U.S. patent application number 13/177086 was filed with the patent office on 2012-07-05 for pyrolysis oil based fuel and method of production.
This patent application is currently assigned to NEW GENERATION BIOFUELS HOLDINGS, INC.. Invention is credited to Andrea FESTUCCIA.
Application Number | 20120167451 13/177086 |
Document ID | / |
Family ID | 44546291 |
Filed Date | 2012-07-05 |
United States Patent
Application |
20120167451 |
Kind Code |
A1 |
FESTUCCIA; Andrea |
July 5, 2012 |
PYROLYSIS OIL BASED FUEL AND METHOD OF PRODUCTION
Abstract
Fuel composition and methods of making fuel compositions
including 50-90 wt % pyrolysis oil, 0.1-40 wt % water, 1-30 wt %
alcohol, and 0.1-4 wt % surfactant, wherein the composition is an
emulsion. The pyrolysis oil may be a crude pyrolysis oil and may be
produced by pyrolysis of biomass material. The pyrolysis oil and
surfactant may form the continuous phase and the water and alcohol
may form the dispersed phase of the emulsion. Alternatively, the
water and alcohol may form the continuous phase and the pyrolysis
oil and surfactant may form the dispersed phase of the
emulsion.
Inventors: |
FESTUCCIA; Andrea; (Rome,
IT) |
Assignee: |
NEW GENERATION BIOFUELS HOLDINGS,
INC.
Lake Worth
FL
|
Family ID: |
44546291 |
Appl. No.: |
13/177086 |
Filed: |
July 6, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61361771 |
Jul 6, 2010 |
|
|
|
Current U.S.
Class: |
44/307 |
Current CPC
Class: |
Y02P 30/20 20151101;
C10L 1/1826 20130101; C10L 1/224 20130101; C10L 1/1963 20130101;
C10L 1/02 20130101; C10G 2300/1055 20130101; C10L 1/191 20130101;
C10G 2300/44 20130101; C10L 1/1985 20130101; C10L 1/026 20130101;
C10L 1/1691 20130101; C10L 1/1817 20130101; C10G 2300/1014
20130101; C10L 1/328 20130101; C10L 1/1824 20130101; C10G 2300/805
20130101 |
Class at
Publication: |
44/307 |
International
Class: |
C10L 1/182 20060101
C10L001/182 |
Claims
1. A fuel composition comprising: 50-90 wt % pyrolysis oil; 0.1-40
wt % water; 1-30 wt % alcohol; and 0.1-4 wt % surfactant; wherein
the composition is an emulsion.
2. The composition of claim 1 wherein the pyrolysis oil comprises
crude pyrolysis oil.
3. The composition of claim 1 wherein the pyrolysis oil is produced
by pyrolysis of biomass material.
4. The composition of claim 3 wherein the biomass comprises
wood.
5. The composition of claim 1 wherein the alcohol comprises one or
more polyalcohols or glycols.
6. The composition of claim 1 wherein the alcohol comprises
propylene glycol or ethylene glycol.
7. The composition of claim 1 wherein surfactant comprises a
non-ionic polymeric surfactant.
8. The composition of claim 7 wherein the surfactant is selected
from the group consisting of Hypermer 1083SF, Monoamine ADD,
Incromide, Chemax EM-1160, and Tween 80.
9. The composition of claim 1 further comprising a
co-surfactant.
10. The composition of claim 9 wherein the surfactant comprises
Hypermer 1083SF and the co-surfactant comprises Monoamine ADD or
Incromide.
11. The composition of claim 9 wherein the surfactant comprises
Chemax EM-1160 and the co-surfactant comprises Tween 80.
12. The composition of claim 1 further comprising diesel fuel.
13. The composition of claim 1 wherein the pyrolysis oil and
surfactant form a continuous phase and the water and alcohol form a
dispersed phase of the emulsion.
14. The composition of claim 1 wherein the water and alcohol form a
continuous phase and the pyrolysis oil and surfactant form a
dispersed phase of the emulsion.
15. A fuel composition emulsion comprising: a first phase
comprising water and alcohol; and a second phase comprising
pyrolysis oil and surfactant; wherein one of the first and second
phases forms a continuous phase and the other of the first and
second phases forms a dispersed phase.
16. A method of forming a stable pyrolysis oil based fuel emulsion
comprising: combining water and alcohol to form a water and alcohol
mixture; separately combining pyrolysis oil and a surfactant to
form a pyrolysis oil and surfactant mixture; adding a first portion
of the water and alcohol mixture to the pyrolysis oil and
surfactant mixture and mixing; adding a second portion of the water
and alcohol mixture to the pyrolysis oil and surfactant mixture;
and mixing until a stable emulsion is formed.
17. The method of claim 16 wherein the first and second portions of
the water and alcohol mixture are formed together when the water
and alcohol mixture is formed, and dividing the mixture into the
first and second portions.
18. The method of claim 16 wherein the first and second portions of
the water and alcohol mixture are made separately by combining a
first quantity of water and a first quantity of alcohol to form the
first portion and by combining a second quantity of water and a
second quantity of alcohol to form the second portion.
19. The method of claim 16 wherein the surfactant is selected from
the group consisting of Hypermer 1083SF, Monoamine ADD, Incromide,
Chemax EM-1160, and Tween 80.
20. A method of forming a stable pyrolysis oil based fuel emulsion
comprising: combining water and alcohol to form a water and alcohol
mixture; separately combining pyrolysis oil and a surfactant to
form a pyrolysis oil and surfactant mixture; adding a first portion
of the pyrolysis oil and surfactant mixture to the water and
alcohol mixture and mixing; adding a second portion of the
pyrolysis oil and surfactant mixture to the water and alcohol
mixture; mixing until a stable emulsion is formed.
Description
PRIORITY
[0001] This application claims priority to U.S. provisional patent
application Ser. No. 61/361,771 filed Jul. 6, 2010 entitled
PYROLYSIS OIL BASED FUEL AND METHOD OF PRODUCTION, the disclosure
of which is hereby incorporated by reference in the entirety.
TECHNICAL FIELD
[0002] Embodiments of the invention related generally to
alternative fuels and methods of producing alternative fuels, and
more specifically to alternative fuels based on pyrolysis oil.
BACKGROUND OF THE INVENTION
[0003] Efforts to find alternative fuels to those derived from
petroleum, such as gasoline and diesel fuel, have led to the
development of various biomass based fuels. One potential biomass
based fuel source is pyrolysis oil, which is an oil or tar product
produced by the pyrolysis of biomass materials such as wood,
agricultural waste, and municipal waste, as well as well as
non-biomass materials.
[0004] Pyrolysis oil presents an attractive source of renewable
energy. It has been considered as a potential substitute for
petroleum, or for use in a blend with petroleum, as a renewable
source of energy. Furthermore, there are many well known and well
developed processes for producing pyrolysis oil, and the source
materials which may be used for the production of pyrolysis oil are
diverse and abundant. However, the physical characteristics of
pyrolysis oil have, so far, limited the usefulness and commercial
development of pyrolysis oil based fuel as a replacement for
petroleum or for use in blending with petroleum.
[0005] Crude pyrolysis oil has numerous problems that limit its
usefulness in petroleum powered engines and other systems.
Pyrolysis oil experiences an increase in viscosity over time.
Although hydrocarbons also become viscous over time, the increase
in viscosity occurs much more quickly for pyrolysis oils. Attempts
have been made to treat this viscosity problem using a thermal
catalytic cracking process at the end of production of the oil
(viscosity breaking). However, this results in a cost increase and
does not completely resolve the problem of polymerization over
time. In addition, pyrolysis oils undergo phase changes over time
which can result in the separation of the oil into multiple phases
including water, wax, sludge, and tar. Pyrolysis oil does not
revaporize following a distillation curve, like hydrocarbons do.
Rather, when pyrolysis oil is heated, volatiles and water vaporize
and the remaining compounds polymerize. In addition, the pH of
pyrolysis oils is very low. Past efforts to increase the pH by
adding base compounds to the pyrolysis oil have been unsuccessful.
The treated pyrolysis oil is unstable, such that over time the
salts precipitate out. In addition, this treatment adds costs and
contaminants to that can lead to polymerization or leaking of the
nozzles of turbines and engines. Finally, pyrolysis oil does not
mix well with hydrocarbons.
SUMMARY OF THE INVENTION
[0006] Embodiments of the invention include fuel compositions
including pyrolysis oil, water, and surfactant. Some embodiments
further include one or more alcohols. The pyrolysis oil fuels are
stable emulsions that may be used as replacements for, or may be
mixed with, fossil fuels such as diesel and gasoline.
[0007] In some embodiments, the fuel composition is an emulsion
including 50-90 wt % pyrolysis oil, 0.1-40 wt % water, 1-30 wt %
alcohol, and 0.1-4 wt % surfactant. The pyrolysis oil comprises
crude pyrolysis oil, which may be derived from biomass such as wood
or other lignocellulosic materials, or from non-biomass sources. In
some embodiments, the fuel composition optionally includes diesel
fuel. The pyrolysis oil and surfactant may form the continuous
phase and the water and alcohol may form the dispersed phase of the
emulsion. Alternatively, the water and alcohol may form the
continuous phase and the pyrolysis oil and surfactant form the
dispersed phase of the emulsion.
[0008] In some embodiments, the alcohol includes one or more
polyalcohols or glycols. In some embodiments, the alcohol comprises
propylene glycol, ethylene glycol and/or ethanol.
[0009] In some embodiments, the surfactant includes a non-ionic
polymeric surfactant, such as Hypermer 1083SF, Monoamine ADD, or
Incromide. In some embodiments, the surfactant includes Chemax
EM-1160. In other embodiments, the surfactant includes Tween 80. In
some embodiments, the composition also includes a co-surfactant. In
some such embodiments, the surfactant is Hypermer 1083SF and the
co-surfactant is Monoamine ADD or Incromide. In other such
embodiments, the surfactant is Chemax EM-1160 and the co-surfactant
is Tween 80.
[0010] Other embodiments of the invention include a first phase
comprising water and alcohol and a second phase comprising
pyrolysis oil and surfactant. Either the first or the second phase
forms a continuous phase and the other of the first and second
phases forms a dispersed phase.
[0011] Embodiments of the invention also include a method of
forming a stable pyrolysis oil based fuel emulsion. In some
embodiments, the method includes combining water and alcohol to
form a water and alcohol mixture, separately combining pyrolysis
oil and a surfactant to form a pyrolysis oil and surfactant
mixture, adding a first portion of the water and alcohol mixture to
the pyrolysis oil and surfactant mixture and mixing, adding a
second portion of the water and alcohol mixture to the pyrolysis
oil and surfactant mixture, and mixing until a stable emulsion is
formed. In some embodiments, the first and second portions of the
water and alcohol mixture are formed together when the water and
alcohol mixture is formed, and then divided into the first and
second portions. In other embodiments, the first and second
portions of the water and alcohol mixture are made separately by
combining a first quantity of water and a first quantity of alcohol
to form the first portion and by combining a second quantity of
water and a second quantity of alcohol to form the second
portion.
[0012] In other embodiments, the method of forming a stable
pyrolysis oil based fuel emulsion includes combining water and
alcohol to form a water and alcohol mixture, separately combining
pyrolysis oil and a surfactant to form a pyrolysis oil and
surfactant mixture, adding a first portion of the pyrolysis oil and
surfactant mixture to the water and alcohol mixture and mixing,
adding a second portion of the pyrolysis oil and surfactant mixture
to the water and alcohol mixture, and mixing until a stable
emulsion is formed. As described above, the first and second
portions of the pyrolysis oil and surfactant mixture may be made
together and then separated into separate portions or the portions
may be made separately.
FIGURES
[0013] FIG. 1 is a flow chart showing an exemplary process for the
production of a pyrolysis oil based fuel according to embodiments
of the invention.
DETAILED DESCRIPTION
[0014] Embodiments of the invention include pyrolysis oil based
fuels, also referred to interchangeably as pyrolysis oil fuels, and
methods of making pyrolysis oil based fuels using an emulsification
process. The pyrolysis oil fuels are renewable fuels which may be
used to replace distillate oil for power generation, electricity,
and diesel generators, for example. The pyrolysis oil fuel may also
be co-fired with coal and/or biomass. Furthermore, it avoids
complicated biofuel processes such as transesterifications used for
traditional biodiesel but rather can be produced using a simple
emulsification process.
[0015] The pyrolysis oil fuel includes pyrolysis oil, water, and
emulsifiers and typically includes one or more alcohols. However,
in some embodiments, the alcohol may be optional. It may also
include other optional components including additives such as
combustibles. In some embodiments, the pyrolysis oil fuel
composition may be used as a neat biofuel. In some embodiments, the
pyrolysis oil fuel includes a petroleum fuel such as diesel. In
other embodiments, the pyrolysis oil fuel may be blended with a
fossil fuel such as diesel and/or gasoline or with a non-fossil
fuel such as biodiesel or bioethanol.
[0016] In one embodiment, the pyrolysis oil fuel includes about
50-95 wt % pyrolysis oil from one or more biomass sources, about
0.1-40 wt % water, about 1-30 wt % alcohol and/or polyalcohol,
about 0.01-4 wt % surfactant. In some embodiments the pyrolysis oil
fuel further includes about 0.01-4 wt % co-surfactant or
stabilizer. Some embodiments may also include about 0.01-15 wt %
diesel fuel. In some embodiments, the surfactant and/or
co-surfactant are non-ionic polymeric surfactants.
[0017] Embodiments of the invention may be formed as emulsions. The
term emulsion refers to a mixture or dispersion of two immiscible
substances, liquids in the present invention, in which one
substance, the dispersed phase, is dispersed in the other
substance, the continuous phase. The emulsion is stabilized, in
other words the dispersed phase remains dispersed during the
relevant time period, such as during storage and/or immediately
prior to and during use, with the assistance of one or more
emulsifiers.
[0018] The pyrolysis oil fuel emulsions include water-in-oil
emulsions, having pyrolysis oil as the continuous phase.
Alternatively, the pyrolysis oil fuel emulsions may be oil-in-water
emulsions, having water as the continuous phase. The type of
emulsion formed may depend upon such variables as the amounts of
pyrolysis oil and water present, the conditions used to prepare the
emulsion, the emulsifier type and amount, the temperature and
combinations of such variables. The emulsions are stable, with the
dispersed phase remaining substantially dispersed in the continuous
phase. In other words, substantially no phase separation occurs as
indicated by visual observation after a period following
preparation of the emulsion of at least about 24 hours; such as at
least about 48 hours or at least about 72 hours. In some
embodiments, substantially no phase separation is observable after
about 4 days or more, at ambient temperatures suitable for use of
the emulsified fuel composition in its intended application, for
example use in burners, motor vehicles and the like.
[0019] In one embodiment, the pyrolysis oil fuel include about
50-95 wt % pyrolysis oil, about 0.1-40 wt % water, about 0-30 wt %
alcohol, about 0.01-4 wt % Hypermer.RTM. 1083SF, about 0.01-4 wt %
MONOAMINE.TM. ADD-100 (Incromide), and about 0-15 wt % #2 Diesel.
In some embodiments, the alcohol includes one or more of propylene
glycol, ethylene glycol, and ethanol.
[0020] In another embodiment, the pyrolysis oil fuel includes 50-95
wt % pyrolysis oil, 0.1-40 wt % water, 0-30 wt % ethylene glycol,
0-30 wt % propylene glycol, 0-30% ethanol, 0.01-4 wt % Chemax
EM-1169, 0.01-4% Tween 80, and 0-15% Diesel fuel, such as #2 Diesel
fuel.
[0021] Pyrolysis oil fuel compositions described herein are
suitable for use in internal combustion engines, including diesel
engines of various configurations, as well as in equipment that
combusts fuels to generate heat, such as furnaces, boilers, power
generating equipment and the like, including gas or combustion
turbines. Diesel engines that may be operated with compositions of
the present invention include all compression-ignition engines for
both mobile (including locomotive and marine) and stationary power
plants. These include diesel engines of the two-stroke-per-cycle
and four-stroke-per-cycle types. The diesel engines, include but
are not limited to light and heavy duty diesel engines and on and
off-highway engines, including new engines as well as in-use
engines. The diesel engines include those used in automobiles,
trucks, buses including urban buses, locomotives, stationary
generators, and the like. For example, with regard to use in
burners, the compositions are useful in different types of oil
burners for domestic and other heating purposes including sleeve
burners, natural-draft pot burners, force-draft pot burners, rotary
wall flame burners, and air-atomizing and pressure-atomizing gun
burners; with the latter type of burner being the most commonly
used burner for home heating, particularly in the United States. In
particular, such compositions are useful fuels for diesel motors
(both new and old generation) and/or boilers and single- or
multi-step burners, also referred to in the art as staged
burners.
[0022] Product and manufacturing costs for the pyrolysis oil fuels
are low and competitive with other fuels, particularly due to the
presence of water in the composition. In addition, some embodiments
of the fuel of the invention are renewable since they are based on
pyrolysis oil obtained from plant material that can be regularly
replaced. Furthermore, the pyrolysis oil biofuels according to
embodiments of the invention exhibit substantial improvement in
physical characteristics as compared to pyrolysis oil.
[0023] The pyrolysis oil fuels according to embodiments of the
invention have a higher flash point than crude pyrolysis oil. The
term flash point generally refers to how easily a substance or
composition, typically a fluid, may ignite or burn and is one
property that needs to be considered in determining the suitability
of a fuel composition for practical use. Materials with higher
flash points are less likely to ignite than those with lower flash
points. Crude pyrolysis oil has a flash point of <38.degree. C.
(<100.degree. F.) or 38-100.degree. C. and is not auto-igniting
in a diesel engine. In contrast, the flash point of the pyrolysis
oil fuels disclosed herein have a flash point of >99.degree. C.
(>210.degree. F.). This flash point allows the pyrolysis oil
fuel to be classified as a combustible rather than a flammable,
like crude pyrolysis oil. This results in cost savings related to
permitting and storage issues in a production plant, because less
mandatory safety equipment is required for combustibles and the
management of health and safety issues is less complicated. The
higher flash point also allows for use in more markets, such as
marine combustion engines and motors, which have a mandatory flash
point of greater than 140.degree. F.
[0024] The viscosity of crude pyrolysis oil is about 60 to 300 cSt
at 40.degree. C., and increases further over time, such as over a
period of 12 months, due to polymerization. The viscosity of the
present biofuels based on pyrolysis oil improves to a value of less
than 10 cST at 40.degree. C. such as 3-5 cST. At this level, the
biofuel is compliant with GE Gas Turbine Fuel Specification (GEI
41047) for high pressure air atomizing system. It is also within
the viscosity range of diesel fuel, which is about 3-5 cST at
40.degree. C.
[0025] The pour point of crude pyrolysis oil is about 4.degree. C.
to -12.degree. C., indicating that it may gel at or below those
temperatures. In contrast, the pour point of the present pyrolysis
oil fuels is enhanced to a maximum of -24.degree. C. and a minimum
of -60.degree. C. At this pour point, the biofuel is suitable for
use in very low temperature and severe cold weather conditions.
[0026] The pH of the pyrolysis oil fuel is increased from about
1.5-3.8 in crude pyrolysis oil to greater than about 5 in some
embodiments. In other embodiments, the pH of the pyrolysis oil fuel
is greater than 6 or greater than 7. At these pH levels, the
corrosive properties of the pyrolysis oil are reduced or
eliminated.
[0027] Crude Pyrolysis oil is polar, due to the large amount of
oxygenated compounds that is contains. This prevents the oil from
readily mixing with hydrocarbons. However, the pyrolysis oil fuel
as disclosed herein is blendable with distillate fuels such as
diesel fuel.
[0028] The cetane number of pyrolysis oil is generally low, only
approximately 10, and is not auto-igniting in a diesel engine. The
cetane number, or CN, refers to a measure of diesel fuel ignition
characteristics, with higher values indicating better performance
The cetane number scale covers the range from zero to 100, but
typical test results for diesel fuel and fuels intended for use in
diesel applications are in the range of about 30 to 65 cetane
number. The cetane number measures how quickly the fuel starts to
burn (auto-ignites) under a standardized set of diesel engine
conditions. The pyrolysis oil fuels according to embodiments of the
invention may have a cetane number greater than 10, due to the
presence of polyalcohols and/or glycols. For example, nitrated
alcohol esters such as tetraethyl glycol dinitrate may enhance the
cetane number of the crude pyrolysis oil.
[0029] Pyrolysis oil is not stable, reacting with air and
degassing. In contrast, the pyrolysis oil fuel compositions remain
stable.
[0030] The pyrolysis oil fuels are emulsions that are stable for an
extended time and over a wide range of temperatures. It can be used
without modification to the tanks and/or piping systems of the
motors and burners in common use. Thus another advantage of the
present invention is that it permits the return at any moment to
the use of traditional fuels without modification of the systems in
which the fuel is used.
[0031] Crude pyrolysis oil cannot be blended with diesel. In
contrast, the pyrolysis oil compositions blend well with diesel or
other distillate fuels such as gasoline.
[0032] The combustion of crude pyrolysis oil results in the
emission of high levels of SOx and NOx. In addition, the crude
pyrolysis oil has a tendency to create coking at the injectors or
nozzles of diesel engines. While sulfur can be removed from crude
pyrolysis oil by processes such as catalytic post combustion of
emissions (including selective non catalytic reduction, SNCR, and
selective catalytic reduction, SCR), these processes are expensive.
In addition, the presence of high levels of alkaline metals can
disrupt the catalyst used in SCR. In the pyrolysis oil fuel
compositions described herein, the presence of water and alcohol in
the emulsion reduces the NOx emissions and, together with the
alcohols, dilutes the sulfur content. In addition to reducing
emissions after combustion of the pyrolysis oil fuel, it also
reduces or prevents clogging of the nozzles or injectors as would
occur with the combustion of crude pyrolysis oil.
[0033] The presence of alcohols and/or polyalcohols in the
pyrolysis oil fuel increases the energy content of the biofuel,
recovering the heat loss of water. The quantity of alcohols and
polyalcohols can be used in the pyrolysis oil fuel can therefore be
adjusted relative to the quantity of water such that the energy
increase due to the alcohols and polyalcohols can balance the lack
of energy contribution from the water.
Pyrolysis Oil
[0034] The fuels useful in the present invention are based on
pyrolysis oil, which is liquid fuel product produced by the
pyrolysis of biomass or other materials and subsequent cooling.
Pyrolysis oil is also known as, and/or includes, biomass pyrolysis
oil, bio-oil, wood pyrolysis oil, wood oil, liquid wood, biomass
pyrolysis liquid, biocrude oil, or pyroligneous tar. Alternatively,
pyrolysis oil may be obtained from nonbiomass sources such as
rubber tires and plastics. Pyrolysis oil is a synthetic fuel
extracted by means of destructive distillation, forming a kind of
tar which normally contains oxygen at levels which are too high for
it to be defined as a hydrocarbon. Pyrolysis oil may form about
50-95 wt % of the fuel. In some embodiments, it is about 60-85 wt %
of the fuel, and in other embodiments it is about 70-75 wt % of the
fuel.
[0035] Biomass pyrolysis for the production of pyrolysis oil may
use any biomass substrate. For example, the biomass substrate may
be hard or soft woody plants including trees and bushes, non-woody
plants, agricultural materials or waste, grasses, municipal waste,
or a combination of one or more biomass materials. Examples of
woody plant material which may be used include trees such as pine,
poplar, birch, willow, fir, spruce, larch, beech, and palm.
Examples of agricultural materials and wastes include bagasse,
corn, corn stover, corn cobs, corn kernels, corn fibers, straw
(rice, oat, wheat, barely, canola), hulls (rice, oat), soybean
stover, cotton stalk, cotton gin, sugarcane, sugar bagasse, and
sugar processing residues. Examples of grasses which may be used
include switchgrass, miscanthus, sorghum, cordgrass, ryegrass,
Bermuda grass, reed canary grass, and alfalfa. Municipal waste
includes waste paper and food and industrial waste such as pager
and other waste.
[0036] Biomass pyrolysis for the production of pyrolysis oil is
performed using a very high heating rate as well as a high heat
flux. Under these conditions, the chemical bonds of the cellulose,
hemicellulose and lignin components of the biomass are cleaved,
producing a vapor, a gas and char. The vapor is then thermally
quenched to prevent further cracking and to produce pyrolysis
oil.
[0037] Alternatively, pyrolysis oil may be produced from waste
products such as tires, plastic scraps and car fluff. Pyrolysis oil
which is derived from non-biomass sources may contain more
contaminants, such as sulphur, and may have a higher btu content
than pyrolysis oil derived from biomass sources. Non-biomass
sources of pyrolysis oil include plastic, such as post consumer
plastic (PCP), which is often mixed with other urban solid waste,
and other solid rubbish.
[0038] Pyrolysis oil may be produced by either fast pyrolysis or
slow pyrolysis, though fast pyrolysis may produce a greater yield
of pyrolysis oil. Generally, the biomass is exposed to temperatures
about 320-500.degree. C., followed by cooling. Various reactor
systems may be used for biomass pyrolysis. These reactors can apply
pyrolysis conditions to the biomass using fluidized beds (bubbling
or circulating), transported beds, circulating fluid beds, ablative
sources (vortex and rotating blades), vacuums, transported beds
without a carrier gas, grate kilns, microwave inputs, or rotating
cones, for example.
[0039] The exact characteristics and composition of the pyrolysis
oil will vary somewhat depending upon the method of pyrolysis
performed and the nature of the biomass feedstock. Pyrolysis oil is
typically of mixture of a large numerous number of compounds which
are fragments of the original biomass component, including a large
amount of oxygenated compounds. Pyrolysis oil includes organic
acids such as formic and acetic acid, resulting in the low pH of
about 1.5-3.8. It is also polar and hydrophobic, and may have an
oxygen content of about 40-50%. It has a density of approximately
1.2-1.3 kg/1 or 10.01-10.85 lbs/gallon, which is higher than that
of diesel.
[0040] Crude pyrolysis oil may include lignin. However, embodiments
of the invention can produce pyrolysis oil based fuel with or
without removal of the lignin from the crude pyrolysis oil. Crude
pyrolysis oil may also have a water content which can vary from
1-30%, for example. This water may have been split during pyrolysis
and may be held separately in other compounds within the complex
pyrolysis liquid. While the water can be removed from the crude
pyrolysis oil, it is an expensive process, and embodiments of the
invention do not require removal of the water from the crude
pyrolysis oil. Rather, the amount of water present in the crude
pyrolysis oil can be used to form a portion or all of the water
content of the final pyrolysis oil based fuel. For example, the
water content of the crude pyrolysis oil to be used for the fuel
production can be measured. Based on the amount of crude pyrolysis
oil to be used, the contribution of this water content to the total
amount of water in the fuel can be calculated. The amount of water
to be added to the fuel can be adjusted down by this amount, to
reach the final desired total water content.
Water
[0041] The water used in the compositions of the present invention
can be from any source. The water employed in preparing the
pyrolysis oil fuel compositions of the present invention can be
deionized, purified for example using reverse osmosis or
distillation, and/or demineralized and have a low content of
dissolved minerals, for example, salts of calcium, sodium and
magnesium, and will similarly include little, if any, chlorine
and/or fluorine as well as being substantially free of undissolved
particulate matter. In some embodiments, the water has been
substantially demineralized by methods well known to those skilled
in the art of water treatment in order to remove dissolved mineral
salts and has also been treated to remove other additives or
chemicals, including chlorine and fluorine. The substantial absence
of such materials may lead to improvements in the condition of
metal surfaces in engines and burners, particularly the inner
surfaces of cylinders and nozzles. Some or all of the water present
in the composition may be provided as water present in the crude
pyrolysis oil, so that refining of the crude pyrolysis oil may be
avoided. The water may be present in the pyrolysis oil fuel
emulsions at amounts of about 0.1% to about 40% by weight;
alternatively about 5% to about 40% by weight; about 10% to about
30% by weight; or about 15% to about 25%.
Emulsifiers
[0042] Emulsifiers used in embodiments of the invention add
stability in the pyrolysis oil fuel and can increase the
blendability of the pyrolysis oil fuel with distillate fuels. The
term emulsifier refers to a compound or mixture of compounds that
has the capacity to promote formation of an emulsion and/or
substantially stabilize an emulsion, at least for the short-term,
i.e., during the time of practical or commercial interest. An
emulsifier provides stability against significant or substantial
aggregation or coalescence of the dispersed phase of an emulsion.
An emulsifier is typically considered to be a surface active
substance in that it is capable of interacting with the dispersed
and continuous phases of an emulsion at the interface between the
two. Surfactants are one type of emulsifier. Within the generic
term surfactant are included various types of surfactants such as
nonionic, ionic or partially ionic, anionic, amphoteric, cationic
and zwitterionic surfactants.
[0043] Emulsifiers such as surfactants may be employed in
accordance with the present invention to enhance the stability of
the pyrolysis oil fuel emulsion, particularly over time. The
following tabulation provides examples of surfactants contemplated
by the invention, although useful surfactants are not limited to
those specifically listed. For example, also useful are surfactants
disclosed in a comprehensive listing of surfactants that can be
found in the spectral database of Bio-Rad Laboratories
(www.informatics.bio-rad.com), including infrared spectra and, in a
number of cases, chemical composition and chemical and physical
properties and sources, incorporated herein by reference. The
compounds are generally characterized as alcohols,
nitrogen-containing compounds, esters of long chain carboxylic
acids, hydrocarbons, various esters and salts of long chain
carboxylic acids, sulfated and sulfonated compounds including
alkylaryl sulfonates isothionates, lignosulfonates, sulfated and
sulfonated alcohols, amines, amides, carboxylic acids, carboxylic
acid esters, sulfated and sulfonated polyalkoxylated materials such
as esters, ethers, nitrogen compounds, aminopolycarboxylic acids
such as ethylenediaminetetraacetic acid (EDTA),
diethylenetriaminepentaacetic acid (DTPA), and nitrilotriacetic
acid (NTA), in other words EDTA, DTPA, NTA acids and salts,
phosphates, silicates and silicones. To the extent that a
particular surfactant includes atoms, groups or compounds that may
unnecessarily contribute to pollution, e.g., sulfur, its use can be
limited to the amount necessary for producing and/or maintaining a
stable emulsion or fuel composition. In some embodiments, the
surfactant may be cetyl alcohol, hydrogenated castor oil or a
mixture of cetyl alcohol and hydrogenated castor oil. The following
materials, referred to as surfactants herein, can be employed in
accordance with the pyrolysis oil fuel compositions of the present
invention.
[0044] In some embodiments, the surfactant is a fatty amine,
ethanol amide or alkoxylated amide, such as those available from
Croda Inc. of Edison, N.J. under the tradenames Cromidet.TM.,
Incromectant.TM., Incromide.TM., and Promidium.TM., such as
Incromide.TM. CDEA and Incromide.TM. LDEA.
[0045] Tabulation of Useful Surfactants
[0046] (A) Nonionic Surfactants:
Esters of polyhydric alcohols; alkoxylated amides; esters of
polyoxyalkylene, polyoxypropylene and of
polyoxyethylene-polyoxypropylene glycols; ethers of polyoxyalkylene
glycols; tertiary acetylenic glycols; and polyoxyethylated alkyl
phosphates. Particularly useful nonionic surfactants include
Hypermer.RTM. 10835, a nonionic surfactant blend, and MONAMINE.TM.
ADD-100 (cocamide DEA (and) Diethanolamine), one of a range of
alkanolamindes known as Incromide.TM. CDEA. Both Hypermer.RTM.
10835 and MONAMINE.TM. ADD-100 are available from Croda Inc. of
Edison, N.J.
[0047] (B) Anionic Surfactants:
Carboxylic acids and soaps; sulfated esters, amides, alcohols,
ethers and carboxylic acids (all salts); sulfonated petroleum,
aromatic hydrocarbons, aliphatic hydrocarbons, esters, amides,
amines, ethers, carboxylic acids, phenols and lignins (all salts);
acylated polypeptides (salts); and phosphates.
[0048] (C) Fatty Acids:
Caprylic acid, abietic acid, pelargonic acid, coconut oil fatty
acids, capric acid, corn oil fatty acids, lauric acid, cottonseed
oil fatty acids, myristic acid, soya oil fatty acids, palmitic
acid, tallow fatty acids, stearic acid, hydrogenated fish oil fatty
acids, behenic acid, tall oil fatty acids, undecylenic acid, dimer
acids, oleic acid, trimer acids, erucic acid, castor oil, linoleic
acid, hydrogenated castor oil, ricinoleic acid, lanolin, naphthenic
acid, and lanolin fatty acids.
[0049] (D) Fatty Acid Salts:
Lithium stearate, ammonium oleate, cadmium stearate, sodium
caprate, ammonium linoleate, calcium stearate, sodium laurate,
ammonium ricinoleate calcium oleate, sodium myristate, ammonium
naphthenates, calcium linoleate, sodium palmitate, ammonium
abietate, calcium ricinoleate, sodium stearate, morpholine laurate,
calcium naphthenates, sodium undecylenate, morpholine myristate,
cobalt stearate, sodium oleate, morpholine palmitate, cobalt
naphthenates, sodium linoleate, morpholine stearate, copper
stearate, sodium ricinoleate, morpholine undecylenate, copper
oleate, sodium naphthenates, morpholine oleate, copper
naphthenates, sodium abietate, morpholine linoleate, iron stearate,
sodium polymerized carboxylates, morpholine ricinoleate, iron
naphthenate, morpholine napthenate, lead stearate, sodium salt of
tall oil, morpholine abietate, lead oleate, potassium caprate,
triethanolamine caprate, lead naphthenate, potassium laurate,
triethanolamine laurate, magnesium stearate, potassium myristate,
triethanolamine myristate, magnesium oleate, potassium palmitate,
manganese stearate, potassium stearate, triethanolamine palmitate,
manganese naphthenate, potassium undecylenate, triethanolamine
stearate, nickel oleate, potassium oleate, strontium stearate,
potassium linoleate, triethanolamine undecylenate, tin oleate,
potassium ricinoleate, zinc laurate, potassium naphthenate,
triethanolamine oleate, zinc palmitate, potassium abietate,
triethanolamine linoleate, zinc stearate, ammonium caprate,
triethanolamine ricinoleate, zinc oleate, ammonium laurate, zinc
linoleate, ammonium myristate, triethanolamine naphthenates, zinc
naphthenate, ammonium palmitate, zinc resinate, ammonium stearate,
triethanolamine abietate, ammonium undecylenate, aluminum
palmitate, aluminum stearate, aluminum oleate, barium stearate, and
barium naphthenate.
[0050] (E) Olefins:
Linear C.sub.14 alpha-olefin, and linear C.sub.16 alpha-olefin.
[0051] (F) Phosphorous Compounds and Mercaptans:
POE octyl phosphate, sodium phosphated castor oil, ammonium
phosphated castor oil, 2-ethylhexyl polyphosphate sodium salt,
capryl polyphosphate sodium salt, sodium di(2-ethylhexyl)phosphate,
lecithin (soy phosphatides), and POE (polyoxyethylene)
tert-dodecylmercaptoethanol.
[0052] (G) Polyethylene and Propylene Glycol Esters:
Hydroxyethyl laurate, PEG monooleate, propylene glycol monolaurate,
hydroxyethoxyethyl laurate, PEG dioleate, ethylene glycol
monoricinoleate, propylene glycol monostearate, hydroxy
ethoxyethoxy ethyl laurate, diethylene glycol monoricinoleate,
propylene glycol dilaurate, PEG monolaurate, PEG monoricinoleate,
propylene glycol distearate, PEG dilaurate, diethylene glycol
coconate, ethylene glycol monostearate, dipropylene glycol
monostearate, POE coco fatty acids ester, diethylene glycol
monostearate, propylene glycol monooleate, POE castor oil,
triethylene glycol monostearate, ethylene glycol hydroxystearate,
propylene glycol monoricinoleate, PEG monostearate, PEG trihydroxy
stearate, propylene glycol monoisostearate, ethylene glycol
distearate, POE hydrogenated castor oil, propylene glycol
monohydroxystearate, PEG distearate, POE tall oil, PEG
monoisostearate, POE abietic acid, propylene glycol dipelargonate,
PEG diisostearate, POE lanolin, hydroxyethyl oleate, acetylated
lanolin, isopropylester of lanolin fatty acids, hydroxyethoxyethyl
oleate, POE lanolin acetylated, methoxy PEG monooleate, POE
propylene glycol monostearate, and hydroxy ethoxyethoxy ethyl
oleate.
[0053] (H) Alcohols, Phenols and Polyoxyethylene Derivates:
Stearyl alcohol, oleyl alcohol, octyl phenol, nonyl phenol,
tert-octylphenoxy ethanol, p-dodecyl phenol, dinonyl phenol,
tridecyl alcohol, tetradecyl alcohol, lanolin alcohols,
cholesterol, dimethyl hexynol, dimethyl octynediol, tetramethyl
decynediol, POE tridecyl phenyl ether, POE lanolin alcohol ether,
POE cholesterol, POE n-octylphenol, POE tert-octylphenol, POE
nonylphenol, POE dinonyl phenol, POE dodecyl phenol, POE lauryl
alcohol ether, POE cetyl alcohol ether, POE stearyl alcohol ether,
POE tetramethyldecynediol, POE oleyl alcohol ether, POP
(polyoxypropylene) EtO, POE isohexadecyl alcohol ether
2,6,8-trimethyl-4-nonyloxypolyethyleneoxyethanol,
polyoxypropylene-polyoxyethylene block copolymer, alkyl ether of
POE/POP, and POE tridecyl alcohol ether.
[0054] (I) Glycerol Esters:
Glycerol monocaprylate, glycerol monolaurate, glycerol
mono/dicocoate, glycerol dilaurate, glycerol monostearate, glycerol
monostearate distilled, glycerol distearate, glycerol monooleate,
glycerol dioleate, glycerol trioleate, glycerol monoisostearate,
glycerol monoricinoleate, glycerol monohydroxystearate, POE
glycerol monostearate, acetylated glycerol monostearate,
succinylated glycerol monostearate, diacetylated glycerol
monostearate tartrate, modified glycerol phthalate resin,
triglycerol monostearate, triglycerol monooleate, triglycerol
monoisostearate, decaglycerol tetraoleate, decaglycerol
decastearate, pentaerythritol monolaurate, pentaerythritol
monostearate, pentaerythritol distearate, pentaerythritol
tetrastearate, pentaerythritol monooleate, pentaerythritol
dioleate, pentaerythritol trioleate, pentaerythritol
tetraricinoleate, sorbitan monolaurate, POE sorbitan monolaurate,
sorbitan monopalmitate, POE sorbitan monopalmitate, sorbitan
monostearate, POE sorbitan monostearate, sorbitan tristearate, POE
sorbitan tristearate, sorbitan monooleate, POE sorbitan monooleate,
sorbitan sesquioleate, sorbitan trioleate, POE sorbitan trioleate,
POE sorbitol hexaoleate, POE sorbitol oleate laurate, POE sorbitol
polyoleate, POE sorbitol, beeswax-ester, sucrose monolaurate,
sucrose cocoate, sucrose monomyristate, sucrose monopalmitate,
sucrose dipalmitate, sucrose monostearate, sucrose distearate,
sucrose monooleate, sucrose dioleate, lauryl lactate, cetyl
lactate, sodium lauryl lactate, sodium stearoyl lactate, sodium
isostearoyl-2-lactylate, sodium stearoyl-2-lactylate, calcium
stearoyl-2-lactylate, sodium capryl lactate, lauryl alcohol, and
cetyl alcohol.
[0055] (J) Amides and Amide Derivatives:
Stearamide, oleamide, erucamide, behenamide, lauric acid
monoethanolamide, tallow monoethanolamide, POE lauric amide,
myristic acid diethanolamide, stearic acid diethanolamide, oleic
acid diethanolamide, POE oleic amide, coco acid diethanolamide, POE
coco amide, POE hydrogenated tallow amide, lauric acid
monoisopropanolamide, and oleic acid monoisopropanolamide.
[0056] (K) Sulfates:
Sodium n-octyl sulfate, sodium 2-ethylhexyl sulfate, sodium decyl
sulfate, sodium lauryl sulfate, sodium tridecyl sulfate, sodium
sec-tetradecyl sulfate, sodium cetyl sulfate, sodium sec-heptadecyl
sulfate, sodium oleyl sulfate, sodium oleyl stearate sulfate,
sodium tridecyl ether sulfate, potassium lauryl sulfate, magnesium
lauryl sulfate, triethanolamine lauryl sulfate, ammonium lauryl
sulfate, diethanolamine lauryl sulfate, triethanolammonium lauryl
sulfate, POE octylphenol sodium salt, alkylaryl polyether sulfate
sodium salt, sulfated POE nonylphenol sodium salt, sulfated
nonylphenyl ether of tetraethyleneglycol ammonium salt, sulfated
lauryl ether of tetraethyleneglycol sodium salt, POE sodium lauryl
monoether sulfate, POE sodium lauryl ether sulfate, POE ammonium
lauryl sulfate, sulfated oleic acid sodium salt, sulfated castor
oil-fatty acids sodium salt, sulfated propyloleate sodium salt,
sulfated isopropyloleate sodium salt, sulfated butyloleate sodium
salt, sulfated glycerol monolaurate sodium salt, sulfated glycerol
trioleate sodium salt, sulfated castor oil sodium salt, sulfonated
marine oil, sulfated neatsfoot oil sodium salt, sulfated rice bean
oil sodium salt, sulfated soya bean oil sodium salt, sulfated
synthetic sperm oil, and sulfated tallow sodium salt.
[0057] (L) Miscellaneous Surfactant Compounds:
Perfluoro surfactant-anionic, perfluoro surfactant-cationic,
ethylenediamine tetraacetic acid disodium salt,
ethylenediaminetetraacetic acid tetrasodium salt, sodium
dihydroxyethyl glycinate, trisodium nitrilotriacetate, sodium
citrate, silicone defoamer-oil, silicone defoamer-water
dispersible, sodium tetraborate, sodium carbonate, sodium
phosphate-tribasic, sodium silicate, and alkyl benzene sulfonic
acid-propylene tetramer.
[0058] (M) Sulfonates:
Sodium toluene sulfonate, sodium xylene sulfonate, sodium cumene
sulfonate, sodium dodecylbenzene sulfonate, sodium tridecylbenzene
sulfonate, sodium kerylbenzene sulfonate, calcium dodecylbenzene
sulfonate, ammonium xylene sulfonate, triethanolammonium
dodecylbenzene sulfonate, alkylammonium dodecyl-benzene sulfonate,
aliphatic hydrocarbons-sulfonic acid, sodium petroleum sulfonate,
calcium petroleum sulfonate, Bryton barium sulfonate, magnesium
petroleum sulfonate, ammonium petroleum sulfonate, isopropylamine
petroleum sulfonate, ethylenediamine petroleum sulfonate,
triethanolamine petroleum sulfonate, sulfonated napthalene sodium
diisopropyl naphthalene sulfonate, sodium dibutyl naphthalene
sulfonate, sodium benzyl naphthalene sulfonate, sodium naphthalene
formaldehyde-condensate sulfonate, sodium polymerized
alkylnaphthalene sulfonate, potassium polymerized alkylnaphthalene
sulfonate, ammonium dibutylnaphthalene sulfonate, ethanolamine
dibutylnaphthalene sulfonate, sodium sulfooleate, sodium
monobutylphenylphenol monosulfonate, disodium dibutylphenylphenol
disulfonate, potassium monoethylphenylphenol monosulfonate,
ammonium monoethylphenylphenol monosulfonate, guanidinium
monoethylphenylphenol monosulfonate, sodium decyldiphenylether
disulfonate, sodium dodecyldiphenylether disulfonate, calcium
polymerized alkyl-benzene sulfonate, sulfonated polystyrene,
sulfonated aliphatic polyester, sodium-2-sulfoethyl oleate, sodium
amyl sulfooleate, sodium lauryl sulfoacetate, sodium diisobutyl
sulfosuccinate, sodium diamyl sulfosuccinate, sodium dihexyl
sulfosuccinate, sodium dioctyl sulfosuccinate, sodium ditridecyl
sulfosuccinate, sodium alkylarylpolyether sulfonate, and sodium
lignosulfonate.
[0059] (N) Amines and Amine Derivatives:
tert-C.sub.11-C.sub.14 amine, n-dodecylamine, n-tetradecylamine,
n-hexadecylamine, n-octadecylamine, C.sub.18-C.sub.24 amine,
oleylamine, cocoamine, hydrogenated tallow amine, tallow amine, POE
ten-amine, POE stearyl amine, POE oleyl amine, C.sub.12-C.sub.14
tert-alkylamines, ethoxylated POE cocoamine, POE tallow amine, POE
soya amine, POE octadecylamine, N-b-hydroxyethyl stearyl
imidazoline, POE (3) N-tallow trimethylene diamine,
N-b-hydroxyethyl cocoimidazoline, N-b-hydroxyethyl oleyl
imidazoline, n-dodecylamine acetate, hexadecylamine acetate,
octadecylamine acetate oleylamine acetate, cocoamine acetate,
hydrogenated tallow amine acetate, tallow amine acetate, soya amine
acetate, N-stearyl-N'.N'-diethylethylene-diamine acetate,
N-oleylethylenediamine formate, cocoamidopropyl dimethyl amine
oxide, lauryl dimethylamine oxide, myristyl dimethylamine oxide,
soya amine, diococoamine, dihydrogenated tallow amine, dimethyl
hexadecylamine, dimethyl octadecylamine, dimethyl cocoamine,
dimethyl soyaamine, N-coco-1,3-diaminopropane,
N-soya-1,3-diaminopropane, N-tallow-1,3-diaminopropane,
N-coco-b-aminobutyric acid, stearamidoethyl diethylamine,
sodium-N-coco-b-amino propionate, N-tallow trimethylene diamine
diacetate, disodium-N-tallow-b-imino dipropionate,
disodium-N-lauryl-b-imino dipropionate, cetyl betaine, coco
betaine, myristamidopropyl betaine, oleyl betaine, coconut amido
betaine, oleyl amido betaine, coconut oil acid ester of sodium
isethionate, cocoamido alkyldimethylamine, behenic amido alkyl
dimethylamine, isostearic amido alkyl dimethylamine, oleic amido
alkyl dimethylamine, sodium-N-methyl-N-palmitoyl taurate,
sodium-N-methyl-N-oleyl taurate, sodium-N-coconut acid N-methyl
taurate, sodium-N-methyl-N-tall oil taurate, N-lauryl sarcosine,
cocoyl sarcosine, N-oleyl sarcosine, sodium-N-lauryl sarcosinate,
sodium carboxymethylnonylhydroxy-ethy imidazolinium hydroxide,
sodium carboxymethylundecylhydroxy-ethyl imidazolinium hydroxide,
sodium carboxymethylcocohydroxy-ethyl imidazolinium hydroxide,
sodium carboxyethyloleylhydroxy-ethyl imidazolinium hydroxide,
sodium carboxymethylstearylhydroxy-ethyl imidazolinium hydroxide,
and sodium carboxymethylsodiumcarboxy-ethyl cocoether
imidazolinium.
[0060] (O) Quaternary Amine Salts:
Dodecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium
chloride, octadecyltrimethyl ammonium chloride, cetyltrimethyl
ammonium bromide, cetyldimethylethyl ammonium bromide, coco
trimethyl ammonium chloride, tallow trimethyl ammonium chloride,
soya trimethyl ammonium chloride, dicoco dimethyl ammonium
chloride, dimethyl 80% behenyl benzyl ammonium chloride, methyl
bis(2-hydroxyethyl)coco ammonium chloride, dihydrogenated tallow
dimethyl ammonium chloride, methyldodecylbenzyl trimethyl ammonium
chloride, n-alkyl dimethyl benzyl ammonium chloride,
alkyldimethyl-3.4-dicholor-benzyl ammoniumchloride,
octylphenoxyethoxyethyl dimethyl-benzyl ammonium chloride,
octylcresoxyethoxyethyl dimethyl-benzyl ammonium chloride,
cocoamidopropyl PG-dimonium chloridephosphate, 2-hydroxyethylbenzyl
stearyl imidazolinium chloride, 2-hydroxyethylbenzyl coco
imidazolinium chloride, ethyl bis(polethoxyethanol)alkyl ammonium
chloride, diethyl heptadecyl imidazolinium ethylsulfate,
lauryldimethylbenzyl ammonium chloride, stearyldimethylbenzyl
ammonium chloride, laurylpyridinium chloride, 1-hexadecylpyridinium
chloride, cetylpyridinium bromide, lauryl isoquinolinium bromide,
and substituted oxazoline.
[0061] In one embodiment the emulsifier or surfactant comprises at
least one sorbitan ester. The sorbitan esters include sorbitan
fatty acid esters wherein the fatty acid component of the ester
comprises a carboxylic acid of about 10 to about 100 carbon atoms,
and in one embodiment about 12 to about 24 carbon atoms. They are
available from Calgene Chemical under the trademark "POLYSORBATE"
and from ICI under the trademark "TWEEN". Typical examples are
polyoxyethylene (hereinafter "POE") (20) sorbitan tristearate
(Polysorbate 65; Tween 65), POE (4) sorbitan monostearate
(Polysorbate 61; Tween 61), POE (20) sorbitan trioleate
(Polysorbate 85; Tween 85), POE (5) sorbitan monooleate
(Polysorbate 81; Tween 81), and POE (80) sorbitan monooleate
(Polysorbate 80; Tween 80). As used herein the number within the
parentheses refers to the number of ethylene oxide units present in
the composition. Other useful emulsifiers include sorbitan
monooleate (Span.RTM. 80) and sorbitan monopalmitate (Span.RTM. 40)
available from Sigma Aldrich, polyoxyethylene(20)sorbitan trioleate
(Tween 85), polyoxyethylene(20) sorbitan monopalmitate (Tween 40)
and polyoxyethylene(20) sorbitan monolaurate (Tween 20).
[0062] Useful emulsifiers can include compounds exhibiting a
hydrophilic-lipophilic balance (HLB, which refers to the size and
strength of the polar (hydrophilic) and non-polar (lipophilic)
groups that comprise the emulsifier or surfactant molecule)
typically in the range of about 1 to about 40; in another
embodiment about 5 to about 20. HLB is a well-known parameter
utilized by those skilled in the art for characterizing
emulsifiers. In some embodiments, the emulsifier has an HLB in the
range of about 1 to about 40; in one embodiment about 1 to about
30; in one embodiment about 1 to 20; and in another embodiment
about 4 to about 18; alternatively, greater than about 8, for
example about 8.5 or about 9 to about 18. Various useful compounds
include those identified herein, including for example, sorbitan
monolaurate, polyoxyethylene(20) sorbitan monooleate, and
polyoxyethylene(20) sorbitan monolaurate.
[0063] It is also possible to obtain stable emulsified fuel
compositions using a combination of emulsifiers. For purposes of
explanation and not limitation, for example instead of a single
emulsifier having an HLB value of about 12, an emulsified fuel
composition can be prepared using a mixture of emulsifiers, such as
a 50/50 mixture two emulsifiers, one having an HLB value of about
16 and the other an HLB value of about 8. Similarly combinations of
three or more emulsifiers can also be used, provided that the HLB
value of the mixture exhibits the desired overall value and the
effect of the mixture is to provide a stable emulsion. For purposes
of a mixed emulsifier composition, the HLB value of the emulsifier
mixture is calculated as a linear sum weighted average based on the
weight fraction that each of the emulsifiers represents compared to
the total amount of emulsifier present.
[0064] In some embodiments, a mixture of two emulsifiers is used
wherein one emulsifier has an HLB value of equal to or less than
about 6, for example about 1 to about 6.0, or about 2 to about 5.9,
or about 3 to about 5.5, or about 4 to about 5.9, and the like; and
the second emulsifier has an HLB value of greater than about 6, for
example about 6 to about 20; or about 6.1 to about 18, or about 6.5
to about 16, or about 7 to about 15, and the like; provided that
both emulsifiers do not have an HLB value of 6. Alternatively, one
emulsifier comprising a bimodal distribution of chemical species
exhibiting each of the HLB properties can be used.
[0065] The use of multiple emulsifiers or co-surfactants in the
same emulsified fuel composition can be advantageous in
compositions in which the total concentration of hydrophilic
components is low. For example, compositions in which the water
concentration is less than about 5 wt %, such as about 1 wt % to
about 5 wt %, or about 1 wt % to about 4 wt %, or 1 wt % to about 3
wt %, or 1 wt % to about 2 wt %. Alternatively, the concentrations
of various hydrophilic or substantially hydrophilic components can
be added together for consideration of the above recited
concentrations, including water, hydroxyl-containing component(s)
such as one or more alcohols or glycols and the like. In
particular, if the ratio of the total amount of such hydrophilic
components to the total amount of lipophilic components, the latter
including but not limited to the pyrolysis oil, is equal to or less
than about 0.25, for example, about 0.05 to about 0.25 or any
specific value there between, including, for example, about 0.06,
0.08, 0.10, 0.12, 0.14, 0.16, 0.18, 0.20, 0.22 or 0.24, it may be
desirable to use a mixture of emulsifiers as described above; in
other words, emulsifier mixtures wherein at least one emulsifier
has an HLB value of equal to or less than about 6 and at least one
emulsifier has an HLB value of greater than about 6 (subject to the
provisos expressed above). In some embodiments, to prepare a stable
emulsion using such components, a mixture of emulsifiers may be
employed, for example, a 50/50 mixture of an emulsifier having an
HLB value of, for example, about 4 and one having an HLB value of
about 15. In contrast, a stable emulsified composition can be
prepared using a single emulsifier where the lipophilic and
hydrophilic components comprise 75 wt % pyrolysis oil, 1 wt %
water, and 23 wt % alcohol. Alternatively, a mixture of emulsifiers
can be used even where the calculated ratio is greater than 0.25,
particularly if the value is only slightly greater, for example
about 5% to about 10% greater. Optionally, a mixture of emulsifiers
can be used if desired; particularly if it is anticipated that the
user of such a fuel composition may subsequently introduce an
additive into the composition that might have the effect of
changing the calculated ratio.
Alcohols
[0066] Embodiments of the invention may include one or more
alcohols which, among other things, increase the pH to improve the
acidity of the pyrolysis oil fuel, reduce the final viscosity, and
enhance the ignition properties of the final fuel. Alcohols useful
in the present invention include hydroxyl-containing organic
compounds selected from the group consisting of (A) monohydric (one
OH group) alcohols characterized as (1) aliphatic, including
straight and branched chain, and sub-characterized within this
group as paraffinic (for example, ethanol) and olefinic (for
example, allyl alcohol); (2) alicyclic (for example, cyclohexanol);
(3) aromatic (for example, phenol, benzyl alcohol); (4)
heterocyclic (for example, furfuryl alcohol); and (5) polycyclic
(for example, sterols); (B) dihydric (two OH groups), including
glycols and derivatives (for example, diols); (C) trihydric (three
OH groups), including glycerol and derivatives; and (D) polyhydric
(polyols), having three or four or more OH groups). In particular,
useful alcohols include alcohols selected from the group consisting
of C1 to C4 straight and branched chain monoalcohols, C2 to C4
mono- and polyalkylene glycols including ethylene glycol,
diethylene glycol, triethylene glycol, propylene glycol,
dipropylene glycol, tripropylene glycol, derivatives of C2 to C4
mono- and polyalkylene glycols provided that the molecular weights
of such polyalkylene glycols are suitable for use in the fuel
compositions of the present invention, and mixtures thereof. In
some embodiments, fuel compositions in which a monoalcohol is
included may also include at least one of tert-butyl alcohol, at
least one C2-C4 alkylene glycol or a mixture of both. In some
embodiments, ethyl alcohol or ethanol and propylene glycol may be
preferred. Ethanol is available commercially in the anhydrous form
(also referred to as absolute alcohol or 100% ethanol) and as
various proofs or percentages of ethanol where the additional
component in the ethanol is water, the most common being 190 proof
or 95 vol %. If ethanol is used for purposes other than as a
beverage, it is denatured by addition of substances, such as
methanol, 2-propanol, ethyl acetate, methyl isobutyl ketone,
heptane or kerosene, to make the product undesirable for human
consumption, but allows for its use for industrial purposes,
including as a component in fuel or as a fuel. As noted, ethanol
other than absolute ethanol is typically identified by use of the
term "proof," where the conversion between proof and the
concentration of ethyl alcohol is that 2 proof equals 1% by volume,
typically measured at 20.degree. C., although measurements at other
temperatures are also accepted, including e.g., 15.6.degree. C.
While various denaturants are available that can render ethanol
(with or without the presence of moisture or water) unsuitable for
human consumption, certain of such denaturants may not be suitable
for use in connection with fuels because of their adverse effects
on fuel stability, vehicle engines and fuel systems and emissions.
A list of denaturants used in connection with ethyl alcohol for
various purposes can be found in The Merck Index, Thirteenth
Edition, 2001, entry 3796, page 670. When used in the pyrolysis oil
emulsion fuel composition of the present invention, alcohol or a
mixture of the alcohols identified herein as useful, are included
at a concentration of about 0 wt % to about 30 wt % based on the
total weight of the fuel composition; or about 1 wt % to about 30
wt %; or about 2 wt % to about 20 wt %; or about 5 wt % to about 10
wt %; or about 7 wt % to about 8 wt %.
[0067] Alternatively, the C4 alcohol butyl alcohol is also useful
in the present invention. Where butyl alcohol is used it may be the
tert-butyl alcohol because it is more readily soluble in water.
However, n-butyl alcohol and sec-butyl alcohol are not completely
soluble in water, they may be used with adjustment in the type and
amount of emulsifier in the fuel composition in order to obtain a
stable emulsion. Tert-butyl alcohol can be used in place of or in
combination with ethanol, for example including mixtures in which
the relative amount, by weight, of ethanol to tert-butyl alcohol is
about 95/5 to 5/95; including useful amounts therebetween such as
about 85/15, 80/20, 75/25, 70/30, 65/35, 60/40, 55/45, 50/50,
45/55, 40/60, 35/65, 30/70, 25/75, 20/80, 15/85, and about
10/90.
Additives
[0068] Optionally, additives may be added to the emulsifier, the
pyrolysis oil, the water or combinations thereof. The additives
include but are not limited to cetane improvers, organic solvents,
other fuels such as diesel fuel, glycols, surfactants or
emulsifiers, other additives known for their use in fuel and the
like. The additives are added to the emulsifier, pyrolysis oil or
the water prior to, or in the alternative at, the emulsification
device(s), depending upon the solubility or other fluid properties
of the additive. The additives are generally in the range of about
1% to about 40% by weight, in another embodiment about 5% to about
30% by weight, and in another embodiment about 7% to about 25% by
weight of the fuel mixture.
[0069] An optional component that may be used as an additive to the
fuel mixture is supplementary combustible liquid such as "paint
thinner," turpentine or mineral spirits. The supplementary
combustible may be characterized as a low viscosity, low density
supplementary combustible liquid additive. Such an optional
component can be useful for the purpose of modifying one or more
properties of the fuel composition, including, for example, the
cetane number, density and viscosity. Consequently, the amount and
type of such component can be selected based on its combustion
properties as measured by the cetane number of the resulting fuel
composition, by the density of the resulting composition and by its
viscosity as well as its effect on the phase distribution of the
microemulsion in view of the amount and type of surfactant used. In
each instance the amount of the liquid added can be suitably
adjusted to produce a fuel composition having the overall balance
of properties suitable for the end use of the fuel product, for
example, as a fuel for a diesel engine, a furnace, etc., or for
adjusting the properties of the fuel composition for the ambient
temperature environment in which it is intended to be used, for
example, as an automotive diesel fuel for winter or summer use.
[0070] Useful supplementary combustible liquid additives of the
paint thinner type include products identified as hydrotreated,
light steam cracked naphtha residuum (petroleum), also referred to
as naphtha, petroleum, hydrotreated heavy, and identified as CAS
64742-48-9. This product has also been described as a complex
combination of hydrocarbons obtained by treating a petroleum
fraction with hydrogen in the presence of a catalyst.
[0071] Supplementary combustible liquids useful in the present
invention can include a broad range of petroleum distillate
materials as well as supplementary combustible liquids from other
sources, for example, plant or vegetable sources. Useful products
generally boil in the range of about 145.degree. C. to about
200.degree. C. Turpentine is a supplementary combustible fluid that
could be used.
[0072] Turpentine substitute is a mineral oil based replacement for
the vegetable-based organic solvent turpentine and it is suitable
for use herein. It is a hydrotreated light distillate of petroleum,
which forms a clear transparent liquid at ambient or room
temperature. It is a complex mixture of highly refined hydrocarbon
distillates mainly in the C9-C16 range. The liquid is highly
volatile and the vapors are flammable. It is a widely available as
a less costly substitute for turpentine. It is commonly used as an
organic solvent in painting and decorating, for thinning oil based
paint and cleaning brushes. Also known as turps substitute, mineral
turpentine, or simply turps, which can cause confusion with
vegetable-based turpentine.
[0073] White spirit, also known as Stoddard solvent is also
suitable for use herein. It is a paraffin-derived clear,
transparent liquid which is a common organic solvent used in
painting and decorating. It is a mixture of saturated aliphatic and
alicyclic C7 to C12 hydrocarbons with a maximum content of 25% of
C7 to C12 alkyl aromatic hydrocarbons. White spirit typically is
used as an extraction solvent, as a cleaning solvent, as a
degreasing solvent and as a solvent in aerosols, paints, wood
preservatives, lacquers, varnishes, and asphalt products. In
western Europe about 60% of the total white spirit consumption is
used in paints, lacquers and varnishes. White spirit is the most
widely used solvent in the paint industry.
[0074] The various fluids identified as "mineral spirits" are
suitable for use as a supplementary combustible fluid in the
present invention. Mineral spirits is commonly used as a paint
thinner and mild solvent and it is suitable for use herein. In
Europe, it is referred to as petroleum spirit. They are especially
effective in removing oils, greases, carbon and other material from
metal. Mineral spirits is derived from the light distillate
fractions during crude oil refining and comprise C6 to C11
compounds, with the majority being C9 to C11. There are many
different substances generally referred to as mineral spirits and
each generally has a different CAS number. One common type is
mineral oil spirits identified as CAS 64475-85-0, Stoddard solvent,
referred to above is a particular type, subcategory or subset of
mineral spirits, identified as CAS 8052-41-3 and contains 30-62 wt
% alkanes, 27-40 wt % cycloalkanes, 0.3-20 wt % alkylbenzenes,
0.007-0.1 wt % other benzenes, 0.2 wt % naphthalenes and 0.3 wt %
acenaphthalenes. Commercial Stoddard Solvent products are available
under the tradenames Varsol 1 and Texsolve S. Similarly, benzine is
another, subset of mineral spirits comprising C5 to C9 hydrocarbons
and boiling at about 154.degree. C. to about 204.degree. C. Mineral
spirits on the other hand comprise 20-65 wt % alkanes, 15-40 wt %
cycloalkanes and 10-30 wt % aromatics; the specific amount of each
varying depending on the particular "mineral spirit" being
considered.
[0075] Another supplementary combustible liquid that can be used is
kerosene. Kerosene is typically defined as a refined petroleum
solvent (predominantly C.sub.9-C.sub.16 hydrocarbon, which is
typically a mixture of 25% normal paraffins, 11% branched
paraffins, 30% monocycloparraffins, 12% dicycloparaffins, 1%
tricycloparrafins, 16% mononuclear aromatics and 5% dinuclear
aromatics. Alternatively, a product known as hydrotreated kerosene
(CAS No. 64742-47-8) can be used. As its name suggests, it is
derived from kerosene, or straight run kerosene, by hydrogenation
in order to saturate the double bonds present in various molecules
of kerosene.
[0076] Various chemical compounds have been identified that have
the ability to improve the cetane number of diesel fuel. Where
necessary or desired to meet specific performance requirements in
certain applications, one embodiment of the pyrolysis oil-based
water-fuel emulsion compositions of the present invention can
optionally include one or more compounds having the ability to
increase cetane number.
[0077] One useful type of cetane improver is nitrated alcohol
esters such as tetraethyl glycol cinitrate. Cetane improvers can be
added to tailor the final cetane number of the pyrolysis oil fuel.
Other useful cetane improvers include but are not limited to one or
more of peroxides, nitrates, nitrites, nitrocarbamates, mixtures
thereof and the like. Useful cetane improvers include but are not
limited to nitropropane, dinitropropane, tetranitromethane,
2-nitro-2-methyl-1-butanol, 2-methyl-2-nitro-1-propanol, and the
like. Also included are nitrate esters of substituted or
unsubstituted aliphatic or cycloaliphatic alcohols which may be
monohydric or polyhydric. These compounds include substituted and
unsubstituted alkyl or cycloalkyl nitrates having up to about 10
carbon atoms, and in one embodiment about 2 to about 10 carbon
atoms. The alkyl group may be either linear or branched, or a
mixture of linear or branched alkyl groups. Examples of such
compounds include methyl nitrate, ethyl nitrate, n-propyl nitrate,
isopropyl nitrate, allyl nitrate, n-butyl nitrate, isobutyl
nitrate, sec-butyl nitrate, tert-butyl nitrate, n-amyl nitrate,
isoamyl nitrate, 2-amyl nitrate, 3-amyl nitrate, tert-amyl nitrate,
n-hexyl nitrate, n-heptyl nitrate, n-octyl nitrate, 2-ethylhexyl
nitrate, sec-octyl nitrate, n-nonyl nitrate, n-decyl nitrate,
cyclopentyl nitrate, cyclohexyl nitrate, methylcyclohexyl nitrate,
and isopropylcyclohexyl nitrate. Also useful are the nitrate esters
of alkoxy-substituted aliphatic alcohols such as 2-ethoxyethyl
nitrate, 2-(2-ethoxy-ethoxy) ethyl nitrate,
1-methoxypropyl-2-nitrate, 4-ethoxybutyl nitrate, etc., as well as
diol nitrates such as 1,6-hexamethylene dinitrate. A useful cetane
improver is 2-ethylhexyl nitrate.
[0078] Organic peroxides can also be useful as cetane improvers in
the fuel compositions herein. Generally useful compounds are
dialkyl peroxides of the formula R1OOR2 wherein R1 and R2 are the
same or different alkyl groups having 1 to about 10 carbon atoms.
Suitable peroxide cetane improver compounds should be soluble in
the fuel composition and thermally stable at typical fuel
temperatures of operating engines. Peroxides wherein R1 and R2 are
tertiary alkyl groups having about 4 or about 5 carbon atoms are
especially useful. Examples of suitable peroxides include
di-tertiary butyl peroxide, di-tertiary amyl peroxide, diethyl
peroxide, di-n-propyl peroxide, di-n-butyl peroxide, methyl ethyl
peroxide, methyl-t-butyl peroxide, ethyl-t-butyl peroxide,
propyl-t-amyl peroxide, mixtures thereof and the like. In some
embodiments, peroxides may exhibit one or more of the following
characteristics: good solubility in the fuel, suitable water
partition coefficient characteristics, good thermal stability and
handling characteristics, have no impact on fuel quality or fuel
system components, and have low toxicity. A useful peroxide is
di-tertiary butyl peroxide, also sometimes referred to as tertiary
butyl peroxide.
[0079] Other suitable optional ingredients can be included in the
compositions of the present invention provided that they do not
substantially adversely affect performance of the composition and
its intended use. Included in the category of such other optional
ingredients would be, for example, thermal and aging stabilizers;
coloring agents, dyes and markers, particularly those permitted in
the European Union as set forth in EN 14214:2003-5.1; agents to
modify the odor of the mixture in order to prevent inadvertent
ingestion, including, for example, alkyds; etc. Alternatively, and
if necessary, agents can be added in a suitable amount, typically
at a low concentration, that are capable of modifying or masking an
unpleasant odor or smell, if any, of the exhausted gas after
combustion. Other conventional additives and blending agents for
fuel compositions of the present invention may be present. For
example, the fuels of this invention may contain conventional
quantities of such conventional additives as rust inhibitors such
as alkylated succinic acids and anhydrides, inhibitors of gum
formation, metal deactivators, upper cylinder lubricants, friction
modifiers, detergents, antioxidants, heat stabilizers,
bacteriostatic agents, microbiocides, fungicides and the like. Such
conventional additives may be present in the fuel composition at
concentrations of up to about 1 wt % based on the total weight of
the water-pyrolysis oil fuel emulsion; for example about 0.01 wt %
to about 1 wt %.
[0080] The amount of additives used can be suitably varied,
depending upon the purpose for which the additive is used and the
use of the final fuel product, for example. In some embodiments,
the additive may be used at about 0.1 wt % to about 30 wt %. In
other embodiments, the additive may be present at about 1 wt % to
about 25% wt %. In embodiments for use with engines, the additive
may be present at about 10 wt % to about 30 wt %, for example. In
embodiments for use with burners and heaters, the additives may be
present at about 10 wt % to about 20 wt %, for example. In some
embodiments, higher amounts of additives can be used, for example,
about 35 wt % or about 40 wt % or up to about 45 wt %.
Emulsification
[0081] The water-pyrolysis oil fuel emulsions comprise a pyrolysis
oil fuel phases and a water or aqueous phase. Either the pyrolysis
oil fuel phase or the aqueous phase may comprise the continuous
phase, with the other phase comprising the discontinuous or
dispersed phase, depending upon the method of preparation of the
fuel. The dispersed phase, being either the pyrolysis fuel phase or
the aqueous phase, may be comprised of droplets having a mean
diameter of about 25 microns or less, for example, 5 microns.
[0082] The emulsions may be prepared by various steps or sequences
of addition as described. For example, the steps may include (1)
mixing the pyrolysis oil and one or more emulsifiers and other
optional desired additives using standard mixing techniques to form
a pyrolysis oil-emulsifier mixture; (2) separately mixing water and
alcohol and other optional desired additives; and (3) mixing the
pyrolysis oil-emulsifier mixture with the water/alcohol mixture
under emulsifying mixing conditions to form the desired
water-pyrolysis oil fuel emulsion. Additional optional additives
may be added, such as during step 3, including for example ethanol,
propylene glycol, cetane improver, or mixtures thereof).
[0083] The water/alcohol mixture can optionally include, but is not
limited to, one or more alkylene glycol, alcohol, cetane improver
or mixtures thereof. In one embodiment the water, alcohol and/or
alkylene glycol and/or the cetane improver are mixed with one
another and fed continuously to the pyrolysis oil/surfactant
mixture. In another embodiment the water, alcohol and/or alkylene
glycol and/or the cetane improver or mixtures thereof flow out of
separate tanks, or various combinations thereof flow out of
separate tanks, into the emulsification device. In one embodiment
the water, alcohol and/or alkylene glycol and/or the cetane
improver mixture meets the pyrolysis oil fuel additives mixture
immediately prior to or in the emulsification device.
[0084] An exemplary flow chart showing the production of 1,000
kilograms of pyrolysis oil based biofuel is shown in FIG. 1. In
step (a), pyrolysis oil (728 kg) is offloaded into a main mix tank
(MMT). While offloading the pyrolysis oil, the mechanical mixer and
forwarding pump are turned on and optionally 1.0 kg of the ultra
low sulfur diesel (ULSD) fuel is added to the main mix tank in step
(b). In step (c), while mixing with the mechanical mixer, 8.5 kg of
Hypermer.RTM. 1083 is added to the main mixer. In step (d), while
mixing with the mechanical mixer, 2.5 kg of Incromide CDEA is
added. After all additions are made, the level of the tank is
recorded. The mixture is processed until the contents are well
mixed, for at least one turn of the tank contents. After the tank
contents are well mixed, the valving is opened and mixing of the
contents of the tank is continued, then the mixers are turned off
and the valves are closed.
[0085] The maximum amount of material, including water and
alcohols, to be put into the secondary mix tank is calculated
according to the size of the secondary mix tank. This is the so
called hydration phase, in which a first batch, such as 30% of the
water and ethylene glycol mixture, will be separately prepared and
added to the main mix tank and mixed for a period of time. The
water and ethylene glycol mixture can be separately prepared and
added in multiple batches, such as 2, 3, 4 or 5 batches, or can be
prepared all at once and added in discrete batches. This will
define the number of times the secondary mix tank will need to be
filled.
[0086] The secondary mix tank is filled with 57 kg. water (30% of
190 kg) in step (f) as the amount required for the hydration phase.
In step (g), the secondary mix tank is filled with 21 kg ethylene
glycol (30% of 70 kg) as the amount required for the hydration
phase. The water/glycol solution is mixed for at least 10 minutes.
While mixing with the mechanical mixer, the glycol solution from
the secondary mix tank is transferred to the main mix tank in step
(h). The mixers are turned on and the valves of the main mix tank
are opened to allow flow of the tank mixture. The mixture is
processed until the contents are well mixed, for at least one turn
of the tank contents, in step (i).
[0087] In step (j), the secondary mix tank is filled with the
second amount of water, 133 kg. (which is 190 kg.-57 kg) In step
(k), the secondary mix tank is filled with the second amount of
ethylene glycol, 49 kg (which is 70 kg-21 kg). The water and glycol
solution are mixed for at least 10 minutes.
[0088] While mixing the main mix tanks with the educators,
perforated line, and mechanical mixer, the water/glycol solution is
slowly transferred to the main mix tank in step 1. The mixers are
turned on and the valves are opened to allow flow of the tank
mixture. The mixture is processed until a stable emulsion has been
achieved.
[0089] Once a stable emulsion has been achieved, the mechanical
mixer can be shut off with valves closed and the contents of the
main mix tank can be routed to a transport tank or product storage
as a finished product in step m.
[0090] Various mixing devices well known in the art can be employed
to facilitate formation of an emulsified composition including, for
example, mixer-emulsifiers, which typically utilize a high speed
rotor operating in close proximity to a stator (such as a type made
by Charles Ross & Sons Co., NY), paddle mixers utilizing
paddles having various design configurations including, for
example, reverse pitch, anchor, leaf, gate, finger, double-motion,
helix, etc., including batch and in-line equipment, and the like.
Other methods of mixing useful in this embodiment as well as
generally in the present invention are further described herein
below. The processes of various embodiments of the present
invention can be carried out at a convenient temperature,
including, for example, at ambient or room temperature, such as
about 20.degree. C. to about 22.degree. C. or even as low as about
5.degree. C. and as high as about 32.degree. C. The time and
temperature of mixing can be varied provided that the desired
emulsified composition is achieved and, based on subsequent
observation and/or testing, it is suitably stable until it is used,
as well as during use. Under conditions wherein sediment may form
following mixing of the components of the fuel composition, it can
be desirable to wait for a period of time in order to allow for
sedimentation, if any, to occur, such material to subsequently be
removed or separated from the emulsified fuel composition.
Typically, such time period is at least about 4 minutes; in some
embodiments, it is about 5 minutes; in still other embodiments, it
is about 6 minutes or more. The amount of time can readily be
determined with limited and simple experiments and such time can be
adjusted, based on, for example, the type, quality and composition
of the pyrolysis employed, as well as the other components of the
mixture, including emulsifier(s).
[0091] Mixing methods in addition to those described above may be
suitable for use in some embodiments. Mixtures can be prepared with
traditional mixing or blending equipment such as vats or tank
equipped with motor driven stirrers having various configurations,
e.g., paddle, helix, etc. Mixing carried out in such equipment may
be time consuming, in some cases requiring greater than 10 minutes
of mixing, for example about 10 to about 30 minutes, alternately
about 15 to about 20 minutes, in order to achieve a uniform and
stable emulsion. However, such emulsions contain dispersed
particles having an average particle size, e.g., diameter or
average dimension on the order of greater than about 20 microns;
for example about 20 to about 50 microns; alternatively about 20 to
about 35 microns. Emulsions having an average particle size of
about 20 microns or greater are referred to as macroemulsions. A
fuel composition having macroemulsion characteristics will
typically exhibit properties that differ from the same fuel
composition having an average particle size that is significantly
smaller, in other words, a microemulsion or one in which the
particle size is less than about 20 microns, such as 19 microns or
less. For example, a given composition in macroemulsion form may
exhibit a higher viscosity, lower flash point and poorer stability
in a process requiring extended recirculation of the fuel
composition as well as requiring a greater amount of emulsifier in
order to produce a satisfactory and stable emulsion compared to the
same composition in microemulsion form.
[0092] In one method, fuel mixtures of the present invention are
prepared using ultrasonic mixing equipment, which equipment may
produce stable emulsions having a small particle size, for example
less than about 10 microns, or about 0.01 to about 5 microns on
average, in other words embodiments of a microemulsion. Equipment
of this type is available commercially as Sonolator ultrasonic
homogenizing system, available from Sonic Corp., of Stratford,
Conn. Such microemulsions may be prepared at ambient temperature,
for example about 22.degree. C., and at pressures of about 500 psi
to about 1500 psi, although pressures as high as 5000 psi can also
be used to produce stable microemulsions. The Sonolator system may
be useful in that it can be operated in alternative, useful modes,
including semi-continuous, continuous, single-feed or
multiple-feed. In particular, such a system operated in
multiple-feed mode can utilize feed tanks containing, for example,
pyrolysis, water, emulsifier and other components, such as alcohol,
cetane enhancer, alkyl glycol or alkyl glycol derivative, etc. Such
a system allows feeding of one or more of the components
simultaneously, sequentially or intermittently in order to achieve
a particularly desirable result, including but not limited to a
specific emulsion particle size, particle size distribution, mixing
time, etc. As noted above, fuel compositions prepared using
ultrasonic emulsification can be accomplished using a lower
concentration of emulsifier for the same concentration of other
components, particularly the pyrolysis oil and water. For example,
where a composition prepared without ultrasonic may require about
1.0 wt % emulsifier to obtain a satisfactory emulsion, it may only
require less than about 0.5 wt % emulsifier with the same
composition using an ultrasonic mixing equipment in order to obtain
a satisfactory emulsion, such as an enhanced emulsion having a
particle size that is smaller, resulting in a microemulsion. The
amount of emulsifier may be about 10% less than would be required
in the absence of ultrasonic emulsification; such as about 20%
less; about 30% less; about 40% less. In some embodiments, about
50%, 60%, 70%, 80% or even 90% less of emulsifier may be required
for a satisfactory emulsion with the use of ultrasonic energy
input. For example, an emulsified fuel composition requiring 1 wt %
emulsifier to obtain an average emulsion particle size of about 20
microns may be replaced with 0.2 wt % of the same emulsifier in the
same composition to obtain an emulsion having a particle size of
about 5 microns. For purposes herein, the use of a device that
introduces ultrasonic energy for mixing and emulsification is
referred to as a "high shear" method, regardless of the physical
processes that may occur on a microscopic or molecular scale.
[0093] Emulsification using high shear such as imparted by an
ultrasonic device results in an emulsion having a mean particle or
droplet size in the range of about 0.01 microns to less than about
20 microns; such as about 0.01 microns to about 15 microns; or
about 0.1 microns to about 10 microns; about 0.1 microns to about 8
microns; about 0.2 microns to about 6 microns; about 0.5 microns to
about 5 microns; about 0.5 microns to about 4 microns; about 0.5
microns to about 3 microns; about 0.5 microns to about 3 microns;
about 0.1 microns to about 2 microns; about 0.1 microns to about 1
micron; or about 0.1 microns to about 1 micron or less, for example
about 0.8 microns. According to one embodiment of the invention,
the dispersed phase of the fuel composition comprises droplets
having a mean diameter, or major dimension, of 5 microns or
less.
[0094] High-shear devices that may be used include but are not
limited to the Sonic Corporation Sonolator Homogenizing System, in
which pressure can be varied over a wide range, for example about
500 to about 5,000 psi; IKA Work Dispax, and shear mixers including
multistage, for example three stage rotor/stator combinations. The
tip speed of the rotor/stator generators may be varied by a
variable frequency drive that controls the motor. Silverson mixer
two-stage mixer, which also incorporates a rotor/stator design and
the mixer employs high-volume pumping characteristics similar to a
centrifugal pump. Inline shear mixers employing a rotor-stator
emulsification approach (Silverson Corporation); Jet Mixers,
venturi-style/cavitation shear mixers; Microfluidizer shear mixers,
high-pressure homogenization shear mixers (Microfluidics Inc.); and
any other available high-shear generating mixer capable of
producing the desired microemulsion, including high shear mixers
selected from the group consisting of Aquashear mixers (Flow
Process Technologies Inc.), pipeline static mixers, hydraulic shear
devices, rotational shear mixers, ultrasonic mixing, and
combinations thereof.
[0095] Mixing of the components may be conducted at ambient, or
substantially ambient, temperature conditions. It has been observed
that in some instances mixing to obtain the emulsified fuel
composition is accompanied by a slight exothermic response. Mixing
can be satisfactorily conducted at temperatures in the range of
about 5.degree. C. to about 75.degree. C.; for example about
10.degree. C. to about 65.degree. C.; or about 15.degree. C. to
about 55.degree. C.; or about 20.degree. C. to about 45.degree. C.;
such as 22.degree. C. to about 35.degree. C.
EXAMPLES
[0096] For the following experiments, the components were combined
using a lab mixer IKA RW20 digital. Low/medium mixing speed was in
the range 700 to 1,100 rpm. Medium/high mixing speed was in the
range 1,000 to 1,800 rpm.
Example 1
TABLE-US-00001 [0097] TABLE 1 Raw Material Weight % Pyrolysis oil
72.90 Water 19.00 Ethylene glycol 7.00 Hypermer 1083SF 0.85
MONAMINE .TM. ADD-100 0.25 (Indromide .TM. CDEA)
[0098] A fuel mixture was prepared according to Table 1, including
the following components: 729 grams pyrolysis oil; 190 grams water;
70 grams ethylene glycol; 8.5 grams of Hypermer 1083SF; and 2.5
grams MONAMINE.TM. ADD-100. The crude pyrolysis oil used in the
example was produced from post consumer plastic treatment.
[0099] In one beaker, the non-ionic polymeric surfactant CRODA
Hypermer 1083SF (0.85%) was added to the CRODA co-surfactant
(0.25%) Monoamine ADD-100. They were mixed using low-medium
speed/shear for a few minutes (about 4 minutes). (Alternatively,
they could be mixed for from about 1-20 minutes, depending upon the
quantity of fuel being produced.) The blend of the two surfactants
was added to the crude pyrolysis oil feedstock (72.90%) and mixed
at medium/high speed/shear for few minutes (from about 5 to about 7
minutes). (Alternatively, they could be mixed for from about 5 to
30 minutes, depending upon the quantity of fuel being
produced.)
[0100] In another beaker, the glycol (7.0%) was blended with the
water (19.0%) and mixed at low/medium speed/shear for a few
minutes. (Alternatively, depending upon the quantity being
produced, it may be mixed from about 1 to about 20 minutes). Twenty
percent in weight of the water/glycol blend was added to the
pyrolysis oil/surfactant blend while stirring with a mixer at
medium/high speed for few minutes (about 10 minutes, but it may
alternatively be mixed from about 5 to about 30 minutes depending
upon the quantity being produced). This is the hydration phase.
[0101] Slowly, allowing about 3 minutes for this addition, the
remaining 80% of the water/glycol blend was added while increasing
the rpm of the mixing process up to medium high speed/shear. The
final emulsion was mixed for few minutes (for about 10 minutes).
(Alternatively, the water/glycol blend may be added over about 1 to
about 30 minutes, and then mixed for about 5 to about 45 minutes,
depending upon the quantity of fuel being produced.)
[0102] The resulting fuel composition was tested for kinematic
viscosity, gross heat of combustion (bomb calorimetry), pH, and
pour point according to standard methods. The results are shown in
Table 2.
TABLE-US-00002 TABLE 2 Test Description Test Method Result
Kinematic Viscosity A5/ASTM D445 5.17 cSt Gross Heat of Combustion
A51/ASTM D240 35.01 MJ/Kg (15,054 btu/lb) pH A23/ASTM E70 7.53 Pour
Point A32/ASTM D6749 -59.degree. C.
[0103] The fuel composition was then successfully combined with 10%
diesel, indicating that the emulsion was dispersible in diesel
fuels.
Example 2
[0104] An oil in water emulsified biofuel was prepared including
the components shown in Table 3 to produce 1000 g of the final fuel
product. The crude pyrolysis oil used in this example was produced
from a feedstock including a combination of post consumer plastic
and paper.
TABLE-US-00003 TABLE 3 Raw Material Weight % Pyrolysis oil 72.40
Water 19.00 Ethylene glycol 7.40 Chemax EM-1169 1.03 Tween 80 0.07
#2 Diesel Fuel 0.10
[0105] A beaker was used having a simple impeller stirrer with a
diameter equal to 2/3 of the diameter of the beaker. The main mix
beaker was filled with the required amount of water. While mixing
with the mixer, the required amount of ethylene glycol was added to
the main mix beaker. The water and ethylene glycol were mixed using
the mixer until the contents were well mixed, for about 3
minutes.
[0106] The required amount of #2 Diesel fuel was added to a
secondary mixing beaker. Next, 30% of the pyrolysis oil was added
to the secondary mixing beaker while mixing, and then 30% of the
Chemax 1169 was added to the secondary mixing beaker while mixing.
Mixing was continued until the contents were well mixed, for about
5 minutes. These steps were repeated with additional quantities of
the pyrolysis oil and the Chemax 1169 being added to the secondary
mixing beaker until only the final amount of each remained. The
final amount the pyrolysis oil was then added to the secondary mix
beaker. While mixing, the final amount of the Chemax 1169 was added
to the secondary mix beaker. Next, again while mixing, the Tween 80
was added to the secondary mix beaker. Mixing was continued until
the mixture was mixed, for about 10 minutes. This mixture was added
to the main mix beaker while mixing with the mixer.
[0107] The combined contents were mixed in the main mixer until a
stable emulsion was achieved. This required about 10 minutes. A
color change of bright white/yellow was seen, indicating that a
stable emulsion had formed. The final product was tested, and the
lab results are shown in the table 4. The lower heat of combustion
for this fuel product, as compared to the fuel product of Example
1, likely reflects the difference in the source materials used for
producing the crude pyrolysis oil used in this example.
TABLE-US-00004 TABLE 4 Method Test Result Units ASTM D4052 Density
of Liquids by Digital 0.9879 Density Meter Relative Density at
15.56.degree. C. ASTM D2709 Bottom water and sediment - <0.05%
stability test by centrifuge ASTM D93 Pensky-Martens Closed Cup
Flash >210.degree. F. Point (Corrected Flash Point) ASTM D445
Kinematic/Dynamic Viscosity 4.94 cSt Kinematic viscosity at
104.degree. F./40.degree. C. ASTM D240 Heat of Combustion by Bomb
28.91 MJ/kg Calorimeter Gross (12,431 btu/lb) ASTM D97 Pour Point
of Petroleum -24.degree. C. (11.2.degree. F.) Products/Pour Point
Digital pH at 20.degree. C. 5.7 pH meter
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