U.S. patent application number 14/023040 was filed with the patent office on 2014-03-13 for systems for decreasing char entrainment during pyrolysis.
This patent application is currently assigned to Phillips 66 Company. The applicant listed for this patent is Phillips 66 Company. Invention is credited to Johnathan T. Gorke, Mark A. Hughes, Samuel T. Jones, J. Scott McQueen, Cory B. Phillips.
Application Number | 20140069799 14/023040 |
Document ID | / |
Family ID | 50231776 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140069799 |
Kind Code |
A1 |
Gorke; Johnathan T. ; et
al. |
March 13, 2014 |
SYSTEMS FOR DECREASING CHAR ENTRAINMENT DURING PYROLYSIS
Abstract
The present disclosure relates generally to novel biomass
pyrolysis processes and systems that decrease entrainment of char
and other contaminants with the produced pyrolysis vapors.
Inventors: |
Gorke; Johnathan T.;
(Owasso, OK) ; Jones; Samuel T.; (Dewey, OK)
; Hughes; Mark A.; (Katy, TX) ; McQueen; J.
Scott; (Bartlesville, OK) ; Phillips; Cory B.;
(Linden, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Phillips 66 Company |
Houston |
TX |
US |
|
|
Assignee: |
Phillips 66 Company
Houston
TX
|
Family ID: |
50231776 |
Appl. No.: |
14/023040 |
Filed: |
September 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61699036 |
Sep 10, 2012 |
|
|
|
Current U.S.
Class: |
202/105 |
Current CPC
Class: |
Y02E 50/14 20130101;
C10B 57/06 20130101; Y02E 50/10 20130101; Y02E 50/30 20130101; Y02P
20/145 20151101; C10G 1/08 20130101; Y02E 50/32 20130101; Y02P
30/20 20151101; C10G 2/32 20130101; C10L 3/08 20130101; C10G
2300/1011 20130101; C10B 49/16 20130101; C10B 53/02 20130101; C10B
43/14 20130101; C10B 53/08 20130101; C10J 3/46 20130101 |
Class at
Publication: |
202/105 |
International
Class: |
C10B 43/14 20060101
C10B043/14 |
Claims
1. A biomass pyrolysis system, comprising: (a) a pelletized biomass
feedstock comprising pellets greater than or equal to 300 microns
in diameter; (b) a pyrolysis reactor comprising at least one inlet
for receiving the pelletized biomass feedstock, a reaction zone for
pyrolyzing the pelletized biomass feedstock to form pyrolysis
vapors and char particles, at least one outlet for the pyrolysis
vapors, and at least one outlet for the char particles, wherein the
pelletized biomass feedstock comprises a particulate biomass and a
binder material that prevents mechanical attrition, thermal
attrition and dissociation of the pelletized biomass feedstock into
particles smaller than 300 microns in diameter either prior to, or
during the pyrolyzing, thereby preventing entrainment of the char
in the pyrolysis vapors.
2. The biomass pyrolysis system of claim 1, wherein the pelletized
biomass feedstock comprises pellets in a range from 750 microns to
1250 microns in diameter.
3. The biomass pyrolysis system of claim 1, wherein the pelletized
biomass feedstock comprises a particulate biomass and a binder
material that prevents mechanical attrition, thermal attrition and
dissociation of the pelletized biomass feedstock into particles
smaller than 500 microns in diameter either prior to, or during the
pyrolyzing, thereby preventing entrainment of the char in the
pyrolysis vapors. The biomass pyrolysis system of claim 1, wherein
the binder material is an upgrading catalyst that catalytically
transforms at least a portion of the pyrolysis vapors to a
bio-derived hydrocarbon fuel, bio-derived fuel component.
4. The biomass pyrolysis system of claim 1, wherein the binder
material is an upgrading catalyst for catalytically transforming at
least a portion of the pyrolysis vapors to upgradeable intermediate
compounds, and the system further comprises at least one upgrading
reactor containing at least one upgrading catalyst for further
upgrading the upgradeable intermediate compounds to a bio-derived
hydrocarbon fuel, or bio-derived fuel component.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims benefit under 35 USC .sctn.119(e) and priority to U.S.
Provisional Application Ser. No. 61/699,036 filed Sep. 10, 2012,
entitled "Processes For Decreasing Char Entrainment During
Pyrolysis", which is hereby incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
FIELD OF THE INVENTION
[0003] This disclosure relates to pyrolysis of organic matter into
useful chemical or fuel products. More specifically, this
disclosure pertains to methods and systems for decreasing the
entrainment of char and other particulate contaminants in pyrolysis
vapors by utilizing a pelletized biomass feedstock in to a specific
size range. A binder material in the pelletized feedstock
facilitates maintaining the diameter of the feedstock pellets above
a given threshold size both before and during pyrolysis. The binder
material optionally possess catalytic activity.
BACKGROUND
[0004] The U.S. Renewable Fuel Standards (RFS) mandate will require
higher volumes of advanced biofuels to be produced in the near
future. One method being developed to meet this mandate is the fast
pyrolysis of biomass. Conventional biomass fast pyrolysis requires
rapid heating of biomass in the absence of oxygen. Products include
a solid carbonaceous char that contains the vast quantities of
metals (e.g. Na, K, Mg) present in the biomass feedstock. The
products also include a highly-oxygenated pyrolysis oil (or pyoil)
that is not practical for upgrading to a transportation fuel
because of thermal stability issues associated with highly reactive
oxygenated components. The remainder of the pyrolysis product is
classified as non-condensable gas.
[0005] To generate a viable transportation fuel, catalysts may be
employed during the fast pyrolysis process. Several known classes
of catalysts can deoxygenate the primary products from pyrolysis to
create chemical intermediates that can be further upgraded to a
hydrocarbon-rich fuel using conventional refining methodology.
Optionally, hydrogen may also be added to perform hydro-catalytic
pyrolysis, which improves the quality of the products by
significantly lowering the oxygen content, the acid content, etc.
The use of hydrogen increases the yield of pyrolysis oil by
hydrogenating the primary pyrolysis products, which removes oxygen
as water instead of oxides of carbon. The relatively low oxygen
content intermediate product is easily upgradable to bio-derived
fuels.
[0006] Unfortunately, when employing this process, the catalysts
tend to rapidly deactivate when contacted by char fines composed of
carbon and metals. Additionally, the char fines are often carried
out of the pyrolyzer by entrainment with the hot pyrolysis vapor,
resulting in a condensed liquid product containing solids and
metals that can negatively impact downstream processes.
[0007] There is a need to improve fast pyrolysis technology to
allow for rapid catalytic upgrading of primary pyrolysis products
into products that are fungible with current petroleum-derived
liquid hydrocarbon fuels, while preventing char and associated
metals from entrainment with these vapors to cause catalyst
deactivation and equipment fouling.
BRIEF SUMMARY OF THE DISCLOSURE
[0008] Certain embodiments comprise a biomass pyrolysis process,
including the steps of: a) providing a particulate biomass
feedstock; b) mixing the particulate biomass feedstock with a
binder material to produce a mixture, and compressing the mixture
to form pellets; c) pyrolyzing the pellets in a reactor to form a
product comprising pyrolysis vapors and char particles, where the
presence of the binder material in the pellets decreases the rate
of mechanical attrition, thermal attrition and dissociation of the
pellets into particles smaller than 300 microns in diameter either
prior to, or during the pyrolyzing; d) obtaining pyrolysis vapors
from an outlet of the reactor that comprise less entrained char (by
weight) due to the increased average diameter of the char particles
of step c).
[0009] Optionally, during the pyrolyzing the binder material may
catalytically transform at least a portion of the pyrolysis vapors
to compounds fungible with a petroleum-derived transportation fuel,
transportation fuel component, mixtures thereof, or a catalytically
upgradeable intermediate that is further upgraded to compounds
fungible with a petroleum-derived transportation fuel,
transportation fuel component or mixtures thereof. Optionally, the
binder material additionally functions to alter the variety and
complexity of chemical compounds produced during the pyrolyzing of
step (c).
[0010] In certain embodiments, the pyrolysis vapors of step (d)
comprise less entrained metals (by weight) due to the decreased
rate of mechanical attrition, thermal attrition and dissociation of
the pellets into particles smaller than 300 microns, 500 microns,
or 750 microns in diameter in step (c). In certain embodiments, the
presence of the binder material in the pellets decreases mechanical
attrition, thermal attrition and dissociation of the pellets into
particles smaller than 300, 500 or 750 microns in diameter either
prior to, or during the pyrolyzing.
[0011] In certain embodiments, the mixture is compressed to form
pellets that are in a range from 300 microns to 1250 microns in
diameter, or alternatively in a range of 750 microns to 1250
microns in diameter, and wherein the presence of the binder
material in the pellets decreases mechanical attrition, thermal
attrition and dissociation of the pellets into particles smaller
than 750 microns in diameter while the pellets remain inside the
reactor.
[0012] In certain embodiments, during the pyrolyzing, the binder
material catalytically transforms at least a portion of the
pyrolysis vapors to product compounds suitable for use as a
hydrocarbon fuel, a hydrocarbon fuel component, a catalytically
upgradeable intermediate or mixtures thereof, where the product
compounds obtained from an outlet of the reactor comprise less
entrained char (by weight) due to the presence of the binder
material in the pellets.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more complete understanding of the present invention and
benefits thereof may be acquired by referring to the follow
description taken in conjunction with the accompanying drawings in
which:
[0014] The FIGURE is a simplified diagram of one embodiment of the
inventive process and system depicting a pyrolysis reactor with an
upgrading reactor to receive and upgrade the vapors from the
pyrolysis reactor.
[0015] The invention is susceptible to various modifications and
alternative forms, specific embodiments thereof are shown by way of
example in the drawings. The drawings may not be to scale. It
should be understood that the drawings and their accompanying
detailed descriptions are not intended to limit the scope of the
invention to the particular form disclosed, but rather, the
intention is to cover all modifications, equivalents and
alternatives falling within the spirit and scope of the present
invention as defined by the appended claims.
DETAILED DESCRIPTION
[0016] Conventional pyrolysis methods and systems have suffered
from either 1) char and/or metal entrainment in the pyrolysis
vapors, leading to deactivation of any downstream upgrading
catalyst, or 2) use of mechanical separation devices to remove
entrained char from pyrolysis vapors, leading to an undesirable
delay prior to catalytic upgrading and increased maintenance due to
fouling/plugging of the separation device. Such a delay can allow
secondary pyrolysis reactions to occur in the primary pyrolysis
vapors that leads to products that may be difficult to upgrade into
a bio-derived hydrocarbon transportation fuel.
[0017] In conventional fast-pyrolysis, an emphasis has been placed
on converting the biomass feedstock to a particle size of less than
20 microns (preferably 1 to 3 microns for fluidized bed pyrolysis).
This allows more rapid heat transfer to the feedstock particles
during pyrolysis, and may minimize char formation. However, we have
found that utilizing feedstock particles less than 300 microns in
diameter in the pyrolysis process also correlates directly with
entrainment of significant quantities of char and metals in the
vapors produced during pyrolysis, as well as product pyrolysis oil.
Such contamination is believed to contribute to the instability of
pyrolysis oils by catalyzing numerous reactions that increase the
viscosity of the oil and make further upgrading difficult.
[0018] In the inventive processes and systems described herein, a
particulate biomass feedstock is fed to a pyrolysis reactor for
conversion by pyrolysis and subsequent catalytic upgrading to
produce a mixture comprising hydrocarbons that are fungible with
petroleum fractions and petroleum-derived fuels. Such fuels may
include, but are not limited to, gasoline, jet/kerosene, diesel and
gasoil. The methods and systems described herein facilitate this
conversion process by one or more of the following: 1) preventing
catalytic transformation of the pyrolysis vapors via contact with
entrained char, as well as via metals impregnated on the char, 2)
preventing poisoning of catalysts utilized to upgrade the pyrolysis
vapors, thereby extending the lifespan of catalysts, and 3)
narrowing the product distribution by limiting the variety and
complexity of chemical compounds produced in the primary pyrolysis
vapors to facilitate catalytic upgrading. Other benefits of the
present processes and systems are disclosed in greater detail
below.
[0019] We show herein that during biomass pyrolysis, metals derived
from the feedstock are largely retained in the solids fraction (see
Example 1). Further, when we sized the feedstock to eliminate
feedstock particles smaller than 300 microns, total metal content
in the resulting pyrolysis oil fractions decreased by 94-97%
relative to the content detected in the feedstock, while metal
content was found to be 16-fold higher in the solids fraction
(comprising mostly char) versus the feedstock. Similarly, when the
feedstock was sized to eliminate feedstock particles having a
diameter less than 750 microns, total metal content detected in the
resulting pyrolysis oil fractions decreased even further (95-99 wt.
%) relative to the content found in the feedstock, while detected
metal content was 8-fold higher in the solids fraction versus the
starting feedstock.
[0020] While not wishing to be bound by theory, we hypothesize that
conventional pyrolysis processes utilize smaller feedstock
particles, which results in the formation of smaller char particles
during pyrolysis. These smaller char particles are then more easily
entrained into the produced pyrolysis vapors and are difficult to
separate from the pyrolysis vapors without implementing a
mechanical separation step such as, for example, hot vapor
filtration or cyclone separation. If not removed prior to cooling
and condensation of the vapors, entrained char particles (and
associated metals) may catalyze undesirable reactions within
uncondensed pyrolysis vapors that prevent subsequent upgrading of
the vapors to fuels. Alternatively, if the pyrolysis vapors are
cooled and condensed to pyrolysis oil, the entrained char and
associated metals contaminate the oil and are associated with a
decrease in pyrolysis oil stability.
[0021] The inventive processes and systems disclosed herein may
serve to decrease the quantity of char (by weight) entrained in the
pyrolysis vapors passing out of the reactor. In certain
embodiments, this is accomplished by utilizing a biomass feedstock
that does not comprise particles smaller than a certain minimum
threshold diameter. Alternatively, this may be accomplished by
compressing a particulate biomass feedstock to form feedstock
pellets larger than a certain threshold diameter.
[0022] By decreasing char entrainment, the inventive process and
system also decreases entrainment of metals in the vapors, leading
to decreased metal content in the produced pyrolysis oil, fuel
precursor product or hydrocarbon fuel depending upon the desired
product specification. This is achieved without the need for
mechanical separation of char from the primary pyrolysis vapors. An
additional potential benefit is that the flow of pyrolysis vapors
leaving the pyrolysis reactor may be increased without dramatically
increasing entrainment of char particles (due to their increased
size and weight). This can facilitate decreased residence times of
the pyrolysis vapors prior to contacting an upgrading catalyst,
while allowing the upgrading catalyst (or catalysts) to be housed
in a container/reactor that is separate from the pyrolysis reactor.
In summary, the inventive process and system can 1) maximize
production of pyrolysis vapors, and 2) minimize residence time of
pyrolysis vapors prior to upgrading, thereby preventing detrimental
secondary pyrolysis reactions, all while 3) effectively preventing
poisoning of downstream pyrolysis vapor upgrading catalyst(s)
resulting from contact with char particles and metals.
[0023] To achieve these benefits, certain embodiments utilize a
particulate biomass feedstock comprising particles that are equal
to or smaller than 300 microns in diameter, or equal to or smaller
than 500 microns in diameter. In certain embodiments, this
particulate biomass feedstock is combined with a binder material to
form a mixture that is then mechanically compressed to form biomass
feedstock pellets that are larger than certain threshold diameter.
In certain embodiments, the threshold diameter may be, for example,
larger than 300 microns, 500 microns or 750 microns. In certain
embodiments, the pellets may be sized to a defined range of sizes,
such as for example, from 300 to 500 microns, or 750 to 1250
microns. Preferably, the resulting compressed feedstock pellets are
resistant to mechanical attrition, thermal attrition and
dissociation following compression and also during pyrolysis. In
certain embodiments, the presence of the binder material in the
pellets decreases the rate of mechanical attrition, thermal
attrition and dissociation of the pellets into particles smaller
than 300 microns in diameter either prior to, or during the
pyrolyzing. In certain embodiments, the presence of the binder
material in the pellets prevents mechanical attrition, thermal
attrition and dissociation of the pellets into particles smaller
than 300 microns (optionally 400, 500, 600, or 750 microns) in
diameter either prior to, or during the pyrolyzing.
[0024] In certain embodiments, the compressing of the feedstock is
accomplished by conventional means, such as by a mechanical or
hydraulic press. While not wishing to be bound by theory,
increasing the average size of char particles formed during
pyrolysis may decrease entrainment of such particles in the
pyrolysis vapors produced during pyrolysis of the feedstock. Metals
present in the feedstock are believed to be highly associated with
the char particles.
[0025] The pyrolysis process may comprise adding a binder material
to particulate biomass (e.g. by mixing or impregnation) followed by
compressing the biomass to form pellets and using the pellets as
feedstock for pyrolysis. In certain embodiments, the presence of a
binder material during compressing or pelletization further
increases resistance of the compressed pellets to mechanical
attrition, thermal attrition and dissociation. Pelletization of the
biomass feedstock also allows for a consistent, uniform feed, and
higher transportation densities than uncompressed biomass
feedstocks. The binder material optionally also functions as a
catalyst either before, during, or after, pyrolysis of the
feedstock. This will be discussed in greater detail later.
[0026] Optionally, the binder material may additionally comprise an
additive that functions during pyrolysis of the biomass to alter
via chemical interaction at least one of the variety, quantity and
complexity of chemical compounds produced by the pyrolysis process.
In certain embodiments, the additive may function to provide a
chemical product distribution of reduced complexity that enables
the selection and development of more task-specific catalysts for
upgrading the pyrolysis vapors. The upgrading (e.g., reduction in
the quantity of carboxylic acids and aldehydes, or
hydrodeoxygenation of phenolics) may occur as a subsequent process
step and/or concurrently with the pyrolysis of the feedstock. The
end result of the process is a product that is partially (or fully)
upgraded to a hydrocarbon transportation fuel, transportation fuel
blend component, or mixtures thereof depending on the desired
specifications.
[0027] When the binder material additionally comprises an additive,
the feedstock may optionally be acted on by the additive during the
pelletization step, thereby eliminating a separate additive
pretreatment process step. For example, a pretreatment step with an
additive solution that contacts the biomass may be used to
passivate alkali metals, thereby improving sugar yields for
upgrading. In the current process, such passivation could be
performed concurrent with pelletization of the feedstock.
[0028] In addition to eliminating a process step, the use of the
solution as a binder ensures more uniform coverage (better alkali
passivation) through intimate contact of biomass and pretreatment
solution. Furthermore, water is a typical binder for biomass
pellets, meaning that the acid concentration can be controlled so
that moisture content of the pellets (which is critical in
pyrolysis) is unaffected. Preferably, the moisture content of the
feedstock pellets is below 15 wt. %. The invention may be also
combined with a torrefaction process so that torrefied biomass,
which has low moisture, may pelletized and pretreated. Torrefied
biomass may also be mixed with untreated biomass prior to
pretreatment.
[0029] In certain embodiments, the additive may be a salt (e.g.,
magnesium chloride), an acid or base (e.g., boric acid, sodium
bicarbonate), a hydrated salt (e.g. magnesium chloride
hexahydrate). The additive may be combined with water (0.1-99.9 wt
%, based on the wt of the biomass) thereby enabling steam-catalyzed
dehydration reactions. The additive may optionally be chosen to be
recyclable or disposable. If disposable, the additive may be chosen
to enhance the composition of the char for soil amendment or other
applications. While not wishing to be bound by theory, it is
hypothesized that certain additives may act by retaining water in
the biomass to higher temperatures, allowing for steam pyrolysis to
take place rather than charring of the biomass. The resulting
pyrolysis vapors are consequently higher in dehydrated products
(such as, for example, furfural) than when conducting conventional
pyrolysis in the absence of an additive, thereby allowing a more
targeted selection of catalyst(s) for upgrading the pyrolysis
vapors.
[0030] A product distribution of reduced complexity enables the
selection, or potential development, of more task-specific
catalyst(s) for upgrading the pyrolysis vapors (e.g., reduction of
carboxylic acids and aldehydes, or hydrodeoxygenation of
phenolics). Such upgrading may occur during pyrolysis, after
pyrolysis, or combinations thereof. The end result would be a
partially-upgraded or fully-upgraded pyrolysis oil, depending on
the desired product specifications. One example of pyrolysis
conducted in the presence of an additive is disclosed in Example
2.
[0031] In certain embodiments, the additive also functions as the
binder material that acts to further increase resistance of the
pellets to mechanical attrition, thermal attrition and dissociation
(both before and during pyrolysis) to particles having a diameter
equal to or less than a given minimum threshold. In certain
embodiments, this minimum threshold may be less than or equal to
300 microns, less than or equal to 500 microns, or less than or
equal to 750 microns. When the additive serves to pre-treat the
feedstock material
[0032] In certain embodiments, the additive also serves as an
upgrading catalyst (or catalysts) that catalytically transforms the
pyrolysis vapors either inside the pyrolysis reactor, or downstream
in an upgrading reactor. The binder material may optionally also
have catalytic activity that upgrades the pyrolysis vapors either
immediately following pyrolysis of the compressed feedstock
pellets, or later in a separate step that is optionally carried out
in a separate reactor. Such catalytic activity may comprise, for
example, a depolymerization catalytic activity, such as may be
provided by a metal oxide or acid to reduce the degree of
polymerization in the pyrolysis vapors. The catalytic activity may
optionally hydrodeoxygenate the pyrolysis vapors non-selectively,
or selectively reduce certain compounds, such as phenolics or
furfurals into saturated hydrocarbons. In certain other
embodiments, the binder material and a physically distinct catalyst
may both be mixed with the particulate biomass feedstock prior to
compressing the feedstock into pellets. The catalytic activity of
the binder material or the physically distinct catalyst may
additionally comprise one or more of catalytic condensation,
deoxygenation, denitrogenation, decarboxylation, dehydration,
dimerization, oligomerization, alkylation, or combinations of two
or more of these catalytic reactions.
[0033] The reactor utilized for conducting pyrolysis of the
particulate biomass feedstock (or pelletized feedstock) can be of
any variety, but preferably comprises at least one auger that
assists in rapidly and evenly distributing heat throughout the
feedstock, as well as helping to convey the feedstock through the
pyrolysis reactor from an inlet end portion towards an outlet end
portion.
[0034] Oxygenated hydrocarbon vapors are produced in the pyrolysis
reactor, and these vapors are conveyed generally upward and out of
the pyrolysis reactor while maintaining the vapors at a temperature
that prevents their condensation. The char created by the process
described herein is conveyed through the reactor along with heat
carrier by the at least one auger, then optimally falls by force of
gravity into a sealed char catch and is eliminated from the
reactor. Removing char prior to contacting pyrolysis products with
catalyst prevents catalyst fouling/poisoning.
[0035] The pyrolysis vapors are preferably contacted with at least
one upgrading catalyst in at least one upgrading reactor to convert
the vapors into a hydrocarbon mixture that is fungible with current
petroleum-derived fuels or upgradeable intermediate compounds that
may be more easily upgraded to a liquid hydrocarbon fuel. Residence
time between production of pyrolysis vapors (i.e., the primary
pyrolysis product) and contact with the at least one upgrading
catalysts is preferably minimized to prevent secondary pyrolysis
reactions that decrease upgradability of the compounds in the
pyrolysis vapors to compounds suitable for use as a transportation
fuel or transportation fuel component. The upgrading reactor may be
operated as a fixed packed bed, fluidized bed, ebullating bed, or
moving bed. The products from the final upgrading reactor are
condensed to a liquid that if fungible with a hydrocarbon
transportation fuel, transportation fuel, or mixtures thereof.
[0036] Examples of biomass feedstock used in the present invention
include, but are not limited to, oil-containing biomass, such as
jatropha plant, macroalgae or microalgae. Carbohydrate-based
biomass may also be used as feedstock, where carbohydrate-based
refers to biomass where at least a fraction of its composition is
made of carbohydrates. Carbohydrate-based biomasses are available
from a variety of sources including cellulosic biomass and algal
biomass. Specific examples of feedstock useful in the current
invention include, but are not limited to: sugars, carbohydrates,
fatty acids, proteins, oils, eucalyptus oil, forest residues, dead
trees, branches, leaves, tree stumps, yard clippings, wood chips,
wood fiber, sugar beets, miscanthus, switchgrass, hemp, corn, corn
fiber, poplar, willow, sorghum, sugarcane, palm oil, corn syrup,
algal cultures, bacterial cultures, fermentation cultures, paper
manufacturing waste, agricultural residues (e.g., corn stover,
wheat straw and sugarcane bagasse), dedicated energy crops (e.g.,
poplar trees, switchgrass, and miscanthus giganteus sugarcane)
sawmill and paper mill discards, food manufacturing waste, meat
processing waste, animal waste, biological waste and/or municipal
sewage.
[0037] The FIGURE depicts an exemplary embodiment for a process and
system for conducting pyrolysis of organic material or biomass to
useful chemical products or fuel products. A pyrolysis reactor 5
comprises an external housing 20, an inlet 17 for a heat carrier
15, an inlet 10 for a pelletized biomass feedstock 12 and one or
more helical augers 22 that when driven by a motor 25 to rotate
about a longitudinal axis convey the pelletized biomass feedstock
12 along the length of the reactor 5 from an inlet end 18 towards
an outlet end 28. Near the outlet end 28, the large majority of
char particles formed during pyrolysis of the pelletized biomass
feedstock 12 fall into a char catch 31 by gravitational force. The
pelletized biomass feedstock 12 is heated in the pyrolysis reactor
5 by at least one heating source that may include a heating jacket
surrounding the housing 20, at least one heated auger 22, or via
introduction of a heat carrier 15 via a heat carrier inlet 17
proximal the inlet end 18 of the reactor. The pyrolysis reactor
depicted in the FIGURE is operated to exclude most oxygen or air by
the introduction of a sweep gas. In the embodiment shown in the
FIGURE , the sweep gas 19 enters through sweep gas inlet 23 near
the outlet end 28 of the housing 20, although the sweep gas 19 may
alternatively enter the system via other points of entry, such as
the biomass feedstock inlet 10 or heat carrier inlet 17. As the
particulate biomass feedstock 12 is rapidly heated, pyrolysis
vapors 37 are produced and rise to the upper portion (or headspace)
of the pyrolysis reactor housing 5 and is swept toward the outlet
end portion 28, exiting through a first outlet 32.
[0038] Further referring to the FIGURE, arranged within close
proximity of the pyrolysis reactor first outlet 32 is an upgrading
reactor 40 containing at least one bed of one or more active
upgrading catalyst(s) 42, wherein each bed of upgrading catalyst 42
may comprise any conventional configuration (e.g, fixed bed,
fluidized bed, bubbling bed, moving bed etc.). In certain
embodiments, the pyrolysis reactor 5 is in direct contact with the
upgrading reactor 40 with minimal distance between the first outlet
32 and the at least one bed of upgrading catalyst 42 contained
within upgrading reactor 40. In the embodiment depicted in the
FIGURE, a distributor plate 52 is placed above the outlet 32. The
distributor plate may optionally assist in retaining within the
reactor 5 any residual particulates that may be entrained in the
pyrolysis vapors 37 leaving the reactor 5 through outlet 32.
Distributor plate 52 may optionally serve to evenly distribute the
pyrolysis vapors within the upgrading reactor 40. In certain
alternative embodiments, the inventive process minimizes the
quantity of char particles that become entrained in the pyrolysis
vapors to the point where there is no need to employ any mechanical
device (e.g., a distributor plate or filter) to assist in retaining
such particles within the pyrolysis reactor.
[0039] When the pyrolysis reactor described herein comprises at
least one auger, the reactor is more efficient in char removal than
a conventional fluidized bed pyrolysis reactor that produces char
fines by attrition that elutriate into the pyrolysis vapors. Again
referring to the FIGURE, in certain embodiments the majority of
char formed during pyrolysis is conveyed by the at least one auger
along with heat carrier toward the outlet end 28 of the pyrolysis
reactor 5. There, the vast majority of char and heat carrier fall
together by force of gravity into a char catch 31 and are removed
from the reactor. Thus, the char is prevented from becoming
entrained in the pyrolysis vapors, from entering the upgrading
reactor 40, and from coming in contact with the upgrading catalyst
bed 42. This dramatically enhances the longevity of the upgrading
catalyst(s).
[0040] As noted above, it is common for the pelletized biomass
feedstock 12 to include measurable amounts of metals that act as
poisons to desirable upgrading catalysts, and we have found that
this metal content becomes concentrated in the char produced during
pyrolysis. Utilizing the processes and systems described herein,
catalysts that are more susceptible to poisoning by metals may be
used to upgrade the pyrolysis vapors, since the impact of metal
poisoning and coke formation is dramatically reduced. In addition,
the product leaving the upgrading bed is free of solids and metals,
thereby removing the need for subsequent particle removal
[0041] The temperature within the pyrolysis reactor may be
maintained via one or more of several mechanisms, such as heating
of the reactor housing, heating of the at least one auger,
microwave or inductive heating of the biomass, addition of a heated
sweep gas, and addition a of a solid particulate heat carrier that
has been pre-heated. Regardless of the heating mechanism utilized,
preferably the pyrolysis reactor and its contents are maintained at
a temperature of at least 600.degree. F. (315.degree. C.). The
pyrolysis may be conducted in an inert environment such as nitrogen
or helium, or in a reactive environment containing 0.1-100%
reactive gas or gas mixtures (e.g. hydrogen, methane, alcohols,
steam, oxygen, etc.).
[0042] lgain referring to the embodiment depicted in the FIGURE, a
disengagement zone 45 is located proximal to the outlet end 28 of
the pyrolysis reactor 5, and near the first outlet 32. The
disengagement zone is designed to provide a space where the upward
local velocity of the pyrolysis vapors 37 prior to passing through
the first outlet 32 is sufficient to entrain less than 0.5% (by
wt.) of the char produced by the pyrolysis of the pelletized
biomass feedstock. In certain embodiments, the upward local
velocity of the pyrolysis vapors 37 prior to passing through the
first outlet 32 entrains less than 0.1% (by wt.) of the char
produced by the pyrolysis of the pelletized biomass feedstock 12.
Achieving this low percentage of char carryover requires designing
the height and diameter of the disengagement zone to allow the
terminal falling velocity of the char and heat carrier particles to
exceed the upward local velocity of the pyrolysis vapors in the
disengagement zone, 45 such that nearly all char particles (greater
than 99%, 99.5% or even 99.9% by weight) being retained in the
pyrolysis reactor 5, thereby preventing these particles from being
carried with the pyrolysis vapors 37 exiting via the first outlet
32 and preventing contact with upgrading catalyst bed 42.
[0043] In certain embodiments, a sweep gas is employed that may
comprise one or more of many gases that are either inert or
reactive. For example, the sweep gas may comprise gases such as
nitrogen, helium, argon, hydrogen, methane and mixtures thereof. If
the sweep gas comprises a reactive gas, the reactive gas may
optionally react with the biomass during pyrolysis, may serve as a
reactant when the pyrolysis products are upgraded by contacting the
upgrading catalyst(s), or both. The sweep gas may be injected into
the system at more than one point, or injected simultaneously at
multiple points. One point may comprise combining the sweep gas
with the feedstock prior to entering the pyrolysis reactor, while
another may comprise injecting sweep gas directly into the
pyrolysis reactor proximal to the biomass feedstock inlet. A third
point may comprise injecting the sweep gas proximal to the first
outlet of the pyrolysis reactor. This may be preferable if the
sweep gas is to be used as a reactant during upgrading of the
primary pyrolysis product.
[0044] In certain embodiments, a gas may be injected just upstream
of the pyrolysis reactor first outlet in order to 1) assist in
preventing entrained char and heat carrier particles from leaving
the pyrolysis reactor, 2) quench the primary pyrolysis product to a
lower temperature, 3) heat the primary pyrolysis product to a
higher temperature, or combinations thereof. In embodiments where
the sweep gas serves to quench the primary pyrolysis product, such
quenching may prevent coking Embodiments where the sweep gas serves
to heat the primary pyrolysis product may prevent formation of char
and secondary pyrolysis reactions that may reduce the subsequent
upgradability of the primary pyrolysis product to a bio-derived
fuel. However, quenching is limited such that the quenched primary
pyrolysis product does not condense prior to contacting the
upgrading catalyst(s). Typically, this requires that the quenched
primary pyrolysis product still maintains a temperature of at least
250.degree. C. to prevent condensation.
[0045] The volumetric flow rate, or "standard gas hourly space
velocity" (SGHSV) of the sweep gas is adjusted to minimize the time
between pyrolysis and catalytic upgrading, such that the upgrading
catalyst (or optionally, catalysts) contacts primary products of
pyrolysis and not secondary pyrolysis products that comprise 16 or
more carbons and are more difficult to upgrade to a bio-derived
fuel. Volumetric flow rate for a given embodiment depends upon
factors including, but not limited to, the volume of the pyrolysis
reactor, the temperature and pressure at which the pyrolysis
reactor is maintained, the feed rate of the particulate biomass
feedstock to the pyrolysis reactor, and the type of feedstock
utilized. A paper by J. N. Brown, et al. provides one example of
how these variables can be adjusted to determine an optimal
volumetric flow rate for a desired pyrolysis outcome, including,
for example, the pyrolysis liquid to pygas ratio, and the relative
percentage of the feedstock converted to char.
[0046] The pressure maintained within the pyrolysis reactor is
generally within a range of about 0 psig to 3000 psig. Preferably,
the pyrolysis reactor is maintained at a pressure in the range of
100 psig to 500 psig to increase throughput of particulate biomass
feedstock, and in certain embodiments, facilitate catalytic
upgrading of the primary pyrolysis product.
[0047] The primary pyrolysis product is driven by the sweep gas (or
optionally, a pressure differential) from the pyrolysis reactor via
the first outlet and enters an upgrading reactor and contacts an
upgrading catalyst. Minimizing residence time of the primary
pyrolysis product in the pyrolysis reactor is important for
maximizing the percentage of primary pyrolysis product that is
successfully upgraded to a bio-derived fuel. Conditions of
temperature and pressure, as well as reactor dimensions are chosen
to assure a residence time of the primary pyrolysis product in the
pyrolysis reactor that is less than 5 seconds, preferably less than
3 seconds, more preferably less than 1 second, even more preferably
less than 0.3 second, and most preferably less than 0.1 second.
[0048] Minimizing residence time of the primary pyrolysis product
in the pyrolysis reactor prevents the occurrence of secondary
pyrolysis reactions that form larger oxygenated species comprising
16 or more carbon atoms. These larger oxygenated species are likely
to form coke, which is extremely detrimental to the process by
fouling process equipment and heat carrier. Additionally, diversion
of the primary pyrolysis product into secondary pyrolysis reactions
decreases the conversion efficiency of the feedstock into smaller
species that are more easily upgraded into a bio-derived fuel.
[0049] The physical distance between the pyrolyzer and the
upgrading catalyst(s) contained within the upgrading reactor may
vary, but is preferably minimized, taking into consideration the
space velocity of the primary pyrolysis product (optionally in a
mixture with a sweep gas) out of the pyrolysis reactor. Minimizing
this distance assists in decreasing the time between production of
the primary pyrolysis product and subsequent contacting with one or
more upgrading catalyst(s). Through optimizing the variables of
distance and space velocity, the current invention assures that the
upgrading catalyst sees primary products from pyrolysis and not
secondary products created by reactions occurring after pyrolysis.
Generally, the distance between the pyrolyzer and the upgrading
catalyst(s) is less than 4 ft. More preferably, this distance is
less than 1 ft., and most preferably, less than 6 inches.
[0050] Optionally, the disengagement zone between the pyrolyzer and
the upgrading catalyst may include additional features to limit
reactivity of the primary pyrolysis product prior to contact with
the upgrading catalyst(s). These may include (but are not limited
to) temperature control, introduction of a gas or fluid to quench
the primary pyrolysis product (as mentioned previously), flow
control through judicious choices in geometry (preferably, a
geometry minimizing bends and small orifices to decrease the
potential for vapor condensation), the presence of a pre-catalyst
(such as zeolite monolith, or any of the above-mentioned upgrading
catalysts) at the interface between reactors.
[0051] In some embodiments, a catalyst monolith may be utilized as
a pre-catalyst bed, or guard bed, while in other embodiments, the
pre-catalyst may comprise a fluidized bed of catalyst integrated
with the distributor assembly to control reactivity in this region.
The fluidized bed of catalyst may additionally function as a moving
bed filter to remove residual particulates. Such methods may be as
described in U.S. Pat. No. 8,268,271, which is hereby incorporated
by reference.
[0052] The at least one upgrading bed may utilize any type of
reactor configuration including, but not limited to, a fixed bed, a
bubbling bed, a circulating bed, a moving bed, a counter current
reactor or combinations of two or more of these configurations.
Each catalyst may be periodically or continuously regenerated as
needed. In certain embodiments, regeneration may comprise
transporting the catalyst to a regenerator for de-coking, then
returning to the pyrolysis reactor. Optionally, fresh catalyst may
be added on a periodic or continuous basis to the pyrolysis reactor
to account for catalyst attrition.
[0053] Examples of some upgrading catalysts and typical reaction
conditions are disclosed in U.S. patent application Ser. No.
13/416,533, although any catalyst known to catalyze the conversion
of primary pyrolysis products to a bio-derived fuel may be
utilized. The catalyst may include, but is not limited to zeolites,
metal modified zeolites, and other modified zeolites. Other
catalysts may include forms of alumina, silica-alumina, and silica,
unmodified or modified with various metals, not limited but
including, Nickel, Cobalt, Molybdenum, Tungsten, Cerium,
Praseodymium, Iron, Platinum, Palladium, Ruthenium and Copper or
mixtures thereof. Still other catalysts may include unsupported
metals, supported or unsupported metal oxides or metal phosphides,
and mixtures thereof. Catalyst types include deoxygenation
catalysts, hydrogenation catalysts, hydrotreating catalysts,
hydrocracking catalysts, water-gas-shift catalysts, and
condensation catalysts. Catalysts may be sulfided or un-sulfided.
In certain embodiments, each catalyst bed may comprise mixtures of
one or more catalysts of the types described above. Optionally,
multiple catalyst beds may be placed within a single reactor, or
multiple catalyst beds may be placed in different reactors to
facilitate different reaction conditions. When multiple reactors
are utilized, they may be arranged to either in parallel or
series.
[0054] If multiple upgrading reactors are utilized, different
conditions may be maintained in each reactor in order to facilitate
a given catalytic reaction. To facilitate flow of the vapors
through multiple reactors, a pressure differential may be
maintained wherein the pressure in each successive reactor
progressively decreases.
[0055] The residence time of the pyrolysis vapors in each upgrading
reactor generally ranges from 0.01 sec to 1000 sec. Preferably, the
residence time is in a range from 0.05 sec to 400 sec. More
preferably, the residence time is in a range from 0.1 sec to 200
sec. Most preferably, the residence time is in a range from 0.1 sec
to 100 sec.
[0056] The temperature maintained within each upgrading reactor is
generally in the range from 72.degree. F. to 1500.degree. F.
Preferably, the temperature is in the range from 100.degree. F. to
1000.degree. F., although if multiple upgrading reactors are used,
each may be maintained at a different temperature within this
range. The flow of one or more of gas, vapors and liquids within
each upgrading reactor is preferably upward, although downward or
lateral gas flow may also be utilized.
[0057] Certain upgrading reactions may be advantageously performed
on the pyrolysis vapors, while other upgrading reactions may
advantageously be performed following condensation of the vapors to
a liquid. Condensation of the vapors may be achieved by any
conventional means known in the art. In certain embodiments, vapors
may be directed to a condensation system that functions to reduce
the temperature of vapors to a temperature that is at or below the
dew point for at least one component of the vapors. Typically, the
conditions utilized do not result in the condensation of methane,
but preferably will condense C4+ hydrocarbons.
[0058] Hydrogen may be separated from the non-condensed gas by a
variety of conventional methods and recycled as the sweep gas. In
certain embodiments, the recycled hydrogen may be added directly
into, or just upstream from, an upgrading reactor to facilitate one
or more upgrading reactions. Alternatively, the entirety, or some
fraction, of the bulk non-condensable gas is used for the same
purpose. In another embodiment, the entirety, or some fraction, of
the bulk of the non-condensable gas is sent to a combustor or
hydrogen generation unit (e.g., a reformer) to generate either heat
or hydrogen, respectively. The resulting heat or hydrogen may then
be partially or entirely recycled back to the process.
[0059] Certain upgrading reactions are advantageously conducted at
a pressure that is greater than atmospheric pressure. The pressure
that is maintained in the one or more upgrading reactors may range
from 0-3000 psig, although a preferred pressure range is zero to
1000 psig. In certain embodiments, the pressure may range from 10
to 800 psig, from 20 to 650 psig, from 100 to 500 psig. An
exemplary pressure might be 400 psig.
[0060] The following examples of certain embodiments of the
invention are given. Each example is provided by way of explanation
of the invention, one of many embodiments of the invention. The
examples are intended to be illustrative of specific embodiments
and should not be interpreted to limit, or define, the scope of the
inventive processes and systems as disclosed herein.
EXAMPLE 1
[0061] Kiln-dried Red Oak was ground and the particles were
subjected to pyrolysis ("Raw Biomass" in Table 1) or pre-sized into
two fractions with a particle diameter ranging from of 300 to 500
microns or a particle size ranging from 750 to 1250 microns (see
Table 1).
[0062] Biomass was added to a pyrolysis reactor with a heat carrier
heated to a temperature greater than about 1200.degree. F. to
thermally decompose solid biomass to condensable pyrolysis vapors,
char, and non-condensable gases. The pyrolysis vapors passed out of
the pyrolysis reactor and were cooled and collected in a collection
system comprised of electrostatic precipitators (ESPs). These ESP
collected vapors that condensed at greater than about 180.degree.
F., while water-cooled condensers collected vapors that condense at
a temperature of less than 180.degree. F.
[0063] In the experiment, solids remained in the pyrolysis reactor
(Table 1) and two fractions were collected (refer to Tables 2 and
3, respectively: 1). The vapor-gas stream was cooled from
850.degree. F. to 320.degree. F. The condensed liquid droplets and
aerosols were then collected in an ESP. This fraction consisted
primarily of anhydrosugars, oligosaccharides, and phenolic
oligomers. 2). Sub-cooled nitrogen further cooled the vapor stream
to 180.degree. F. at the entry to a second ESP. The condensed
liquid droplets were collected. This fraction contains mainly
phenolic and furanic species. The chosen temperature minimized
water condensation while still effectively condensing phenols and
furans.
[0064] Following collection, pyrolysis oils and biochar were
analyzed by inductively coupled plasma (ICP) for metal content.
Solid weight fraction was estimated by comparing the amount of
potassium and calcium in the pyrolysis oil to the amount of Ca and
K per unit weight of biochar. Biochar was assumed to be the only
solid found in the pyrolysis oils and the only source of Ca and K.
This assumption was made because the Ca/K ratio for biomass,
biochar, and the oils was substantially similar.
[0065] The data shows that upon the pyrolysis of red oak, metals
derived from the feedstock are largely retained in the solids
fraction (Table 1). When the feedstock was sized to a particle
diameter ranging from 300-500 microns (second column), total metal
content in the resulting pyrolysis oil fractions decreased by 94%
in the first fraction (Table 2 second column) and by 97% in the
second pyrolysis oil fraction (Table 2 second column) relative to
the content detected in the feedstock (Table 1, column 1). Detected
metal content was 16-fold higher in the solids fraction (Table 1,
second column) versus the feedstock (Table 1, first column).
Similarly, when the feedstock was sized to a particle diameter
ranging from 750-1250 microns (Tables 1-3, third column), total
metal content detected in the resulting pyrolysis oil fractions
(Tables 2 and 3) decreased even further (95-99%, respectively)
relative to the metal content found in the feedstock (Table 1,
first column), while detected metal content was 8-fold higher in
the solids fraction (Table 1, third column) versus the metal
content detected in the feedstock (Table 1, first column).
TABLE-US-00001 TABLE 1 Metal Content of Solids, wt ppm Raw
Pyrolytic Char Pyrolytic Char Biomass (300 to 500 .mu.m) (750 to
1250 .mu.m) Red Oak Jan. 26, 2011 Jan. 18, 2011 Jan. 26, 2011 Al
1.51 208 18.0 As <20.2 <20.1 <20.3 B <5.14 19.5 11.8 Ba
8.19 152 44.2 Ca 785 5300 4390 Cd <2.06 <2.04 <2.07 Co
<2.20 3.61 <2.21 Cr <4.52 451 32.0 Cu <1.10 57.7 17.9
Fe 108 14500 4820 K 587 3600 3150 Li <1.06 <1.05 <1.07 Mg
36.7 820 258 Mn 35.7 321 254 Mo <3.15 19.2 4.32 Na 10.7 389 89.4
Ni <2.09 192 19.6 P 17.3 332 85.2 Pb <15.5 <15.4 <15.6
Sb <7.11 <7.05 <7.14 Sn <1.30 <1.29 6.43 Sr 5.16
35.7 27.7 Ti <2.08 46.2 <2.09 V <4.09 <4.06 <4.11 Zn
0.915 39.6 7.49 Zr <1.53 <1.52 <1.54 Detected 1596 26467
13236
TABLE-US-00002 TABLE 2 Metal Content of Pyrolysis Oil - Fraction 1,
wt ppm Jan. 18, 2011 Jan. 26, 2011 Particle Size Red Oak Oil
300-500 .mu.m 750-1250 .mu.m Al 1.67 <0.560 As <20.1 -- B
<5.11 <5.35 Ba <3.01 <3.15 Ca 25.5 1.86 Cd <2.05
<2.14 Co <2.19 <2.29 Cr <4.50 <4.71 Cu <1.07
<1.12 Fe 59.3 22.7 K <28.9 <30.2 Li <1.06 <1.11 Mg
4.13 <1.34 Mn 1.27 <0.315 Mo <3.13 <3.28 Na 10.5 8.46
Ni <2.08 <2.17 P <7.07 <7.41 Pb <15.4 -- Sb <7.07
-- Sn <1.30 -- Sr <0.263 <0.276 Ti <2.07 <2.16 V
<4.07 <4.26 Zn <0.443 <0.464 Zr <1.52 <1.59
Detected 102.4 33.0 Solids Estimate 0.48% 0.042%
TABLE-US-00003 TABLE 3 Metal Content of Pyrolysis Oil - Fraction 2,
wt ppm Jan. 18, 2011 Jan. 26, 2011 Particle Size Red Oak Oil
300-500 .mu.m 750-1250 .mu.m Al 1.18 <0.533 As <20.0 -- B
<5.09 <5.09 Ba <3.00 <3.00 Ca 35.2 2.47 Cd <2.04
<2.04 Co <2.18 <2.18 Cr <4.48 <4.48 Cu <1.07 1.28
Fe 9.45 10.4 K <28.7 <28.8 Li <1.05 <1.05 Mg <1.28
<1.28 Mn <0.300 <0.300 Mo <3.12 <3.12 Na <7.35
<7.36 Ni <2.07 <2.07 P <7.04 <7.05 Pb <15.4 -- Sb
<7.04 -- Sn <1.29 -- Sr <0.262 <0.262 Ti <2.06
<2.06 V <4.05 <4.06 Zn 9.80 <0.441 Zr <1.52 <1.52
Detected 55.6 14.2 Solids Estimate 0.66% 0.056%
EXAMPLE 2
[0066] One example of a compound that can be used as an additive in
the inventive processes and systems described herein is magnesium
chloride. We performed pyrolysis of red oak impregnated at 1:10
ratio of magnesium chloride to biomass and dried at 70.degree. C.
Pyrolysis was performed at 475.degree. C. in a non-reactive helium
atmosphere. Production of furfural (and other C5+ oxygenates) and
anhydrosugar were enhanced as compared to conventional pyrolysis.
Lower yields of phenolics and oxygenated aromatics were also
observed. Catalytic pyrolysis of the same feedstock with ZSM-5
catalyst in a 5:1 ratio resulted in a decreased yield of oxygenates
and higher yield of hydrocarbons compared to non-impregnated
biomass (see Table 4; numbers represent percent of total carbon
yield as determined by Gas Chromatography/Mass Spectrometry). The
yield of char decreased marginally for pyrolysis of impregnated
biomass, improving overall liquid yield.
TABLE-US-00004 TABLE 4 Pyrolysis Product Distribution Following
Impregnation with MgCl.sub.2 Non-Impregnated 1:10 MgCl.sub.2:Red
Red Oak Oak Product (% wt. Carbon) No catalyst ZSM-5 No catalyst
ZSM-5 Oxygenates 73.2 23.6 70.5 18.9 Phenolics 25.2 12.9 16.8 18.9
Oxy-aromatics 7 6.2 1.8 2.1 C5+ Oxygenates 13.7 0.3 16.7 1.5 Light
Oxygenates 11.6 2.9 8.1 2.9 Anhydrosugars 8.3 0.0 19.5 1.9 Acetic
Acid 7.2 1.3 7.5 4.3 Formic Acid 0.1 0.0 0.1 0.0 Hydrocarbons 0.4
29.5 0.7 35.5 Benzene 0.0 1.7 0.0 1.9 Toluene 0.0 2.9 0.2 3.1
Xylenes 0.0 4.3 0.0 4.7 Napathalenes 0.0 6.6 0.0 10.3 PAH 0.0 3.3
0.0 4.4 Other Aromatic 0.2 10.1 0.0 10.9 C5+ Hydrocarbons 0.2 0.3
0.5 0.3 Non-condensable Gases 2.6 5.4 5.4 10.9 Nitrogen Compounds
0.0 0.1 0.0 0.1 Water 2.1 5.9 2.1 7.1 Not Identified 5.7 0.5 7.7
2.8 Char 16.0 35.0 14.0 25.0
Definitions
[0067] As used herein, the term "entrainment" is defined as
transport of a solid particle by a gas stream. Entrainment of a
given solid particle typically occurs when the local velocity of a
gas stream exceeds the terminal falling velocity of the
particle.
[0068] As used herein, the term "standard gas hourly space
velocity" or "SGHSV" refers to the gas hourly space velocity of a
gas stream measured at standard conditions.
[0069] Feedstock particles are by their nature irregularly shaped.
Thus, as used herein, the "diameter" of a particle refers to its
diameter at the widest cross-section of the particle.
[0070] In closing, it should be noted that the discussion of any
reference is not an admission that it is prior art to the present
disclosure, in particular, any reference that may have a
publication date after the priority date of this application. At
the same time, each and every claim below is hereby incorporated
into this detailed description or specification as an additional
embodiment of the present invention.
[0071] Although the systems and processes described herein have
been described in detail, it should be understood that various
changes, substitutions, and alterations can be made without
departing from the spirit and scope of the invention as defined by
the following claims. Those skilled in the art may be able to study
the preferred embodiments and identify other ways to practice the
invention that are not exactly as described herein. It is the
intent of the inventors that variations and equivalents of the
invention are within the scope of the claims while the description,
abstract and drawings are not to be used to limit the scope of the
invention. The invention is specifically intended to be as broad as
the claims below and their equivalents.
REFERENCES
[0072] All of the references cited herein are expressly
incorporated by reference. The discussion of any reference is not
an admission that it is prior art to the present invention,
especially any reference that may have a publication data after the
priority date of this application. Incorporated references are
listed again here for convenience: [0073] 1. Brown, J. N., et al.
"Process Optimization of an Auger Pyrolyzer with Heat Carrier Using
Response Surface Methodology." Biores. Tech.
103:405-4141(2012).
* * * * *