U.S. patent application number 13/178578 was filed with the patent office on 2013-01-10 for gasification process.
Invention is credited to Peter M. FRITZ, Ramachandran KRISHNAMURTHY, Satish TAMHANKAR.
Application Number | 20130008772 13/178578 |
Document ID | / |
Family ID | 47437974 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130008772 |
Kind Code |
A1 |
FRITZ; Peter M. ; et
al. |
January 10, 2013 |
GASIFICATION PROCESS
Abstract
A method for converting biomass into syngas by converting the
biomass into a viscous, pumpable pyrolysis liquid and feeding this
liquid into a gasifier. The biomass is first fed to a pyrolysis
unit which will convert the biomass in part to the viscous,
pumpable pyrolysis liquid. This pyrolysis liquid is then fed into a
gasifier either by itself or with a solid carbon-containing
component where it will react to form syngas.
Inventors: |
FRITZ; Peter M.;
(Unterhaching, DE) ; KRISHNAMURTHY; Ramachandran;
(Chestnut Ridge, NY) ; TAMHANKAR; Satish; (Scotch
Plains, NJ) |
Family ID: |
47437974 |
Appl. No.: |
13/178578 |
Filed: |
July 8, 2011 |
Current U.S.
Class: |
201/21 |
Current CPC
Class: |
C10J 3/466 20130101;
Y02E 50/14 20130101; C10J 2300/0976 20130101; Y02E 50/30 20130101;
Y02E 50/32 20130101; C10J 2300/0959 20130101; C10B 53/02 20130101;
Y02E 50/10 20130101; Y02E 20/18 20130101; Y02P 20/145 20151101;
C10J 2300/093 20130101; C10J 2300/0903 20130101; C10J 2300/0916
20130101; C10J 2300/094 20130101; C10J 3/66 20130101; C10J
2300/0943 20130101; C10J 2300/0926 20130101 |
Class at
Publication: |
201/21 |
International
Class: |
C10B 57/04 20060101
C10B057/04 |
Claims
1. A method of gasifying biomass comprising the steps of converting
the biomass into a liquid, adding a solid carbon-containing
component and feeding the combination of liquid biomass and solid
carbon-containing component into a gasifier.
2. The method as claimed in claim 1 wherein said biomass comprises
wood, straw, plant deposits, woodchips, grasses forestry waste,
municipal solid waste, waste water sludge, manure, and waste
fats.
3. The method as claimed in claim 1 wherein biomass is converted
into liquid in a pyrolysis unit
4. The method as claimed in claim 1 wherein said liquid is
pyrolysis liquid.
5. The method as claimed in claim 3 wherein said pyrolysis unit
further yields char and gas.
6. The method as claimed in claim 1 wherein syngas is recovered
from said gasifier.
7. The method as claimed in claim 4 said pyrolysis liquid is
purified prior to being fed into said gasifier.
8. The method as claimed in claim 1 wherein char is recovered from
said gasifier.
9. The method as claimed in claim 1 wherein the combination of
liquid biomass and solid carbon-containing component remains
pumpable.
10. A method of gasifying biomass comprising the steps of
converting the biomass into a liquid and feeding the liquid into a
gasifier.
11. The method as claimed in claim 9 wherein said biomass comprises
wood, straw, plant deposits, woodchips, grasses forestry waste,
municipal solid waste, waste water sludge, manure, and waste
fats.
12. The method as claimed in claim 9 wherein biomass is converted
into liquid in a pyrolysis unit.
13. The method as claimed in claim 9 wherein said liquid is
pyrolysis liquid.
14. The method as claimed in claim 11 wherein said pyrolysis unit
further yields char and gas.
15. The method as claimed in claim 9 wherein syngas is recovered
from said gasifier.
16. The method as claimed in claim 9 said pyrolysis liquid is
purified prior to being fed into said gasifier.
17. The method as claimed in claim 9 wherein solid
carbon-containing components are mixed with said liquid.
18. The method as claimed in claim 9 wherein char is recovered from
said gasifier.
19. The method as claimed in claim 9 wherein said pyrolysis liquid
remains pumpable.
20. A method for producing syngas comprising the steps of
converting biomass into a liquid, gasifying the liquid and
recovering syngas.
21. The method as claimed in claim 19 wherein said biomass
comprises wood, straw, plant deposits, woodchips, grasses forestry
waste, municipal solid waste, waste water sludge, manure, and waste
fats.
22. The method as claimed in claim 19 wherein biomass is converted
into liquid in a pyrolysis unit.
23. The method as claimed in claim 19 wherein said liquid is
pyrolysis liquid.
24. The method as claimed in claim 22 wherein said pyrolysis unit
further yields char and gas.
25. The method as claimed in claim 19 said pyrolysis liquid is
purified prior to being fed into said gasifier.
26. The method as claimed in claim 19 wherein solid
carbon-containing components are mixed with said liquid.
27. The method as claimed in claim 19 wherein char is recovered
from said gasifier.
28. The method as claimed in claim 19 wherein said pyrolysis liquid
remains pumpable.
Description
BACKGROUND OF THE INVENTION
[0001] The invention provides for methods for using biomass to
produce syngas or other chemical compounds in an efficient and
environmentally friendly manner. The biomass is first converted
into a liquid which is fed to a gasifier by itself or with a solid
carbon-containing component which will convert the liquid into the
syngas which can be recovered or further processed into additional
chemical compounds.
[0002] With the desire to minimize dependence on coal, oil and gas,
and to reduce the emission of carbon dioxide has arisen the
consideration of biomasses for conversion into oil-based products.
Biomass is typically wood, straw, plant deposits, woodchips,
grasses and byproducts of farming and furniture manufacturing
operations and other organic compounds. It is proving desirable to
convert these biomass sources into oil-based products such as
petrol, diesel, chemicals and plastics through the intermediate
step of forming syngas (hydrogen and carbon monoxide).
[0003] A significant number of industrial and agricultural
processes generate biomass, waste and by-products that contain
polymeric sugars such as starch, cellulose and hemicellulose. The
conversion of these biomasses into materials of higher value is of
great interest to industry today. The use of biomass as a sole
feedstock has certain disadvantages though. For example, biomass
must be put into bales and loaded onto skids where it will be moved
by truck or rail lines. These bales are heavy and are consequently
expensive to move. Alternatively, a liquefied version of biomass
such as biooil has a greater amount of stored energy than biomass
and can be stored and transported in drums or tanks which are
easier and more economical to transport than traditional methods of
moving biomass.
[0004] Biomasses such as wood, straw and plant deposits can be
converted into oil-based products such as petrol, diesel, chemicals
and plastics through the formation of syngas by use of a gasifier.
Syngas which is primarily carbon monoxide and hydrogen also
contains some impurities. Gasification is a well-known technology
where hydrocarbon bonds are broken down to produce syngas, under
the addition of oxygen and stream, preferably under high pressures
and temperatures. The amount of air or oxygen inside the gasifier
is controlled so that the hydrocarbons do not combust into carbon
dioxide but only oxidizes partially.
[0005] One obstacle to obtain the full benefit from gasification of
biomass compared to for example coal is how to pre-treat the
biomass in a way that makes it suitable to be economically
gasified. Syngas production from coal gasification is a long
standing commercially available technology. Coal is relatively easy
to grind and feed into a pressurized gasifier; biomass in general
is often difficult to grind and be fed into a pressurized gasifier.
This is partially due to biomass being inhomogeneous compared to
coal and is difficult to grind down to a relatively homogeneous
particle size required for entrained flow gasification where the
residence time is very short. Furthermore, it is also difficult to
pressurize a solid material with very uneven and larger particles
size.
[0006] Traditionally, biomass to be fed into a gasifier has been
pretreated using such methods as direct pulverization, combustion
and pulverization, production of charred sludge through flash
pyrolysis or production of gaseous fuels through low temperature
fluid-bed gasification. Previous methods include pneumatically or
by means of screw conveyors injecting biomass as a fine solid
powder into a gasification reactor. This process requires grinding
and drying steps. Since gasifiers are typically large units, there
needs to be substantial on site preparation of the biomass to
accommodate this option. All these processes add to the cost of
using biomass but have difficulties in that specialized equipment
now needs to accompany the gasification process which might not
always be readily accomplished.
[0007] The mixture of the liquefied biomass and solid
carbon-containing component is easier to feed to a gasifier than
pure biomass. The combination of the liquefied biomass and solid
carbon-containing component contains more energy than the liquefied
biomass by itself. The use of the liquefied biomass and solid
carbon-containing component allows for high pressure operations at
the gasifier and results in downstream savings as additional
compression equipment will not be required to raise the pressure of
the gasified product for further downstream processing or feeding
to designated storage units.
[0008] The present inventors have discovered a new method whereby
biomass is introduced into a gasifier either by itself or with a
solid carbon-containing component. The biomass is first converted
into a liquid (pyrolysis liquid or biooil) which can then be added
to the gasifier as a pumpable slurry allowing for the conversion of
the biomass into syngas without the necessity of grinding,
pulverization or other mechanical treatments.
SUMMARY OF THE INVENTION
[0009] The invention provides for a method of gasifying biomass
comprising the steps of converting the biomass into a liquid,
adding a solid carbon-containing component and feeding the
combination of liquid biomass and solid carbon-containing component
into a gasifier.
[0010] The invention further provides for a method of gasifying
biomass comprising the steps of converting the biomass into a
liquid and feeding the liquid into a gasifier.
[0011] Alternatively the invention provides for a method for
producing syngas comprising the steps of converting biomass into a
liquid, gasifying the liquid and recovering syngas.
[0012] The gasification process can be used to produce other syngas
based chemicals through for example the Fischer-Tropsch reaction or
integrated gasification combined cycle (IGCC) or the gasification
products can be used for power generation purposes. These chemicals
can include hydrogen, carbon monoxide, hydrogen/carbon monoxide
mixtures, methanol, ammonia, and synthetic natural gas (SNG).
[0013] The biomass for purposes of the invention comprises wood,
straw, plant deposits, woodchips, grasses forestry waste, municipal
solid waste, waste water sludge, manure, waste fats and byproducts
of farming, furniture manufacturing operations or other industrial
process where organic plant stuff is a by-product or waste. The
biomass is first fed to a pyrolysis unit where it is subjected to
high temperatures for short durations of time. These rapid
pyrolysis reactions are typically performed at temperatures greater
than 400.degree. C. and near atmospheric pressures in a relatively
oxygen-free atmosphere in the presence or absence of a catalyst and
also in the presence or absence of hydrogen.
[0014] The resulting reactions will form a mixture of gas, char and
a liquid (biooil or pyrolysis oil) where the liquid portion is
about 70% of the biomass converted.
[0015] In a different embodiment, the liquid portion of the
converted biomass can be combined with one or more fuel stocks such
as coal, biomass, biocoke, coke or other solid carbon-containing
component for purposes of the invention which has greater carbon
(fuel) content than the converted biomass liquid. The solid
carbon-containing component can be added in any amount to the mass
of the biomass liquid as long as the appropriate viscosity is
maintained such that the resulting slurry can be readily fed to the
gasifier.
[0016] As an optional step, the liquid can be purified by processes
such as vacuum distillation or phase separation prior to it being
fed to the gasifier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The FIGURE is a schematic of the gasification process of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The FIGURE is a schematic of the operation of the invention.
Biomass which is selected from the group consisting of wood, straw,
plant deposits, woodchips, grasses forestry waste, municipal solid
waste, waste water sludge, manure, waste fats and byproducts of
farming, furniture manufacturing operations or other industrial
process where organic plant stuff is a by-product or waste is fed
through line 1 to a pyrolysis unit A. The biomass may be treated
beforehand to a shredder/crusher (not shown) in order to allow for
easier feeding into the pyrolysis unit A. In the pyrolysis unit A,
fast or rapid pyrolytic reactions are performed on the biomass at
temperatures greater than 400.degree. C. and at near atmospheric
pressures in an atmosphere that is low in oxygen content. A
catalyst may or may not be presence in the pyrolysis unit A and
hydrogen may or may not be present in the pyrolysis unit A
either.
[0019] The by-products of the pyrolytic reaction will exit the
pyrolysis unit as char through line 2 and as a gas through line 3.
The pyrolysis liquid which is about 70% of the mass of the biomass
will exit the pyrolysis unit A through line 4 where it will be fed
to an optional purification unit B such as vacuum distillation,
phase separation operations or other known separation
processes.
[0020] The purified pyrolysis liquid will exit the purification
unit B through line 5 and enter the gasifier C. Additional carbon
fuel stock compounds such as coal, biomass, biocoke, coke ("solid
carbon-containing component") may be added to the gasifier C
through line 6 which connects to line 5 prior to entering the
gasifier C. The only caveat with regards to the addition of the
solid carbon-containing component is that the pyrolysis liquid
remains viscous enough to be pumpable into the gasifier C.
[0021] In the gasifier C, the pyrolysis liquid will be reacted at
high temperature in the presence of a controlled amount of oxygen
and/or steam. The resulting gas mixture is syngas or a mixture of
carbon monoxide and hydrogen. The syngas can be removed from the
gasifier C through line 7. Reaction by-products such as char can be
removed through line 8 and in some instances can be recycled to
line 6 for reentry into the gasifier C.
[0022] While this invention has been described with respect to
particular embodiments thereof, it is apparent that numerous other
forms and modifications of the invention will be obvious to those
skilled in the art. The appended claims in this invention generally
should be construed to cover all such obvious forms and
modifications which are within the true spirit and scope of the
invention.
* * * * *