U.S. patent application number 13/914146 was filed with the patent office on 2013-12-12 for catalytic pyrolysis of biomass in an auger reactor.
The applicant listed for this patent is Phillips 66 Company. Invention is credited to Daren E. Daugaard, Kening Gong, Samuel T. Jones, Edgar Lotero, Alexandru Platon.
Application Number | 20130327626 13/914146 |
Document ID | / |
Family ID | 49714403 |
Filed Date | 2013-12-12 |
United States Patent
Application |
20130327626 |
Kind Code |
A1 |
Daugaard; Daren E. ; et
al. |
December 12, 2013 |
CATALYTIC PYROLYSIS OF BIOMASS IN AN AUGER REACTOR
Abstract
The present invention relates generally to the thermal
conversion of biomass. Processes are disclosed for converting algal
biomass to condensable vapor intermediates such as pyrolysis oil by
means of pyrolysis in a reactor comprising at least one auger. The
intermediates may be further processed for production of renewable
hydrocarbon fuels. The disclosed processes assist in preventing
premature devolatization of algal biomass during pyrolysis, thereby
increasing efficiency and commercial feasibility.
Inventors: |
Daugaard; Daren E.;
(Skiatook, OK) ; Jones; Samuel T.; (Dewey, OK)
; Platon; Alexandru; (Bartlesville, OK) ; Gong;
Kening; (Bartlesville, OK) ; Lotero; Edgar;
(Cleveland, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Phillips 66 Company |
Houston |
TX |
US |
|
|
Family ID: |
49714403 |
Appl. No.: |
13/914146 |
Filed: |
June 10, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61658512 |
Jun 12, 2012 |
|
|
|
Current U.S.
Class: |
201/2.5 |
Current CPC
Class: |
C10G 1/02 20130101; C10G
1/08 20130101 |
Class at
Publication: |
201/2.5 |
International
Class: |
C10G 1/02 20060101
C10G001/02 |
Claims
1. A process comprising: (a) providing a thermal reactor comprising
at least one auger, and a first mixture comprising a heat carrier
and at least one catalyst; (b) introducing a feedstock comprising
biomass to the thermal reactor and contacting therein with the
first mixture to produce a second mixture, wherein at least a
portion of the feedstock is converted to condensable vapor
intermediates via pyrolysis, wherein the catalyst facilitates the
rate at which the feedstock is converted, wherein rotation of the
at least one auger increases heat transfer from the heat carrier to
the feedstock and increases contact between the feedstock and the
first mixture, (c) conveying the second mixture through the reactor
for a defined residence time prior to removal from the reactor.
2. The process of claim 1, wherein said thermal reactor is
maintained at a pressure in a range from about 50 psig to about 500
psig and a temperature in a range from about 250.degree. C. to
about 1000.degree. C.
3. The process of claim 1, wherein said thermal reactor is
maintained at a pressure in a range from about 15 psig to about 50
psig and a temperature in a range from about 350.degree. C. to
about 700.degree. C.
4. The process of claim 1, wherein upon introducing the feedstock
to the reactor, the feedstock is heated at a rate from about
100.degree. C. per second to about 10,000.degree. C. per
second.
5. The process of claim 1, wherein the first mixture is introduced
at a first location that is proximal to a reactor first end and is
conveyed by the at least one auger to a second location located
downstream, wherein the feedstock is introduced at the second
location and combines with the first mixture to form a second
mixture.
6. The process of claim 1, wherein the feedstock is introduced at a
first location that is proximal to a reactor first end and is
conveyed by the at least one auger to a second location located
downstream, wherein the first mixture is introduced at the second
point and combines with the feedstock to form a second mixture
7. The process of claim 1, wherein the defined residence time is
decreased as a result of step (b)
8. The process of claim 1, wherein the heat carrier and the at
least one catalyst are particulate solids, thereby increasing the
surface area available for direct contact with the feedstock.
9. The process of claim 1, wherein the at least one catalyst
increases the rate of pyrolysis, such that the temperature required
for pyrolysis is lowered, the required residence time of the
feedstock is decreased, or combinations thereof.
10. The process of claim 1, wherein the feedstock is converted in
an atmosphere comprising an inert gas and less than 0.5 mol %
oxygen gas.
11. The process of claim 1, wherein the feedstock is converted to
condensable vapor intermediates in the presence of a reactive gas
selected from a group consisting of hydrogen, synthesis gas (i.e.,
CO +H2), steam/water, ammonia, methane, ethane, propane, butane,
pentane, and natural gas, etc., and any combinations thereof.
12. The process of claim 1, wherein rotation of the at least one
auger increases contact between the heat carrier and the feedstock
to increase the heating rate of the feedstock.
13. The process of claim 1, wherein rotation of the at least one
auger increases contact between the catalyst and the feedstock to
increase the catalytic pyrolysis of the feedstock.
14. The process of claim 1, wherein the at least one catalyst
comprises at least one of Co, Ni, Mo, W, Zn, Ga a zeolite, a
metal-impregnated zeolite, and combinations thereof.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims benefit under 35 USC .sctn.119(e) to U.S. Provisional
Application Ser. No. 61/658,512 filed Jun. 12, 2012, entitled
CATALYTIC PYROLYSIS OF BIOMASS IN AN AUGER REACTOR, which is
incorporated herein in its entirety.
STATEMENT OF FEDERALLY SPONSORED RESEARCH
[0002] None.
FIELD OF THE DISCLOSURE
[0003] The present invention relates generally to pyrolytic
conversion of biomass in the presence of a catalyst and a heat
carrier in a reactor comprising at least one auger.
BACKGROUND
[0004] The Renewable Fuels Standards (RFS) enacted by the US
Government mandate the increased use of renewable energy sources to
reduce emissions of carbon based fuels and provide alternatives to
petroleum based energy and feedstock.
[0005] One of the alternatives being explored is the use of
biomass. Biomass is any carbon containing material derived from
living, or recently-living, organisms. The ability to convert
biomass derived from plants, animals, and industrial waste provides
a direct source for renewable fuels including gasoline, diesel,
oils and other products that can substitute for fuel products
produced from non-renewable fossil fuels.
[0006] Processes to convert renewable resources into transportation
fuels usually involve several steps. One approach is to use acids
to convert carbohydrates, starches, lignins, and other biomass into
sugars such as glucose, lactose, fructose, sucrose, dextrose.
Another approach is to utilize pyrolysis to convert biomass solids
and liquids into pyrolysis oil, or bio-oil.
[0007] Pyrolysis is the chemical decomposition of organic materials
by heating in the absence of oxygen or other reagents. Pyrolysis
can be used to convert biomass into pyrolysis oil (or bio-oil).
Bio-oil is typically produced by heating biomass to a temperature
between 250.degree. C. to 1000.degree. C. in a predominantly inert
atmosphere for a short time. The bio-oil thereby produced contains
molecules derived from the original biomass feedstock, and is
consequently a mixture of primarily oxygenated products. Bio-oil
typically is thermally unstable, acidic, and not miscible with
petroleum feedstocks. Thus, it is normally further processed to
create hydrocarbon products that are fungible with current
petroleum-based fuels.
[0008] A number of methods are known for the pyrolytic conversion
of biomass; however, these conventional methods need to be further
optimized to reduce the overall costs associated with biofuels
production, thereby making the use of these fuels more attractive.
What is needed are methods for converting a biomass-derived
feedstock to biofuels that can reduce cost, increase throughput,
and require less maintenance of process equipment.
BRIEF DESCRIPTION OF THE DISCLOSURE
[0009] The present disclosure provides novel processes for
converting biomass to bio-oil by means of pyrolysis. Certain
embodiments comprise a process for pyrolysis in the presence of a
catalyst, wherein the catalyst may be combined with a heat carrier
in a reactor comprising at least one auger.
[0010] In certain embodiments, the process comprises providing a
thermal reactor containing at least one auger, as well as a first
mixture comprising a heat carrier and at least one catalyst. A
biomass feedstock is introduced to the thermal reactor and conveyed
through the reactor via at least one auger for a defined residence
time prior to removal from the reactor. In certain embodiments, the
at least one auger increases contact between the heat carrier and
the feedstock to increase the heating rate of the feedstock. In
certain embodiments, the rotation of the at least one auger may
increase contact between the catalyst and the feedstock to increase
the catalytic pyrolysis of the feedstock.
[0011] The feedstock contacts the heat carrier and at least one
catalyst to convert at least a portion of the feedstock to
condensable vapor intermediates via pyrolysis. The catalyst
facilitates the rate at which the feedstock is converted, and
rotation of the auger increases heat transfer to the feedstock and
increases contact between the feedstock and the catalyst. In
certain embodiments, the thermal reactor is maintained at a
pressure in a range from about 50 psig to about 500 psig and a
temperature in a range from about 250.degree. C. to about
1000.degree. C. In certain alternative embodiments, the thermal
reactor is maintained at a pressure in a range from about 15 psig
to about 50 psig and a temperature in a range from about
350.degree. C. to about 700.degree. C.
[0012] In certain embodiments, the heat carrier and at least one
catalyst is introduced proximal to a reactor first end and is
conveyed by at least one auger to a point downstream where the
feedstock is introduced to combine with the first mixture to form a
second mixture. Upon introducing the feedstock to the reactor, the
feedstock is heated at a rate from about 100.degree. C. per second
to about 10,000.degree. C. per second.
[0013] Generally, the presence of at least one catalyst increases
the rate of pyrolysis, such that the temperature required for
pyrolysis is lowered, the required residence time of the feedstock
is decreased, or combinations thereof. In certain embodiments, the
atmosphere maintained inside the thermal reactor comprises an inert
gas and less than 0.5 mol % oxygen gas. In certain alternative
embodiments, the atmosphere maintained inside the thermal reactor
comprises a reactive gas selected from a group consisting of
hydrogen, synthesis gas (i.e., CO +H2), steam/water, ammonia,
methane, ethane, propane, butane, pentane, and natural gas, etc.,
and any combinations of these gases. In certain embodiments, the
catalyst comprises at least one of Co, Ni, Mo, W, Zn, Ga a zeolite,
a metal-impregnated zeolite, and combinations of these
catalysts.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1 is a simplified flow-chart representing an embodiment
of the inventive processes disclosed herein.
DETAILED DESCRIPTION
[0015] Pyrolysis is the chemical decomposition of biomass by
heating in the absence of oxygen or other reagents. Intermediates
produced via pyrolysis may be further processed by one or more
refining means for production of renewable hydrocarbon fuels.
Pyrolysis has been studied extensively, and a variety of pyrolysis
processes and conditions are known. Pyrolysis may be conducted at a
variety of temperatures and pressures, in the presence (or absence)
of an inert gaseous atmosphere and may be facilitated by a catalyst
or a heat-carrier.
[0016] The biomass to be pyrolyzed according the methods disclosed
herein may be any type of biomass derived from plants or animals.
The biomass to be utilized as feedstock is selected according to
its pyrolysis characteristics and ash fusion point. Typically,
biomass (or a mixture of biomass derived from different sources)
with an ash fusion point no less than 700.degree. C. is fed into a
pyrolysis reactor after being collected, screened, dried and
crushed. The pyrolysis temperature and reaction time are carefully
controlled to rapidly decompose the reactant by heat to form a gas,
at least a portion of which is condensed to form a liquid
intermediate product comprising pyrolysis oil.
[0017] Examples of biomass feedstock may include, but are not
limited to biomass derived from plants, protists (including
micro-algae and macro algae), and animal biomass. Lignocellulosic
biomass is commonly utilized as a feedstock for production of
biofuels, and may be comprised of cellulose, hemicellulose, and
lignin. Cellulose and hemicellulose are carbohydrate polymers. The
carbohydrate polymers are tightly bound to the lignin.
Lignocellulosic biomass may be grouped into four main categories:
(1) agricultural residues, (2) dedicated energy crops, (3) wood
residues, and (4) municipal solid waste. The agricultural residues
may include, but not limited to, corn stover, wheat straw and
sugarcane bagasse. Many energy crops may also be of interest for
their ability to provide high yields of biomass and may be
harvested multiple times each year. These may include, but not
limited to, poplar trees, switchgrass, and miscanthus giganteus.
The premier energy crop is sugarcane, which is a source of the
readily fermentable sucrose and the lignocellulosic side product
bagasse. The wood residues may include, but are not limited to,
sawmill and paper mill discards.
[0018] In the pyrolysis processes disclosed herein, the feedstock
is rapidly heated to produce one or more volatile gases. In certain
embodiments, the feedstock is heated in a reactor comprising at
least one auger, where the reactor is maintained in a range from
about 250.degree. C. to 1000.degree. C. In certain embodiments, the
feedstock is heated in a reactor maintained in a range from about
350.degree. C. to about 750.degree. C.
[0019] In some embodiments, the feedstock is heated in an
atmosphere comprising an inert gas and in the absence of oxygen.
The inert gas may be, but is not limited to, nitrogen, argon,
helium, or carbon dioxide, or combinations of these gases. In
certain embodiments, the feedstock is heated in an atmosphere
comprising an inert gas and oxygen, where the concentration of
oxygen is in the range from about 0.0 mol % to about 0.5 mol %. In
another embodiment, the gaseous atmosphere may comprise oxygen in
the range from about 0.5 mol % to about 5 mol %.
[0020] Alternatively, the feedstock is heated in the presence of an
atmosphere comprising a one or more gaseous compounds that can
donate hydrogen. These gases may include, but are not limited to,
hydrogen, synthesis gas (i.e., CO +H.sub.2), steam/water, ammonia,
methane, ethane, propane, butane, pentane, and natural gas. Certain
embodiments may combine one of these gases with an inert gas. Not
intending to be bound by theory, it is believed that these various
mixtures may create a reducing atmosphere and quench any unstable
radical species formed during heating of the feedstock. When using
a hydrogen donor compound or hydrocarbon, mass ratios for feedstock
to hydrogen donor compound or hydrocarbon may be in the order of
0.1-to-2.
[0021] One or more catalysts may be utilized for the pyrolysis
reaction to promote hydrogenation/hydrogenolysis reactions. These
catalysts may comprise, but are not limited to, those
conventionally used in hydroprocessing of hydrocarbons, such as,
for example, those comprising metals such as Co, Ni, Mo and W. More
specific examples of catalysts that have been utilized in catalytic
pyrolysis include various zeolites as well as metal-impregnated
zeolites, such as, for example HUSY, REY, HZSM-5, Ni-Mo-HUSY,
Ni-Mo-REY. The catalyst may be placed on any solid material known
to be suitable as a solid catalyst support. In certain embodiments,
the solid support is gamma alumina.
[0022] Additional examples of zeolites suitable for use as
catalysts for the inventive processes disclosed herein include, but
are not limited to, those disclosed in Kirk-Othtmer Encyclopedia of
Chemical Technology, third edition, volume 15, pages 638-669 (John
Wiley & Sons, New York, 1981). Generally, zeolites useful in
the present invention have a constraint index (as defined in U.S.
Pat. No. 4,097,367, which is incorporated herein by reference) in
the range of from about 0.4 to about 12, and preferably in the
range of from about 2 to about 9. In addition, the molar ratio of
SiO.sub.2 to Al.sub.2O.sub.3 in the crystalline framework of the
zeolite is at least about 5:1 and can range up to infinity. In one
embodiment of the present invention, the molar ratio of SiO.sub.2
to Al.sub.2O.sub.3 in the crystalline framework of the zeolite is
in the range of from about 8:1 to about 200:1. In another
embodiment of the present invention, SiO.sub.2 to Al.sub.2O.sub.3
in the crystalline framework of the zeolite is in the range of from
about 12:1 to about 100:1. Zeolites useful in the present invention
include but are not limited to ZSM-5, ZSM-8, ZSM-11, ZSM-12,
ZSM-35, ZSM-38 and combinations thereof. Some of these zeolites are
also known as "MFI" or "Pentasil" zeolites. In one embodiment of
the present invention, the zeolite is ZSM-5. Modified zeolites can
also be used. Modified zeolites can include zeolites modified by
metal cations, such as, for example, zinc, gallium, or nickel.
Zeolites can also be modified by steam treatment and/or acid
treatment. In addition, zeolites of the present invention may be
combined with a clay, promoter, and/or a binder. Zeolites useful in
the present invention may also contain an inorganic binder (also
referred to as matrix material) selected from the group consisting
of alumina, silica, alumina-silica, aluminum phosphate, clays (such
as bentonite), and combinations thereof. The type of zeolite used
will cause the final product to vary considerably.
[0023] The conventional pyrolysis of biomass is often conducted in
fluidized bed reactors. A heated carrier gas is mixed with the
biomass feedstock, and bubbles through the biomass to cause mixing,
thereby facilitating heart transfer through the feedstock. The
methods described herein instead utilize a reactor comprising at
least one mechanical auger (hereby termed "auger reactor") to
mechanically mixing the feedstock (or a mixture of feedstock and a
heat-carrier) to facilitate a high rate of heat transfer to the
feedstock. This requires that only moderate temperatures be
maintained within the reactor to effectively promote pyrolysis of
the feedstock, while also preventing premature devolatilization of
the feedstock. The current disclosure discloses novel processes
that additionally comprise a catalyst to further facilitate
pyrolysis in an auger reactor.
[0024] FIG. 1 provides a general flow diagram for one embodiment of
the inventive process disclosed herein. A first mixture 110
comprising at least one particulate solid catalyst and a
particulate solid heat carrier is heated in an oven, then
introduced near a first end of a reactor 125 comprising at least
one auger 150 (or auger reactor). As the at least one auger
rotates, the first mixture is conveyed through the auger reactor
away from the first end and mechanically mixed to assure even and
rapid heat transfer. At a point downstream from the entry point of
the first mixture, a biomass feedstock 175 is introduced to the
auger reactor at a ratio of heat carrier to feedstock of between
about 1:1 and about 50:1. Rotation of the at least one auger
mechanically mixes the first mixture with the biomass feedstock,
thereby producing a second mixture that is conveyed through the
reactor away from the first end. Mechanically mixing by the auger
also assures even and rapid heat transfer from the heat carrier to
the feedstock. In certain alternative embodiments, the feedstock
may be introduced upstream from the first mixture. In such cases, a
portion of the heating of the feedstock may occur inside the
reactor prior to contacting the first mixture.
[0025] In certain alternative embodiments, the biomass feedstock
and the catalyst may be mixed prior to heating, and then added to a
pre-heated heat carrier. In still other alternative embodiments,
the catalyst may be heated separately from the heat carrier, for
example, to a temperature approximately equal to or less than the
temperature maintained within the reactor, then combined with heat
carrier immediately 1) prior to, 2) after, or 3) simultaneous with
entry into the reactor. Separate heating of the catalyst may
preserve the activity of catalysts having a propensity to sinter at
temperatures higher than those maintained inside the reactor, as
oftentimes the heat carrier in pyrolysis reactions is heated to a
temperature that is from about 150.degree. C. to 300.degree. C.
greater than the reactor temperature.
[0026] In certain embodiments, the conditions maintained within the
auger reactor 125 include a temperature of between about
250.degree. C. and about 1000.degree. C. Preferably, the auger
reactor is maintained at a temperature of between about 350.degree.
C. and about 700.degree. C. Upon introduction to the reactor, the
biomass feedstock is rapidly heated at a rate in the range of about
100.degree. C. sec.sup.-1 to about 10,000.degree. C. sec.sup.-1.
Heating of the biomass feedstock may be performed by heat transfer
from a carrier gas, through direct contact with the rector walls,
through contact with a solid heat carrier (as discussed above).
Pressure within the reactor is generally maintained between about
atmospheric pressure to about 500 psig, and in certain embodiments
is maintained at a pressure of between about 15 psig to about 50
psig. The total residence time of the feedstock within the reactor
is maintained in a range of between about 0.1 sec and about 10 sec.
In certain embodiments, the total residence time within the reactor
is maintained between 1 sec and about 40 sec.
[0027] While not wishing to be bound by theory, the processes
disclosed herein are believed to facilitate rapid and even heating
of the feedstock while also continuously moving the first and
second mixture downstream toward the second end of the reactor,
thereby assuring a constant residence time for the second mixture
within the reactor. The residence time can be adjusted by adjusting
the rotational speed of the at least one auger. An additional
advantage is that as the biomass feedstock enters the pyrolysis
reactor, it always contacts fresh (or freshly regenerated)
catalyst, thus, which allows more efficient catalytic pyrolysis,
thereby and improving the quality of the produced bio-oil, and
decreasing the formation of char and coke. More efficient pyrolysis
enabled by the presence of a catalyst potentially allows a lower
temperature to be maintained in the reactor, a higher throughput of
feedstock by decreasing required residence time, or combinations of
these benefits. Additionally, certain embodiments of the present
disclosure may preserve the activity of catalysts having a
propensity to sinter at temperatures higher than those maintained
inside the reactor. This can be achieved by allowing separate
preheating of the catalyst and the heat carrier. This allows the
catalyst to be pre-heated to a lower temperature than the
temperature to which the heat carrier is pre-heated.
[0028] Additional benefits of the processes disclosed herein
include a decreased requirement for carrier gas (i.e., inert
carrier gas or reactive carrier gas) to be mixed with the feedstock
prior to entering the pyrolysis reactor, because the auger reactor
does not utilize carrier gas as the method of primary heat
transfer. Instead, the auger reactor achieves efficient heat
transfer via constant mechanical mixing via the at least one auger.
The decreased requirement for carrier gas also allows for easier
collection of the liquid intermediate product.
[0029] A heat carrier is often utilized to increase the heating
rate of the feedstock during pyrolysis and thereby reduce the
amount of char formed. Any material capable of absorbing and
transferring heat to a biomass feedstock may be utilized in the
processes disclosed herein. Conventional heat carriers include, for
example silica and granulated metal, such as steel shot, alumina,
magnesium oxide, a zeolite and combinations thereof, although any
other known solid heat carrier material or mixture of heat carrier
materials may be useful.
[0030] Again referring to FIG. 1, upon reaching the second end of
the auger reactor, the heat carrier, catalyst, and any char and ash
remaining after pyrolysis of the biomass are removed from the
reactor and collected 190. The char and ash may then be separated
from the mixture of heat carrier and catalyst by conventional
methods. The char may be further separated and used for combustion,
while the catalyst and (optionally) the heat carrier may be
conveyed to a regeneration reactor (not depicted) for regeneration
of the catalyst at a temperature generally ranging from 400.degree.
C. to 1200.degree. C. in the presence of oxygen, such that any coke
deposits on the catalyst are removed by combustion. In certain
embodiments, the catalyst and the heat carrier may be conveyed to
the regeneration reactor as a mixture. In these embodiments, the
catalyst, or the regenerated mixture of catalyst and heat carrier
is then conveyed to a chamber that is maintained at a temperature
approximately equal to or higher than the temperature inside the
auger reactor. As discussed previously, in alternative embodiments,
fresh catalyst may be pre-heated separately from heat carrier
(usually to a lower temperature) then co-fed to the reactor or
combined with the biomass feedstock and co-fed into the reactor. In
embodiments where the catalyst is relatively inexpensive to obtain
or synthesize, regeneration may not be cost-effective. In these
embodiments, the catalyst and heat carrier may be discarded and
replaced with fresh heat carrier and catalyst. In certain
embodiments, oxygen maybe at least partially replaced (or mostly
replaced) by an inert gas atmosphere prior to returning the
regenerated mixture to the auger reactor.
[0031] The volatile gases created during pyrolysis are conveyed
from the reactor 125, and are rapidly quenched. At least a portion
of the vapors are condensed to generate a mixture of hydrocarbons
and oxygenates 215. The mixture generated by condensation of these
volatile gases is generally termed as bio-oil. In certain
embodiments, the quenching may be carried out at a pressure in the
range from about 1.4 psig to about 100 psig and at a temperature in
a range from about -20.degree. C. to about 80.degree. C.
[0032] Depending on the degree of deoxygenation achieved and the
components of the heating atmosphere, three or four product phases
are obtained, i.e., solid, liquid and gas. The solid phase is
composed mainly of char and used catalyst, if the latter is used.
The gas phase contains mainly carbon oxides and light hydrocarbons.
The liquid phase may be one or two phases. When two phases are
formed, one phase is mainly aqueous with some polar organics
dissolved. The other phase has a lower concentration of water and
is mainly a mixture of organic compounds, such as those named
above. Separation of the organic phase can be carried out by
decantation when two separated liquid phases are obtained. The
recovered gases produced during catalytic pyrolysis can optionally
be used for hydrogen production using conventional technologies as
described in that art.
[0033] The processes disclosed herein result in the production of a
bio-oil (pyrolysis oil), which is a mixed liquid product derived
from biomass pyrolyzed by heating in the absence (or near absence)
of O.sub.2. Bio-oil components vary relative to the composition of
the original biomass. Typically, bio-oil contains molecules derived
from the cellulose, hemicellulose, lignin and other biological
molecules in the biomass feedstock, and is consequently a mixture
of a variety of oxygenated products. The bio-oil comprises a
mixture of several organic compounds, including hydrocarbons, sugar
and derivatives, alcohols or polyols (such as glycerol, sorbitol,
xylitol, for example), esters, alcohols, ketones, aldehydes,
carboxylic acids, phenolics and polymers, along with tars, oils and
water-insoluble solids. Bio-oil is thermally unstable, acidic, and
is not typically miscible with petroleum feedstocks.
[0034] The bio-oil produced by the catalytic pyrolysis processes
described herein may be further processed by one or more refining
means to produce biofuels or hydrocarbons that can be used in
blends with conventional fuels such as gasoline and diesel. The one
or more refining means may include, but are not limited to,
hydro-treating, fluidized catalytic cracking, hydro-cracking and
coking. These are all conventional methods understood by one having
skill in the art. The refining may be carried by any conventional
methods and the scope of the present invention should not be
limited to the examples provided herein.
[0035] The following example is provided by way to better explain
one or more of the various embodiments, and should not be
interpreted as limiting, or defining the scope of the
invention.
Example 1
[0036] Either micro-algal or lignin biomass was dried at 70.degree.
C. for 12 hours, then pyrolyzed with and without zeolite catalyst
in inert (He) atmosphere. Pyrolysis was conducted at 475.degree. C.
pyrolysis temperature, heating rate .about.10,000.degree. C./s and
a 5:1 catalyst ratio (when used). Vapors were analyzed by gas
chromatography/mass spectrometry (GC/MS). Char was measured by
gravimetric difference. All yields are on a mass basis.
[0037] The data (see Tables 1 and 2) show a greater than 60% yield
of condensable vapors from both micro-algal (Table 1) and lignin
(Table 2) biomass in un-catalyzed pyrolysis and 50% or greater
yield during catalyzed pyrolysis. Adding a zeolite catalyst
improved yield of hydrocarbons in the vapor phase, while also
increasing char yield.
TABLE-US-00001 TABLE I Yield of pyrolysis products from dried,
whole microalgae. Yield %, Yield %, Product no catalyst zeolite
catalyst Noncondensable gas* 6 17 Char* 19 28 Condensable vapors*
74 55 Hydrocarbons in vapor** 9 44 *Yield based on total biomass
**Yield based on condensable vapors only
TABLE-US-00002 TABLE II Yield of pyrolysis products using lignin
from corn stover hydrolysate: Yield %, Yield %, Product no catalyst
zeolite catalyst Noncondensable gas* 2 6 Char* 37 44 Condensable
vapors* 61 50 Hydrocarbons in vapor** 3 40 *Yield based on total
biomass **Yield based on condensable vapors only
[0038] As used herein, the term "auger reactor" is defined as any
cylindrical, oval, or frusto-conically shaped reactor comprising at
least one auger, which in turn, comprises a shaft passing axially
therethrough, wherein each shaft is attached to one edge of a
continuous blade having a non-perpendicular angle, or pitch,
relative to the shaft, wherein rotation of the shaft causes the
continuous blade to rotate, such that a material fed into one end
of the reactor is mechanically conveyed through the reactor by the
screw-like movement of at least one blade. Certain embodiments of
an auger reactor may comprise multiple augers, wherein the augers
may act in concert to mechanically mix the material passed through
the reactor.
[0039] In closing, it should be noted that the discussion of any
reference is not an admission that it is prior art to the present
invention, in particular references that have a publication date
after the priority date of this application. The claims listed
below are hereby incorporated into this detailed description or
specification as additional embodiments of the present inventive
disclosure.
[0040] 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 disclosed embodiments and identify other ways to practice the
invention that are not exactly as described herein, but are
equivalent. 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.
REFERENCES
[0041] 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: [0042] 1. U.S. Pat. No.
7,578,927, US Ser. No. 2008/0053870, WO2008/027699, Marker, et al.,
"Gasoline And Diesel Production From Pyrolytic Lignin Produced From
Pyrolysis Of Cellulosic Waste," UOP L.L.C. (2006). [0043] 2. U.S.
Ser. No. 13/274,754, Lotero Alegria, et al., "Hydrocarbons From
Pyrolysis Oil," ConocoPhillips Company (2011). [0044] 3. U.S. Ser.
No. 13/280,982, Gong, et al., "Process For Producing High Quality
Pyrolysis Oil From Biomass," ConocoPhillips Company (2011). [0045]
4. U.S. Ser. No. 61/411,531, Gong, et al., "Heat Integrated Process
For Producing High Quality Pyrolysis Oil From Biomass,"
ConocoPhillips Company (2010). [0046] 5. U.S. Ser. No. 61/427,270,
Gong, et al., "Integrated FCC Biomass Pyrolysis/Upgrading,"
ConocoPhillips Company (2010). [0047] 6. Lu, Changbo, et al.
"Kinetics of Biomass Catalytic Pyrolysis" Biotech Advances 27
(2009) 583-587.
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