U.S. patent application number 14/140766 was filed with the patent office on 2015-07-02 for biomass bio oil upgrade method.
The applicant listed for this patent is Mahesh Talwar. Invention is credited to Mahesh Talwar.
Application Number | 20150184098 14/140766 |
Document ID | / |
Family ID | 53481033 |
Filed Date | 2015-07-02 |
United States Patent
Application |
20150184098 |
Kind Code |
A1 |
Talwar; Mahesh |
July 2, 2015 |
Biomass Bio Oil Upgrade Method
Abstract
A bio oil pyrolysis and conditioning system produces a useful
fuel oil. The pyrolysis system includes an auger carrying biomass
feed material though an oxygen rare pyrolysis chamber. Vapor phase
bio oil is collected at three locations along the length of the
pyrolysis chamber and carried from the pyrolysis chamber to
condensers and quenched by a water spray before release into the
condensers. The water also serving as a solvent to reduce pH in the
liquid phase raw bio oil. The raw bio oil is carried to a
conditioning system where the raw bio oil resides in a separation
tank where the water separates and is removed producing refined bio
oil. Ethanol is mixed with the refined bio oil to provide the fuel
oil.
Inventors: |
Talwar; Mahesh; (Somis,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Talwar; Mahesh |
Somis |
CA |
US |
|
|
Family ID: |
53481033 |
Appl. No.: |
14/140766 |
Filed: |
December 26, 2013 |
Current U.S.
Class: |
44/307 |
Current CPC
Class: |
C10B 47/44 20130101;
C10L 2290/06 20130101; C10L 2290/02 20130101; Y02E 50/10 20130101;
Y02P 20/145 20151101; C10L 2290/52 20130101; C10L 2290/54 20130101;
Y02E 50/14 20130101; C10B 53/02 20130101; C10L 1/02 20130101; Y02E
50/32 20130101; C10K 1/06 20130101; Y02E 50/30 20130101; C10L
2290/50 20130101; C10B 57/02 20130101 |
International
Class: |
C10L 1/18 20060101
C10L001/18 |
Claims
1. A method for producing a useful bio oil material, the method
comprising: feeding biomass into a pyrolysis chamber; heating the
biomass to create vapor phase bio oil; carrying the vapor phase bio
oil to a condenser; condensing the bio oil vapor into liquid phase
raw bio oil in the condenser; separating water from the raw bio oil
in a separator to produce refined bio oil; and processing the
refined bio oil into a useful material.
2. The method of claim 1, further including quenching the vapor
phase bio oil before releasing the vapor phase bio oil into the
condenser.
3. The method of claim 2, wherein quenching comprises spraying
water into the vapor phase bio oil before releasing the vapor phase
bio oil into the condenser.
4. The method of claim 3, wherein spraying the water into the vapor
phase bio oil comprises spraying the water into the vapor phase bio
oil, resulting in the raw bio oil including 40 to 50 percent of the
water by volume and 50 to 60 percent liquid phase bio oil by
volume.
5. The method of claim 1, wherein: the condenser is a double wall
condenser; and further including providing a coolant flow between
the double walls of the condenser to cool the vapor phase bio oil
flowing through the center of the condenser.
6. The method of claim 5, wherein providing a coolant flow between
the double walls of the condenser comprises providing a flow of
cool water between the double walls of the condenser
7. The method of claim 1, wherein processing the refined bio oil
into a useful material comprises mixing the refined bio oil with
ethanol to produce a fuel oil.
8. The method of claim 7, wherein mixing the refined bio oil with
ethanol to produce a fuel oil comprises mixing one part of the
refined bio oil with at least 0.2 parts of the ethanol.
9. The method of claim 7, wherein mixing the refined bio oil with
ethanol to produce a fuel oil comprises mixing one part refined bio
oil with about 0.2 parts ethanol.
10. The method of claim 1, wherein feeding biomass comprises
feeding dry sawdust.
11. The method of claim 1, wherein feeding biomass into a pyrolysis
chamber comprises feeding biomass into an oxygen rare pyrolysis
chamber.
13. The method of claim 1, wherein; the pyrolysis chamber comprises
at least three zones: a first zone nearest to the entry of the
biomass feed material; a second zone in the middle; and a third
zone opposite to the first zone; and the method further including:
collecting vapor phase bio oil in collectors residing in each zone;
and carrying the collected vapor phase bio oil independently from
each collector to corresponding condensers.
14. A method for producing fuel oil from biomass material, the
method comprising: feeding biomass material into an oxygen rare
pyrolysis chamber, the pyrolysis chamber comprises at least three
zones: a first zone nearest to the entry of the biomass feed
material; a second zone in the middle; and a third zone opposite to
the first zone; heating the biomass material to create vapor phase
bio oil; collecting vapor phase bio oil in collectors residing in
each zone; and carrying the collected vapor phase bio oil
independently from each collector to corresponding condensers;
quenching the vapor phase bio oil before releasing the vapor phase
bio oil into the condensers; condensing the vapor phase bio oil
into liquid phase raw bio oil in the condensers; releasing the
liquid phase raw bio oil into a separation tank; removing water
from the liquid phase raw bio oil to produce refined bio oil;
carrying the refined bio oil into a mixing tank; mixing an amount
of ethanol of at least 20 percent by volume of the refined bio oil
with the refined bio oil to produce fuel oil; and releasing fuel
oil from the mixing tank.
15. A method for producing fuel oil from biomass material, the
method comprising: feeding dry sawdust into an oxygen rare
pyrolysis chamber; heating the dry sawdust to create vapor phase
bio oil; carrying the vapor phase bio oil to a condenser; quenching
the vapor phase bio oil with water before releasing the vapor phase
bio oil into the condenser; condensing the bio oil vapor into
liquid phase raw bio oil in the condenser; carrying the liquid
phase raw bio oil into a separation tank; removing water from the
liquid phase raw bio oil to produce refined bio oil in the
separation tank; carrying the refined bio oil from the separation
tank into a mixing tank; mixing one part of the refined bio oil
with about 0.2 parts ethanol to produce fuel oil; and releasing
fuel oil from the mixing tank.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to biomass bio oil and in
particular to a method for converting biomass feed material into a
useful fuel oil.
[0002] Biomass is comprised mainly of cellulose, hemi cellulose and
lignin. A typical woody biomass may contain 40-50% cellulose,
25-35% hemi cellulose, and 15-18% lignin. Typical yields from a
slow pyrolysis machine are 30% charcoal containing 70% plus carbon,
35% non-condensable gases containing hydrogen, methane, carbon mono
oxide, carbon dioxide primarily, and 35% pyrolysis oil, also known
as bio oil or bio crude, consisting tar, aldehydes, formic acid,
acetic acid, water, esters, phenols, sugar derivatives, lignins.
Such typical slow pyrolysis machine yields oil and charcoal in
nearly equal portions. Slow pyrolysis involves heating of dried
biomass (<8% moisture) in an oxygen free environment at 450-500
degrees centigrade in heated auger tubes. The process involves
thermo chemical conversion of solid biomass to a liquid product,
bio oil, and solid material, charcoal. Non condensable gases are
utilized to heat the incoming wet biomass material, thus creating a
closed loop system.
[0003] Convention slow pyrolysis process yields bio oil that has
the following properties:
[0004] Chemical formula: CH.sub.1.3O.sub.0.47
[0005] Flash point: 80 deg C.
[0006] pH=2.5
[0007] Sp Cr.=1.2
[0008] Moisture content: 20-25%
[0009] Heating value=7,522 btu/lb (17.5 mj/kg)
[0010] Viscosity=60-100 cp and
[0011] Elemental Analysis:
[0012] C=55-60%
[0013] H=5-8%
[0014] O=28-40%
[0015] N=0.06%
[0016] Unfortunately, there are several issues with the use of such
bio oil as a heating oil. The bio oil has a very low pH. Formation
of acetic acid and formic acid during the pyrolysis process
(derived mainly from the hemi cellulose portion of the wood) are
the cause of low and highly acidic pH which makes it difficult to
use this fuel with carbon steel, aluminum and natural rubber due to
corrosion issues. To avoid corrosion issues, pH of the fuel should
be close to neutral 7. The viscosity of bio oil can be as high as
100 cp and as a result can cause issues with the spray nozzles,
fuel pumps, and other fuel handling equipment. Very heavy fuel oil
such as Bunker C can have very high viscosity, however, upon
heating; the viscosity of heavy petroleum fuels goes down to
acceptable levels. Heating of bio oil leads to polymerization and
hardening of fuel, thus making the problem worse. Additionally, the
bio oil is immiscible with all petroleum fuels, so it cannot be
mixed with other low viscosity fuel oils to lower its viscosity
either. Over time, the bio oil starts to degrade due to the
polymerization reactions. It becomes more viscous and water starts
to separate out. This phenomenon can happen in as little as 30
days. Viscosity can increase tenfold at times. Heating value of bio
oil is approximately 45% of that of fuel oil due to the presence of
high levels of oxygen and water.
[0017] Other attempted uses of bio oil include utilization as a
substitute for road asphalt, also known as hot mix asphalt. Asphalt
is currently derived from petroleum sources. Road asphalt may
contain certain additives to prevent cracking, providing
elasticity, and increased weather resistance. Raw bio oil, when
heated, would indeed polymerize and harden; however, it still does
not harden enough for use as road asphalt. Asphalt application for
road requires that the asphalt harden within 24 hours to resume
traffic, bio oil's utilization as asphalt does not contain this
quick hardening property
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention addresses the above and other needs by
providing a bio oil pyrolysis and conditioning system which
produces a useful fuel oil. The pyrolysis system includes an auger
carrying feed material though a oxygen rare pyrolysis chamber.
Vapors are carried from the pyrolysis chamber to condensers and pH
is reduced using a solvent and condensed raw bio oil is drained
into storage tanks. The raw bio oil is provided to the conditioning
system where further oil/water separation is performed to produce
refined bio oil. Ethanol is mixed with the refined bio oil to
provide the fuel oil.
[0019] In accordance with one aspect of the invention, there is
provided a pyrolysis system including quenching of bio oil in vapor
phase. Longer residence times of vapors from a pyrolysis chamber in
the presence of charcoal tend to increase tar formation. To reduce
such tar formation, vapors coming from the pyrolysis chamber are
quickly quenched by a spray of cooling water. Other oils, for
example, bio diesel or the pyrolysis oil itself, may be used as a
cooling medium, however, the use of water is beneficial for the
following step explained below. Reduction in tar formation helps
keep the viscosity of the bio oil lower and prevents clogging of
the lines and equipment from tar formation.
[0020] In accordance with another aspect of the invention, bio oil
pH is reduced by removing water soluble formic and acetic acids
from the bio oil using water as a solvent. Experiments with varying
amounts of water found that water addition in the amount of 40-50
percent in the liquid phase bio oil by volume results in the
formation of two district phases, an aqueous phase and an oil
phase, with the aqueous phase floating to the top. Additionally,
the aqueous phase pulls the water soluble acidic constituents of
raw bio oil resulting in a refined bio oil. The aqueous phase is
drained providing the refined bio oil for further processing. The
pH of the aqueous phase is generally about 2.5, while the pH of the
refined bio oil is generally about 6.2. The water added during the
quenching process thus provides two advantages: a) better contact
of water and oil and b) a cooling medium at the same time.
[0021] In accordance with yet another aspect of the invention, the
bio oil is mixed with at least 20% ethanol (i.e., one part bio oil
and at least 0.2 parts ethanol) and preferably the bio oil is mixed
with at about 20% ethanol. Bio oil is soluble in ethanol. Viscosity
of bio oil obtained from mixing of ethanol is reduced to 4-5 cp
which makes it very comparable to that of fuel oil. The bio oil can
now be used as fuel without heating. Methanol may be used, but
ethanol is renewable and has a higher heating value of compared to
methanol. Additionally, stability of bio oil was enhanced with the
addition of ethanol. Ethanol also has a higher flash point compared
to methanol and is therefore easier and safer to handle. Due to the
solvent nature of ethanol, no water separation has been observed
and the bio oil remains in homogeneous phase with no increase in
viscosity for the observation period of six months. Additional of
ethanol also helps as an ignition improver. Ethanol also helps
improve clogging in lines and keeps the storage and contact
surfaces clean.
[0022] In accordance with still another aspect of the invention,
the heating value of the bio oil is increased from 17.5 kj/kg to
22.5-25 kj/kg, thus making the bio oil closer to petroleum fuel
oils and a viable fuel.
[0023] In accordance with another aspect of the invention, a
combination of quench, water extraction, ethanol addition resulted
in fuel that has higher pH, more stable, extremely low viscosity,
stable and useable as a heating fuel (closer to #4 fuel oil)
without needing any external heating. The heating value of bio oil
unexpectedly increased about 25%, providing a commercial viability
bio oil.
[0024] In accordance with yet another aspect of the invention,
there is provided a substitute for road asphalt, also known as hot
mix asphalt. Currently, asphalt is derived from petroleum sources.
Road asphalt may contain certain additives to prevent cracking,
providing elasticity, and increased weather resistance. There are
several issues with the use of Raw Bio Oil: Raw bio oil when heated
would indeed polymerize and harden; however, it still does not
harden enough for use as road asphalt. Asphalt application for road
also require that the asphalt harden within 24 hours to resume
traffic, bio oil's utilization as asphalt does not contain this
quick hardening property. The substitute for road asphalt is
obtained using refined bio oil, which is essentially devoid of
acidic components to reduce pH, mixed with an equal or greater
amount of petroleum asphalt. Such a mixture unexpectedly hardens
and behaves like a standard asphalt. Greater amounts of petroleum
asphalt may be used if desired. A secondary benefit is that using
of raw bio oil as a road asphalt ingredient also imparted a shiny
glow to the surface which improves appearance.
[0025] In accordance with another aspect of the invention, there is
provided a method for processing bio mass. The method includes
feeding biomass material into an oxygen rare pyrolysis chamber,
heating the biomass material to create vapor phase bio oil,
carrying vapor phase bio oil from the pyrolysis chamber to a
condenser, quenching the vapor phase bio oil before releasing into
the condenser, cooling the vapor phase bio oil in the condenser,
condensing the vapor phase bio oil into liquid phase raw bio oil in
the condenser, separating water from the raw bio oil to produce
refined bio oil, and mixing ethanol with the refined bio oil to
produce a fuel oil.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0026] The above and other aspects, features and advantages of the
present invention will be more apparent from the following more
particular description thereof, presented in conjunction with the
following drawings wherein:
[0027] FIG. 1 is a pyrolysis system for producing bio oil according
to the present invention.
[0028] FIG. 2 is a bio oil conditioning system according to the
present invention.
[0029] FIG. 3 is a method according to the present invention.
[0030] Corresponding reference characters indicate corresponding
components throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The following description is of the best mode presently
contemplated for carrying out the invention. This description is
not to be taken in a limiting sense, but is made merely for the
purpose of describing one or more preferred embodiments of the
invention. The scope of the invention should be determined with
reference to the claims.
[0032] A pyrolysis system 10 for producing bio oil according to the
present invention is shown in FIG. 1. The pyrolysis system 10
primarily includes a pyrolysis chamber 12 and condensers 38a, 38b,
and 38c. An auger 16 residing in an auger housing 14 extends
through the length of the pyrolysis chamber 12 and is rotated by a
motor 18. Biomass feed material 20, for example dry sawdust, is fed
through an entry 21 into the auger housing 14 at one end of the
pyrolysis chamber 12 and charcoal material 22 is released from the
auger housing 14 through a chute 23 at an opposite end of the
pyrolysis chamber 12. The interior of the pyrolysis chamber 12 is
substantially oxygen free and at a high temperature, causing the
biomass feed material 20 to release vapors phase bio oil into the
interior of the pyrolysis chamber 12. A hot air tube 24 runs
through the pyrolysis chamber 12 above the auger housing 14
carrying ambient air 28 heated and pumped by heater 26 and released
on the opposite end of the pyrolysis chamber 12. The exhaust 30
from the hot air tube 24 is directed to dry incoming biomass
material 20.
[0033] The vapor phase bio oil generated in the pyrolysis chamber
12 is collected in the collectors 38a, 38b, and 38c and vapor flows
36a, 36b, and 36c respectively are carried to double wall
condensers 38. The collectors 38a, 38b, and 38c receive the vapor
phase bio oil from three zones of the pyrolysis chamber 12. A first
zone, zone Z1, is approximately the first third of the pyrolysis
chamber 12 length which will allow the collection of mostly
moisture vaporized along with some very light ends. A second zone,
zone Z2, is approximately the second third of the pyrolysis chamber
12 length to collect light vapors and acid constituents vapors
along with the reaction water. A third zone, zone Z3, is
approximately the last third of the pyrolysis chamber 12 length to
collect heavier vapors, for example, vapor phase tar. The multiple
collectors 38a, 38b, and 38c allow product segregation from light
to heavy ends in addition to keeping the water content of light and
heavy liquid products low. Additionally, the multiple collectors
38a, 38b, and 38c allow for heavy liquid to have pH closer to 6
rather than 2.5. The light liquid will have pH of 2.5 but the
absence of tar in that allows lowering of pH by conventional means,
such as addition of alkali.
[0034] Temperature indicators 34 monitor the temperature of the
vapor flows 36. Quench water 40 is introduced into the vapor phase
bio oil flows 36a, 36b, and 36c through valves V1 before the vapors
enter the condensers 38a, 38b, and 38c, and cooling water 42 is
provided between the double walls 39 of the condensers 38a, 38b,
and 38c to cool the vapor phase bio oil flows 36a, 36b, and 36c
passing through the centers of the double wall condensers 38a, 38b,
and 38c, the cooling water 42 exits the condensers 38a, 38b, and
38c as flows 32. The amounts of quench water 40 is controlled to
obtain desired properties of a liquid phase bio oil 50a and 50.
Quench water 40 also acts as solvent to extract acidic components
from the liquid phase bio oil 50a and 50 which makes the bio oil
more transportable and stable.
[0035] The amounts of quench water 40 provided is preferably
determined by the biomass feed material 20 feed rate into the
pyrolysis chamber 12. The rate which the biomass feed material 20
is fed into the pyrolysis chamber 12 is monitored and an expected
production of refined bio oil 86 is calculated. The refined bio oil
86 production is generally about 35 percent by weight of the
biomass feed material 20. The rate of providing the quench water 40
is preferably controlled to result in a mixture 40 to 50 percent by
volume of the quench water 40 and 50 to 60 percent by volume of bio
oil in the raw bio oil 50.
[0036] Condensed bio oil 50a drains from the condensers 38a, 38b,
and 38c into storage tanks 48. Condensed water 44 collected between
the condensers 38a, 38b, and 38c and the storage tanks 48, and
condensed water 44a from storage tanks 48, is carried to a water
Knock Out (KO) drum 46. Raw bio oil 50a is released from the
storage tanks 48 through second valves V2.
[0037] FIG. 2 is a bio oil fuel conditioning system 60 according to
the present invention. The bio oil fuel conditioning system 60
includes an oil/water separator 62 which receives the raw bio oil
50 from the storage tanks 48 and separates water from the raw bio
oil 50 to produce refined bio oil 86. The water 66 is transferred
to a pH balance tank 64 which also receives a pH control additive
68 to produce pH balanced water. The pH balanced water 70. The pH
balance water 70 is pumped by pump 72 from the pH balance tank 64
through a filter 76 to produces filtered water 78, and through a
cooler 80 to produce cooled water 82, and to a cooled water supply.
Optionally, additional water 51 may be added to the oil/water
separator 62 if necessary as a solvent.
[0038] Separated refined bio oil 86 is carried to a mixing tank 84
where ethanol 88 is mixed with the refined bio oil 86 to create a
useful fuel oil 90. An amount of ethanol 88 equal to at least 20
percent by volume of the refined bio oil 86, is mixed with the
refined bio oil 86 to produce a useful fuel oil.
[0039] A method for processing biomass according to the present
invention is shown in FIG. 3. The method includes feeding biomass
material into an oxygen rare pyrolysis chamber at step 100, heating
the biomass material to create vapor phase bio oil at step 102,
carrying vapor phase bio oil from the pyrolysis chamber to a
condenser at step 104, quenching the vapor phase bio oil before
releasing into the condenser at step 106, cooling the vapor phase
bio oil in the condenser at step 108, condensing the vapor phase
bio oil into liquid phase raw bio oil in the condenser at step 110,
separating water from the raw bio oil to produce refined bio oil at
step 112, and mixing ethanol with the refined bio oil to produce a
fuel oil at step 114.
[0040] While the invention herein disclosed has been described by
means of specific embodiments and applications thereof, numerous
modifications and variations could be made thereto by those skilled
in the art without departing from the scope of the invention set
forth in the claims.
* * * * *