aluminum main base plate, a 3 3/16 inch thick block
of closed-cell glass foam (trade name "Foamglas" from Dow Corning)
material (not pictured) was cut from larger pieces and was
laminated top and bottom with a 1/32 inch thick aluminum sheet
metal to avoid crumbling the material. The laminating was performed
using a Dow Corning 736 High Temperature RTV Silicone sealant using
a thin layer to adhere the metal to the glass foam. The length at
145/8'' was slightly less than the enclosure base length and the
width was 5 5/16'', allowing clearance for the heat transfer plate
locating and positioning brackets. The SAT enclosure 140 thus was
mounted to the cart so that it was separated from the cart by the
Foamglas block.
[0185] Enclosure 140 is designed to contain a moderately
pressurized gaseous atmosphere, some of which flows over the
contacting catalyst materials. The enclosure 140 has the
dimensions, 18''.times.5.5''.times.7.5'', with a one-inch thick
metal base 141 and a welded metal frame 143 supporting five sides
that form an enclosed volume of about 8.5 liters. The frame and
base were fabricated from X-750 material and all the fully annealed
parts were welded together using type 80 filler rod and
subsequently annealed again before finish machining Each frame end
is formed of one inch thick 5.5'' by 7.5'' X-750 material. The ends
are each closed by a 1/2-inch thick metal bulkhead flat ground
plate 145, 147, of 316L material that has penetrations for the
input gases and the thermocouple sensors. Both of these bulkhead
plates are secured with 6 mm stainless DIN cap screws and self
leveling spherical washers (JERGENS stainless self aligning
washers) threaded to the tapped holes in the enclosure frame ends.
Viton O-rings of 1/8-inch nominal diameter material in a groove in
each bulkhead plate seal them to provide leak free operation. The
top and the two sides employ thick (e.g., 9 mm) borosilicate plate
glass windows 149 (Schott Glass) that form a pressure sealed
enclosure, using similar Viton O-rings to seal the sides. These
O-rings were fabricated by vulcanizing to size by a commercial
vendor using a reference plate with all the required three
different rectangular grooves milled into this plate as a check on
the proper dimensioning. The front glass window is removable. The
top of enclosure 140 also employs a borosilicate glass window and
has a hole 151 located directly above the Alnico 8 magnet 330
attached to the top of the striker carrier upper foil clamp plate
332. A PIN link air-bearing assembly 132, the structure of which is
shown in greater detail in FIGS. 17A-C, is installed with sealing
O-rings and silicone rubber gaskets so that the 0.030'' diameter
316L wire link rod 131 is freely moved by an electromagnetic drive
system 130 positioned directly above it.
[0186] The electromagnetic drive system 130 is mounted on a 1/2
inch thick Boom plate (not pictured) (VPN) mounted vertically on a
Mast (VRT) (not pictured) made from an aluminum heavy-weight 6''
wide channel that is solidly anchored by bolts to a mating thick
mounting block (not pictured), also securely bolted to a 30-inch
square 3/4 inch thick aluminum horizontal main base plate (not
pictured). This main mechanical base rests on several inflated
bicycle tires (not pictured) forming an effective isolation of
low-level vibration from the cart equipment or building
structure-borne sources, reducing undefined and uncontrolled levels
of vibrating variation of contact force between the striker and the
anvil.
SAT General Test Protocol
[0187] As described above, the SAT system is composed of six basic
sub-systems. [0188] 1) gas sources and regulators, [0189] 2) valves
and gas flow controls, [0190] 3) SAT test enclosure, [0191] 4)
Valco selector valve, [0192] 5) Agilent 5879 Mass Selective
Detector [0193] 6) Data logging computer and striker drive control
electronics
[0194] A test run begins with the front window of the enclosure 140
opened. The bayonet connected internal magnet link 133 to the PIN
header 132 is removed to allow the foil frame 310 to be rotated
upward via rotational mount 360 exposing the striker post 301 so
that it may be removed and replaced by a desired striker/catalyst
post and the corresponding anvil insert 201 with its catalyst
material similarly removed and replaced with one desired for the
test run. These parts were prepared prior to setting up a test run.
After installing the desired striker 301 and anvil 200, the next
step was to begin a break-in run of the new striker and anvil. A
break-in run was started by first selecting the number of strokes
to be taken by striker post 300. Typically, 3000 strokes were used
with the system normally operating at 3 strokes per second. After
the break-in run, the anvil insert 201 and striker post 200 were
examined in the SEM with photo data taken and an EDAX analysis
taken. The insert and post were returned to the SAT enclosure and
the front glass side of the enclosure 140 was reinstalled.
[0195] The gas flow conditions were then established for the test.
For the palladium catalyst material runs, zero grade pure nitrogen
carrier gas was used at a flow rate of 2.5 liters per minute into
the main port of the enclosure 140. Methane reactant gas was fed to
the inlets 142 at a rate of one liter per minute. Prior to
beginning the test gas run, the chamber and nozzles were fed pure
helium gas for 20 minutes to clear all lines. The shutoff valve 503
between the output of the Valco selector valve 504 and MSD 502 was
kept closed until pressure indicated on the output of the enclosure
140 read stable at more than 1.5 psi. During this period of initial
gas flow into the enclosure the MSD's internal calibration spectrum
test was run using the test substance injector built in to the MSD
502. After completion of this test, MSD 502 is allowed to pump down
and, when stable, the shutoff valve is opened and the test run was
begun. Throughout the test run, the performance of MSD 502 and
temperature conditions were logged by the system computer. After
stable gas flow is established, the temperature adjustment program
was started for set points desired for the temperature of the test
operation.
[0196] Test runs were conducted at various temperature levels and
over varied time periods as described more fully below. The test
runs were performed at 3 strokes per second with a strike force of
about 12 g. After each run, the striker 301 and anvil 200 were
again examined by SEM and EDAX for mechanical changes or other
surface effects. Typically, no alterations were found.
[0197] As shown in the results data described below, generally,
substantial increases in catalyzed product abundance were observed
in samples taken from the contacted area of anvil 200 (e.g.,
portion 212) relative to the two un-contacted areas of anvil 200
(e.g., portions 210 and 214). The Valco selector valve 504 was used
to sample sequentially product gas from portions 210, 212, and 214
of anvil 200, as well as the input gas stream for portions 210,
212, and 214. For example, portion 210 was sampled first, portion
212 was sampled second, and portion 214 was sampled third. In some
cases, "unstruck" portion 214 was sampled too quickly after
"struck" portion 212, and carryover material (e.g., excess product)
was observed for "unstruck" portion 214. This anomaly was confirmed
by reversing the rotation of selector valve 504, such that portion
214 was sampled first, portion 212 was sampled second, and portion
210 was sampled third. As expected, when "unstruck" portion 210 was
sampled too quickly after "struck" portion 212, carryover material
(e.g., excess product) was observed for "unstruck" portion 210.
When a longer period of time was allowed for clearing lines between
each sampling, the carry over effects were largely reduced. The
catalytic enhancement effects far exceeded carryover effects.
Test Example 6
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas at 70.degree. C.
[0198] The SAT apparatus described above was fitted with a
5''.times.12'' Pd anvil and a 3''.times.3'' Pd striker and the test
run was performed generally as described above. In this example,
the SAT apparatus was heated to 70.degree. C., and methane gas was
fed into inlets 142 at a rate of one liter per minute. During the
test run, the striker contacted the anvil at a rate of 3 strokes
per second with a strike force of about 12 g. Samples of the
reactant gas from the "struck" portion and the "unstruck" portions
of the anvil were fed into the mass spectrometer over various
periods of time to measure levels of product produced during the
test run.
[0199] FIG. 18A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
The peaks having a mass number of about 14 correspond to the
methane starting material, while the peaks at about 30 mass number
correspond to a higher hydrocarbon product. FIG. 18B shows the mass
numbers (x axis) and abundance of species (y axis) in the product
gas for the "struck" portion of the anvil, sampled at various times
(z axis) during the test run. Comparing FIGS. 18A with 18B shows
that the ratio of the product abundance to the methane starting
material abundance for the "unstruck" portion of the anvil is
substantially less than that for the "struck" portion of the anvil,
indicating that the contact between the Pd anvil and Pd striker
substantially enhanced the catalytic reactivity of Pd in the
synthesis of higher hydrocarbons from methane at this
temperature.
Test Example 7
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas at 150.degree. C.
[0200] This test run was conducted as described in Test Example 6,
except that the SAT apparatus was heated to 150.degree. C. during
the test run.
[0201] FIG. 19A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 19B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 19A with 19B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane at this temperature.
Test Example 8
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 71.degree. C. to 31.degree. C.
[0202] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
71.degree. C., and the temperature was lowered to 31.degree. C.
over the course of the test run.
[0203] FIG. 20A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 20B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 20A with 20B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
Test Example 9
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 60.degree. C. to 80.degree. C.
[0204] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
60.degree. C., and the temperature was raised to 80.degree. C. over
the course of the test run.
[0205] FIG. 21A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 21B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 21A with 21B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
Test Example 10
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 30.degree. C. to 92.degree. C.
[0206] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
30.degree. C., and the temperature was raised to 92.degree. C. over
the course of the test run.
[0207] FIG. 22A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 22B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 22A with 22B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
Test Example 11
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 100.degree. C. to 200.degree. C.
[0208] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
100.degree. C., and the temperature was raised to 200.degree. C.
over the course of the test run.
[0209] FIG. 23A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 23B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 23A with 23B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
Test Example 12
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 85.degree. C. to 40.degree. C.
[0210] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
85.degree. C., and the temperature was lowered to 40.degree. C.
over the course of the test run.
[0211] FIG. 24A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 24B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 24A with 24B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
Test Example 13
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 24.degree. C. to 130.degree. C.
[0212] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
24.degree. C., and the temperature was raised to 130.degree. C.
over the course of the test run.
[0213] FIG. 25A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 25B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 25A with 25B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
[0214] Test Example 14
Use of SAT Apparatus for Pd-catalyzed Synthesis of Hydrocarbons
from Methane Gas from 100.degree. C. to 65.degree. C.
[0215] This test run was conducted as described in Test Example 6,
except that the test run began with the SAT apparatus heated to
100.degree. C., and the temperature was lowered to 65.degree. C.
over the course of the test run.
[0216] FIG. 26A shows the mass numbers (x axis) and abundance (y
axis) of species in the reactant gas for an "unstruck" portion of
the anvil, sampled at various times (z axis) during the test run.
FIG. 26B shows the mass numbers (x axis) and abundance of species
(y axis) in the product gas for the "struck" portion of the anvil,
sampled at various times (z axis) during the test run. Comparing
FIGS. 26A with 26B shows that the ratio of the product abundance to
the methane starting material abundance for the "unstruck" portion
of the anvil is substantially less than that for the "struck"
portion of the anvil, indicating that the contact between the Pd
anvil and Pd striker substantially enhanced the catalytic
reactivity of Pd in the synthesis of higher hydrocarbons from
methane over this temperature range.
[0217] While several embodiments of the invention have been
described and illustrated herein, those of ordinary skill in the
art will readily envision a variety of other means and structures
for performing the functions and/or obtaining the results or
advantages described herein, and each of such variations,
modifications and improvements is deemed to be within the scope of
the present invention. More generally, those skilled in the art
would readily appreciate that all parameters, dimensions,
materials, and configurations described herein are meant to be
exemplary and that actual parameters, dimensions, materials, and
configurations will depend upon specific applications for which the
teachings of the present invention are used. Those skilled in the
art will recognize, or be able to ascertain using no more than
routine experimentation, many equivalents to the specific
embodiments of the invention described herein. It is, therefore, to
be understood that the foregoing embodiments are presented by way
of example only and that, within the scope of the appended claims
and equivalents thereto, the invention may be practiced otherwise
than as specifically described. The present invention is directed
to each individual feature, system, material and/or method
described herein. In addition, any combination of two or more such
features, systems, materials and/or methods, provided that such
features, systems, materials and/or methods are not mutually
inconsistent, is included within the scope of the present
invention.
[0218] In the claims (as well as in the specification above), all
transitional phrases or phrases of inclusion, such as "comprising,"
"including," "carrying," "having," "containing," "composed of,"
"made of," "formed of," "involving" and the like shall be
interpreted to be open-ended, i.e., to mean "including but not
limited to" and, therefore, encompassing the items listed
thereafter and equivalents thereof as well as additional items.
Only the transitional phrases or phrases of inclusion "consisting
of" and "consisting essentially of" are to be interpreted as closed
or semi-closed phrases, respectively. The indefinite articles "a"
and "an," as used herein in the specification and in the claims,
unless clearly indicated to the contrary, should be understood to
mean "at least one."
[0219] The phrase "and/or," as used herein in the specification and
in the claims, should be understood to mean "either or both" of the
elements so conjoined, i.e., elements that are conjunctively
present in some cases and disjunctively present in other cases.
Other elements may optionally be present other than the elements
specifically identified by the "and/or" clause, whether related or
unrelated to those elements specifically identified. Thus, as a
non-limiting example, a reference to "A and/or B" can refer, in one
embodiment, to A only (optionally including elements other than B);
in another embodiment, to B only (optionally including elements
other than A); in yet another embodiment, to both A and B
(optionally including other elements); etc. As used herein in the
specification and in the claims, "or" should be understood to have
the same meaning as "and/or" as defined above. For example, when
separating items in a list, "or" or "and/or" shall be interpreted
as being inclusive, i.e., the inclusion of at least one, but also
including more than one, of a number or list of elements, and,
optionally, additional unlisted items. Only terms clearly indicated
to the contrary, such as "only one of" or "exactly one of," will
refer to the inclusion of exactly one element of a number or list
of elements. In general, the term "or" as used herein shall only be
interpreted as indicating exclusive alternatives (i.e., "one or the
other but not both") when preceded by terms of exclusivity, such as
"either," "one of," "only one of," or "exactly one of."
[0220] As used herein in the specification and in the claims, the
phrase "at least one," in reference to a list of one or more
elements, should be understood, unless otherwise indicated, to mean
at least one element selected from any one or more of the elements
in the list of elements, but not necessarily including at least one
of each and every element specifically listed within the list of
elements and not excluding any combinations of elements in the list
of elements. This definition also allows that elements may
optionally be present other than the elements specifically
identified within the list of elements that the phrase "at least
one" refers to, whether related or unrelated to those elements
specifically identified. Thus, as a non-limiting example, "at least
one of A and B" (or, equivalently, "at least one of A or B," or,
equivalently "at least one of A and/or B") can refer, in one
embodiment, to at least one, optionally including more than one, A,
with no B present (and optionally including elements other than B);
in another embodiment, to at least one, optionally including more
than one, B, with no A present (and optionally including elements
other than A); in yet another embodiment, to at least one,
optionally including more than one, A, and at least one, optionally
including more than one, B (and optionally including other
elements); etc.
[0221] Any terms as used herein related to shape, orientation,
and/or geometric relationship of or between, for example, one or
more articles, structures, forces, fields, flows,
directions/trajectories, and/or subcomponents thereof and/or
combinations thereof and/or any other tangible or intangible
elements not listed above amenable to characterization by such
terms, unless otherwise defined or indicated, shall be understood
to not require absolute conformance to a mathematical definition of
such term, but, rather, shall be understood to indicate conformance
to the mathematical definition of such term to the extent possible
for the subject matter so characterized as would be understood by
one skilled in the art most closely related to such subject matter.
Examples of such terms related to shape, orientation, and/or
geometric relationship include, but are not limited to terms
descriptive of: shape--such as, round, square, circular/circle,
rectangular/rectangle, triangular/triangle, cylindrical/cylinder,
ellipitical/ellipse, (n)polygonal/(n)polygon, etc.; angular
orientation--such as perpendicular, orthogonal, parallel, vertical,
horizontal, collinear, etc.; contour and/or trajectory--such as,
plane/planar, coplanar, hemispherical, semi-hemispherical,
line/linear, hyperbolic, parabolic, flat, curved, straight,
arcuate, sinusoidal, tangent/tangential, etc.; direction--such as,
north, south, east, west, etc.; surface and/or bulk material
properties and/or spatial/temporal resolution and/or
distribution--such as, smooth, reflective, transparent, clear,
opaque, rigid, impermeable, uniform(ly), inert, non-wettable,
insoluble, steady, invariant, constant, homogeneous, etc.; as well
as many others that would be apparent to those skilled in the
relevant arts. As one example, a fabricated article that would
described herein as being "square" would not require such article
to have faces or sides that are perfectly planar or linear and that
intersect at angles of exactly 90 degrees (indeed, such an article
can only exist as a mathematical abstraction), but rather, the
shape of such article should be interpreted as approximating a
"square," as defined mathematically, to an extent typically
achievable and achieved for the recited fabrication technique as
would be understood by those skilled in the art or as specifically
described.
[0222] All references cited herein, including patents and published
applications, are incorporated herein by reference. In cases where
the present specification and a document incorporated by reference
and/or referred to herein include conflicting disclosure, and/or
inconsistent use of terminology, and/or the incorporated/referenced
documents use or define terms differently than they are used or
defined in the present specification, the present specification
shall control.
* * * * *
References