U.S. patent application number 16/530560 was filed with the patent office on 2020-02-06 for biomass processing devices, systems, and methods.
The applicant listed for this patent is EnerSysNet U.S. Holdings, Inc.. Invention is credited to Paul F. Bryan, James M. Colthart, Charles Robert Rapier, Gary E. Scoggins.
Application Number | 20200040259 16/530560 |
Document ID | / |
Family ID | 69227653 |
Filed Date | 2020-02-06 |
United States Patent
Application |
20200040259 |
Kind Code |
A1 |
Scoggins; Gary E. ; et
al. |
February 6, 2020 |
BIOMASS PROCESSING DEVICES, SYSTEMS, AND METHODS
Abstract
Biomass processing devices, systems and methods used to convert
biomass to, for example, liquid hydrocarbons, renewable chemicals,
and/or composites are described. The biomass processing system can
include a pyrolysis device, a hydroprocessor and a gasifier.
Biomass, such as wood chips, is fed into the pyrolysis device to
produce char and pyrolysis vapors. Pyrolysis vapors are processed
in the hydroprocessor, such as a deoxygenation device, to produce
hydrocarbons, light gas, and water. Water and char produced by the
system can be used in the gasifier to produce carbon monoxide and
hydrogen, which may be recycled back to the pyrolysis device and/or
hydroprocessor.
Inventors: |
Scoggins; Gary E.; (Kent,
WA) ; Colthart; James M.; (Boca Grande, FL) ;
Bryan; Paul F.; (Pinole, CA) ; Rapier; Charles
Robert; (Chandler, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EnerSysNet U.S. Holdings, Inc. |
Millinocket |
ME |
US |
|
|
Family ID: |
69227653 |
Appl. No.: |
16/530560 |
Filed: |
August 2, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62714386 |
Aug 3, 2018 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10J 2200/31 20130101;
C10G 45/02 20130101; C10K 1/024 20130101; C10J 2300/092 20130101;
C10B 7/10 20130101; C10G 2300/4068 20130101; C10G 2300/1014
20130101; C10B 27/06 20130101; C10J 2300/1884 20130101; C10J 3/62
20130101; C10J 2300/1861 20130101; C10G 3/42 20130101; C10J
2300/1696 20130101; C10B 47/44 20130101; C10G 1/002 20130101; C10G
1/02 20130101; C10G 3/50 20130101; C10B 53/02 20130101; C10G
2300/202 20130101; C10J 2300/0916 20130101; C10J 3/66 20130101 |
International
Class: |
C10B 7/10 20060101
C10B007/10; C10J 3/66 20060101 C10J003/66; C10J 3/62 20060101
C10J003/62; C10G 45/02 20060101 C10G045/02; C10B 53/02 20060101
C10B053/02; C10B 27/06 20060101 C10B027/06 |
Claims
1. A pyrolysis device comprising: a housing having an inlet and an
outlet; and an auger positioned within the housing, the auger
having: an upstream end adjacent the inlet of the housing; a
downstream end adjacent the outlet of the housing; a core extending
between the upstream end and the downstream end; and a helical
blade wound around the core between the upstream end and the
downstream end; wherein: the inlet of the housing is configured to
receive biomass; and the pyrolysis device is configured to convert
the biomass to a pyrolysis vapor and to produce a pressure seal
formed by material in transition between biomass and pyrolysis
vapor, the pressure being seal positioned between the inlet of the
housing and the outlet of the housing.
2. The pyrolysis device of claim 1, wherein the core of the auger
is tapered from a first diameter at the upstream end to a second
diameter at the downstream end, the first diameter being smaller
than the second diameter.
3. The pyrolysis device of claim 2, wherein: the helical blade has
a blade height measured from an outer surface of the core in a
direction perpendicular to a rotational axis of the core to a
terminal end of the helical blade; and the height of the helical
blade varies from the upstream end to the downstream end of the
auger.
4. The pyrolysis device of claim 3, wherein the height of the
helical blade decreases from the upstream end to the downstream
end.
5. The pyrolysis device of claim 4, wherein the height of the
helical blade decreases at a rate proportional to the increase in
the diameter of the core of the auger such that a distance between
the terminal end of the blade and the rotational axis of the auger
is substantially constant along the length of the auger.
6. The pyrolysis device of claim 1, further comprising: a heater
surrounding a portion of the auger between the inlet of the housing
and the outlet of the housing.
7. The pyrolysis device of claim 1, wherein during operation: a
pressure within the housing between the inlet and the pressure seal
is approximately atmospheric pressure; and a pressure within the
housing between the pressure seal and the outlet is at least 300
psia.
8. The pyrolysis device of claim 1, wherein the inlet of the
housing is configured to receive biomass in the form of wood chips,
sawdust, or a combination thereof.
9. The pyrolysis device of claim 1, further comprising a gas inlet
for introducing gas into the housing.
10. The pyrolysis device of claim 1, wherein the gas inlet is in
fluid communication with a carbon monoxide source or a hydrogen
source.
11. A biomass processing system comprising: a pyrolysis device
configured to receive biomass, pyrolyze the biomass to produce
pyrolysis vapors, and output the pyrolysis vapors; and a
deoxygenation device in fluid communication with the pyrolysis
device, the deoxygenation device configured to receive the
pyrolysis vapors and deoxygenate the pyrolysis vapors to produce a
deoxygenation product stream comprising at least two of water,
hydrocarbons, and fuel gas.
12. The biomass processing system of claim 11, wherein
deoxygenating the pyrolysis vapors is performed without condensing
the pyrolysis vapors to bio-oil.
13. The biomass processing system of claim 11, wherein the
pyrolysis device outputs pyrolysis vapors at a pressure of at least
300 psia.
14. The biomass processing system of claim 11, wherein pyrolyzing
the biomass further produces char, and the system further comprises
a filter in fluid communication with the pyrolysis device, the
filter being configured to separate the char from the pyrolysis
vapors.
15. The biomass processing system of claim 14, further comprising:
a separator in fluid communication with the deoxygenation device,
the separator configured to separate the deoxygenation product
stream into a water stream, a hydrocarbons stream, and a fuel gas
stream.
16. The biomass processing system of claim 15, further comprising:
a gasifier in fluid communication with the separator, the gasifier
configured to receive the water stream produced by the separator
and the char produced by the filter and produce a hydrogen stream
and a carbon monoxide stream.
17. The biomass processing system of claim 16, wherein the
pyrolysis device is in fluid communication with the gasifier and
the pyrolysis device is configured to receive the carbon monoxide
stream.
18. The biomass processing system of claim 16, wherein the
deoxygenation device is in fluid communication with the gasifier
and the deoxygenation device is configured to receive the hydrogen
stream.
19. The biomass processing system of claim 15, wherein the
separator comprises a cyclone.
20. The biomass processing system of claim 11, further comprising:
a filter in fluid communication with the pyrolysis device, the
filter being configured to separate sulfur from the pyrolysis
vapors.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] The present application claims priority under 35 U.S.C.
.sctn. 119(e) to U.S. Provisional Patent Application No.
62/714,386, filed Aug. 3, 2018, the entirety of which is hereby
incorporated by reference.
TECHNICAL FIELD
[0002] The present technology generally relates to biomass
processing devices, systems and methods used to convert biomass to,
for example, liquid hydrocarbons, renewable chemicals, and/or
composites.
BACKGROUND
[0003] As atmospheric carbon dioxide levels continue to rise,
efforts to produce carbon-neutral and/or reduced-carbon fuels have
increased exponentially. Innovations in wind, solar, tidal, and
other energy sources are continually developed as alternatives to
traditional fossil-based fuels.
[0004] Another abundant source of fuel is the biomass found in
forests and other natural environments. Biomass is an abundant fuel
source found in many regions and topographies around the world.
However, converting this biomass (e.g., vegetation, wood, etc.) has
faced many challenges. For example, converting biomass to fuel is
often inefficient, with little of the constituent components of the
biomass being converted to usable fuel. Additionally, challenges
arise with respect to converting biomass into a fuel that is usable
by existing systems and devices, including vehicles, utilities, and
other fuel-using systems. Other challenges are logistical. For
example, abundant sources of biomass tend to be found in remote or
semi-remote locations. In order to reduce the energy costs of
shipping the biomass to a more convenient location (e.g., a fixed
conversion plant or other immovable structure), it is desirable
that the biomass be collected and converted in locations where
biomass is presently in abundance.
[0005] Accordingly, a need exists for devices, systems and methods
of processing biomass that address some or all of the problems
discussed above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Many aspects of the present technology can be better
understood with reference to the following drawings. The components
in the drawings are not necessarily to scale. Instead, emphasis is
placed on illustrating clearly the principles of the present
technology.
[0007] FIG. 1 is a schematic illustration of an embodiment of a
biomass processing system.
[0008] FIG. 2 is a schematic illustration of another embodiment of
a biomass processing system.
[0009] FIG. 3 is schematic illustration of another embodiment of a
biomass processing system.
[0010] FIG. 4 is a schematic illustration of another embodiment of
a biomass processing system.
[0011] FIG. 5 is a schematic illustration of a pyrolysis device,
including an auger, for use with a biomass processing system.
[0012] FIG. 6 is a side plan view of an auger for use with a
pyrolysis device of a biomass processing system.
[0013] FIG. 7 is a longitudinal cross-section view of the auger of
FIG. 6, taken along the cut-plane A-A of FIG. 6.
[0014] FIG. 8 is a side plan view of a deoxygenation device for use
in a biomass processing system.
[0015] FIGS. 9A and 9B are a longitudinal cross-section view and a
transverse cross-section view, respectively, of a portion of a
catalyst bed of a deoxygenation device for use in a biomass
processing system.
DETAILED DESCRIPTION
[0016] Specific details of several embodiments of biomass
processing systems, as well as associated systems and methods, are
described below. Generally, the biomass processing systems of the
present disclosure include a pyrolysis device. This device can
include an intake configured to receive biomass (e.g., chipped wood
and/or other vegetation). The pyrolysis device can be configured to
receive and process biomass without the need to pre-treat the
biomass. For example, the pyrolysis device can receive wood chips
as output by a standard wood chipper without the need for further
size reduction to the wood chips. The pyrolysis device can be
configured to output pyrolysis vapors and char (e.g., biochar) at
elevated pressures.
[0017] The biomass processing system can further include a
hydroprocessing unit (e.g., de-oxygenation reactor) configured to
process the vapors and/or char. In some embodiments, the
hydroprocessing unit can convert the vapors to usable hydrocarbons.
This hydroprocessing can take place without the need for
intermediate conversion of the hydrocarbons to bio-oil or other
intermediate products.
[0018] In some embodiments, the biomass processing systems of the
present disclosure can include one or more gasification units
configured to facilitate conversion of reaction constituents (e.g.,
CO.sub.2, H.sub.2O, char, etc.) into usable/desired constituents
(e.g., H.sub.2, CO, hydrocarbons, etc.).
[0019] In some embodiments, the biomass processing system of the
present disclosure is a remote biomass processing system capable of
operating in remote locations and of being moved to additional
locations as desired. Such a system can be configured to operate
"off the grid" such that existing electrical, water, or other
utility systems are not required to operate the biomass processing
system. Preferably, the biomass processing systems are configured
to operate with little or no additional fuel or other inputs, other
than the locally-sourced biomass.
[0020] Preferably, the biomass processing systems of the present
disclosure, and specifically the remote biomass processing systems,
are relatively small. For example, the systems can have a footprint
less than 200 square feet, less than 240 square feet, less than 300
square feet, and/or less than 400 square feet. The systems can be
capable of throughput rates of at least 2 tons per day, at least 3
tons per day, at least 4 tons per day, at least 6 tons per day,
and/or at least 8 tons per day of biomass. In some embodiments, the
systems are configured to output at least 150 gallons, at least 200
gallons, at least 300 gallons, and/or at least 400 gallons of
usable hydrocarbons per day.
Biomass Processing Systems
[0021] FIG. 1 provides a schematic illustration of an embodiment of
biomass processing system 10. The system 10 can generally include a
pyrolysis device 12, a hydroprocessor (e.g., de-oxygenator or
hydrodeoxygenation unit (HDU)) 14, and/or a gasifier 16. Various
mass transfer pathways can extend between the various components to
facilitate movement of materials between units and devices of the
system 10.
[0022] The pyrolysis device 12 can include, for example, an auger
configured to process wood biomass 13. Exemplary biomass that can
be introduced into pyrolysis device 12 includes, but is not limited
to, wood chips and saw dust. In some embodiments, the biomass is
treated prior to introduction into the pyrolysis device 12 in order
to reduce the moisture content of the biomass. In some embodiments,
the biomass is treated to reduce the moisture content to 10 wt % or
less. As discussed in more detail with respect to later
embodiments, the auger can be tapered such that a hub of the auger
increases in size from an inlet end to an outlet end of the
pyrolysis device 12. As also discussed in more detail with respect
to later embodiments, the pyrolysis device 12 can include a seal
between the inlet receiving a first portion 15 of biomass 13 and
the outlet of the pyrolysis device 12. A second portion 17 of
biomass 13 can be directed to, for example, the gasifier 16.
[0023] The pyrolysis device 12 operates to convert biomass to
pyrolysis vapors and/or char through the application of heat and/or
pressure. Any suitable heat and/or pressure parameters can be used
in the pyrolysis device 12 provided that biomass is converted to
pyrolysis vapors and/or char. The pyrolysis device 12 can output
pyrolysis vapors and/or char, at which point the output material
can be separated. For example, pyrolysis vapors can be separated
from char such that pyrolysis vapors (or predominantly pyrolysis
vapors) are transported to the hydroprocessor 14 via transfer path
18, while char (or predominantly char) is diverted away from the
hydroprocessor 14 via transfer path 20. Any and all transfer paths
discussed herein, including transfer paths 18, 20 can include one
or more pipes, tube, and/or other channels or conduits. Similarly,
any transfer paths discussed herein can include one or more valves
that are positioned therein. The valves can be check valves
configured to open at a minimum cracking pressure. In some
embodiments, the valves are solenoid valves or other valves
configured to be controlled (e.g., via a controller) to transition
between opened and closed configurations.
[0024] The hydroprocessor 14 can be configured to convert the
pyrolysis vapors produced by the pyrolysis device 12 into usable
substances. For example, the hydroprocessor 14 can include one or
more catalysts positioned within the hydroprocessor 14. In some
embodiments, catalyst is coated on various internal surfaces of the
hydroprocessor 14. In some embodiments, catalyst is loaded in tubes
extending through the hydroprocessor 14. These catalysts, discussed
in more detail below, can be configured to process the pyrolysis
vapors to produce a mixture of water, hydrocarbons, and/or light
gases. In some embodiments, the hydroprocessor 14 is configured to
process the pyrolysis vapors at elevated pressure and temperature
without needing to condense the vapors prior to processing.
Preferably, the product mixture resulting from the hydroprocessing
carried out in the hydroprocessor 14 is immiscible, allowing for
easy separation (e.g., via siphoning) of the hydrocarbons, water,
and light gases from each other.
[0025] As further illustrated in FIG. 1, the product mixture
produced by the hydroprocessor 14 can be subjected to separation to
form a water stream, a hydrocarbon stream and a light gas stream.
The hydrocarbon stream can be output from the hydroprocessor 14 via
an output path 22. The output path 22 can direct the hydrocarbons
to a storage tank, to a further processing device, and/or to one or
more components of the biomass processing system 10. The light
gases can be directed from the hydroprocessor 14 via a second
output path 24. The second output path 24 from the hydroprocessor
14 can direct the light gases to a storage tank. In some
embodiments, the light gases and/or hydrocarbons are used to
operate other components of the biomass processing system 14. For
example, the light gases or hydrocarbons can be used to operate an
internal combustion engine or other mechanism configured to operate
the pyrolysis device 12. In some embodiments, the light gases or
hydrocarbons are used to heat the pyrolysis device 12 (e.g., via a
heat sleeve, molten salt loop, electric heat sleeve, or other
heating mechanism).
[0026] While a portion of the output of the pyrolysis device 12
(e.g., pyrolysis vapors) can be directed to the hydroprocessor 14
via transfer path 18, another portion of the output of the
pyrolysis device 12 (e.g., char) can be directed to a gasifier 16
via transfer path 20. As noted previously, the output content from
pyrolysis device 12 can be selectively directed to the transfer
paths 18, 20 via use of filters and/or valves to reduce the amount
of char directed to the hydroprocessor 14 while reducing the amount
of vapor directed to the gasifier 16.
[0027] In some embodiments, the water produced by the
hydroprocessor 14, or at least a portion thereof, is directed to
the gasifier 16 via transfer pathway 26. The gasifier 16 can be
configured to use the water from the hydroprocessor 14, the char
from the pyrolysis device 12, and/or biomass (e.g., the second
portion 17 of biomass directed to the gasifier 16) to produce
desired chemical compounds. For example, the gasifier 16 can be
configured to output CO to the pyrolysis device 12 via transfer
path 28 to increase the efficiency of the pyrolysis device 12. In
some embodiments, the gasifier 16 produces hydrogen that is output
to the hydroprocessor 14 via transfer path 30 to increase the
efficiency (e.g., amount of hydrocarbon production) of the
hydroprocessor 14.
[0028] As shown in FIG. 1, water output by the hydroprocessor 14
and carbon monoxide and hydrogen output by the gasifier 16 are
reused in the overall process, which results in improved C and H
efficiency.
[0029] FIG. 2 illustrates an embodiment of a biomass processing
system 110 that is similar to or the same as the biomass processing
system 10 in several aspects. For example, the biomass processing
systems 110, 10 can be similar to each other in one or both of
structure and function. In the proceeding description, like numbers
(e.g., pyrolysis device 12 vs. pyrolysis device 112, wherein the
last two digits in the reference number are shared) are used to
denote features that can be similar or the same between the two
biomass processing systems 10, 110.
[0030] As illustrated in FIG. 2, the hydroprocessor 114 can include
a deoxygenation device 132. The deoxygenation device 132 can be
configured to receive the pyrolysis vapors from the pyrolysis
device 112 via the transfer path 118. The deoxygenation device 132
can include one or more catalysts embedded in, coated on, or
otherwise associated with the deoxygenation device 132. The
deoxygenation device 132 can be configured to receive hydrogen
and/or some other compound from the gasifier 116 or other source to
aid in the deoxygenation of the pyrolysis vapors received from the
pyrolysis device 112. Generally speaking, the deoxygenation process
carried out by the deoxygenation device 132 rejects oxygen by
making water. The deoxygenation device 132 also enables
deoxygenation to hydrocarbons in the vapor phase.
[0031] The hydroprocessor 114 can also include a condenser 134 or
other component (e.g., a container, fluid separator, or other
device) configured to receive the output from the deoxygenation
device 132. The condenser 134 can condense the output water, light
gas, and/or hydrocarbons from the deoxygenation device 132.
Preferably, the output constituents from the deoxygenation device
132 are immiscible and easily separated into their respective parts
(e.g., water, light gas or hydrocarbons). The light gases can be
output to a combined heat and power (CHP) system 136 via the
transfer path 124. The water can be recycled back to the gasifier
116 via the transfer path 126. In some embodiments, the
hydrocarbons are transferred to a storage container or to some
other component of the system 110 via the transfer path 122. The
condenser 134 operates to ensure no loss of carbon to phase
separation or bio-oil re-vaporization.
[0032] FIG. 3 illustrates an embodiment of a biomass processing
system 210 that is similar to or the same as the pyrolysis systems
10, 110 in several aspects. For example, the biomass processing
systems 210, 110, 10 can be similar to each other in one or both of
structure and function. In the proceeding description, like numbers
(e.g., pyrolysis device 12 vs. pyrolysis device 112 vs. pyrolysis
device 212, wherein the last two digits in the reference number are
shared) are used to denote features that can be similar or the same
between the biomass processing systems 10, 110, 210.
[0033] As illustrated in FIG. 3, the hydroprocessor 214 can include
a filter device 240. The filter or separator device 240 is
configured to separate pyrolysis vapors from char, both of which
are received from the pyrolysis device 212 via the transfer path
218. As will be explained in further detail below, one or more
components of the hydroprocessor 214 are configured to operate in
the presence of char. As such, complete filtering of the char from
the pyrolysis vapor is not required for all embodiments. After
separating (at least partially) the char from the pyrolysis vapor,
the filter device 240 is configured to output char (or
predominantly char) via a transfer path 242 and to output pyrolysis
vapor (or predominantly pyrolysis vapor) via a second transfer path
244. The transfer path 242 for char from the filter device 240 can
lead to a container. In some embodiments, the char from the filter
device 240 is directed to a gasifier or other component for use in
chemical reactions, as discussed in further detail below.
[0034] The hydroprocessor 214 can optionally include a condenser
246. The condenser 246 can be configured to condense the mixture
(e.g., water, hydrocarbons, and/or light gases) received from the
deoxygenation device 232. The condensed mixture can be directed to
a separation device 248 configured to separate the constituents of
the mixture. The separation device can be configured to output
water via a transfer path 222 and to output hydrocarbons via a
second transfer path 226. The separation device 248 can output fuel
gases (e.g., light gases) via a third transfer path 224. The water
and/or hydrocarbons can be directed to other components of the
system 210 for use as fuel and/or in chemical reactions.
[0035] In some embodiments, the fuel gases, or some portion
thereof, are directed to an actuator 250. The actuator 250 can be
configured to operate the pyrolysis device 212 (e.g., to rotate the
auger). Example actuators 250 include internal combustion engines,
electric motors, turbomachinery, or other mechanisms configured to
provide power to the pyrolysis device 212. In some embodiments,
fuel gas is directed to a generator configured to provide electric
power to the actuator 250 and/or to provide power to other
components of the system 210.
[0036] The pyrolysis system 210 can include a fuel gas reservoir
252 configured to retain fuel gas provided by the hydroprocessor
214 prior to its use in the actuator 250. In some embodiments, the
fuel gas reservoir 252 is at least partially filled using
conventional fossil fuels or other fuels not produced by the system
210 to provide initial or supplemental energy to the system
210.
[0037] At least a portion of the fuel gas stored in reservoir 252
can be directed to a burner 254. As illustrated in FIG. 3, in some
embodiments the fuel gas is provided to the burner 254 via a
transfer path 256 from the fuel gas reservoir 252. The burner 254
can be configured to burn the fuel gas to provide heat to a heat
pipe 258 or other heating mechanism. The heat pipe 258 can be
configured to provide heat to the pyrolysis device 212. For
example, the heat pipe 258 can provide heat to a portion of the
pyrolysis device 212 along a length of the pyrolysis device 212.
The heat can be directed around all or a portion of an outer
surface of the pyrolysis device 212 along at least a portion of the
length of the pyrolysis device 212. In some embodiments, heat from
the heat pipe 258 heats a jacket surrounding a portion of the
pyrolysis device 212. In some embodiments, exhaust gases 260 from
the actuator 250 can also be directed to the heat pipe 258 to
supplement the heat provided to the pyrolysis device 212. In some
embodiments, an electric heater can be used in addition to or
instead of the heat pipe 258. The electric heater can surround a
portion of the pyrolysis device 212 along a portion of the length
of the pyrolysis device 212.
[0038] In some embodiments, the biomass processing system 210
includes a fuel processor 262 upstream of the actuator 250 and/or
reservoir 252. In some embodiments, the fuel processor 262 can be
positioned between (e.g., physically between and/or in the fluid
path between) the fuel gas reservoir 252 and the separation device
248. The fuel processor 262 can be, for example, a gasifier and/or
a device having a hydrogen separation membrane or other structure
configured to separate hydrogen from the fuel gas. The fuel
processor 262 can be configured to direct separated hydrogen to the
pyrolysis device 212 to bolster pyrolysis of the biomass in the
pyrolysis device 212. In some embodiments, the biomass processing
system 210 includes a secondary source of hydrogen 264 configured
to provide hydrogen to the separation device 262 and/or to the
pyrolysis device 212.
[0039] FIG. 4 illustrates an embodiment of a biomass processing
system 310 that is similar to or the same as the pyrolysis systems
10, 110, 210 in several aspects. For example, the biomass
processing systems 310, 210, 110, 10 can be similar to each other
in one or both of structure and function. In the proceeding
description, like numbers (e.g., pyrolysis device 12 vs. pyrolysis
device 112 vs. pyrolysis device 212 vs. pyrolysis device 312,
wherein the last two digits in the reference number are shared) are
used to denote features that can be similar or the same between the
biomass processing systems 10, 110, 210, 310.
[0040] As illustrated in FIG. 4, a first separation unit 340 in the
form of a cyclone is provided for separating pyrolysis vapor and
char. The cyclone 340 receives the product of the pyrolysis unit
312 via transfer path 318 and separates the pyrolysis vapor from
the char using, e.g., centrifugal force. The char exits the cyclone
340 via transfer path 342, while pyrolysis vapors are transported
via transfer path 344a to a second separation unit 341 in the form
of a sulfur guard bed. The sulfur guard bed 341 removes sulfur from
the pyrolysis vapor to achieve near zero sulfur content in the
pyrolysis vapor. The scrubbed pyrolysis vapor is then transported
to the deoxygenation device 332 via transfer path 344b. Hydrogen
source 333 is provided so as to supply additional hydrogen to the
deoxygenation device 332. The hydrogen 333 is provided at a partial
pressure, and in conjunction with catalysts included within the
deoxygenation device 332, work to optimize selectivity and
yield.
Pyrolysis Device and Auger
[0041] FIG. 5 illustrates an embodiment of a pyrolysis device 512.
Any or all of the pyrolysis devices 12, 112, 212, 312 can share all
or some of the features of the pyrolysis device 512. As
illustrated, the pyrolysis device 512 can include an auger 570. The
auger 570 can have an inlet end 572 and an outlet end 574. The core
of the auger 570 can be outwardly tapered from the inlet end 572
toward the outlet end 574. The auger 570 can include a blade 576
wrapped around the core (e.g., in a helical pattern). The blade 576
can have a blade height as measured from the core in a direction
perpendicular to the rotational axis of the core. The height of the
blade 576 can vary from the inlet end 572 to the outlet end 574 of
the auger 570. For example, the height of the blade 576 can
decrease between the inlet end 572 and the outlet end 574. In some
embodiments, the height of the blade 576 between the inlet and
outlet ends 574 can decrease at a rate proportional to the increase
in diameter of the core of the auger 570 such that a distance
between the outer tip of the blade 576 (e.g., as measured from the
rotational axis of the auger 570) and the rotational axis of the
auger 570 is substantially constant along the length of the auger
570.
[0042] A heater 575 can be positioned around a portion of the auger
570 between the feed inlet 571 and the outlet of the pyrolysis
device 512. In the illustrated example, the heater 575 is an
electric band heater. As explained with respect to previous
embodiments, the heater 575 can be a heat jacket, a heat pipe,
and/or any other structure or method for heating all or a portion
of the pyrolysis device 512. Preferably, the heater 575 completely
surrounds a portion of a length of the pyrolysis device 512 (e.g.,
the auger 570). In some embodiments, molten salt can be used
instead of or in addition to a heater 575 to provide heat to the
pyrolysis device 512. The molten salt can be introduced via a
molten salt inlet 581 at a first temperature to the pyrolysis
device 512 and can leave the pyrolysis device 512 via a molten salt
outlet 582 at a second, lower temperature. The first temperature
can be, for example, at least 300.degree. C., at least 400.degree.
C., at least 500.degree. C., at least 600.degree. C., and/or at
least 800.degree. C. The second temperature can be less than or
equal to 900.degree. C., less than or equal to 800.degree. C., less
than or equal to 600.degree. C., less than or equal to 400.degree.
C., and/or less than or equal to 200.degree. C. In some
embodiments, the molten salt is provided by a gasifier.
[0043] During operation of the pyrolysis device 512, a seal 577 can
be formed at a point along the length of the auger 570. More
specifically, as the biomass transitions from biomass material to
pyrolysis vapor and char, the biomass goes through a transition
phase. Due at least in part to the thermoplastic nature of the
biomass, the transitioning biomass between the inlet and the outlet
of the pyrolysis device 512 forms a high-pressure seal 577 (e.g., a
"melt" seal) capable of supporting high pressure within the
pyrolysis device 512 between the seal 577 and the outlet of the
pyrolysis device 512. These high pressures can be at least 300
psia, at least 400 psia, at least 500 psia, at least 1,000 psia,
and/or at least 2,000 psia. At the same time, the operating
pressure at the inlet 571 and upstream of the pressure seal 577 can
be substantially equivalent to atmospheric pressure (e.g., between
approximately 14-15 psia), which can allow for direct feeding of
the biomass into the pyrolysis device 512 without need for valves
or other pressure-maintenance mechanism at the inlet 571. Use of
the biomass to form a seal 577 can reduce or eliminate the need for
additional seals or other pressure-increasing or
pressure-maintenance mechanisms in the upstream portion of the
auger 570. In some applications, the pressure seal 577 eliminates
the need for a compressor or other mechanism to increase the
pressure within the pyrolysis device 512. Preferably, the melt seal
577 is gradually ablated and replenished during normal operation of
the auger 570. For example, as a downstream side of the melt seal
577 is ablated, an upstream side of the melt seal 577 is
replenished from biomass upstream of the seal 577.
[0044] In some embodiments, the melt seal 577 is located at or near
an upstream end of the heater 575. In some embodiments, the melt
seal 577 is positioned between the upstream and downstream ends of
the heater 575. In some embodiments, the melt seal 577 spans the
upstream end of the heater 575.
[0045] Pyrolysis device 512 can also include a hydrogen inlet 583
for supplying hydrogen to the pyrolysis device 512. Hydrogen can be
sourced from, for example, fuel processor 262 (FIG. 3). The
addition of hydrogen to the pyrolysis device can bolster pyrolysis
of the biomass in the pyrolysis device 512.
[0046] In some embodiments, all or a portion of the auger 570
and/or auger housing 573 is coated with catalytic compounds. These
catalysts can be configured to augment the pyrolysis process within
the pyrolysis device to deoxygenate the vapor within the device 512
and/or to produce favorable carbon chains within the vapor. In some
embodiments, various catalysts are used to coat various portions of
the auger 570 and/or housing 573. Example catalysts can include
molybdenum (Mo)-based catalysts (e.g., Cobalt-Mo, Nickel-Mo, etc.).
Use of Mo-based catalysts can provide a cheaper alternative to
noble-metal based catalysts and other more expensive, difficult-to
obtain catalysts.
[0047] FIGS. 6 and 7 provide an isolated view of the auger 570 of
pyrolysis device 512. As illustrated, the auger 570 can be formed
from two or more separate portions. For example, the auger 570 can
include an upstream segment 578 and a downstream segment 580. The
two segments can be joined via threaded engagement 579 between the
upstream and downstream segments 578, 580.
[0048] The depth of the blade 576 (e.g., the threads) of the auger
570, as measured from the core of the auger 570 to the tip of the
blade 576 in a direction perpendicular to the rotational axis of
the auger 570, can vary along the length of the auger 570. For
example, a ratio between the depth of the blade 576 (e.g., the
blade height) at the inlet end 572 can be greater than ten times,
greater than 8 times, greater than 6 times, greater than 3 times,
and/or greater than 1.5 times the depth of the blade 576 at or near
the outlet end 574 of the auger 570. In some embodiments, the ratio
of the max depth of the blade 576 and the minimum depth of the
blade is between approximately 7:1 and approximately 18:1.
Deoxygenation Device
[0049] The deoxygenation device of the systems described herein can
be configured to deoxygenize the pyrolysis vapors at the increased
pressure in the vapor phase without requiring condensation to
bio-oil and subsequent vaporization of the bio-oil. The
hydrocarbons, water, and/or light gases produced by the
deoxygenation device can be directed to a condenser to condense out
water, hydrocarbon fuels, and light gases. Some or all of the water
can be directed to the gasifier to produce CO, H.sub.2, and/or
other desired compounds for use in components of the system to
increase efficiency and to produce a higher yield of hydrocarbons.
The deoxygenation device of the systems described herein can also
be configured to utilize catalysts and mixing structures to convert
the pyrolysis vapors into hydrocarbons, water, and/or fuel gas.
[0050] FIG. 8 illustrates a deoxygenation device 632. The
deoxygenation devices and/or hydroprocessors described above with
respect to FIGS. 1-4 can share some or all of the structural and/or
functional characteristics of the deoxygenation device 632
described below.
[0051] As illustrated, the deoxygenation device 632 can include a
processing portion 682 extending between an upstream end 684 and a
downstream end 686. The upstream and downstream ends 684, 686 can
be configured to connected to one or more mass transfer structures
such as tubes, hoses, pipes, and/or other structures. The upstream
end 684 can be configured to receive pyrolysis vapors from the
pyrolysis device. The pyrolysis vapors can be received at the
elevated pressures and temperatures realized downstream of the melt
seal or other seal of the pyrolysis device.
[0052] The processing portion 682 of the deoxygenation device 632
can include a single tube 688. The tube 688 can be surrounded by a
heat exchanger tube (not shown) or some other structure configured
to control temperature of the tube 688. In some embodiments, one or
more mixing structures 690 are provided within the tube 688. The
mixing structures 690 can be, for example, fins, helixes, ribs,
protrusions, or other physical structures positioned within the
tube 688.
[0053] The tube 688 and/or mixing structures 690 can be coated
and/or embedded with one or more catalysts configured to aid in the
process of deoxygenating the pyrolysis vapor. The catalysts can be
hydrotreating catalysts. In some embodiments, more than one
catalyst is used. For example, a first catalyst can be used on an
upstream portion of the tube 688 and/or mixing structures 690 and
one or more additional catalysts of a different type can be used on
portions of the tube 688 and/or mixing structure 690 downstream.
Use of static components (e.g., the mixing structures 690 and tube
688) can facilitate easy replacement of portions of the
deoxygenation device 632 when catalysts need to be reapplied and/or
changed.
[0054] The mixing structures 690 can be configured to increase
turbulence within the deoxygenation device 632. Increasing
turbulence within the deoxygenation device 632 can increase mass
transfer during the chemical reactions within the deoxygenation
device 632. In some embodiments, the surface area of the mixing
structures 690 is increased through use of fibrous, roughened,
and/or porous material. For example, metal fiber sheets (e.g.,
sintered metal fiber sheets) can be used to form the mixing
structures 690 and/or to cover the mixing structures 690. Example
metal fiber materials include sintered metal fiber sheets
manufactured by Bekaert.RTM. AISI 316L, Hastelloy C276, Inconel
600, and Hastelloy X. Other materials are also usable.
[0055] Use of high-surface area materials for the mixing structures
690 and/or tube 688 can increase the amount of catalysts that can
be applied to the surfaces of the deoxygenation device 632. For
example, atomic layer deposition may be used to deposit catalyst
layers with precision. In some embodiments, the surfaces of the
mixing structure 690 and/or the tube 688 can be decorated with
nanoparticles (e.g., Nickel and/or Iron nanoparticles) to increase
the ability of the mixing structures 690 and/or tube 688 to receive
catalysts thereon. In some embodiments, portions of the
deoxygenation device 632 are dipped or otherwise coated in
suspensions containing nanoparticles. Increased catalyst content
can increase the amount of usable hydrocarbons produced by the
deoxygenation device 632. The resulting multi-scale composite of
fibrous structures coated with catalyst materials can allow for a
structurally-sound, highly efficient deoxygenation process within
the deoxygenation device 632.
[0056] In some embodiments, use of the above-described multi-scale
composites can allow for large fluid pathways through the
deoxygenation device 632. Use of large pathways with static
structures and/or few constrictions can allow the deoxygenation
device 632 to be tolerant of the presence of bio-chars in the vapor
mixture. Tolerating bio-chars can allow for use of the bio-chars to
increase the efficiency of the deoxygenation device 632 and can
reduce or eliminate the need to filter out the bio-chars from the
output of the pyrolysis device.
[0057] Further increase in surface area within the deoxygenation
device 632 can be realized through use of carbon nanotubes and/or
nanofibers on the surfaces of one or both of the mixing structure
690 and the tube 688. The nanotubes/nanofibers can have very high
surface areas (e.g., 200-1,100 m.sup.2/g) capable of being coated
with catalyst materials. In some embodiments, the nanotubes and/or
nanofibers can be doped with nitrogen to enhance catalytic
activity.
[0058] FIGS. 9A and 9B illustrate an embodiment of the
deoxygenation device wherein multiple tubes 903 are disposed within
the deoxygenation device and the tubes 903 are filled or coated
with catalysts 904 to promote the deoxygenation reaction. These
tubes 903 can be used as part of a shell and tube heat exchanger
901 so that heat produced by the deoxygenation reaction can be used
in other parts of the system. In some embodiments, the tubes 903
are filled with different catalysts 904a, 904b, 904c, etc., along
the length of the tube 903 to effect consecutive reactions in order
to produce the desired final product molecules.
[0059] With reference to FIG. 9B, the shell and tube heat exchanger
901 that can be employed within the deoxygenation device generally
includes an outer shell 902 in which a plurality of tubes 903 are
disposed. Within the tubes 903, catalyst 904 is packed to fill some
or all of the void space within the tubes 903. While not shown in
FIG. 9B, catalyst can also be coated on the interior walls of the
tubes 903. Pyrolysis vapors are passed though the length of the
tubes 903, and deoxygenation reactions occur within the tubes 903.
The deoxygenation reaction is initiated and/or promoted due to the
presence of the catalyst 904. The tubes 903 do not fill all of the
void space within the shell 902, and therefore channels are formed
within the shell 902 but exterior to the tubes 902. Heat given off
by the deoxygenation reaction can travel through the tubes and into
the channels within the shell 902. If another material is passed
through the channels (e.g., counter-currently to the direction that
pyrolysis vapors pass through the tubes 903), then the material can
be heated by the heat generated from the deoxygenation
reaction.
[0060] With reference to FIG. 9A, the catalyst 904 can be loaded in
the tube 903 in a manner such that the type of catalyst 904 changes
along the length of the tube 903. By carefully calibrating the type
of catalyst 904 used along the length of the tube 903, different
reactions can be promoted at different points along the length of
the tube 903. Thus, as the makeup of the pyrolysis vapor changes as
it passes through the tube 903, the catalyst 904 can be altered to
promote specific reactions based on, e.g., reactant expected to be
available at different points along the length of the tube 903.
FIG. 9A shows arrow 905 indicating the direction of flow of
pyrolysis vapors through the tube 903. At a first region closer to
the upstream side of the tube 903, catalyst 904a is provided to
promote a first reaction. The result of the first reaction is a
change in the types of material present at the intermediate portion
of the tube 903. As such, a second catalyst 904b is provided at the
intermediate portion of the tube 903, with the second catalyst 904b
designed to promote a second reaction that requires reactants
present in a higher amount or concentration due to the first
reaction. Closer to a downstream end of the tube 903 is a third
catalyst 904c. The third catalyst 904c is designed to promote a
third reaction that requires reactants present in a higher amount
or concentration due to the second reaction. Based on this
configuration, the efficiency of the deoxygenation device is
improved (for example, in terms of converting pyrolysis vapors to
the desired end products). While FIG. 9A shows three different
types of catalyst along the length of the tube 903, it should be
appreciated that any number of different types of catalyst can be
used within the tube 903.
[0061] The systems described herein can incorporate a pressure
coupling that allows the pyrolysis device and the hydroprocessor
(e.g., deoxygenation unit) to separate. This separation point
allows access to both the pyrolysis unit and the hydroprocessor.
For example, using the pressure coupling, catalyst can be replaced
in the hydroprocessor by removing and replacing tubes in the shell
when a shell and tube configuration is employed without impacting
the pyrolysis device. Similarly, catalyst in, for example, a sulfur
guard bed positioned between the pyrolysis device and the
deoxygenation device (e.g., as shown in FIG. 4), can be removed
without impacting the deoxygenation device.
Carbon Efficiency
[0062] In some embodiments, use of the pyrolysis systems described
above can allow for increased carbon efficiency as compared to
prior art systems. For example, the above-recited systems can allow
for the primary rejection product from the hydroprocessing and/or
deoxygenation processes to be water in order to divert more of the
carbon into hydrocarbons (e.g., as opposed to carbon dioxide).
Hydrogen from the water can then be produced using byproduct carbon
(e.g., char) in an integrated gasification process. An example of a
theoretical mass balance is illustrated in the below reactions
(amounts in megamoles):
0.23CH.sub.1.33O.sub.0.56+0.15H.sub.2.fwdarw.0.16CH.sub.2+0.12H.sub.2O+0-
.07CH.sub.71O.sub.0.09,
0.07CH.sub.0.71O.sub.0.09+0.13H.sub.2O.fwdarw.0.15H.sub.2+0.07CO.sub.2
In the above-recited reactions, approximately 5 tons/hour of
biomass (0.225 megamoles of CH.sub.1.33O.sub.0.56) reacts with 0.3
tons/hour of H.sub.2 to produce 2.2 tons/hour of hydrocarbons
(e.g., CH.sub.2 in this example) along with 2.1 tons of water and
0.9 tons of char (CH.sub.0.71O.sub.0.09). This means that 30% of
the carbon in the feed biomass is rejected ultimately as carbon
dioxide but 95% of the energy in the original biomass is retained
in the produced hydrocarbon.
Hydrogen Efficiency
[0063] The char yield noted in the above mass balance can be steam
gasified with 2.3 tons of water to produce the required hydrogen
along with 2.9 tons of carbon dioxide. In some embodiments, carbon
monoxide can be fed to the pyrolysis device to incorporate
water-gas shift in the pyrolysis step to produce additional
H.sub.2. The below illustrative reactions illustrate how carbon
monoxide can be both used to generate hydrocarbons and produced by
reacting char with carbon dioxide (e.g., with carbon dioxide
produce in the formation of H.sub.2 from char and water):
0.23CH.sub.1.33O.sub.0.56+0.11H.sub.2+0.04CO.fwdarw.0.16CH.sub.2+0.08H.s-
ub.2O+0.04CO.sub.2+0.07CH.sub.0.71O.sub.0.09
0.05CH.sub.0.71O.sub.0.09+0.09H.sub.2O.fwdarw.0.11H.sub.2+0.05CO.sub.2
0.02CH.sub.0.71O.sub.0.09+0.02CO.sub.2.fwdarw.0.01H.sub.2+0.04CO
Each of the above-recited reactions illustrates how carbon and
hydrogen can be recycled with the disclosed pyrolysis systems to
increase overall hydrocarbon yield.
Additional Examples
[0064] Several aspects of the present technology are set forth in
the following examples:
[0065] 1. A pyrolysis device comprising: [0066] a housing having an
inlet and an outlet; and [0067] an auger positioned within the
housing, the auger having: [0068] an upstream end adjacent the
inlet of the housing; [0069] a downstream end adjacent the outlet
of the housing; [0070] a core extending between the upstream end
and the downstream end; and [0071] a helical blade wound around the
core between the upstream end and the downstream end; [0072]
wherein: [0073] the inlet of the housing is configured to receive
biomass; and [0074] the pyrolysis device is configured to convert
the biomass to a pyrolysis vapor and to [0075] produce a pressure
seal formed by material in transition between biomass and pyrolysis
vapor, the pressure being seal positioned between the inlet of the
housing and the outlet of the housing.
[0076] 2. The pyrolysis device of claim 1, wherein the core of the
auger is tapered from a first diameter at the upstream end to a
second diameter at the downstream end, the first diameter being
smaller than the second diameter.
[0077] 3. The pyrolysis device of claim 2, wherein: [0078] the
helical blade has a blade height measured from an outer surface of
the core in a direction perpendicular to a rotational axis of the
core to a terminal end of the helical blade; and [0079] the height
of the helical blade varies from the upstream end to the downstream
end of the auger.
[0080] 4. The pyrolysis device of claim 3, wherein the height of
the helical blade decreases from the upstream end to the downstream
end.
[0081] 5. The pyrolysis device of claim 4, wherein the height of
the helical blade decreases at a rate proportional to the increase
in the diameter of the core of the auger such that a distance
between the terminal end of the blade and the rotational axis of
the auger is substantially constant along the length of the
auger.
[0082] 6. The pyrolysis device of claim 1, further comprising:
[0083] a heater surrounding a portion of the auger between the
inlet of the housing and the outlet of the housing.
[0084] 7. The pyrolysis device of claim 1, wherein during
operation: [0085] a pressure within the housing between the inlet
and the pressure seal is approximately atmospheric pressure; and
[0086] a pressure within the housing between the pressure seal and
the outlet is at least 300 psia.
[0087] 8. The pyrolysis device of claim 1, wherein the inlet of the
housing is configured to receive biomass in the form of wood chips,
sawdust, or a combination thereof.
[0088] 9. The pyrolysis device of claim 1, further comprising a gas
inlet for introducing gas into the housing.
[0089] 10. The pyrolysis device of claim 1, wherein the gas inlet
is in fluid communication with a carbon monoxide source or a
hydrogen source.
[0090] 11. A biomass processing system comprising: [0091] a
pyrolysis device configured to receive biomass, pyrolyze the
biomass to produce pyrolysis vapors, and output the pyrolysis
vapors; and [0092] a deoxygenation device in fluid communication
with the pyrolysis device, the deoxygenation device configured to
receive the pyrolysis vapors and deoxygenate the pyrolysis vapors
to produce a deoxygenation product stream comprising at least two
of water, hydrocarbons, and fuel gas.
[0093] 12. The biomass processing system of claim 11, wherein
deoxygenating the pyrolysis vapors is performed without condensing
the pyrolysis vapors to bio-oil.
[0094] 13. The biomass processing system of claim 11, wherein the
pyrolysis device outputs pyrolysis vapors at a pressure of at least
300 psia.
[0095] 14. The biomass processing system of claim 11, wherein
pyrolyzing the biomass further produces char, and the system
further comprises a filter in fluid communication with the
pyrolysis device, the filter being configured to separate the char
from the pyrolysis vapors.
[0096] 15. The biomass processing system of claim 14, further
comprising: [0097] a separator in fluid communication with the
deoxygenation device, the separator configured to separate the
deoxygenation product stream into a water stream, a hydrocarbons
stream, and a fuel gas stream.
[0098] 16. The biomass processing system of claim 15, further
comprising: [0099] a gasifier in fluid communication with the
separator, the gasifier configured to receive the water stream
produced by the separator and the char produced by the filter and
produce a hydrogen stream and a carbon monoxide stream.
[0100] 17. The biomass processing system of claim 16, wherein the
pyrolysis device is in fluid communication with the gasifier and
the pyrolysis device is configured to receive the carbon monoxide
stream.
[0101] 18. The biomass processing system of claim 16, wherein the
deoxygenation device is in fluid communication with the gasifier
and the deoxygenation device is configured to receive the hydrogen
stream.
[0102] 19. The biomass processing system of claim 15, wherein the
separator comprises a cyclone.
[0103] 20. The biomass processing system of claim 11, further
comprising: [0104] a filter in fluid communication with the
pyrolysis device, the filter being configured to separate sulfur
from the pyrolysis vapors.
[0105] 21. A deoxygenation device comprising: [0106] an inlet;
[0107] an outlet; [0108] a housing extending between the inlet and
the outlet; [0109] one or more mixing structures positioned within
the housing between the inlet and the outlet, the mixing
structures; and [0110] a catalyst material deposited within the
housing, the catalyst being configured to promote a deoxygenation
reaction.
[0111] 22. The deoxygenation device of claim 21, wherein the one or
more mixing structures comprises one or more metal fiber sheets
upon which carbon nanotubes, carbon nanofibers, or both are
deposited.
[0112] 23. The deoxygenation device of claim 22, wherein the
catalyst is deposited on one or more of an interior surface of the
housing, the one or more mixing structures, and the carbon
nanotubes and/or carbon nanofibers.
[0113] 24. The deoxygenation device of claim 21, further
comprising: [0114] a shell and tube heat exchanger located within
the housing, the shell and tube heat exchanger comprising a
plurality of tubes, wherein the catalyst is packed within each of
the plurality of tubes.
[0115] 25. The deoxygenation device of claim 24, wherein each tube
comprises a upstream end and a downstream end, and wherein a first
type of catalyst configured to promote a first reaction is packed
proximate the upstream end and a second type of catalyst configured
to promote a second reaction is packed proximate the upstream
end.
[0116] 26. A method of processing biomass, comprising: [0117]
pyrolyzing biomass to produce char and pyrolysis vapors; [0118]
separating the char from the pyrolysis vapors; [0119] deoxygenating
the pyrolysis vapors to produce a deoxygenation product stream, the
deoxygenation product stream comprising water, hydrocarbons and
fuel gas; [0120] separating the deoxygenation product stream into
water, hydrocarbons and fuel gas, and [0121] gasifying the char and
the water to produce hydrogen and carbon monoxide.
[0122] 27. The method of claim 26, further comprising: [0123] using
the hydrogen in deoxygenating the pyrolysis vapors.
[0124] 28. The method of claim 26, further comprising: [0125] using
the carbon monoxide in pyrolyzing the biomass.
[0126] 29. The method of claim 26, further comprising: [0127]
condensing the deoxygenation product stream prior to separating the
deoxygenation product stream.
[0128] 30. The method of claim 26, further comprising: [0129]
processing the fuel gas to separate hydrogen from the fuel gas.
[0130] 31. The method of claim 30, further comprising: [0131]
burning the fuel gas to drive the pyrolysis of the biomass.
[0132] 32. The method of claim 26, further comprising: [0133]
separating sulfur from the pyrolysis vapors prior to deoxygenating
the pyrolysis vapors.
[0134] The above detailed descriptions of embodiments of the
technology are not intended to be exhaustive or to limit the
technology to the precise form disclosed above. Although specific
embodiments of, and examples for, the technology are described
above for illustrative purposes, various equivalent modifications
are possible within the scope of the technology, as those skilled
in the relevant art will recognize. For example, while steps are
presented in a given order, alternative embodiments may perform
steps in a different order. Moreover, the various embodiments
described herein may also be combined to provide further
embodiments. Reference herein to "one embodiment," "an embodiment,"
or similar formulations means that a particular feature, structure,
operation, or characteristic described in connection with the
embodiment can be included in at least one embodiment of the
present technology. Thus, the appearances of such phrases or
formulations herein are not necessarily all referring to the same
embodiment.
[0135] Moreover, unless the word "or" is expressly limited to mean
only a single item exclusive from the other items in reference to a
list of two or more items, then the use of "or" in such a list is
to be interpreted as including (a) any single item in the list, (b)
all of the items in the list, or (c) any combination of the items
in the list. Where the context permits, singular or plural terms
may also include the plural or singular term, respectively.
Additionally, the term "comprising" is used throughout to mean
including at least the recited feature(s) such that any greater
number of the same feature and/or additional types of other
features are not precluded. Directional terms, such as "upper,"
"lower," "front," "back," "vertical," and "horizontal," may be used
herein to express and clarify the relationship between various
elements. It should be understood that such terms do not denote
absolute orientation. Further, while advantages associated with
certain embodiments of the technology have been described in the
context of those embodiments, other embodiments may also exhibit
such advantages, and not all embodiments need necessarily exhibit
such advantages to fall within the scope of the technology.
Accordingly, the disclosure and associated technology can encompass
other embodiments not expressly shown or described herein.
* * * * *