U.S. patent application number 10/207585 was filed with the patent office on 2004-05-27 for high performance continuous reaction/separation process using a continuous liquid-solid contactor.
Invention is credited to Chiang, Chen-Chou, Fair, David L..
Application Number | 20040099605 10/207585 |
Document ID | / |
Family ID | 30770470 |
Filed Date | 2004-05-27 |
United States Patent
Application |
20040099605 |
Kind Code |
A1 |
Chiang, Chen-Chou ; et
al. |
May 27, 2004 |
High performance continuous reaction/separation process using a
continuous liquid-solid contactor
Abstract
A process for reaction and separation which comprises inputting
a process material into at least one column of a plurality of
columns wherein each column has at least one inlet for accepting
flow from another column or group of columns, an external feed
stream, an external eluent stream or a combination thereof, and
each column has at least one outlet for connecting to another
column, a group of columns, an external product stream or a
combination thereof. Each column is independently operable in an
up-flow or down-flow mode and connected independently to one of the
group comprising another column, an external feed stream, an
external eluent stream, an external product stream and combinations
thereof.
Inventors: |
Chiang, Chen-Chou; (Wexford,
PA) ; Fair, David L.; (Imperial, PA) |
Correspondence
Address: |
Cohen & Grigsby, P.C.
15th Floor
11 Stanwix Street
Pittsburgh
PA
15222
US
|
Family ID: |
30770470 |
Appl. No.: |
10/207585 |
Filed: |
July 29, 2002 |
Current U.S.
Class: |
210/657 |
Current CPC
Class: |
C07C 39/16 20130101;
C07C 37/20 20130101; B01D 2215/023 20130101; B01D 15/1864 20130101;
B01D 2215/028 20130101; B01D 15/1857 20130101; C07C 37/20
20130101 |
Class at
Publication: |
210/657 |
International
Class: |
C02F 001/28; C07C
069/00 |
Claims
What is claimed is:
1. A process for reaction and separation which comprises: (a)
inputting a process material into at least one column of a
plurality of columns, each said column having at least one inlet
for accepting flow from another column or group of columns, an
external feed stream(s), an external eluent stream(s) or a
combination thereof, and at least one outlet for connecting to
another column, a group of columns, an external product stream(s)
or a combination thereof; each said column being independently
operable in an up-flow or down-flow mode and connected
independently to one of the group comprising another column, an
external feed stream(s), an external eluent stream(s), an external
product stream(s) and combinations thereof; (b) reacting and
separating said process material in one or more said columns; and
(c) extracting material therefrom.
2. In a process using a liquid-solid contacting apparatus, the
improvement therein comprising the process set forth in claim
1.
3. In a process using a liquid-solid contacting apparatus having a
plurality of packed columns, each of which has a supply conduit and
a discharge conduit adapted for connection to a disk having a
plurality of ports for connection being associated with supply and
discharge conduits, said columns or said disk being mounted for
rotation about an axis so that by rotation said conduits and said
ports in the disk are alignable for direct flow communication
therebetween such that, a plurality of supply and discharge
conduits communicate with associated other supply and discharge
conduits of the columns, and by synchronizing rotation of at least
the columns and the disk, the improvement therein comprising
flowing a process material through each of said columns to react
and separate said flow material.
4. In a process using a liquid-solid contacting apparatus having a
multiport rotary valve for directing fluid streams comprising: (a)
a first head having opposed surfaces, comprising at least two first
ports located on the same surface for connection with an external
fluid stream, and having a separate channel associated with each
first port leading to a second port corresponding to the first port
and located on the surface opposite the first port; (b) a rotatable
second head having at least two third ports each in communication
with a separate second port and channel and located on a surface in
contact with the surface of the first head containing the second
ports, said third ports leading to an inlet or outlet of a chamber
containing a fluid-solid contacting medium so as to form a fluid
seal between the chamber and an external fluid stream; and (c) a
drive for rotating at least one of said heads to interconnect a
selected external fluid stream with a selected chamber for a
predetermined period of time before permitting interconnection of
said external fluid stream with a different chamber; (d) the ports
being configurable to permit said external fluid streams to be
delivered to multiple or successive chambers in series or in
parallel or to bypass a selected chamber simultaneous with the
delivery of other external fluid streams; the improvement therein
comprising flowing a process material through said chambers to
react and separate said flow material.
5. A process for conducting reaction and separation in a material
flow as set forth in claims 1, 2, 3 or 4, wherein said columns are
configured to provide at least one reverse flow.
6. A process for conducting reaction and separation in a material
flow as set forth in claims 1, 2, 3 or 4, wherein at least two said
columns will have a flow therein parallel in the connected to
provide a parallel flow configuration.
7. A process for conducting reaction and separation in a material
flow as set forth in claims 1, 2, 3 or 4, having a
separation/reaction process zone, wherein one or multiple columns
are connected together separately inside of said
separation/reaction process zone.
8. A process for conducting reaction and separation in a material
flow as set forth in claims 1, 2, 3 or 4, having a
separation/reaction process zone, wherein one or multiple columns
are connected together in a zone within said unit but outside of
said separation/reaction process zone.
9. A process for conducting a reaction and separation in a material
flow as set forth in claims 1, 2, 3 or 4, having a
separation/reaction process zone, wherein one or more said columns
are connected to provide a flow pattern selected from the group
consisting of: reverse flow, parallel flow, a separated reaction
zone inside of a separation/reaction process zone, separated
reaction zone in a zone within said unit but outside of said
separation/reaction process zone, and a combination of any one or
more of these configurations.
Description
FIELD OF INVENTION
[0001] This invention relates to a process for chemical reaction
and separation using a liquid-solid contacting system and, more
particularly, to a chemical reaction and separation process using a
plurality of columns wherein each column can be independently
connected and independently operated for flow inlet and outlet,
such as parallel fluid flow, reverse fluid flow or combination of
flows.
BACKGROUND OF THE INVENTION
[0002] Combining a process for conducting a continuous reaction
with concurrent separation into a single process technique has
received renewed attention in recent years. Various
reaction/separation technologies are being investigated and have
reached differing degrees of development or commercial viability.
Fairly developed techniques include, for example, reactive
distillation techniques and reactive chromatography. Other
techniques, such as reactive membranes and reactive crystallization
techniques, are also being developed. Some of these techniques have
provided certain benefits such as reduced capital costs, higher
productivity, higher product yields and improved selectivity when
competing reactions are taking place. For instance, reactive
distillation, where simultaneous reaction and distillation
separation processes are carried out, has been implemented for the
production of methyl acetate. This technique resulted in five times
lower investment and five times lower energy use than the
traditional two-step process where the reaction is carried out as a
first step and the distillation separation is carried out as a
separate second step. Despite these advantages, however, this
technique has drawbacks, which include temperature sensitivity and
azeotrope formation.
[0003] Reactive chromatography systems have also been used for
conducting combined reaction and separation. Several different
reactive chromatography systems have been investigated including a
fixed bed with a pressure swing, cylindrical annular bed with a
rotating feed input source, a countercurrent moving bed, and a
simulated bed. The choice of a particular reaction/separation
technology is made based on the specific requirements of specific
applications. Each application will have a particular set of
requirements in terms of product yield, purity, process
productivity, material handling, etc. (See generally, Vaporciyan,
G. G.; Kadelec, R. H. AIChE J. 1987, 33 (8), 1334-1343; Fish, B.
B.; Carr, R. W. Chem. Eng. Sci. 1989, 44, 1773-1783; and Carr, R.
W.; In Preparative and Production Scale Chromatography, Ganetsos,
G., Barker, P. E., Eds.; Chromatographic Science Series Vol. 61;
Marcel Dekker: New York, 1993; Chapter 18.) Traditionally, the
preferred method for carrying out continuous reactive
chromatography is the simulated moving bed reactor (SMB)
configuration.
[0004] Traditional SMB technology (as shown in FIG. 1) comprises a
circulation flow path having multiple beds packed with solid
separation/catalyst filler connected in series and allowing a
circulation liquid to be forcibly circulated through in one
direction. It also has a port for introducing desorbing liquid into
the circulation flow path, an extract port for removing circulation
liquid carrying the adsorptive constituents (extracts) from the
circulation flow path, a feedstock port for introducing feed stock
which contains the constituents to be separated, or reacted and
separated, into the circulation flow path, and a raffinate port for
removing circulation liquid carrying the weakly adsorptive
constituents (raffinate) from the circulation flow path.
[0005] As shown in the prior art in FIG. 1, the prior art SMB
process is illustrated showing a combined reaction and separation
by the general reaction A.fwdarw.B+C. The process is illustrated
using four "zones." Typically, although not always, there are two
inlets and two outlets in the SMB system unit. The areas defined
between them create the four zones. Component A is feed material
11, which is fed into the SMB system between Zone II and Zone III.
Component A decomposes to form Component B and Component C.
Component B is the more strongly adsorbed component and therefore
moves with the solid in the direction of the extract outlet, which
lies between Zone III and Zone IV. At the extract outlet, Component
B is collected as extract product 17. Component C is the more
weakly adsorbed component and moves with the liquid in the
direction of the raffinate outlet, which lies between Zone I and
Zone II. At the raffinate outlet, Component C is collected as the
raffinate 19 product. The eluent 15 is introduced to the system
between Zone I and Zone IV to remove the more strongly adsorbed
Component B and to act as the liquid carrier for the system. A
number of reactions have been reported:
[0006] The SMB process has been demonstrated to significantly
increase product yield from equilibrium-limited, liquid phase
esterification reactions. Esterification of acetic acid with
.beta.-phenethyl alcohol is disclosed in M. Kawase, T. B. Suzuki,
K. Inoue, K. Yoshimoto, K. Hashimoto, Chem. Eng. Sci., Vol 51,
2971-2976 (1996). Esterification of acetic acid with ethanol is
disclosed in M. Mazzotti, A. Kruglov, B. Neri, D. Gelosa, M.
Morbidelli, Chem. Eng. Sci., Vol 51, 1827-1836 (1996); and acetic
acid esterification with methanol is disclosed in U.S. Pat. Nos.
5,405,992 and 5,618,972.
[0007] U.S. Pat. No. 5,502,248 shows that the equilibrium-limited,
liquid phase ester hydrolysis reaction of methyl acetate can be
significantly increased through the use of reactive SMB.
[0008] Ray A., Tonkovich, A. L., Aris, R., Carr, R. W., Chem. Eng.
Sci., Vol. 45, No. 8, 2431-2437 (1990) demonstrates that the
product yield from the gas phase equilibrium-limited reaction for
hydrogenation of mesitylene can be significantly increased using
reactive SMB.
[0009] A. V. Kruglov, M. C. Bjorklund, R. W. Carr, Chem. Eng. Sci.,
Vol 51, 2945-2950 (1996), demonstrates that reactive SMB can be
used to increase the product yield with the gas phase reaction for
oxidative coupling of methane.
[0010] The feasibility of the condensation of phenol with acetone
to form bisphenol-A and water and the simultaneous separation of
the products has been predicted through a numerical simulation
(Kawase, M.; Inoue, Y.; Araki, K.; Hashimoto, K. Catalyst Today
1999, 48, 199-209).
[0011] Despite these advantages, the traditional SMB techniques
have certain drawbacks. The traditional SMB configuration has
always been defined as a plurality of beds connected in series and
employing a unidirectional fluid flow. This limited configuration
inherently prevents the system from handling many
reaction/separation applications, such as those that require high
mass flow, toxin removal, and individual optimization of reaction
and separation conditions. With these applications, the traditional
SMB reactor system becomes very complicated, very expensive, and
sometimes impractical. Furthermore, none of the present
technologies allow for a continuous reaction and separation process
using contacting beds arranged in parallel, rather than series,
having reverse flow capabilities, or combination unit capabilities.
Accordingly, it is an object of the present invention to provide a
process for performing combined reaction and separation that
further provides parallel fluid flow, reverse flow, or combination
unit design, or a combination of any of these thereby eliminating
many of the prior art limitations. It is a further object of the
invention to provide a process for performing combined
reaction/separation step in a single processing unit to greatly
decrease processing cost while increasing throughout.
SUMMARY OF INVENTION
[0012] Generally, the present invention provides a reactive
chromatography process for performing the dual functions of
chemical reaction and separation either simultaneously or
sequentially using a plurality of beds or columns comprised of a
solid or mixture of solids independently connected in a either a
series or parallel configuration. Each column has at least one
inlet for accepting flow from a connected column, an external
stream feed, an external eluent stream or a combination thereof,
and at least one outlet for connecting to another column, an
external product stream or a combination thereof; each said column
being operable in an up-flow or down-flow mode. The up-flow mode
can be described by fluid flowing in the direction of the top of
the column and the down-flow mode has a fluid flow from the top of
the column in a general vertical direction downward. Independently
connected can include a column or a group of columns each connected
to another column, columns or group of columns or any other sources
such as feed, external, event, or external products in any way the
process requires without any preset flow pattern. The external
product can be raffinate or extract or both. Each column, for
example, the flow configuration can be modified to allow for
reverse fluid flow. In another example, the beds are arranged to
create a combination unit design configuration. In still another
example, the process provides for a parallel fluid flow
configuration wherein at least one of the beds is connected in
parallel.
[0013] The beds preferably contain a solid or mixture of solids
that act as a catalyst for the desired reaction and an adsorbent or
separation media for removing the reaction product or other desired
components. There are a wide variety of solid catalysts and
adsorbents available. Such materials include, but are not be
limited to, activated carbon, silica gels, aluminas, zeolites,
zirconias, titanias, silicates, diatomaceous earths, and ion
exchange resins. In one embodiment, a solid is referred where it
sufficiently performs both the catalyic and adsorbent function.
Where two or more solids are used, one performs the catalyic
function while the other perform the separation function. These
materials are chosen to provide enhanced reaction and separation
over a single material. Also, it is possible that the solid acts
only as a separation medium and the catalyst is not part of the
solid phase but rather is dissolved in the liquid phase.
[0014] The process of the invention also uses one or more eluents
to selectively desorb the reaction products, byproducts, or
contaminants from the bed using an isocratic elution or a gradient
elution process. The eluent comprises or contains a liquid capable
of displacing such reaction product, byproduct, or contaminant from
the adsorption bed. Examples of eluents include, for example,
alcohols, ketones, esters, aliphatic hydrocarbons, aromatic
hydrocarbons, ethers, carboxylic acids, halogenated hydrocarbons,
amides, nitrites, water, or buffered solutions. Mixtures of eluents
may also be used.
[0015] The feedstock supplied to the present invention may be a
single compound or multiple compounds as either a neat material or
a solute in solution. It may include a wide variety of materials
such as commercial chemicals, fine chemicals, drugs,
pharmaceuticals, agrochemicals, foodstuffs, perfumes, flavors,
fragrances, odorants, colorants, petrochemicals, etc.
[0016] Preferably, the present invention is used in combination
with a continuous liquid-solid contacting device. Continuous
liquid-solid contacting devices generally strive to move a liquid
phase in counter-current contact with a solid phase through various
means. Some systems use multiple columns and a plurality of valves.
Others use bed sections stacked in a vertical tower and fed by a
rotary valve. A general review of the various devices can be found
in U.S. Pat. No. 5,676,826, which is incorporated herein by
reference. Although any of the devices can be used with the present
invention to achieve the desired continuous reaction and
separation, preferred devices include those disclosed in U.S. Pat.
Nos. 5,676,826; 4,808,317; 4,764,276; 4,522,726 and U.S. patent
application Ser. No. 09/452,256. U.S. patent application Ser. No.
09/452,256 is incorporated herein by reference.
[0017] In a preferred embodiment, the process uses a liquid-solid
contacting apparatus having a plurality packed columns of, each of
which have a supply conduit and a discharge conduit adapted for
connection to a disk having a plurality of ports for connection
being associated with supply and discharge conducts at least said
columns or said disk being mounted for rotation about an axis so
that by rotation said conduits and said ports in the disk are
alignable for direct flow communication therebetween between such
that, a plurality of supply and discharge conduits to communicate
with associated other supply and discharge conduits of the columns,
and by synchronizing rotation at least the columns and the disk by
the improvement therein comprising flowing a process material
through each of said columns to react and separate said flow
material.
[0018] Particularly, when used with the present process, this
device allows for a wide variety of processing possibilities that
have not been taught in the prior art of combined
reaction/separation technologies. The ability to incorporate
parallel liquid flow, reverse liquid flow, and combination unit
configuration, as single or multiple zones and in any combination
within a single unit, is a capability that is unique to the present
invention. This can prove especially advantageous in the present
invention because this process is not limited to a series bed
arrangement and unidirectional fluid flow as is the prior art. This
flexibility advantageously increases productivity, reduces costs
and improves product quality over traditional processes. Other
features, aspects and advantages of the present invention will
become better understood or apparent from a perusal of the
following detailed description and examples of the invention and
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a schematic representation of a prior art
configuration of a general SMB process.
[0020] FIG. 2 is a schematic representation of an embodiment of the
present invention using a reverse flow configuration.
[0021] FIG. 3 is a schematic representation of an embodiment of the
present invention using a parallel flow configuration.
[0022] FIG. 4 is a schematic representation of an embodiment of the
present invention using a combination unit design.
[0023] FIG. 5 is a schematic representation of an embodiment of the
present invention using another combination unit design.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention provides a process for chemical
reaction and separation using multiple beds comprised of a solid or
mixture of solids connected in series, parallel, or combination of
such configurations. The reaction/separation can occur concurrently
or sequentially. In a preferred arrangement, the beds are
configured to have a reverse flow, or a combination unit
configuration or a parallel flow configuration or any combination
thereof. Preferably, the invention is used in combination with a
continuous liquid-solid contacting device. The examples below
further show the various configurations of the process. Each may be
used alone or in combination with any of the others.
EXAMPLE 1
Reverse Flow Configuration
[0025] In an embodiment of the present invention, a unit is
designed to operate with a liquid flow direction and a solid flow
direction as depicted in FIG. 2. FIG. 2 depicts one possible
reverse flow configuration where columns 20 and 21 operate in an
up-flow mode whereas the other columns in the unit operate in the
down-flow mode. This is just one example of the use of reverse
flow.
[0026] The reverse flow configuration provides a variety of uses.
For instance, it can be used to remove very strongly adsorbed
components. FIG. 2 illustrates the use of the reverse flow
configuration. It includes one weakly adsorbed component and two
strongly adsorbed components (one of which is more strongly
adsorbed). The weakly adsorbed component moves with the liquid in
the direction of the raffinate 19 outlet and is removed as the
raffinate product. The two strongly adsorbed components move with
the solids in the direction of the extract outlets 17,18. The less
strongly adsorbed component of the two moves with the solid in the
direction of the extract I outlet 17 where it is eluted from the
system by eluent I 15 and becomes the extract I product 17. The
more strongly adsorbed component of the two continues to move past
the extract I outlet 17 in the direction of the extract II outlet
18. This component is eluted by eluent II 16 and becomes the
extract II outlet 18. These components may include a product,
byproduct, inhibitor, contaminant, etc. An esterification reaction
illustrates one of the advantages of the reverse flow
configuration:
Alcohol+Carboxylic Acid .tau. Ester+Water
[0027] In this example, alcohol and carboxylic acid act as feed 11
which is introduced into the top of the column. The water is a
strongly adsorbed product that is generated by the chemical
reaction and moves with the solid in the direction of an extract I
outlet 17. At outlet 17, the water is extracted by eluent 15 as
extract I product. A more weakly adsorbed product which is also
generated by the chemical reaction, the ester, moves with the
liquid in the direction of raffinate outlet 19 and collected from
the system as raffinate product. In this case the alcohol could
also be used as the eluent 15, which will remove the water from the
solid phase as extract at outlet 17 and also act as a liquid
carrier for the rest of the system.
[0028] The very strongly adsorbed component will accumulate at the
top of the column(s). Then, eluent I 15 or a different eluent,
eluent II 16, is directed into the system in the reverse flow
configuration to elute this very strongly adsorbed component out of
the top of column 21. Elution of extract at outlet 18 from the top
of the column eliminates the need for the eluent to carry the very
strongly adsorbed component all the way through the series of
columns to effectuate its removal, as is required in the
traditional SMB process. Instead, the reverse flow configuration
decreases the length of time for the elution or amount of eluent
necessary to complete the process thereby resulting in decreased
cost and improved productivity and efficiency of the elution step.
Further, this reverse flow configuration can also accommodate two
different eluents for desorption of the two different strongly
adsorbed components.
[0029] The use of the reverse flow configuration is not limited to
the previous specific example. Those skilled in the art would
realize that, with the present invention, the unique reverse flow
configuration can advantageously be incorporated anywhere within
the process: elution zone, reaction zone, separation zone, and the
like. Because traditional SMB is carried out with unidirectional
flow, the present technique is outside of the realm of traditional
SMB.
[0030] The ability to incorporate reverse flow configuration into a
process will provide the user with certain advantages. The reverse
flow configuration can also be used to remove solids that would
accumulate on the top of the column(s), therefore allowing the use
of a process stream which contains a certain amount of solids or a
process stream which has the potential to form solids in the course
of the reaction/separation process. In this way solids can be
removed continuously from the top of the column, thereby overcoming
a disadvantage of the traditional SMB system which is limited to a
unidirectional liquid flow. The SMB process does not allow for
continuous removal of solids. The solids would either be trapped in
the unit or plug the liquid flow all together.
[0031] The use of the present invention is not restricted to the
specific configuration shown in FIG. 2. Those skilled in the art
will realize that many different variations are possible because of
the flexibility and versatility of the present invention.
EXAMPLE 2
Parallel Flow Configuration
[0032] In another embodiment of the present invention, multiple
columns are connected together in parallel flow mode. As shown for
example in FIG. 3, the feed 11 column is connected in parallel. The
components of the process system can, either alone or alternatively
in combination, employ parallel flow, including the feed, eluent,
raffinate, or extract streams. This offers the ability to obtain
high flow rates while maintaining an acceptable pressure drop and
reaction performance for the process. These capabilities prove
especially useful for reactions that require long hold-up time and
high mass flow. Such reactions can encounter high pressure drops
when performed using the prior art configuration where the columns
are connected in a series configuration. The pressure drop
requirement for a given process is a very important design
parameter. As the pressure drop requirement increases, the cost of
the equipment increases and at some point the process become
impractical or even impossible. The present parallel flow process
reduces the cost of the equipment and increases its productivity.
In processes where a reduction in pressure drop is not required,
the parallel flow configuration allows for higher productivity at a
given pressure drop.
EXAMPLE 3
2-in-1 Configuration (Type A)
[0033] In another embodiment of the present invention, one or
multiple columns are connected together separately inside of a
separation train, as shown for example in FIG. 4. This combination
unit configuration is also referred to herein as a "2-in-1 flow
configuration." The 2-in-1 flow configuration optimizes the
reaction and separation operations by allowing each to be carried
out under different conditions. In addition to reaction/separation,
another reaction may be conducted, i.e.,
reaction/separation/reaction or 3-in-1. This configuration is not
limited to 2-in-1 or 3-in-1, but may be used to perform multiple
reactions and separations in N-in-1 configuration, where N is an
integer greater than 1. The feed 11 column is not connected
directly in series with the column that precedes it, but rather is
connected independently into the liquid flow of the system. Thus,
the user can vary the hold-up time, the composition, and the
temperature for the reaction in the feed 11 column without limiting
the conditions that can be applied to the rest of the process.
[0034] This 2-in-1 flow configuration further combines a fixed bed
type reactor and SMB type separation reactor into a single unit to
provide the reaction zone in the middle of the process. In this
arrangement, feed 11 column acts as a fixed bed reactor that feeds
a reaction product to an SMB unit for separation and additional
reaction as needed. The lines physically connect with a T, as shown
for example in FIG. 4. The advantage of feeding the fixed bed
reacted product into a separate SMB unit has been realized in prior
art, such as in U.S. Pat. No. 5,618,972. The combination improves
the effectiveness of the fixed bed reactor while also improving the
cost efficiency of the SMB unit. The present invention further
improves this process by combining two units into a single unit. It
eliminates the costs associated with maintaining two freestanding
units that are then physically connected together.
[0035] An esterification reaction is used here to illustrate one of
the many uses of the 2-in-1 configuration.
Alcohol+Carboxylic Acid .tau. Ester+Water
[0036] The alcohol and carboxylic acid are feed 11. Water is the
more strongly adsorbed product and therefore moves with the solid
in the direction of extract outlet 17 where it is eluted as extract
17 product. The ester, raffinate 19 product, is the more weakly
adsorbed product and moves with the liquid in the direction of the
raffinate 19 outlet. In this case, the alcohol could also be used
as the eluent 15. In this case, because this 2-in-1 configuration
provides for a feed column that is not directly connected in
series, it allows the user to optimize the process parameters for
the reaction zone independently from the process parameters that
are required for the separation by being able to adjust the
temperature, hold up time, and feed composition. This type of
process flexibility where one can carry out reaction and separation
in one unit while still being able to separately optimize process
conditions for each, is not realized with traditional SMB processes
that, by definition, entails columns connected in series,
[0037] Those skilled in the art will realize that this technique
can be advantageously applied to wide variety of reactions, such as
esterification, ester hydrolysis, etherification, isomerization,
condensations, amide synthesis, peptide synthesis, dehydrations,
oxidations just to name a few. It will also be realized that the
use of the present invention is not restricted to the specific
configuration shown in FIG. 3. Those skilled in the art will
realize that many different variations are possible because of the
flexibility and versatility of the present invention.
EXAMPLE 4
2-in-1 Configuration (Type B)
[0038] In another embodiment of the present invention, one or
multiple columns are connected together in a zone that is still
within the same unit but outside the separation process zone. The
2-in-1 flow configuration (type A) shown in Example 3 incorporates
a reaction zone into the middle of a traditional SMB process. The
composition of the material in the reaction zone is influenced by
the composition of the adjacent column which will move into the
reaction zone position. With the 2-in-1 flow configuration (type
B), the reaction zone V receives the next column from elution in
zone I. Because of this process feature, the reaction zone is a
clean column rather than a column that already contains a certain
composition of material. This allows for additional process
optimization that goes beyond the 2-in-1 (type A) configuration.
This type of process is also outside the traditional SMB process
which relies on columns that are endlessly connected in series. The
prior art of reactive SMB does not teach about the use of this type
of configuration as it would not necessarily be advantageous under
its limited operating conditions.
[0039] The use of the present invention is not restricted to the
specific configuration shown in FIG. 5. Those skilled in the art
will realize that many different variations of 2-in-1
configurations are possible because of the flexibility and
versatility of the present invention.
[0040] The previous examples illustrate the versatility of the
present invention. Although the illustrations depict one particular
example of each configuration, those skilled in the art will
realize that a large number of variations are possible within the
scope of this invention. Any given configuration may contain more
or less zones than shown in FIGS. 2-5. Each zone may contain
anywhere from one to zero to multiple columns. The special function
zones (reverse flow, parallel flow, etc.) may be used anywhere in
the system and are not limited to the location shown in the
illustrations. More than one configuration may be used in a unit
and multiple functions can be combined in one unit.
[0041] Those skilled in the art, will realize that this level of
process flexibility becomes very complicated and very expensive
with the traditional SMB technologies. The advantages listed above
will result in reduced capital costs, higher productivity, higher
yields, and improved selectivity.
[0042] Those skilled in the art will also realize that the present
invention can also be used with many different reaction/separation
applications. The present invention can be used for, but not
limited to, esterification, ester hydrolysis, etherification,
isomerizations, condensations, amide synthesis, peptide synthesis,
dehydrations, and oxidations just to name a few.
[0043] While the foregoing has been set forth in considerable
detail, the examples and methods are presented for elucidation and
not limitation. It will be appreciated from the specification that
various modifications of the invention and combinations of
elements, variations, equivalents, or improvements therein may be
made by those skilled in the art, and are still within the scope of
the invention as defined in the appended claims.
* * * * *