U.S. patent application number 12/147783 was filed with the patent office on 2009-01-01 for aviation-grade kerosene from independently produced blendstocks.
This patent application is currently assigned to ENERGY & ENVIRONMENTAL RESEARCH CENTER FOUNDATION. Invention is credited to Ted R. Aulich, Carsten Heide, Ron C. Timpe, Chad A. Wocken.
Application Number | 20090000185 12/147783 |
Document ID | / |
Family ID | 40158759 |
Filed Date | 2009-01-01 |
United States Patent
Application |
20090000185 |
Kind Code |
A1 |
Aulich; Ted R. ; et
al. |
January 1, 2009 |
AVIATION-GRADE KEROSENE FROM INDEPENDENTLY PRODUCED BLENDSTOCKS
Abstract
Aviation-grade kerosene comprising a first blendstock derived
from non-petroleum feedstock and comprising primarily hydrocarbons
selected from the group consisting of isoparaffins and normal
paraffins, and a second blendstock comprising primarily
hydrocarbons selected from the group consisting of cycloalkanes and
aromatics. A method for the production of aviation-grade kerosene
comprising producing a first blendstock from at least one
non-petroleum feedstock, the first blendstock comprising primarily
hydrocarbons selected from the group consisting of isoparaffins and
normal paraffins; producing a second blendstock comprising
primarily hydrocarbons selected from the group consisting of
cycloalkanes and aromatics; and blending at least a portion of the
first blendstock with at least a portion of the second blendstock
to produce aviation-grade kerosene.
Inventors: |
Aulich; Ted R.; (Grand
Forks, ND) ; Timpe; Ron C.; (Grand Forks, ND)
; Wocken; Chad A.; (Grand Forks, ND) ; Heide;
Carsten; (Fible, DE) |
Correspondence
Address: |
CONLEY ROSE, P.C.;David A. Rose
P. O. BOX 3267
HOUSTON
TX
77253-3267
US
|
Assignee: |
ENERGY & ENVIRONMENTAL RESEARCH
CENTER FOUNDATION
Grand Forks
ND
|
Family ID: |
40158759 |
Appl. No.: |
12/147783 |
Filed: |
June 27, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60947126 |
Jun 29, 2007 |
|
|
|
Current U.S.
Class: |
44/308 ;
44/300 |
Current CPC
Class: |
C10G 2300/1014 20130101;
C10G 2400/08 20130101; C10G 2300/1011 20130101; C10G 2300/1022
20130101; C10G 2300/1025 20130101; C10G 2/32 20130101; Y02P 30/20
20151101; C10L 1/04 20130101 |
Class at
Publication: |
44/308 ;
44/300 |
International
Class: |
C10L 1/18 20060101
C10L001/18 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] This invention was made with government support under
contract W911NF-07-C-0046 awarded by the Defense Advanced Research
Projects Agency (DARPA). The government has certain rights in the
invention.
Claims
1. Aviation-grade kerosene comprising: a first blendstock derived
from non-petroleum feedstock and comprising primarily hydrocarbons
selected from the group consisting of isoparaffins and normal
paraffins; and a second blendstock comprising primarily
hydrocarbons selected from the group consisting of cycloalkanes and
aromatics.
2. The aviation-grade kerosene of claim 1 wherein the second
blendstock is derived from feedstock comprising non-petroleum
feedstock.
3. The aviation-grade kerosene of claim 1 that is capable of being
blended with petroleum-derived jet fuel in any proportion such that
the resulting blend meets fuel grade specification of the
petroleum-derived jet fuel.
4. The aviation-grade kerosene of claim 3 comprising up to 95 vol.
% of first blendstock and up to 35 vol. % of second blendstock.
5. The aviation-grade kerosene of claim 4, comprising up to 95 vol.
% first blendstock, from about 0 vol. % to about 30 vol. %
cycloalkanes, and from about 0 vol. % to about 15 vol. %
aromatics.
6. The aviation-grade kerosene as in claim 5 wherein
fit-for-purpose requirements are met.
7. The aviation-grade kerosene of claim 6 wherein at least 50
weight % of the kerosene is derived from coal, natural gas, or a
combination thereof.
8. The aviation-grade kerosene of claim 6 wherein the second
blendstock is derived from coal, biomass, oil-shale, tar, oil
sands, or a combination thereof.
9. The aviation-grade kerosene of claim 6 wherein at least 50
weight % of the kerosene is derived from biomass.
10. The aviation-grade kerosene of claim 1 wherein at least 10
weight % of the kerosene is derived from non-cracked bio-oil.
11. A method for the production of aviation-grade kerosene
comprising: producing a first blendstock from at least one
non-petroleum feedstock, the first blendstock comprising primarily
hydrocarbons selected from the group consisting of isoparaffins and
normal paraffins; producing a second blendstock comprising
primarily hydrocarbons selected from the group consisting of
cycloalkanes and aromatics; and blending at least a portion of the
first blendstock with at least a portion of the second blendstock
to produce aviation-grade kerosene.
12. The method of claim 11 wherein first and second blendstocks are
independently-produced.
13. The method of claim 11 wherein the non-petroleum feedstock is
selected from the group consisting of coal, natural gas, biomass,
vegetable oils, biomass pyrolysis bio-oils, biologically-derived
oils and combinations thereof.
14. The method of claim 13 wherein first blendstock is produced via
indirect liquefaction.
15. The method of claim 14 wherein indirect liquefaction comprises
Fischer-Tropsch processing of a feedstock selected from the group
consisting of natural gas, coal, biomass, and combinations
thereof.
16. The method of claim 15 wherein the kerosene comprises up to
about 90 vol. % first blendstock.
17. The method of claim 11 wherein the at least one non-petroleum
feedstock comprises triglyceride and/or fatty acid feedstock.
18. The method of claim 17 wherein the kerosene comprises from
about 65 vol. % to about 75 vol. % first blendstock.
19. The method of claim 18 wherein the kerosene comprises about 70
vol. % first blendstock produced via catalytic processing of
triglyceride and/or fatty acid feedstock and about 30 vol. % second
blendstock produced via pyrolysis processing of high
cycloalkane-content material.
20. The method of claim 18 wherein second blendstock is produced by
catalytic cyclization and/or reforming of a portion of the first
blendstock.
21. The method of claim 20 wherein the kerosene comprises about 65
vol. % first blendstock and about 35 vol. % second blendstock.
22. The method of claim 11 wherein second blendstock is produced
via pyrolysis of a feedstock selected from the group consisting of
coal, oil shale, oil sands, tar, biomass, and combinations
thereof.
23. The method of claim 22 wherein the kerosene comprises about 80
vol. % first blendstock produced via Fischer-Tropsch processing of
natural gas, coal, and/or biomass and about 20 vol. % second
blendstock produced via pyrolysis processing of coal tar
fraction.
24. The method of claim 11 wherein second blendstock is produced
via direct liquefaction.
25. The method of claim 24 wherein the kerosene comprises about 25
vol. % second blendstock.
26. The method of claim 25 wherein the kerosene comprises about 75
vol. % first blendstock derived from Fischer-Tropsch processing of
natural gas, coal, and/or biomass.
27. The method of claim 11 wherein second blendstock is produced
from a biomass-derived lignin feedstock.
28. The method of claim 27 wherein kerosene comprises from about 25
vol. % to about 30 vol. % second blendstock.
29. The method of claim 28 wherein kerosene comprises about 30 vol.
% second blendstock produced via pyrolysis processing of
biomass-derived lignin and about 70 vol. % first blendstock
produced via Fischer-Tropsch processing of natural gas, coal,
and/or biomass.
30. The method of claim 28 wherein kerosene comprises about 25 vol.
% second blendstock and about 75 vol. % first blendstock derived
from catalytic processing of triglyceride feedstock.
31. The method of claim 12 further comprising testing the aviation
grade kerosene for at least one requirement selected from the group
consisting of fit-for-purpose requirements, ASTM requirements, and
combinations thereof.
32. The method of claim 31 further comprising adjusting the ratio
of first blendstock and second blendstock in the kerosene to meet
at least one requirement selected from the group consisting of
fit-for-purpose requirements, ASTM requirements, and combinations
thereof.
33. The method of claim 31 further comprising adjusting the amount
of cycloalkanes and aromatics in the second blendstock to meet at
least one requirement selected from the group consisting of
fit-for-purpose requirements, ASTM requirements, and combinations
thereof.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. 119(e)
of U.S. Provisional Patent Application No. 60/947,126 entitled
"Aviation-Grade Kerosene From Independently Produced Blendstocks,"
filed Jun. 29, 2007, the disclosure of which is hereby incorporated
herein by reference.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0003] The present invention relates generally to aviation-grade
high-cetane kerosene fuel. More particularly, herein disclosed is
an aviation-grade kerosene fuel produced in part or fully from
non-petroleum feedstocks. Specifically, the disclosed kerosene fuel
comprises at least two independently produced blendstocks, with the
first blendstock comprising primarily isoparaffins and normal
paraffins (I/N) derived from non-petroleum feedstocks and the
second blendstock comprising primarily cycloalkanes and aromatics
(C/A) derived from petroleum or non-petroleum feedstocks. In
embodiments, a kerosene fuel suitable for use as aviation turbine
fuel having drop-in and fit-for-purpose compatibility with
conventional petroleum-derived fuels comprises up to 95 volume %
(vol. %) I/N blendstock and up to 35 vol. % C/A blendstock.
BACKGROUND OF THE INVENTION
[0004] The generic term "kerosene" is used to describe the fraction
of crude petroleum that boils approximately in the range of
293.degree. F. to 572.degree. F. (145.degree. C. to 300.degree. C.)
and consists of hydrocarbons primarily in the range of
C.sub.8-C.sub.16. Kerosenes are the lighter end of a group of
petroleum substances known as middle distillates.
[0005] As an example, the predominant use of high-cetane kerosene
in the United States is aviation turbine fuel for civilian (Jet A
or Jet A-1) and military (JP-8 or JP-5) aircraft. Kerosene-based
fuels differ from each other in performance specifications. Jet A
and Jet A-1 are kerosene-type fuels. The primary physical
difference between Jet A and Jet A-1 is freeze point (the
temperature at which wax crystals disappear in a laboratory test).
Jet A, which is mainly used in the United States, must have a
freeze point of -40.degree. C or below, while Jet A-1 must have a
freeze point of -47.degree. C. or below. Jet A does not normally
contain a static dissipater additive, while Jet A-1 often requires
this additive. There are additional differences between the two
fuels, and full specifications are outlined under the ASTM D1655
and Def Stan 91-91/5 standards, respectively.
[0006] Military turbine fuel grades such as JP-5 and JP-8 are
defined by Mil-DTL-5624 and Mil-DTL-83133, respectively. These
fuels are kerosene-type fuels made to more exacting specifications
than the commercial jet fuels. They also contain unique performance
enhancing additives. Throughout the world, many governments have
issued a variety of standards such as for TS-1 premium kerosene,
TS-1 regular kerosene, and T-1 regular kerosene in Russia. The
crude oil fraction for all of these aviation-grade kerosenes is
basically limited to the range of 300.degree. F. to 500.degree. F.
(149.degree. C. to 260.degree. C.), with additional specifications
based on recovery rates at given temperature points. Hydrocarbons
are primarily in the range of C.sub.8-C.sub.16.
[0007] The ready availability of crude petroleum has encouraged the
establishment of the above-mentioned specifications for kerosene as
the basis for fuels in engines of various types, and engines have
thus been optimized to run on kerosene having these specifications.
Concern has arisen regarding the reliability and availability of
the petroleum supply. This concern has stimulated a search for
substitutes. Liquids derived from coal, shale, tar sands, and
renewable resources such as biomass, in particular, plant material,
have been proposed. These processes have not adequately produced
aviation-grade kerosene that complies with today's jet fuel
specifications.
[0008] The failure of obtaining suitable aviation-grade kerosenes
from non-petroleum feedstocks has triggered development in
downstream processing of the products. For example, U.S. Pat. No.
4,645,585 discloses the production of novel fuel blends from
hydroprocessing highly aromatic heavy oils such as those derived
from coal pyrolysis and coal hydrogenation.
[0009] International Patent WO 2005/001002 A2 relates to a
distillate fuel comprising a stable, low-sulfur, highly paraffinic,
moderately unsaturated distillate fuel blendstock. The highly
paraffinic, moderately unsaturated distillate fuel blendstock is
prepared from a Fischer-Tropsch-derived product that is
hydroprocessed under conditions during which a moderate amount of
unsaturates are formed or retained to improve stability of the
product.
[0010] Although many physical properties for aviation-grade
kerosene can be matched and even outperformed, the fuels derived by
hydroprocessing and additional upgrading as described above do not
provide drop-in compatibility with conventional petroleum-derived
aviation-grade kerosene, as they lack some of the major hydrocarbon
constituents of typical petroleum-derived kerosene.
[0011] An attempt for better modeling of the variety of different
hydrocarbon constituents was made by Violi et al. (Violi, A.; Yan,
S.; Eddings, E. G.; Sarofim, A. F.; Granata, S.; Faravelli, T.;
Ranzi, E.; Combust. Sci. Technol. 2002, 174 (11-12) 399-417). Violi
et al. modeled JP-8 as a six-compound blend of well-known
hydrocarbons with the following molar composition: 10% iso-octane
(C.sub.8H.sub.18), 20% methylcyclohexane (C.sub.7H.sub.14), 15%
m-xylene (C.sub.8H.sub.10), 30% normal-dodecane (C.sub.12H.sub.26),
5% tetralin (C.sub.10H.sub.12), and 20% tetradecane
(C.sub.14H.sub.30). This surrogate blend simulates the volatility
and smoke point of a practical JP-8 fuel. However, this method of
reducing the fuel to a mere six-compound blend does not reproduce
all required performance specifications of JP-8.
[0012] A different route was pursued in U.S. Patent Application
2006/0138025, which relates to distillate fuels or distillate fuel
blendstocks comprising a blend of a Fischer-Tropsch-derived product
and a petroleum-derived product that is then hydrocracked under
conditions to preserve aromatics. While this may produce some
required characteristics from certain petroleum feedstocks, such as
seal swell and density, this approach reduces the ability to
achieve competing characteristics, such as freeze point
specifications.
[0013] Accordingly, there is an ongoing need for a fuel and process
that allow use of environmentally-sensitive processes as a bridge
to the future and provide drop-in compatibility with existing
petroleum-based aviation-grade kerosene for clean fuels produced
from secure domestic resources.
SUMMARY
[0014] Herein disclosed is aviation-grade kerosene comprising: a
first blendstock derived from non-petroleum feedstock and
comprising primarily hydrocarbons selected from the group
consisting of isoparaffins and normal paraffins, and a second
blendstock comprising primarily hydrocarbons selected from the
group consisting of cycloalkanes and aromatics. In embodiments, the
second blendstock is derived from feedstock comprising
non-petroleum feedstock. It is desirable for the aviation-grade
kerosene is capable of being blended with petroleum-derived jet
fuel in any proportion such that the resulting blend meets fuel
grade specification of the petroleum-derived jet fuel. In
embodiments, the aviation-grade kerosene comprises up to 95 vol. %
of first blendstock and up to 35 vol. % of second blendstock.
[0015] In specific embodiments, the aviation-grade kerosene
comprises up to 95 vol. % first blendstock, from about 0 vol. % to
about 30 vol. % cycloalkanes, and from about 0 vol. % to about 15
vol. % aromatics. In embodiments, this kerosene comprising up to 95
vol. % first blendstock, from about 0 vol. % to about 30 vol. %
cycloalkanes, and from about 0 vol. % to about 15 vol. % aromatics
meets fit-for-purpose requirements. In embodiments, at least 50
weight % of the kerosene is derived from coal, natural gas, or a
combination thereof. In embodiments, the second blendstock is
derived from coal, biomass, oil-shale, tar, oil sands, or a
combination thereof. In embodiments, at least 50 weight % of the
kerosene is derived from biomass. In embodiments, at least 10
weight % of the kerosene is derived from non-cracked bio-oil.
[0016] Also disclosed herein is a method for the production of
aviation-grade kerosene comprising: producing a first blendstock
from at least one non-petroleum feedstock, the first blendstock
comprising primarily hydrocarbons selected from the group
consisting of isoparaffins and normal paraffins; producing a second
blendstock comprising primarily hydrocarbons selected from the
group consisting of cycloalkanes and aromatics; and blending at
least a portion of the first blendstock with at least a portion of
the second blendstock to produce aviation-grade kerosene. In
embodiments of the method for the production of aviation-grade
kerosene, first and second blendstocks are independently-produced.
In embodiments of the method, the non-petroleum feedstock is
selected from the group consisting of coal, natural gas, biomass,
vegetable oils, biomass pyrolysis bio-oils, biologically-derived
oils and combinations thereof.
[0017] In some embodiments of the method, at least a portion of
first blendstock is produced via indirect liquefaction. Indirect
liquefaction may comprise Fischer-Tropsch processing of a feedstock
selected from the group consisting of natural gas, coal, biomass,
and combinations thereof. The kerosene may comprise up to about 90
vol. % first blendstock produced via indirect liquefaction.
[0018] In embodiments of the method for the production of
aviation-grade kerosene, the at least one non-petroleum feedstock
comprises triglyceride and/or fatty acid feedstock. The kerosene
may comprise from about 65 vol. % to about 75 vol. % of first
blendstock, the at least one non-petroleum feedstock for which
comprises triglyceride and/or fatty acid feedstock. In embodiments,
second blendstock is produced by catalytic cyclization and/or
reforming of a portion of first blendstock, the at least one
non-petroleum feedstock for which comprises triglyceride and/or
fatty acid feedstock. The kerosene may comprise about 65 vol. %
first blendstock, the at least one non-petroleum feedstock for
which comprises triglyceride and/or fatty acid feedstock; and about
35 vol. % second blendstock produced by catalytic cyclization
and/or reforming of a portion of first blendstock.
[0019] In some embodiments, the kerosene comprises about 70 vol. %
first blendstock produced via catalytic processing of triglyceride
and/or fatty acid feedstock and about 30 vol. % second blendstock
produced via pyrolysis processing of high cycloalkane-content
material.
[0020] In embodiments of the method for the production of
aviation-grade kerosene, second blendstock is produced via
pyrolysis of a feedstock selected from the group consisting of
coal, oil shale, oil sands, tar, biomass, and combinations thereof.
In specific embodiments, the kerosene may comprise about 80 vol. %
first blendstock produced via Fischer-Tropsch processing of natural
gas, coal, and/or biomass and about 20 vol. % second blendstock
produced via pyrolysis processing of coal tar fraction.
[0021] In some embodiments of the method for the production of
aviation-grade kerosene, the second blendstock is produced via
direct liquefaction. In embodiments, the kerosene comprises about
25 vol. % second blendstock produced via direct liquefaction. In
specific embodiments, the kerosene further comprises about 75 vol.
% first blendstock derived from Fischer-Tropsch processing of
natural gas, coal, and/or biomass.
[0022] In some embodiments of the method for the production of
aviation-grade kerosene, second blendstock is produced from a
biomass-derived lignin feedstock. The kerosene may comprise from
about 25 vol. % to about 30 vol. % second blendstock produced from
a biomass-derived lignin feedstock. In some embodiments, the
kerosene comprises about 30 vol. % second blendstock produced via
pyrolysis processing of biomass-derived lignin and about 70 vol. %
first blendstock produced via Fischer-Tropsch processing of natural
gas, coal, and/or biomass. In embodiments, the kerosene comprises
about 25 vol. % second blendstock produced from a biomass-derived
lignin feedstock and about 75 vol. % first blendstock derived from
catalytic processing of triglyceride feedstock.
[0023] In embodiments of the method for the production of
aviation-grade kerosene, the method further comprises testing the
aviation grade kerosene for at least one requirement selected from
the group consisting of fit-for-purpose requirements, ASTM
requirements, and combinations thereof. In embodiments, the method
further comprises adjusting the ratio of first blendstock and
second blendstock in the kerosene to meet at least one requirement
selected from the group consisting of fit-for-purpose requirements,
ASTM requirements, and combinations thereof. In some embodiments,
the method further comprises adjusting the amount of cycloalkanes
and aromatics in the second blendstock to meet at least one
requirement selected from the group consisting of fit-for-purpose
requirements, ASTM requirements, and combinations thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] For a more detailed description of the preferred embodiment
of the present invention, reference will now be made to the
accompanying drawings, wherein:
[0025] FIG. 1 is a schematic of an indirect liquefaction process
suitable for producing isoparaffin/n-paraffin (I/N) blendstock
according to an embodiment of the present disclosure.
[0026] FIG. 2 is a schematic of a pyrolysis process suitable for
producing cycloalkane/aromatic (C/A) blendstock according to an
embodiment of the present disclosure.
[0027] FIG. 3 is a schematic of a direct liquefaction process
suitable for producing cycloalkane/aromatic (C/A) blendstock
according to an embodiment of the present disclosure.
[0028] FIG. 4 is a comparison of gas chromatography data from FT
(FT derived liquid fuel from natural gas--bottom) and Fuel Sample A
(top) produced from two discrete blendstocks and technological
process: (1) an isoparaffinic kerosene (IPK) produced from FT
technology and natural gas feedstock and (2) an
aromatic/cycloparaffinic blendstock produced from petroleum
feedstock.
[0029] FIG. 5 is a comparison of gas chromatography data from
typical JP-8 (bottom) and Fuel Sample C (top) produced from two
discrete blendstocks and technological process: (1) an
isoparaffinic kerosene (IPK) produced from a crop oil feedstock and
(2) an aromatic/cycloparaffinic blendstock produced from a crop oil
feedstock.
NOTATION AND NOMENCLATURE
[0030] The term "I/N blendstock" as used herein refers to a
material that comprises at least 95 weight % of isoparaffins,
normal paraffins, or a mixture thereof.
[0031] The term "C/A blendstock" as used herein refers to a
material that comprises at least 95 weight % of cycloalkanes,
aromatics, or a mixture thereof.
[0032] The terms "aviation-grade kerosene" or "jet fuel" as used
herein refer to kerosene-type fuels that are specified by military
turbine fuel grades such as JP-5 and JP-8 and defined by
Mil-DTL-5624 and Mil-DTL-83133, respectively, or civilian aviation
jet fuels such as Jet A or Jet A-1 with full specifications
outlined under the ASTM D1655 and Def Stan 91-91/5 standards,
respectively. Throughout the world there exist a variety of similar
standards that might change over time and are considered under this
definition.
[0033] The term "fit-for-purpose requirements" as used herein
refers to fuel property requirements that are not necessarily
addressed by military or ASTM standards, but are still important to
fuel performance and stability in jet engines and during fuel
handling, distribution, and storage. Examples of fit-for-purpose
requirements include fuel compatibility with aircraft fuel and
engine system materials of construction, adequate fuel performance
in compression ignition (versus turbine) engines in a wide variety
of ground environments, and possible fuel performance requirements
related to swelling of elastomeric seals in, for example, turbine
engines.
[0034] The term "drop-in compatibility" as used herein refers to
aviation-grade kerosene capable of being blended with
petroleum-derived jet fuel in any proportion (i.e. from 0% to 100%)
such that the resulting blend meets fuel grade specification and
fit-for-purpose requirements of the equivalent petroleum-based jet
fuel.
[0035] The term "I/N-C/A fuel" as used herein refers to
aviation-grade kerosene derived from at least two independently
produced blendstocks, with a first I/N blendstock derived from
non-petroleum feedstocks and a second C/A blendstock derived from
petroleum or non-petroleum feedstocks.
DETAILED DESCRIPTION
I. OVERVIEW
[0036] Herein disclosed are a fuel and a method for making the fuel
whereby the fuel has drop-in compatibility with existing
petroleum-derived fuels and enables production of most or all of a
fuel from domestic, non-petroleum, and/or renewable feedstocks. The
method of making this aviation-grade jet fuel may allow broad
flexibility in fuel formulation in order to meet specific end-use
requirements. The disclosed I/N-C/A fuel comprises a blend of fuel
components, namely straight-chain (normal) and branched (iso-)
paraffins, cycloalkanes, and/or aromatics.
[0037] Meeting a specification for aviation-grade kerosene requires
providing a complex mixture of fuel chemical classes that have
conflicting effects on physical properties. For example, longer
carbon chain molecules serve to reduce volatility and increase
density, which in turn raises freeze point above acceptable levels
for high altitude flight. Balancing these characteristics along
with energy density, flash point, viscosity, smoke point,
seal-swelling capacity, and other characteristics makes fuel
formulation difficult when derived from a single non-petroleum
resource.
[0038] The aviation-grade kerosene herein disclosed is produced
from at least two independently-produced blendstocks, with a first
blendstock comprising primarily hydrocarbons selected from the
group consisting of isoparaffins and normal paraffins (I/N) and
derived from non-petroleum feedstocks and a second blendstock
comprising primarily hydrocarbons selected from the group
consisting of cycloalkanes and aromatics (C/A) and derived from
petroleum or non-petroleum feedstocks. In embodiments, the finished
I/N-C/A jet fuel comprises up to 95 volume % (vol. %) I/N
blendstock and up to 35 (vol. %) C/A blendstock.
II. KEROSENE
[0039] Petroleum-based kerosene may be obtained either from the
atmospheric distillation of crude oil ("straight-run" kerosene) or
from cracking of heavier petroleum streams ("cracked" kerosene).
The kerosene is further treated by a variety of processes to remove
or reduce the level of undesirable components, e.g., aromatic
hydrocarbons, sulfur, nitrogen, or olefinic materials. This
additional processing also reduces compositional variation and
enriches components that improve performance (cycloalkanes and
isoparaffins, for example). In practice, the major processes used
are hydrodesulfurization (treatment with hydrogen to remove sulfur
components), washing with caustic soda solution (to remove sulfur
components), and hydrogenation (to remove, for example, olefins,
sulfur, metals, and/or nitrogen components). Aromatics that may
have formed during the cracking process are removed via solvent
extraction. For instance, hydrodesulfurized kerosene is obtained by
treating a kerosene-range petroleum stock with hydrogen to convert
organic sulfur to hydrogen sulfide, which is then removed. These
subsequent treatments may blur the distinction between straight-run
and cracked kerosenes.
[0040] While kerosenes are essentially similar in composition, the
precise composition of a specific kerosene-range refinery stream
depends on the crude oil from which the kerosene was derived and on
the refinery processes used for its production. Because they are
complex hydrocarbon mixtures, materials in this category are
typically not defined by detailed compositional data but instead by
process history, physical properties, and product-use ASTM and
similar specifications.
[0041] Consequently, detailed compositional information for the
streams in this category is limited. General compositional
information on representative kerosene-range refinery streams and
fuels, presented in Table 1, illustrates the fact that the
materials in this category are similar in physical properties and
composition. Regardless of crude oil source or processing history,
major components of kerosenes comprise branched and straight-chain
paraffins (iso- and normal or n-alkanes) and naphthenes
(cycloparaffins or cycloalkanes), which normally account for at
least 75 vol. % of a finished fuel. Aromatic hydrocarbons in this
boiling range, such as alkylbenzenes (single ring) and
alkylnaphthalenes (double ring) do not normally exceed 25 vol. % of
a kerosene product. Olefins are usually not present at more than 5%
by volume. The distillation range of kerosenes is such that benzene
(80.degree. C. boiling point) and normal-hexane (69.degree. C.
boiling point) concentrations are generally less than 0.01% by
mass. The boiling points of the 3-7 fused-ring polycyclic aromatic
compounds (PACs) are well above the boiling range of straight-run
kerosene streams. Consequently, the concentrations of PACs found in
kerosenes are very low, if not below the limits of detection of the
available analytical methods. A detailed analysis of a
hydrodesulfurized kerosene illustrates this and is presented as
Table 2.
TABLE-US-00001 TABLE 1 General Kerosene Compositional Information
Hydrodesulfurized Kerosene Jet A JP-8 API Gravity 39-45.5 37.2-46.1
37.0-46.7 Aromatic Content, 18-21.4 11.6-24.0 13.6-22.1 vol. %
Olefin Content, vol. % 1.0-1.66 0.0-4.1 0.6-3.0 Saturates Content,
77.2-82 71.9-88.4 74.9-85.8 vol. % 10% Distillation, .degree. F.
329-406 294-394 333-390 FBP Distillation, .degree. F. 451-568
404-510 419-474 (Final Boiling Pt.) (90%) (90%)
TABLE-US-00002 TABLE 2 Hydrodesulfurized Kerosene Component Weight
Percent Nonaromatics 80.27 Saturates 78.61 Olefins 1.66 Aromatics
19.72 Less than Three-Ring PAC 19.72 Three- to Seven-Ring PAC
<0.01
III. I/N BLENDSTOCK
[0042] The herein disclosed I/N-C/A blend fuel comprises at least
one I/N blendstock comprising primarily hydrocarbons selected from
the group consisting of isoparaffins and normal paraffins, the
hydrocarbons derived from non-petroleum feedstock. The finished
I/N-C/A jet fuel comprises up to 95 vol. % of I/N blendstock. In
embodiments, I/N blendstock comprises isoparaffin and/or normal
paraffin compounds containing primarily from eight to sixteen
carbon atoms per molecule (C8 to C16 compounds). In embodiments,
these compounds are produced directly via a chemical process such
as, but not limited to, Fischer-Tropsch condensation of syngas,
thermocatalytic processing of vegetable oils, pyrolysis,
liquefaction, and gas-to-liquids processing.
[0043] In embodiments, I/N blendstock is derived from one or a
combination of the following feedstocks: natural gas, coal,
biomass, vegetable oils, biomass pyrolysis bio-oils, and other
biologically-derived oils. I/N blendstock can be produced by
several routes. In a specific embodiment, as shown in FIG. 1,
indirect liquefaction is used to produce I/N blendstock. Indirect
liquefaction feedstock, such as coal or biomass, 10 is gasified in
gasifier 40 with steam 20 and/or oil 30. Gasifier effluent 50, may
comprise carbon monoxide, hydrogen, carbon dioxide, hydrogen
sulfide, and/or ammonia. Gasifier effluent 50 is purified and
upgraded in step 60, whereby a contaminant stream(s) 70 comprising,
for example, hydrogen sulfide, ammonia, and/or carbon dioxide is
removed. Syngas stream 80, comprising primarily CO and H.sub.2,
undergoes liquefaction 90 to yield liquid products 100. In
embodiments, liquid products 100 are synthesized from syngas 80 by
catalytic Fischer-Tropsch (F-T) processing. The Fischer-Tropsch
reactions produce a wide spectrum of oxygenated compounds, in
particular, alcohols and paraffins ranging in carbon numbers from
C.sub.1-C.sub.3 (gases) to C.sub.35+ (solid waxes). These
Fischer-Tropsch products yield distillate fuels that comprise
C.sub.8-C.sub.16 paraffins and, through isomerization, C8-C.sub.16
isoparaffins that have excellent cetane numbers and very low sulfur
and aromatic content. These properties make F-T products suitable
for use as I/N blendstock. However, because of the lack of adequate
cycloalkanes and aromatics, Fischer-Tropsch distillate fuels are
typically unable to meet all military and ASTM specifications and
fit-for-purpose requirements. Therefore, as described further
hereinbelow, I/N blendstock is blended with C/A blendstock to
obtain aviation-grade I/N-C/A fuel. In embodiments, I/N-C/A fuel
comprises up to 95 vol. % I/N blendstock, alternatively about 90
vol. % I/N blendstock derived from Fischer-Tropsch processing of
natural gas, coal, and/or biomass. In embodiments, the I/N-C/A fuel
comprises about 80 vol. % I/N blendstock derived from
Fischer-Tropsch processing of natural gas, coal, and/or biomass. In
alternative embodiments, I/N-C/A fuel comprises about 70 vol. % I/N
blendstock derived from Fischer-Tropsch processing of natural gas,
coal, and/or biomass.
[0044] In embodiments, I/N blendstock is produced from triglyceride
and/or fatty acid feedstocks. I/N blendstock n-paraffins may be
produced, for example, via: (1) catalytic triglyceride dissociation
into fatty acids and glycerol, (2) glycerol removal, and (3) oxygen
removal from fatty acids (e.g., via catalytic decarboxylation
and/or reduction) to yield normal paraffins. I/N blendstock
isoparaffins may be produced via (4) catalytic isomerization of a
portion of these normal paraffins to yield isoparaffins.
[0045] In embodiments, I/N-C/A fuel comprises from about 65 vol. %
to about 95 vol. % I/N blendstock derived from catalytic processing
of triglyceride feedstock. In specific embodiments, I/N-C/A fuel
comprises about 75 vol. % I/N blendstock derived from catalytic
processing of triglyceride feedstock. In alternative embodiments,
I/N-C/A fuel comprises about 80 vol. % I/N blendstock derived from
catalytic processing of triglyceride feedstock. In alternative
embodiments, I/N-C/A fuel comprises about 80 to 90 vol. % I/N
blendstock derived from catalytic processing of triglyceride
feedstock.
IV. C/A BLENDSTOCK
[0046] As mentioned hereinabove, I/N blendstock typically has a
density below minimum requirements. For example, the I/N blendstock
typically has a density below the MIL-DTL-83133-specified minimum
requirement of 0.775 kg/L and may be very near to exceeding or may
exceed the freeze point maximum requirement of less than
-47.degree. C. As it is desirable for the I/N-C/A fuel to meet
standard (for example, MIL-DTL-83133-specified) density, freeze
point, and flash point requirements, the disclosed I/N-C/A fuel
further comprises at least one independently-produced C/A
blendstock to obtain required density and cold-flow performance.
The C/A blendstock comprises primarily hydrocarbons selected from
the group consisting of cycloalkanes and aromatics. The
aviation-grade I/N-C/A fuel comprises an appropriate blend of
aromatics and cycloalkanes whereby requisite density and freeze
point specifications of the resulting high cetane kerosene fuel are
met. In embodiments, the hydrocarbons of the C/A blendstock are
derived from petroleum feedstocks. In embodiments, the hydrocarbons
of the C/A blendstock are derived from non-petroleum feedstocks. In
embodiments, the hydrocarbons of the C/A blendstock are derived
from a combination of petroleum and non-petroleum feedstocks. In
embodiments, the I/N-C/A fuel comprises up to 35 vol. % C/A
blendstock.
[0047] In embodiments, the C/A blendstock comprises aromatics. In
embodiments, the C/A blendstock comprises aromatics selected
primarily from the group consisting of C9 to C15 aromatics which
provide the requisite density. In embodiments, the aromatics are
primarily alkylated benzene compounds. In addition to providing
density, aromatics may also contribute to beneficial seal swelling
and may provide needed lubricity and viscosity. In embodiments, the
C/A blendstock comprises less than about 15 vol. % aromatics. In
embodiments, the C/A blendstock comprises from about 0 vol. % to
about 15 vol. % aromatics.
[0048] In embodiments, C/A blendstock comprises cycloalkanes. In
embodiments, the C/A blendstock comprises cycloalkanes primarily
selected from the group consisting of C9 to C15 cycloalkanes which
reduce freeze point (to counteract the freeze point increase
resulting from aromatic addition) without adversely decreasing
flash point. In embodiments, C/A blendstock comprises less than
about 30 vol. % cycloalkane. In embodiments, suitable freezepoint
are obtained in the I/N-C/A fuel by selection of aromatics (i.e.
having high density and low freezepoint) for the C/A blendstock
such that the C/A blendstock comprises 0% cycloalkanes. In
embodiments, C/A blendstock comprises from about 0 vol. % to about
30 vol. % cycloalkane. In embodiments, jet-fuel compliant I/N-C/A
fuel comprises up to 95 vol. % of paraffins selected from
isoparaffins and normal paraffins, from about 0 vol. % to about 30
vol. % cycloalkanes, and from about 0 vol. % to about 15 vol. %
aromatics. In embodiments, I/N-C/A fuel comprises about 95 vol. %
I/N blendstock and about 5% high density low freezepoint
aromatic.
[0049] Without limitation, C/A blendstock may be derived from one
or a combination of the following feedstocks: petroleum, oil shale,
oil sands, natural gas, coal, biomass, vegetable oil, biomass
pyrolysis bio-oil, and other biologically-derived oils. In
embodiments, aviation-grade I/N-C/A kerosene comprises at least 50
weight % of hydrocarbons selected from cycloalkanes and aromatics,
said hydrocarbons derived from coal, biomass, or a combination
thereof.
[0050] C/A blendstock may be produced by several methods. FIG. 2
shows an embodiment for the production of C/A blendstock via
pyrolysis (heating in a deficiency of oxygen). Pyrolysis may be
performed by any method known to one of skill in the art. In FIG.
2, pyrolysis feedstock 110 undergoes pyrolysis 120. Suitable
pyrolysis feedstock 110 includes, without limitation, coal, oil
shale, oil sands, biomass, and combinations thereof. Gases 140 and
char/ash/minerals 130 are removed. Pyrolysis oil vapors are
condensed, the resulting pyrolysis oil 150 is hydrotreated as is
known to those of skill in the art. In embodiments, catalytic
hydrotreating is used to reduce the level of at least one
contaminant selected from the group consisting of nitrogen, sulfur,
oxygen, and metals. In embodiments, pyrolysis oil 150 is treated
with hydrogen 180 and the level of sulfur and/or nitrogen in
pyrolysis oil 150 is reduced via elimination of gas stream(s) 170
comprising, for example, hydrogen sulfide and/or ammonia. Via
hydrotreating 160, contaminant-reduced liquid products 190 are
obtained. This procedure is similar to the procedure used in
upgrading crude oil in a refinery to produce a variety of liquid
fuels, as known to those of skill in the art. Table 3 presents a
comparison of pyrolyzed coal tar fractions based on typical boiling
range and major hydrocarbon constituents.
TABLE-US-00003 TABLE 3 Typical Coal Tar Fractions Boiling Range,
Typical HC Constituents Fraction .degree. C. and Carbon Numbers
Ammoniacal Liquor ~100 -- Light Oil <170 Benzene, C.sub.6;
Toluene, C.sub.7; Xylene, C.sub.8 Middle Oil or Carbolic Oil
170-230 Naphthalene, C.sub.10 Heavy Oil or Creosote Oil 230-270
Naphthalene, C.sub.10 Green Oil or Anthracene Oil 270-360
Anthracene, C.sub.14 Residue or Pitch >360 --
[0051] In particular, low-temperature tar and light oils formed
from sub-bituminous and bituminous coals at temperatures below
about 700.degree. C. as relatively fluid, dark brown oils that
comprise phenols, pyridines, paraffins, and/or olefins. The oils
are heterogeneous, with any one component constituting only a
fraction of a percent of the total mass. The lignite tars may also
contain up to 10% of paraffin waxes, so the product has a
"butter-like consistency" and solidifies at temperatures as high as
6.degree. C. to 8.degree. C. The primary high-temperature tar
vapors formed above 700.degree. C. are more homogeneous. The light
oils are predominantly benzene, toluene, and xylenes (BTX) and the
tars are bitumen-like viscous mixtures that contain high
proportions of polycondensed aromatics. For the most part, the
pyrolysis tars and oils are not suitable final fuel products. Often
they are unstable, and when warmed, they polymerize and become more
viscous. Ash and mineral matter 130 is removed in pyrolysis 120,
which increases the heating value, but sulfur and nitrogen are not
completely removed in pyrolysis 120. A more stable and useful
product is obtained by hydrogenating 160 and removing the sulfur
and/or nitrogen from the fuel as hydrogen sulfide and/or ammonia in
stream(s) 170. These procedures are, as noted previously, similar
to the various refinery procedures used to upgrade natural crude
oils. The hydrotreated liquid products 190 may be further refined
and upgraded, by any methods known to one of skill in the art, to
yield a mix of cycloalkanes and aromatics of which the C/A
blendstock is comprised.
[0052] In embodiments, the I/N-C/A fuel comprises about 20 vol. %
C/A blendstock derived from pyrolysis processing of a coal tar
fraction. In embodiments, the I/N-C/A fuel comprises about 80 vol.
% I/N blendstock derived from Fischer-Tropsch processing of natural
gas, coal, and/or biomass, and about 20 vol. % C/A blendstock
derived from pyrolysis processing of coal tar fraction. In
embodiments, I/N-C/A fuel comprises about 30 vol. % C/A blendstock
derived from pyrolysis processing of a high cycloparaffin-content
material derived from oil shale or oil sand feedstock. In
embodiments, I/N-C/A fuel comprises about 70 vol. % I/N blendstock
derived from catalytic processing of triglyceride feedstock and
about 30 vol. % C/A blendstock derived from pyrolysis processing of
a high cycloparaffin-content material derived from an oil shale or
oil sand feedstock.
[0053] In another embodiment of the invention, shown in FIG. 3,
direct liquefaction 220 of liquefaction feedstock 210 is used to
produce C/A blendstock. Liquefaction feedstock 210 may comprise,
for example, coal and/or biomass. There are two basic procedures:
hydroliquefaction and solvent extraction. In hydroliquefaction,
coal 210 is mixed with recycled coal oil 230 and, together with
hydrogen 240, fed to high-pressure catalytic reactor 220 where
hydrogenation of coal 210 takes place. In solvent extraction, also
termed "solvent refining," coal 210 and hydrogen 240 are dissolved
at high pressure in a recycled coal-derived solvent 230 which
transfers hydrogen 240 to coal 210. After phase separation 260,
wherein gases 270 and ash 280 may be removed from coal liquid 250
which may be further cleaned and upgraded by refinery procedures to
produce liquid fuels 290. In solvent refining, with a low level of
hydrogen transfer, a solid, relatively clean fuel termed "solvent
refined coal" 290 is obtained. As in pyrolysis, the compounds are
similar to the coal tars and highly aromatic in nature.
Hydrogenation and selective catalytic processing, as known to one
of skill in the art, may be performed to yield a mix of
cycloalkanes and aromatics that provide the C/A blendstock.
[0054] In embodiments, the I/N-C/A fuel comprises about 20 vol. %
C/A blendstock derived from direct liquefaction of a coal
feedstock. In embodiments, the I/N-C/A fuel comprises about 80 vol.
% I/N blendstock derived from Fischer-Tropsch processing of natural
gas, coal, and/or biomass, and about 20 vol. % C/A blendstock
derived from direct liquefaction of a coal feedstock.
[0055] In an embodiment, C/A blendstock comprises cycloalkanes
obtained by separation (e.g., via distillation or extraction) of
cycloalkanes selected from the group consisting of C9-C15
cycloalkanes from petroleum feedstocks. In embodiments, C/A
blendstock comprises aromatic compounds obtained by separation
(e.g., via distillation or extraction) of aromatic compounds
selected from the group consisting of C9-C15 single-ring aromatic
compounds from petroleum feedstocks. Suitable petroleum feedstocks
comprise oil sand- and/or oil shale-derived products that are
inherently rich in cycloalkanes.
[0056] In an embodiment, C/A blendstock is produced by catalytic
cyclization and/or reforming of I/N blendstock prepared from
triglyceride and/or fatty acid feedstocks as disclosed hereinabove.
In this embodiment, I/N blendstock may be produced via: (1)
catalytic triglyceride dissociation into fatty acids and glycerol,
(2) glycerol removal, (3) oxygen removal from fatty acids (via
catalytic decarboxylation and/or reduction) to yield normal
paraffins, and, to the extent desired, (4) catalytic isomerization
of a portion of these normal paraffins to yield isoparaffins. In
embodiments, I/N-C/A fuel comprises about 35 vol. % C/A blendstock
derived from catalytic processing of triglyceride feedstock. In
embodiments, I/N-C/A fuel comprises about 65 vol. % I/N blendstock
derived from catalytic processing of triglyceride feedstock and
about 35 vol. % C/A blendstock derived from catalytic processing of
triglyceride feedstock.
[0057] In another embodiment of the invention, C/A blendstock is
produced from biomass-derived lignin feedstock. C/A blendstock may
be produced via catalytic depolymerization of biomass-derived
lignin feedstock followed by hydroprocessing as required to yield a
desired proportion (for example, JP-8-quality) of cycloalkanes and
aromatics. In embodiments, the I/N-C/A fuel comprises about 20 vol.
% C/A blendstock derived from pyrolysis of biomass-derived lignin.
In alternative embodiments, I/N-C/A fuel comprises about 15 vol. %
C/A blendstock derived from catalytic processing of lignin. In
embodiments, I/N-C/A fuel comprises about 80 vol. % I/N blendstock
derived from Fischer-Tropsch processing of natural gas, coal,
and/or biomass, and about 20 vol. % C/A blendstock derived from
pyrolysis processing of biomass-derived lignin. In embodiments,
I/N-C/A fuel comprises about 85 vol. % I/N blendstock derived from
catalytic processing of triglyceride feedstock and about 15 vol. %
C/A blendstock derived from catalytic processing of lignin.
V. I/N-C/A FUEL
[0058] A finished I/N-C/A fuel may have "drop-in compatibility"
with its petroleum-derived counterpart, i.e. the I/N-C/A fuel may
be blended in any proportion, from 0 vol. % to 100 vol. % with a
petroleum-derived counterpart. The disclosed I/N-C/A fuel provides
for the blending of fuel components (including isoparaffins, normal
paraffins, cycloalkanes, and/or aromatics), at least two of which
are derived from disparate processes, to create I/N-C/A fuel. In
embodiments, at least 50 weight % of an aviation-grade I/N-C/A
kerosene fuel is derived from coal, natural gas, or a combination
thereof. In embodiments, at least 50 weight % of an I/N-C/A fuel is
derived from biomass. In embodiments, at least 10 weight % of an
I/N-C/A fuel is derived from non-cracked bio-oil. In embodiments,
I/N-C/A fuel has a cetane number of greater than about 70.
[0059] In embodiments, the I/N-C/A fuel complies with
specifications for Jet A and/or another civilian jet fuel. In
embodiments, the I/N-C/A fuel complies with a military jet fuel
specification selected from JP-8 and other military-grade jet fuel
specifications.
[0060] In addition to meeting fuel property and performance
requirements listed in U.S. military and ASTM (American Society for
Testing and Materials) International aviation jet fuel
specifications, in embodiments, an I/N-C/A-blended fuel will also
meet applicable U.S. military-specified fit-for-purpose
requirements that address a variety of fuel performance and
materials compatibility issues. As mentioned hereinabove,
fit-for-purpose requirements refers to fuel property requirements
that are not necessarily addressed by military or ASTM standards,
but are important to fuel performance and stability in jet engines
and during fuel handling, distribution, and storage. Examples of
fit-for-purpose requirements include fuel compatibility with
aircraft fuel and engine system materials of construction, adequate
fuel performance in compression ignition (versus turbine) engines
in a wide variety of ground environments, and possible fuel
performance requirements related to swelling of elastomeric seals
in, for example, turbine engines. These fit for purpose
requirements, in addition to feedstock properties and ASTM
standards are used to determine the optimal ratio of the I/N
blendstock to the C/A blendstock.
VI. EXAMPLES
Example 1
Fuel Sample A
[0061] A FT fuel produced from natural gas containing
iso-paraffinic and normal paraffin hydrocarbons did not comply with
density requirement of the JP-8 military specification
(MIL-DTL-83133E). In this example, a mixture of aromatic
hydrocarbon fluid containing aromatic hydrocarbons ranging in
carbon chain length from 8-16, was blended to a concentration of
23% by weight with the FT fuel. A summary of results from Fuel
Sample A compared to specification requirements outlined in
MIL-DTL-83133E is provided in Table 4.
TABLE-US-00004 TABLE 4 Results from Jet Fuel Specification Tests of
Fuel Sample A Comprising Blend of Aromatic Hydrocarbon and
Fischer-Tropsch Derived Fuel Specification Test Sample A Military
Spec Acid Number, mg KOH/gm 0.003 0.015 max Aromatics, vol % 19.4
25 vol % max Olefins, vol % 0.0 5 vol % max Sulfur, mass % 0.0 0.30
max Heat of Combustion, Btu/lb 18500 18400 Distillation: 10%
recovered, .degree. C. 172 205 max Endpoint, .degree. C. 274 300
max Residue, vol % 1.4 1.5 max Loss, vol % 0.4 1.5 max Flash Point,
.degree. C. 48 >38 Freeze Point, .degree. C. -57 -47 max
Hydrogen Content, mass % 14.0 13.4 min API Gravity @ 60.degree. F.
48.2 37.0-51.0 Specific Gravity @ 15.degree. C. 0.787
0.775-0.84
[0062] As seen in the data presented in Table 2, the resulting fuel
had a density of 0.788 g/ml achieving the minimum specification
requirement of 0.775 as defined by MIL-DTL-83133E while complying
with all of the parameters contained within the specification. Data
from gas chromatography of Sample A and a typical FT fuel is
provided in FIG. 4.
Example 2
Fuel Sample B
[0063] The same FT fuel as used in Example 1 was blended at 82% wt.
with 8% wt. of a mixed aromatic fluid and 10% wt. cycloparaffinic
fluid. A summary of Fuel Sample B results from key specification
parameters is provided in Table 5.
TABLE-US-00005 TABLE 5 Results for Key Jet Fuel Specification Tests
of Fuel Sample B Comprising Blend of Aromatic and Cycloparaffin
Hydrocarbons with Fischer-Tropsch Derived Fuel Freeze Specific
Point, Flash HHV, Gravity .degree. C. Point, .degree. C. MJ/kg Mil
Spec 0.775-0.84 -47 >38 C. >42.8 Specification value is a
lower heating value Sample B 0.779 -61.4 48 46.1 Lab analysis FT
Fuel 0.755 -56.7 48 46.6 Lab analysis
[0064] As seen in the results in Table 5, the resulting fuel Sample
B possessed a MIL-DTL-83133E specification compliant fuel with a
density of 0.779 g/ml.
Example 3
Fuel Sample C
[0065] Two hydrocarbon blendstocks, one consisting of normal- and
iso-paraffinic hydrocarbon and the second consisting a mixture of
aromatic and cycloparaffinic hydrocarbon, were produced exclusively
from crop oil and blended to achieve a fuel sample complying with
the requirements of MIL-DTL-83133E. In this example, neither fuel
blendstock possessed, on its own, the physical characteristics
required by the specification; however, through blending at a ratio
of 44% normal and iso-paraffinic blendstock, and 66% aromatic and
cycloparaffinic blendstock, the resulting fuel achieved the
necessary characteristics. A summary of results from Fuel Sample C
compared to specification parameters outlined in MIL-DTL-83133E is
provided in Table 6. Data from gas chromatography of Sample C and a
typical JP-8 fuel is provided in FIG. 5.
TABLE-US-00006 TABLE 6 Results from Jet Fuel Specification Tests of
Fuel Sample C Comprising a Blend of Two Discrete Hydrocarbon
Blendstocks Produced from Crop Oil Specification Test Sample C
Military Spec Aromatics, vol % 19.8 25 vol % max Olefins, vol % 1.9
5 vol % max Heat of Combustion, Btu/lb 18400 18400 Distillation:
10% recovered, .degree. C. 171 205 max Endpoint, .degree. C. 255
300 max Residue, vol % 1.2 1.5 max Loss, vol % 0.4 1.5 max Flash
Point, .degree. C. 49 >38 Freeze Point, .degree. C. -52 -47 max
API Gravity @ 60.degree. F. 44.3 37.0-51.0 Specific Gravity @
15.degree. C. 0.805 0.775-0.84
[0066] While preferred embodiments of the invention have been shown
and described, modifications thereof can be made by one skilled in
the art without departing from the spirit and teachings of the
disclosure. The embodiments described herein are exemplary only,
and are not intended to be limiting. Many variations and
modifications of the invention disclosed herein are possible and
are within the scope of the invention. Where numerical ranges or
limitations are expressly stated, such express ranges or
limitations should be understood to include iterative ranges or
limitations of like magnitude falling within the expressly stated
ranges or limitations (e.g., from about 1 to about 10 includes, 2,
3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). Use
of the term "optionally" with respect to any element of a claim is
intended to mean that the subject element is required, or
alternatively, is not required. Both alternatives are intended to
be within the scope of the claim. Use of broader terms such as
comprises, includes, having, etc. should be understood to provide
support for narrower terms such as consisting of, consisting
essentially of, comprised substantially of, etc.
[0067] Accordingly, the scope of protection is not limited by the
description set out above but is only limited by the claims which
follow, that scope including all equivalents of the subject matter
of the claims. Each and every claim is incorporated into the
specification as an embodiment of the present invention. Thus, the
claims are a further description and are an addition to the
preferred embodiments of the present invention. The discussion of a
reference is not an admission that it is prior art to the present
invention, especially any reference that may have a publication
date after the priority date of this application. The disclosures
of all patents, patent applications, and publications cited herein
are hereby incorporated by reference, to the extent they provide
exemplary, procedural or other details supplementary to those set
forth herein.
* * * * *