U.S. patent application number 12/142229 was filed with the patent office on 2009-12-24 for diesel composition and method of making the same.
This patent application is currently assigned to CHEVRON U.S.A. INC.. Invention is credited to Paul A. Allinson, William Cannella, Janine Lichtenberger, Jaime Lopez, Ronald K. Meeker.
Application Number | 20090313890 12/142229 |
Document ID | / |
Family ID | 41429805 |
Filed Date | 2009-12-24 |
United States Patent
Application |
20090313890 |
Kind Code |
A1 |
Lopez; Jaime ; et
al. |
December 24, 2009 |
DIESEL COMPOSITION AND METHOD OF MAKING THE SAME
Abstract
A diesel fuel composition comprising a (1) sulfur content of
less than 10 ppm; (2) a flash point of greater than 50.degree. C.;
(3) a UV absorbance, A.sub.total, of less than 1.5 as determined by
the formula comprising A.sub.total=A.sub.x+10(A.sub.y) wherein
A.sub.x is the UV absorbance at 270 nanometers; and wherein A.sub.y
is the UV absorbance at 310 nanometers; (4) a naphthene content of
greater than 5 percent; (5) a cloud point of less than -12.degree.
C.; (6) a nitrogen content of less than 10 ppm; and (7) a 5%
distillation point of greater than 300 F and a 95% distillation
point of greater than 600 F.
Inventors: |
Lopez; Jaime; (Benicia,
CA) ; Lichtenberger; Janine; (Berkeley, CA) ;
Meeker; Ronald K.; (Clayton, CA) ; Allinson; Paul
A.; (Danville, CA) ; Cannella; William;
(Orinda, CA) |
Correspondence
Address: |
CHEVRON CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
CHEVRON U.S.A. INC.
San Ramon
CA
|
Family ID: |
41429805 |
Appl. No.: |
12/142229 |
Filed: |
June 19, 2008 |
Current U.S.
Class: |
44/385 ; 208/61;
44/300 |
Current CPC
Class: |
C10G 65/12 20130101;
C10L 1/19 20130101; C10G 2400/04 20130101; C10L 1/224 20130101;
C10G 2300/202 20130101; C10L 1/08 20130101; C10L 1/1881 20130101;
C10G 65/08 20130101; C10G 45/52 20130101; C10G 45/44 20130101; C10L
10/08 20130101 |
Class at
Publication: |
44/385 ; 44/300;
208/61 |
International
Class: |
C10L 1/18 20060101
C10L001/18; C10L 1/00 20060101 C10L001/00; C10G 69/04 20060101
C10G069/04 |
Claims
1. A petroleum-derived diesel fuel composition having: (a) a sulfur
content of less than 10 ppm; (b) a flash point of greater than
50.degree. C.; (c) a UV absorbance, A.sub.total, of less than 1.5
as determined by the formula comprising
A.sub.total=A.sub.x+10(A.sub.y) wherein A.sub.x is the UV
absorbance at 270 nanometers; and wherein A.sub.y is the UV
absorbance at 310 nanometers; (d) a naphthene content of greater
than 5 percent; (e) a cloud point of less than -12.degree. C.; (f)
a nitrogen content of less than 10 ppm; and (g) a 5% distillation
point of greater than 300 F and a 95% distillation point of greater
than 600 F.
2. The composition of claim 1, wherein the sulfur content is less
than 6 ppm.
3. The composition of claim 1, wherein the 5% distillation point as
determined by ASTM D2887 is greater than 320.degree. F.
4. The composition of claim 1, wherein the 5% distillation point as
determined by ASTM D2887 is greater than 340.degree. F.
5. The composition of claim 1, wherein the 5% distillation point as
determined by ASTM D2887 is greater than 375.degree. F.
6. The composition of claim 1, wherein the composition further
comprises a lubricity additive package.
7. The composition of claim 6, wherein the lubricity additive
package comprises monocarboxylic fatty acids, amides, esters, or
mixtures thereof.
8. The composition of claim 1 wherein the boiling point range is
from about 300.degree. F. to about 730.degree. F.
9. The composition of claim 1 wherein the aromatic content is less
than 10 wt %.
10. The composition of claim 1 wherein the viscosity at 40.degree.
C. is less than 4.1 mm/Cst.
11. The composition of claim 1 wherein the net heat of combustion
is greater than 18,000 Btu/lb.
12. A process for preparing a petroleum-derived fuel composition
comprising: (a) feeding a hydrocarbonaceous feedstock having at
least 50 ppm sulfur and at least 25 percent by weight aromatic
content to a reactor system over a hydrotreating catalyst
comprising a Group VI or a non-noble metal Group VIII or mixtures
thereof, thereby producing a hydrotreated product; (b) feeding the
hydrotreated product to at least one separation unit, thereby
separating the producing a product stream having a sulfur content
of less than 50 ppm by weight; (c) feeding the product stream to a
hydrogenation reactor system over a noble metal hydrogenation
catalyst, thereby producing a hydrogenated product; and (d) feeding
the hydrogenated product to at least one separation unit thereby
producing a diesel product stream, wherein the diesel product
stream has an aromatic content of less than 7.5 percent by weight,
a sulfur content of less than 10 ppm and a flash point of greater
than 50 degrees C.
13. The process of claim 12 wherein the hydrotreating catalyst is
selected from the group consisting of a nickel-molybdenum catalyst,
a nickel-tungsten catalyst, a molybdenum-tungsten catalyst, a
nickel-molybdenum catalyst and a molybdenum-cobalt catalyst.
14. The-process of claim 12 wherein the hydrogenation catalyst is
comprises platinum, palladium or mixtures thereof.
15. A process for preparing a petroleum-derived fuel composition
comprising: (a) feeding a hydrocarbonaceous feedstock having at
least 50 ppm sulfur and at least 25 percent by weight aromatic
content to a first reactor system over a hydrotreating catalyst
comprising a Group VI element or a non-noble metal Group VIII
element or mixtures, thereby producing a hydrotreated product; (b)
feeding the hydrotreated product to a second reactor system over a
hydrocracking catalyst, thereby producing a hydrocracked product;
(c) feeding the hydrocracked product to at least one separation
unit, thereby separating the hydrocracked product into a first
product stream and a second product stream; (d) feeding the second
product stream to at least one reactor comprising a catalyst to
convert the paraffins into iso-paraffins, thereby producing a
de-waxed product; (e) feeding the de-waxed product to at least one
reactor comprising a hydrogenation catalyst to hydrofinish, thereby
producing a hydrofinished product; (f) feeding the hydrofinished
product to at least one separation unit, thereby separating the
hydrofinished product into a diesel product stream and at least a
base oil product stream, wherein the diesel product stream has an
aromatic content of less than 7.5 percent by weight, a sulfur
content of less than 10 ppm and a flash point of greater than 50
degrees C.
16. A process for preparing a petroleum-derived fuel composition
comprising: (a) feeding a hydrocarbonaceous feedstock to a reactor
system containing a high activity base metal catalyst, thereby
hydrogenating the hydrocarbonaceous feedstock and producing a
hydrogenated product; and (b) feeding the hydrogenated product to
at least one separation unit, thereby separating the hydrogenated
product into a naphtha product stream, a jet product stream and a
diesel product stream, wherein the diesel product stream has an
aromatic content of less than 7.5 percent by weight, a sulfur
content of less than 10 ppm and a flash point of greater than 50
degrees C.
17. The process of claim 16 wherein the high activity base metal
catalyst comprises Group VI base metals and Group VIII noble
metals.
18. A process for preparing a petroleum-derived fuel composition
comprising: (a) feeding a hydrocarbonaceous feedstock having less
than 100 ppm by weight sulfur to a reactor system over a high
activity noble metal catalyst, thereby producing a hydrogenated
product; and (b) feeding the hydrogenated product to at least one
separation unit thereby producing a diesel product stream, wherein
the diesel product stream has an aromatic content of less than 7.5
percent by weight, a sulfur content of less than 10 ppm and a flash
point of greater than 50 degrees C.
19. The process of claim 18 wherein the high activity noble metal
catalyst comprises platinum, palladium or mixtures thereof.
20. A method of decreasing soot in an internal combustion engine
comprising injecting the fuel composition of claim 1 into an
internal combustion engine and combusting the fuel composition.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a premium diesel fuel
composition, derived from petroleum, and method of making the
same.
BACKGROUND OF THE INVENTION
[0002] Un-combusted diesel fuel, including ultra-low sulfur diesel
(ULSD), has a strong odor. The odor often associated with diesel is
unpleasant and may deter customers from purchasing diesel vehicles.
In particular, the diesel fuel, when spilled, especially on one's
hands or clothing, may have a prolonged bad odor. Also diesel fuel
stored in equipment contained in garages, basements, sheds, or even
houses can emit an odor that may make it undesirable to store the
equipment or fuel indoors.
[0003] Emissions from vehicles utilizing diesel are also relatively
high and require extensive after treatment technology to meet
governmental regulations. Older vehicles, which do not have the
extensive after-treatment equipment, should have lower emissions
with this premium, odorless diesel product.
[0004] Several factors lead to diesel fuel odor. Eliminating only
some of the factors can result in a diesel fuel that still has an
unacceptable odor. Understanding and controlling most or all the
factors is necessary to achieve a fuel that has a truly low odor
level or no odor. Another important consideration is that when the
odor causing components are eliminated from the prospective fuel it
may no longer meet all the required specifications for the fuel.
Only by careful balancing of the factors can a fuel be produced
that both has low odor and meets diesel fuel specifications.
[0005] It has been discovered that some key factors in reducing or
eliminating diesel fuel odor are adjusting the aromatic content,
adjusting the amounts of volatile and low-boiling point compounds,
and controlling the amount of sulfur and other heteroatoms in the
diesel fuel.
DESCRIPTION OF THE RELATED ART
[0006] Murakami, et al., U.S. Pat. No. 5,730,762 teach a diesel
fuel of reduced sulfur content which contains an alkyl side chain
on the aromatic ring and also contains hetero nitrogen compounds
with an alkyl side chain. The composition also includes carbazole
and indole compounds as components of the fuel composition.
[0007] Nikanjam et al., U.S. Pat. No. 5,389,112 disclose a diesel
fuel with low aromatic content and high cetane number. There are
controlled amounts of aromatics in the fuel to produce an optimum
cetane number as defined by a graph set forth in the patent. The
fuel can also have added thereto a cetane improver. The composition
also includes 2-ethyl-hexylnitrate as the cetane improver.
[0008] Russell, U.S. Pat. No. 5,792,339 discloses a diesel fuel
which minimizes the production of pollutants from vehicles by
adjusting the amounts of aromatic compounds in the fuel. The
composition also includes polycyclic aromatics of between 5.0 to
8.6 weight %.
[0009] Hubbard et al., U.S. Pat. No. 6,096,103 teach the use of
mineral spirits with low sulfur and low odor in diesel engines.
[0010] Hubbard et al., U.S. Pat. No. 6,291,732 teach a diesel fuel
comprising a blend of aromatic and aliphatic mineral spirits having
a low sulfur content for use in cold climates.
[0011] Ellis et al., U.S. Pat. No. 6,893,475 disclose a distillate
fuel having a sulfur level of less than about 100 wppm, a total
aromatics content of about 15 to 35 wt. %, a polynuclear aromatics
content of less than about 3 wt. %, wherein the ratio of total
aromatics to polynuclear aromatics is greater than about 11.
[0012] While low sulfur diesel fuels and low emissions diesel fuels
are known in the art, diesel fuels specifically formulated to have
low or no odor through the reduction of sulfur, nitrogen, aromatic,
and volatile compounds are novel.
SUMMARY OF THE INVENTION
[0013] In one embodiment, the present invention is directed to a
petroleum derived diesel fuel composition having: [0014] (a) a
sulfur content of less than 10 ppm; [0015] (b) a flash point of
greater than 50.degree. C.; [0016] (c) a UV absorbance,
A.sub.total, of less than 1.5 as determined by the formula
[0016] A.sub.total=A.sub.270+10(A.sub.310) [0017] wherein A.sub.270
is the UV absorbance at 270 nanometers; and [0018] wherein
A.sub.310 is the UV absorbance at 310 nanometers; [0019] (d) a
naphthene content of greater than 5 percent; [0020] (e) a cloud
point of less than -12.degree. C.; [0021] (f) a nitrogen content of
less than 10 ppm; and [0022] (g) a 5% distillation point of greater
than 300.degree. F. and a 95% distillation point of greater than
600.degree. F.
[0023] In another embodiment, the present invention is directed to
a process for preparing a petroleum-derived fuel composition
comprising: [0024] (a) feeding a hydrocarbonaceous feedstock having
at least 50 ppm sulfur and at least 25 percent by weight aromatic
content to a reactor system over a hydrotreating catalyst
comprising a Group VI or a non-noble metal Group VIII or mixtures
thereof, thereby producing a hydrotreated product; [0025] (b)
feeding the hydrotreated product to at least one separation unit,
thereby separating the producing a product stream having a sulfur
content of less than 50 ppm by weight; [0026] (c) feeding the
product stream to a hydrogenation reactor system over a noble metal
hydrogenation catalyst, thereby producing a hydrogenated product;
and [0027] (d) feeding the hydrogenated product to at least one
separation unit thereby producing a diesel product stream, wherein
the diesel product stream has an aromatic content of less than 7.5
percent by weight, a sulfur content of less than 10 ppm and a flash
point of greater than 50 degrees C.
[0028] In another embodiment, the present invention is directed to
a process for preparing a petroleum-derived fuel composition
comprising: [0029] (a) feeding a hydrocarbonaceous feedstock having
at least 50 ppm sulfur and at least 25 percent by weight aromatic
content to a first reactor system over a hydrotreating catalyst
comprising a Group VI element or a non-noble metal Group VIII
element or mixtures, thereby producing a hydrotreated product;
[0030] (b) feeding the hydrotreated product to a second reactor
system over a hydrocracking catalyst, thereby producing a
hydrocracked product; [0031] (c) feeding the hydrocracked product
to at least one separation unit, thereby separating the
hydrocracked product into a first product stream and a second
product stream; [0032] (d) feeding the second product stream to at
least one reactor comprising a catalyst to convert the paraffins
into iso-paraffins, thereby producing a de-waxed product; [0033]
(e) feeding the de-waxed product to at least one reactor comprising
a hydrogenation catalyst to hydrofinish, thereby producing a
hydrofinished product; [0034] (f) feeding the hydrofinished product
to at least one separation unit, thereby separating the
hydrofinished product into a diesel product stream and at least a
base oil product stream, wherein the diesel product stream has an
aromatic content of less than 7.5 percent by weight, a sulfur
content of less than 10 ppm and a flash point of greater than 50
degrees C.
[0035] In another embodiment, the present invention is directed to
a process for preparing a petroleum-derived fuel composition
comprising: [0036] (a) feeding a hydrocarbonaceous feedstock to a
reactor system containing a high activity base metal catalyst,
thereby hydrogenating the hydrocarbonaceous feedstock and producing
a hydrogenated product; and [0037] (b) feeding the hydrogenated
product to at least one separation unit, thereby separating the
hydrogenated product into a naphtha product stream, a jet product
stream and a diesel product stream, wherein the diesel product
stream has an aromatic content of less than 7.5 percent by weight,
a sulfur content of less than 10 ppm and a flash point of greater
than 50 degrees C.
[0038] In another embodiment, the present invention is directed to
a process for preparing a petroleum-derived fuel composition
comprising: [0039] (a) feeding a hydrocarbonaceous feedstock having
less than 100 ppm by weight sulfur to a reactor system over a high
activity noble metal catalyst, thereby producing a hydrogenated
product; and [0040] (b) feeding the hydrogenated product to at
least one separation unit thereby producing a diesel product
stream, wherein the diesel product stream has an aromatic content
of less than 7.5 percent by weight, a sulfur content of less than
10 ppm and a flash point of greater than 50 degrees C.
[0041] In another embodiment, the present invention is directed to
a method of decreasing soot in an internal combustion engine
comprising injecting a petroleum derived diesel fuel composition
having: [0042] (a) a sulfur content of less than 10 ppm; [0043] (b)
a flash point of greater than 50.degree. C.; [0044] (c) a UV
absorbance, A.sub.total, of less than 1.5 as determined by the
formula
[0044] A.sub.total=A.sub.270+10(A.sub.310) [0045] wherein A.sub.270
is the UV absorbance at 270 nanometers; and [0046] wherein
A.sub.310 is the UV absorbance at 310 nanometers; [0047] (d) a
naphthene content of greater than 5 percent; [0048] (e) a cloud
point of less than -12.degree. C.; [0049] (f) a nitrogen content of
less than 10 ppm; and [0050] (g) a 5% distillation point of greater
than 300.degree. F. and a 95% distillation point of greater than
600.degree. F.
[0051] into an internal combustion engine and combusting the fuel
composition.
BRIEF DESCRIPTION OF THE DRAWING
[0052] FIG. 1 depicts the correlation between odor, aromatic
content and flash point;
[0053] FIG. 1a depicts the correlation between flash point as
determined by Pensky-Marten, ASTM D93 and 5% initial boiling point
as determined by ASTM D2187;
[0054] FIG. 2 depicts a first embodiment of making a low or no odor
diesel fuel composition;
[0055] FIG. 3 depicts a second embodiment of making a low or no
odor diesel fuel composition;
[0056] FIG. 4 depicts a third embodiment of making a low or no odor
diesel fuel composition;
[0057] and FIG. 5 depicts a fourth embodiment of making a low or no
odor diesel fuel composition.
DETAILED DESCRIPTION OF THE INVENTION
[0058] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are herein
described in detail. It should be understood, however, that the
description herein of specific embodiments is not intended to limit
the invention to the particular forms disclosed, but on the
contrary, the intention is to cover all modifications, equivalents,
and alternatives falling within the spirit and scope of the
invention as defined by the appended claims.
Definitions
[0059] HD--refers to "hydrotreater."
[0060] HDC refers to "hydrocracker."
[0061] IDW--refers to "dewaxing."
[0062] MUH2--refers to "makeup hydrogen."
[0063] Hydrogenation/hydrocracking catalyst may also be referred to
as "hydrogenation catalyst" or "hydrocracking catalyst."
[0064] The terms "feed", "feedstock" or "feedstream" may be used
interchangeably.
[0065] The term "heteroatom" refers to any atom that is not carbon
or hydrogen. Typical heteroatoms include, but are not limited to,
nitrogen, sulfur, phosphorus, and oxygen.
[0066] The term "UV" refers to ultraviolet wavelengths of light in
the range of about 10 nanometers to about 400 nanometers.
[0067] All elemental group notations (e.g., Group VIII) refer to
CAS Notation.
Diesel Fuel Composition
[0068] One embodiment of the present invention is directed to a
diesel fuel composition. A diesel fuel composition comprises
various compounds including sulfur compounds, nitrogen compounds,
aromatic compounds and volatile compounds (light ends). In order to
achieve a low or no odor diesel fuel, it has been discovered that
heteroatom-containing compounds, aromatic content, and volatile
light ends need to be reduced.
[0069] Elimination of most of the sulfur compounds that make up the
diesel fuel composition results in a diesel fuel that has reduced
odor. Furthermore, if the diesel fuel composition has some sulfur
compounds, the type of sulfur compound will dictate, whether the
diesel fuel composition has a strong odor. The total sulfur content
of the diesel fuel composition of the invention is less than 10
ppm; more preferred, less than 6 ppm; and most preferred, less than
3 ppm.
[0070] Another type of heteroatom which can impart an odor to
diesel fuel is nitrogen. Nitrogen containing compounds can be
organic compounds such as aliphatic or aromatic hydrocarbons with a
nitrogen containing substitutent or inorganic nitrogen containing
compounds such as ammonium compounds, nitrates, and nitrites.
Accordingly, the diesel fuel composition of the invention may have
a nitrogen content of less than 10 ppm; more preferred, less than 5
ppm; and most preferred, less than 1 ppm.
[0071] Aromatic compounds are other compounds that have also been
found to contribute to diesel fuel odor. It has been discovered
that reduction of the aromatic content of the fuel can also greatly
reduce the odor of the fuels. As with sulfur and nitrogen
compounds, the species of aromatic compounds in the fuel can have
an effect on the odor, but generally it has been found that a
diesel fuel composition with very low total aromatic levels has a
decreased odor.
[0072] Aromatic content may also be approximated by the UV
absorbance at specific wavelengths, namely at 272 and 310 nm.
Aromatic compounds typically absorb ultraviolet (UV) wavelengths of
light in the range of 270 nanometers (nm) and 310 nanometers (nm).
Accordingly, the sum of UV absorbances, given as A.sub.total, is
related to the aromatic content of a given diesel fuel. We have
found that A.sub.total as given in the formula
A.sub.total=A.sub.270+10(A.sub.310)
[0073] wherein A.sub.270 is the UV absorbance at 270 nm and wherein
A.sub.310 is the UV absorbance at 310 nm, must be less than about
1.5, preferably less than about 1.0, and most preferably less than
about 0.8 to have the odorless diesel fuel composition of the
present invention.
[0074] In an embodiment of the present invention, the total
aromatic compound content of the fuel is less than 10%, preferably
less than 7.5%, more preferably less than 5%, most preferably less
than 2%, oven more preferred less than 1%, and even most preferred
less than 0.5%. Aromatic content was measured using Supercritical
Fluid Chromatography (SFC), ASTM D5186.
[0075] By measuring the A.sub.total of a given feedstock, the
degree in which to hydrotreat is determined in order to produce a
low odor diesel fuel.
[0076] Still yet another factor that has been found to be important
or critical in achieving a low or no odor fuel is the amount of the
volatile or tight boiling components in the fuel. These components
are often referred to as light ends or "front end" of the diesel
fuel range. It has been found that by decreasing the light boiling
components of the diesel fuel, in combination with decreasing the
other components listed above, a low or no odor diesel fuel can be
obtained. One useful measure for evaluating the front end of the
diesel fuel is using the 5% initial boiling point and 95% final
boiling point of the fuel as measured by ASTM D2887. In the present
invention, the 5% initial boiling point of the fuel should be
greater than 300 degrees F., preferably greater than 320 degrees
F., more preferably greater than 340 degrees F., and most
preferably greater than 375 degrees F. The 95% final boiling point
of the diesel fuel composition of the present invention is greater
than 600.degree. F., preferably, greater than 675 degrees F., more
preferred, greater than 725 F. Another measure for evaluating the
volatility of the diesel fuel is the boiling point. Preferably the
boiling point range of the diesel fuel composition of the present
invention is from about 300.degree. F. to about 730.degree. F.
[0077] The flash point of the diesel fuel composition of the
present invention has a flashpoint within diesel specifications.
Preferably the flash point is greater than about 50.degree. C.,
preferably, greater than about 55.degree. C., more preferred
greater than 60.degree. C., even more preferred greater than about
70.degree. C., and most preferred greater than 75.degree. C. as
measured by the Pensky-Martin closed cup method.
[0078] The cloud point refers to the temperature below which
solids, such as wax, start to precipitate in the diesel fuel
leading to a cloudy appearance. The cloud point is an important
measure of the cold temperature characteristics of a diesel fuel.
The diesel fuel of the present invention has a cloud point less
than -12.degree. C.
[0079] The diesel fuel composition of the present invention will be
low in aromatic compounds. The feedstock prior to hydrotreating may
contain a significant amount of aromatic species. For example, the
feedstock prior to hydrotreatment may contain at least 5%
aromatics. The feedstock may contain at least 10% aromatics or the
feedstock may contain at least 20% aromatics. During
hydrotreatment, the aromatics can be, at least in part, converted
to napthenes by hydrodearomatization reactions. In accordance with
the present invention, the naphthene content of the diesel fuel
composition of the present invention is greater than 5%. The
naphthenes may be formed from hydrodearomatization of the feedstock
during hydrotreatment or the naphthenes may be present in the
feedstock prior to hydrotreatment as long as the diesel fuel
composition of the present invention has a naphthene content of
greater than 5%.
[0080] In one embodiment of the present invention, the diesel fuel
composition comprises a sulfur content of less than 6 ppm, a flash
point of greater than or equal to 60.degree. C., a nitrogen content
of less than 10 ppm, a 5% distillation point of greater than
300.degree. F. and a 95% distillation point of greater than
600.degree. F., a cloud point of less than -12.degree. C., a
naphthene content of greater than 5%, and an aromatic content, as
given by A.sub.total, of less than 1.5.
[0081] In another embodiment of the present invention, the diesel
fuel composition comprises a sulfur content of less than 6 ppm, a
flash point of greater than or equal to 60.degree. C., a nitrogen
content of less than 10 ppm, a 5% distillation point of greater
than 300.degree. F. and a 95% distillation point of greater than
600.degree. F., a cloud point of less than -12.degree. C., a
naphthene content of greater than 5%, and an aromatic content, as
given by A.sub.total, of less than 1.0.
[0082] In another embodiment of the present invention, the diesel
fuel composition comprises a sulfur content of less than 6 ppm, a
flash point of greater than or equal to 60.degree. C., a nitrogen
content of less than 10 ppm, a 5% distillation point of greater
than 300.degree. F. and a 95% distillation point of greater than
600.degree. F., a cloud point of less than -12.degree. C., a
naphthene content of greater than 5%, and an aromatic content, as
given by A.sub.total, of less than 0.8.
[0083] The diesel fuel of the present invention, in addition to the
characteristics noted above, may, in some embodiments, comprise
other characteristics such as viscosity. The viscosity is a measure
of the resistance to flow of the diesel fuel, and it will decrease
as the diesel fuel oil temperature increases. If the diesel fuel is
used in a diesel engine, for example, the viscosity of the diesel
fuel must be low enough to flow freely at its lowest operational
temperature, yet high enough to provide lubrication to any moving
parts in the engine. Viscosity also will determine the size of the
fuel droplets, which, in turn, govern the atomization and
penetration qualities of the fuel injector spray. In one
embodiment, the diesel fuel of the present invention may have a
viscosity at 40.degree. C. of less than 4.1 mm/cSt as measured by
ASTM D445-64.
[0084] The diesel fuel of the present invention, may, in some
embodiments, comprise other characteristics such as net heat of
combustion as determined by ASTM D4868. Preferably the diesel fuel
of the present invention will have a net heat of combustion greater
than 18,000 Btu/lb and more preferably more than 18,500 Btu/lb. It
should be noted that viscosity and net heat of combustion describe
the characteristics of some embodiments of the diesel fuel
composition of the present invention. Not all embodiments of the
diesel fuel composition of the present invention need to possess
one or more of these physical characteristics. Moreover, the
physical characteristics outside the preferred ranges are still
within the scope of the invention as described and claimed
herein.
[0085] If desired, the diesel fuel composition of the present
invention may include additives to improve the lubricity of the
diesel fuel composition. When used in a diesel engine, for example,
some diesel fuels, especially low sulfur content fuels, offer
limited protection against engine wear. The wear occurs to the
injector needle due to rubbing contact with the surface of its
container. Also, various parts of fuel pumps such as internal gears
and cams are subject to wear due to fuel related problems. In some
embodiments, to increase the diesel fuel lubricity, one or more
lubricity enhancing additives can be mixed with the diesel fuel.
Typically, the concentration of the lubricity enhancing additive in
the fuel falls in the range of from about 1 to about 50,000 ppm,
preferably about 10 to about 20,000 ppm, and more preferably from
about 25 to about 10,000 ppm. Any lubricity enhancing additives can
be used. These lubricity enhancing additives include, but are not
limited to, fatty alcohols, fatty acids, amines, ethoxylated
amines, borated esters, other esters, phosphates, phosphites,
phosphonates, and mixtures thereof.
Method of Making the Diesel Fuel Composition
[0086] As discussed herein, several hydrotreating or hydrogenation
or both methods (generally, hydroconversion method) may be employed
to produce a diesel composition having low or no odor. A suitable
hydroconversion method is determined based upon the aromatic
content of the hydrocarbonaceous feedstock.
[0087] In one embodiment, both a hydrotreating catalyst (base
metal) and a hydrogenation catalyst (noble metal) are employed to
produce the diesel composition described hereinabove.
[0088] A hydrocarbonaceous feedstock having at least 50 ppm sulfur
and at least 25 percent by weight aromatic content is fed to a
hydrotreater over a hydrotreating catalyst thereby producing a
hydrotreated product.
[0089] Hydrotreating catalysts are suitable for hydroconversion of
feedstocks containing high amounts of sulfur, nitrogen and/or
aromatic-containing molecules. Such catalysts generally contain at
least one metal component selected from non-noble Group VIII (CAS
Notation) or at least one metal component selected from the Group
VI B (CAS notation) elements or mixtures thereof. Group VIB
elements include chromium, molybdenum and tungsten. Group VIII
elements include iron, cobalt and nickel. The amount(s) of metal
component(s) in the catalyst suitably range from about 0.5% to
about 25% by weight of Group VIII metal component(s) and from about
0.5% to about 25% by weight of Ciroup VI B metal component(s),
calculated as metal oxide(s) per 100 parts by weight of total
catalyst, where the percentages by weight are based on the weight
of the catalyst before sulfiding. The metal components in the
catalyst may be in the oxidic and/or the sulphidic form. If a
combination of at least a Group VI B and a Group VIII metal
component is present as (mixed) oxides, it may be subjected to a
sulfiding treatment prior to proper use in hydrotreating. Suitably,
the catalyst comprises one or more components of nickel and/or
cobalt and one or more components of molybdenum and/or
tungsten.
[0090] The hydrotreating catalyst particles of this invention are
suitably prepared by impregnating, blending, or co-mulling, active
sources of the aforementioned metals with a support or binder.
Examples of suitable supports or binders include silica, alumina,
clays, zirconia, titania, magnesia and silica-alumina. Preference
is given to the use of alumina as a support or a binder or both.
Other components, such as phosphorous, may be added as desired to
tailor the catalyst particles for a desired application. When
co-mulling, the blended components are then shaped, such as by
extrusion, dried and calcined at temperatures up to 1200.degree. F.
(649.degree. C.) to produce the finished catalyst particles.
Alternatively, equally suitable methods of preparing the amorphous
catalyst particles include preparing oxide binder particles, such
as by extrusion, drying and calcining, followed by depositing the
aforementioned metals on the oxide particles, using methods such as
impregnation. The catalyst particles, containing the aforementioned
metals, are then further dried and calcined prior to use as a
hydrotreating catalyst.
[0091] Suitable hydrotreating catalysts generally comprise a metal
component, suitably Group VIB or VIII metal, for example
cobalt-molybdenum, nickel-molybdenum, on a porous support, for
example silica, silica-alumina, alumina or mixtures thereof.
Examples of suitable hydrotreating catalysts are the commercial ICR
106, ICR 120 of Chevron Research and Technology Co.; DN-200 of
Criterion Catalyst Co.; TK-555 and TK-565 of Haldor Topsoe A/S;
HC-K, HC-P, HC-R and HC-T of UOP; KF-742, KF-752, KF-846, KF-848
STARS and KF-849 of AKZO Nobel/Nippon Ketjen; and HR-438/448 of
Procatalyse SA.
[0092] Catalysts used in carrying out hydrotreating operations are
well known in the art. See, for example, U.S. Pat. Nos. 4,347,121
and 4,810,357 for general descriptions of hydrotreating, and
typical catalysts used in hydrotreating processes.
[0093] The hydrotreating catalyst employed in the present invention
is selected from the group consisting of a nickel-molybdenum
catalyst, a nickel-tungsten catalyst, a molybdenum-tungsten
catalyst, a nickel-molybdenum-tungsten catalyst and a
molybdenum-cobalt catalyst. Preferably, the catalyst employed is a
nickel-molybdenum catalyst on an alumina support.
[0094] The hydrotreated product is then fed to at least one
separation unit and separated into at least two product streams: a
first product stream and a second product stream. Preferably, the
hydrotreated product is separated into a naphtha product stream, a
jet product stream, and a heavy product stream. Typically, the
second product stream or the heavy product stream has a sulfur
content that is less than 50 ppm by weight. Preferably, the
hydrotreated product is fed to at least two separation units, one
of which includes a distillation column. The heavy product stream
is then fed to a hydrogenation reactor system. The heavy product
stream is fed to the hydrogenation reactor system over a noble
metal hydrogenation catalyst, thereby producing a hydrogenated
product. Optionally, an isomerization catalyst may be added to the
hydrogenation reactor system to control cloud point. The
hydrogenated product is then fed to at least one separation unit
thereby producing a naphtha product stream, a jet product stream
and a diesel product stream. Preferably, the hydrogenated product
is fed to at least one separation unit, one of which may include a
distillation column, thereby producing a diesel product stream
having an aromatic content of less than 7.5 percent by weight, a
sulfur content of less than 10 ppm, and a flash point of greater
than 50 degrees Celsius.
[0095] Suitable hydrogenation catalysts generally comprise Group
VIII noble metals or oxides thereof. Platinum catalyst or palladium
catalyst or mixtures thereof may be employed. Optionally, a reduced
Group VIII base metal, such a nickel, may be employed as the
hydrogenation catalyst.
[0096] FIG. 2 further depicts a process of making an odorless
diesel fuel composition. FIG. 2 illustrates a hydrocarbonaceous
feed, entering the process through stream 100, combined with stream
110 comprising make-up hydrogen and combined with stream 140 which
comprises recycled hydrogen to form stream 115. Hydrogen in stream
140 is prepared by compressing the high pressure separator 20 gas
effluent stream 130.
[0097] Stream 115 is heated prior to entering the first stage
hydroprocessing unit, vessel 10. Vessel 10 is preferably operated
as a hydrotreater where the hydrocarbonaceous feed's sulfur is
removed to very low levels, preferably <100 ppm, more preferably
less than 50 ppm, most preferably <20 ppm. The feed flows
downward through at least one bed of catalyst. Preferably, the feed
flows through more than one bed of catalyst.
[0098] Hydrotreated effluent exits vessel 10 through stream 120 and
is flashed in the high pressure separator, vessel 20. This vessel
is a simple flash drum, separating the liquid hydrocarbon from the
hydrogen rich recycle gas stream 130. The recycle gas stream 130 is
compressed by the recycle gas compressor 30 and recycled to the
hydrotreater reactor 10 inlet.
[0099] The high pressure liquid effluent stream 150 is reduced in
pressure valve 35 to low pressure, typically, below 60 psig, to
form stream 155. Stream 155 is flashed in the low pressure
separator, vessel 40. This vessel is a simple flash drum separating
the liquid hydrocarbon (stream 170) from the product gases (stream
160).
[0100] The liquid effluent stream 170 is heated and separated into
several streams including, but not limited to, a diesel or
diesel/jet stream in stripper 50 to remove the light gases (stream
180) and naphtha (stream 190). As an option, the product jet fuel,
i.e., having a jet fuel boiling point range, (stream 195) can
either be stripped in stripper 50 or combined with the diesel
(stream 200) boiling range material in stream 200 to produce a
jet/diesel stream.
[0101] The diesel or the jet/diesel stream 200 is pumped to
hydrogenation pressure and combined with stream 210 comprising
make-up hydrogen and with stream 240 comprising recycled hydrogen
to form stream 215. Hydrogen in stream 240 is prepared by
compressing the high pressure separator gas effluent stream
230.
[0102] Stream 215 is heated prior to entering the hydrogenation
unit, vessel 60. Vessel 60 is preferably operated as a
hydrogenation unit, preferably charged with high activity, noble
base metals, where the hydrocarbon feed's aromatics are saturated
to the levels require to make the diesel product odorless. The feed
flows downward through at least one or more catalyst beds.
[0103] Typically, the catalyst employed in the hydrogenation unit
comprises noble metals supported on silica or alumina or silica
alumina or combinations of these supports. The catalyst cracking
activity may be enhanced by adding zeolites to the catalysts.
[0104] Hydrogenated effluent exits vessel 60 through stream 220 and
is flashed in the high pressure separator, vessel 70. This vessel
is a simple flash drum, separating the liquid hydrocarbon from the
hydrogen rich recycle gas stream 230. The recycle gas stream 230 is
compressed with the recycle gas compressor 80 to the pressure of
the hydrogenation reactor inlet.
[0105] The high pressure liquid effluent stream 250 is reduced in
pressure (valve 85) to a low pressure, typically below 60 psig, to
form stream 255. Stream 255 is flashed in the low pressure
separator, vessel 90. This vessel is a simple flash drum separating
the liquid hydrocarbon (stream 270) from the product gases (stream
260).
[0106] The liquid effluent stream 270 is heated and separated into
at least two streams. To remove the light gases (stream 280), the
liquid effluent stream is separated in stripper 95 into (1) naphtha
(stream 290), (2) jet fuel (stream 300) and (3) an odorless diesel
product (stream 310). By removing the lighter components in the
stripper, the flash point is raised to meet the odorless diesel
limitation of 50.degree. C.
[0107] In one embodiment, a hydrocarbonaceous feedstock, having at
least 50 ppm sulfur, is fed to a first reactor system (e.g., a
hydrotreating unit) over a hydrotreating catalyst as described
hereinabove, thereby producing a hydrotreated product. The catalyst
system in the hydrotreating step takes places in a reactor that
that has at least two reactor beds. The first reactor bed comprises
at least two catalyst layers comprising a hydrotreating catalyst
layer and a hydrotreating/hydrogenation/hydrocracking catalyst
layer. Optionally, a hydrodemetallization layer may also be
employed in the first reactor bed. The hydrotreated product is then
fed to a second reactor bed which comprises at least two layers.
Preferably, the second reactor bed comprises a
hydrotreating/hydrogenation/hydrocracking catalyst layer, a
hydrocracking layer and a hydrotreating layer. The hydrotreated
product is fed through second reactor bed over the catalysts
layers, thereby producing a hydrocracked product.
[0108] The hydrocracking catalyst employed is typically a base
metal containing catalyst. In general, the hydrocracking catalyst
comprises a cracking component and a hydrogenation component on an
oxide support material or binder. The cracking component may
include an amorphous cracking component and/or a zeolite, such as a
Y-type zeolite, an ultrastable Y type zeolite, or a dealuminated
zeolite. A suitable amorphous cracking component is
silica-alumina.
[0109] The hydrogenation component of the hydrocracking catalyst is
selected from those elements known to provide catalytic
hydrogenation activity. At least one metal component selected from
the Group VIIIB (CAS Notation) elements and/or from the Group VIB
(CASNotation) elements are generally chosen. Group VIB elements
include chromium, molybdenum and tungsten. Group VIIIB elements
include iron, cobalt, and nickel. The amount(s) of hydrogenation
component(s) in the catalyst suitably range from about 0.5% to
about 30% by weight of Group VIIIB metal component(s) and from
about 0.5% to about 25% by weight of Group VIB metal component(s),
calculated as metals per 100 parts by weight of total catalyst,
where the percentages by weight are based on the weight of the
catalyst before sulfiding. The hydrogenation components in the
catalyst may be in the oxidic and/or the sulphidic form. If a
combination of at least a Group VIB and a Group VIIIB metal
component is present as (mixed) oxides, it will be subjected to a
sulfiding treatment prior to proper use in hydrocracking. Suitably,
the catalyst comprises one or more components of nickel and/or
cobalt and one or more components of molybdenum and/or tungsten.
Catalysts containing nickel and molybdenum or nickel and tungsten
are particularly preferred.
[0110] The hydrocracking catalyst particles of this invention may
be prepared by impregnating, blending, or co-mulling, active
sources of hydrogenation metals with a binder. Examples of suitable
binders include silica, alumina, clays, zirconia, titania, magnesia
and silica-alumina. Preference is given to the use of alumina as
binder. Other components, such as phosphorous, may be added as
desired to tailor the catalyst particles for a desired application.
The blended components are then shaped, such as by extrusion, dried
and calcined at temperatures up to 1200.degree. F. (649.degree. C.)
to produce the finished catalyst particles. Alternatively, equally
suitable methods of preparing the amorphous catalyst particles
include preparing oxide binder particles, such as by extrusion,
drying and calcining, followed by depositing the hydrogenation
metals on the oxide particles, using methods such as impregnation.
The catalyst particles, containing the hydrogenation metals, are
then further dried and calcined prior to use as a hydrocracking
catalyst.
[0111] The hydrocracked product is then fed to at least one
separation unit and separated into at least two product streams.
Preferably, the hydrocracked product is separated into a first
product stream and a second product stream. The first product
stream has a boiling point range of from about 80.degree. F. to
about 450.degree. F. The second product stream has a boiling point
range of from about 450.degree. F. to about 900.degree. F. The
second product stream is then fed to at least one reactor.
Preferably, the second product stream is fed to at least two
reactors, a first and second reactor. The first reactor comprises
at least one catalyst layer. Preferably, the first reactor
comprises at least two catalysts layers which comprises a
hydrogenation catalyst and an isomerization de-waxing catalyst to
convert the paraffins into iso-paraffins, thereby producing a
de-waxed product stream. The de-waxed product stream is then fed to
the second reactor, a hydrofinishing reactor, thereby producing a
hydrofinished effluent product stream.
[0112] Typically, the isomerization catalyst comprises intermediate
pore size catalysts. The term "intermediate pore size" refers to an
effective pore aperture in the range of from 5.3 angstroms to 6.5
angstroms when the porous inorganic oxide is in the calcined form.
Molecular sieves having pore apertures in this range tend to have
unique molecular sieving characteristics. Unlike small pore
zeolites such as erionite and chabazite, they will allow
hydrocarbons having some branching into the molecular sieve void
spaces. Unlike larger pore zeolites, such as the faujasites and
mordenites, they can differentiate between n-alkanes and slightly
branched alkanes, and larger branched alkanes having, for example,
quaternary carbon atoms.
[0113] The effective pore size of the molecular sieves can be
measured using standard adsorption techniques and hydrocarbonaceous
compounds of known minimum kinetic diameters. See Breck, Zeolite
Molecular Sieves. 1974 (especially Chapter 8); Anderson, et al., J.
Catalysis 58,114 (1979); and U.S. Pat. No. 4,440,871, the pertinent
portions of which are incorporated herein by reference.
[0114] In performing adsorption measurements to determine pore
size, standard techniques are used. It is convenient to consider a
particular molecule as excluded if it does not reach at least 95%
of its equilibrium adsorption value on the molecular sieve in less
than about 10 minutes (p/po=0.5; 25.degree. C.).
[0115] Intermediate pore size molecular sieves will typically admit
molecules having kinetic diameters of 5.3 to 6.5 angstroms with
little hindrance. Examples of such compounds (and their kinetic
diameters in angstroms) are: n-hexane (4.3), 3-methylpentane (5.5),
benzene (5.85), and toluene (5.8). Compounds having kinetic
diameters of about 6 to 6.5 .ANG. can be admitted into the pores,
depending on the particular sieve, but do not penetrate as quickly
and in some cases are effectively excluded. Compounds having
kinetic diameters in the range of 6 to 6.5 .ANG. include:
cyclohexane (6.0), 2,3-dimethylbutane (6.1), and m-xylene (6.1).
Generally, compounds having kinetic diameters of greater than about
6.5 .ANG. do not penetrate the pore apertures and thus are not
absorbed into the interior of the molecular sieve lattice. Examples
of such larger compounds include: o-xylene (6.8),
1,3,5-trimethylbenzene (7.5), and tributylamine (8.1).
[0116] The preferred effective pore size range is from about 5.5 to
about 6.2 .ANG..
[0117] It is essential that the intermediate pore size molecular
sieve catalysts used in the practice of the present invention have
a very specific pore shape and size as measured by X-ray
crystallography. First, the intracrystalline channels must be
parallel and must not be interconnected. Such channels are
conventionally referred to as 1-D diffusion types or more shortly
as 1-D pores. The classification of intrazeolite channels as 1-D,
2-D and 3-D is set forth by R. M. Barrer in Zeolites, Science and
Technology, edited by F. R. Rodrigues, L. D. Rollman and C.
Naccache, NATO ASI Series, 1984 which classification is
incorporated in its entirety by reference (see particularly page
75). Known 1-D zeolites include cancrinite hydrate, laumontite,
mazzite; mordenite and zeolite I.
[0118] None of the above listed 1-D pore zeolites, however,
satisfies the second essential criterion for catalysts useful in
the practice of the present invention. This second essential
criterion is that the pores must be generally oval in shape, by
which is meant the pores must exhibit two unequal axes referred to
herein as a minor axis and a major axis. The term oval as used
herein is not meant to require a specific oval or elliptical shape
but rather to refer to the pores exhibiting two unequal axes. In
particular, the 1-D pores of the catalysts useful in the practice
of the present invention must have a minor axis between about 3.9
.ANG. and about 4.8 .ANG. and a major axis between about 5.4 .ANG.
and about 7.0 .ANG. as determined by conventional X-ray
crystallography measurements.
[0119] The most preferred intermediate pore size
silicoaluminophosphate molecular sieve for use in the process of
the invention is SAPO-11. SAPO-11 comprises a molecular framework
of corner-sharing [SiO.sub.2] tetrahedra, [AlO.sub.2] tetrahedra
and [PO.sub.2] tetrahedra, [i.e., (S.sub.xAl.sub.yP.sub.z)O.sub.2
tetrahedral units]. When combined with a Group VIII metal
hydrogenation component, the SAPO-11 converts the waxy components
to produce a lubricating oil having excellent yield, very low pour
point, low viscosity and high viscosity index. SAPO-11 is disclosed
in detail in U.S. Pat. No. 5,135,638, which is hereby incorporated
by reference for all purposes.
[0120] Other intermediate pore size silicoaluminophosphate
molecular sieves useful in the process of the invention are SAPO-31
and SAPO-41, which are also disclosed in detail in U.S. Pat. No.
5,135,638.
[0121] Also useful are catalysts comprising an intermediate pore
size nonzeolitic molecular sieves, such as ZSM-22, ZSM-23 and
ZSM-35, and at least one Group VIII metal. X-ray crystallography of
SAPO-11, SAPO-31, SAPO-41, ZSM-22, ZSM-23 and ZSM-35 shows these
molecular sieves to have the following major and minor axes:
SAPO-11, major 6.3 .ANG., minor 3.9 .ANG.; (Meier, W. H., Olson, D.
H., and Baerlocher, C., Atlas of Zeolite Structure Types, Elsevier,
1996), SAPO-31 and SAPO-41, believed to be slightly larger than
SAPO-11, ZSM-22, major 5.5 .ANG., minor 4.5 .ANG. (Kokotailo, C.
T., et al, Zeolites, 5, 349(85)); ZSM-23, major 5.6 .ANG., minor
4.5 .ANG.; ZSM-35, major 5.4 .ANG., minor 4.2 .ANG. (Meier, W. M.
and Olsen, D. H., Atlas of Zeolite Structure Types, Butterworths,
1987).
[0122] The intermediate pore size molecular sieve may be used in
admixture with at least one Group VIII metal. Preferably the Group
VIII metal is selected from the group consisting of at least one of
platinum and palladium and optionally, other catalytically active
metals such as molybdenum, nickel, vanadium, cobalt, tungsten, zinc
and mixtures thereof. More preferably, the Group VIII metal is
selected from the group consisting of at least one of platinum and
palladium. The amount of metal ranges from about 0.01% to about 10%
by weight of the molecular sieve, preferably from about 0.2% to
about 5% by weight of the molecular sieve. The techniques of
introducing catalytically active metals into a molecular sieve are
disclosed in the literature, and preexisting metal incorporation
techniques and treatment of the molecular sieve to form an active
catalyst such as ion exchange, impregnation or occlusion during
sieve preparation are suitable for use in the present process. Such
techniques are disclosed in U.S. Pat. Nos. 3,236,761; 3,226,339;
3,236,762; 3,620,960; 3,373,109; 4,202,996; 4,440,781 and 4,710,485
which are incorporated herein by reference.
[0123] The term "metal" or "active metal" as used herein means one
or more metals in the elemental state or in some form such as
sulfide, oxide and mixtures thereof. Regardless of the state in
which the metallic component actually exists, the concentrations
are computed as if they existed in the elemental state.
[0124] The catalyst may also contain metals, which reduce the
number of strong acid sites on the catalyst and thereby lower the
selectivity for cracking versus isomerization. Especially preferred
are the Group IIA metals such as magnesium and calcium.
[0125] It is preferred that relatively small crystal size catalyst
be utilized in practicing the invention. Suitably, the average
crystal size is no greater than about 10.mu., preferably no more
than about 5.mu., more preferably no more than about 1.mu. and
still more preferably no more than about 0.5.mu.
[0126] Strong acidity may also be reduced by introducing nitrogen
compounds, e.g., NH.sub.3 or organic nitrogen compounds, into the
feed; however, the total nitrogen content should be less than 50
ppm, preferably less than 10 ppm. The physical form of the catalyst
depends on the type of catalytic reactor being employed and may be
in the form of a granule or powder, and is desirably compacted into
a more readily usable form (e.g., larger agglomerates), usually
with a silica or alumina binder for fluidized bed reaction, or
pills, prills, spheres, extrudates, or other shapes of controlled
size to accord adequate catalyst-reactant contact. The catalyst may
be employed either as a fluidized catalyst, or in a fixed or moving
bed, and in one or more reaction stages.
[0127] The intermediate pore size molecular sieve catalyst can be
manufactured into a wide variety of physical forms. The molecular
sieves can be in the form of a powder, a granule, or a molded
product, such as an extrudate having a particle size sufficient to
pass through a 2-mesh (Tyler) screen and be retained on a 40-mesh
(Tyler) screen. In cases wherein the catalyst is molded, such as by
extrusion with a binder, the silicoaluminophosphate can be extruded
before drying, or, dried or partially dried and then extruded.
[0128] The molecular sieve can be composited with other materials
resistant to temperatures and other conditions employed in the
isomerization process. Such matrix materials include active and
inactive materials and synthetic or naturally occurring zeolites as
well as inorganic materials such as clays, silica and metal oxides.
The latter may be either naturally occurring or in the form of
gelatinous precipitates, sols or gels including mixtures of silica
and metal oxides. Inactive materials suitably serve as diluents to
control the amount of conversion in the isomerization process so
that products can be obtained economically without employing other
means for controlling the rate of reaction. The molecular sieve may
be incorporated into naturally occurring clays, e.g., bentonite and
kaolin. These materials, i.e., clays, oxides, etc., function, in
part, as binders for the catalyst. It is desirable to provide a
catalyst having good crush strength because in petroleum refining,
the catalyst is often subjected to rough handling. This tends to
break the catalyst down into powder-like materials which cause
problems in processing.
[0129] Naturally occurring clays which can be composited with the
molecular sieve include the montmorillonite and kaolin families,
which families include the sub-bentonites, and the kaolins commonly
known as Dixie, McNamee, Georgia and Florida clays or others in
which the main mineral constituent is halloysite, kaolinite,
diokite, nacrite or anauxite. Fibrous clays such as halloysite,
sepiolite and attapulgite can also be use as supports. Such clays
can be used in the raw state as originally mined or initially
subjected to calcination, acid treatment or chemical
modification.
[0130] In addition to the foregoing materials, the molecular sieve
can be composited with porous matrix materials and mixtures of
matrix materials such as silica, alumina, titania, magnesia,
silica-alumina, silica-magnesia, silica-zirconia, silica-thoria,
silica-beryllia, silica-titania, titania-zirconia as well as
ternary compositions such as silica-alumina-thoria,
silica-alumina-titania, silica-alumina-magnesia and
silica-magnesia-zirconia. The matrix can be in the form of a
cogel.
[0131] The catalyst used in the process of this invention can also
be composited with other zeolites such as synthetic and natural
faujasites, (e.g., X and Y) erionites, and mordenites. It can also
be composited with purely synthetic zeolites such as those of the
ZSM series. The combination of zeolites can also be composited in a
porous inorganic matrix.
[0132] As discussed above, a de-waxed product stream results from
contacting the second product stream with an isomerization
catalyst. The de-waxed product stream is fed to at least one
reactor comprising a noble metal hydrogentation catalyst as
described hereinabove. The de-waxed product stream is hydrofinished
thereby producing a hydrofinished product stream. The hydrofinished
product stream is then fed to at least one separation unit and
separated into a naptha product stream, a jet product stream, a
diesel product stream and at least one base oil product stream.
Preferably, the hydrofinished product stream is then fed to at
least one separation unit and separated into a naphtha product
stream, a jet product stream, a diesel product stream, a first base
oil product stream and a second base oil product stream.
Preferably, the hydrofinished product stream is fed to at least two
separation units, one of which includes a distillation column, and
separated into a naphtha product stream, a jet product stream, a
diesel product stream and at least one base oil product stream,
preferably at least two base oil product streams, a first base oil
product stream and a second base oil product stream. The diesel
product stream has an aromatic content of less than 7.5 percent by
weight, a UV@272 nm+10*UV@310 nm of less than 1.5, a sulfur content
of less than 10 ppm and a flash point of greater than 50.degree.
C.
[0133] FIG. 3 further depicts one embodiment of a process of making
an odorless diesel fuel composition. FIG. 3 illustrates a
hydrocarbonaceous feed having a boiling point range of 550 F to
1000 F. The feed, stream 100, is combined with stream 110, which
comprises make-up hydrogen, and with stream 140, which comprises
recycled hydrogen, to form stream 115. Hydrogen in stream 140 is
prepared by compressing the high pressure separator 20 gas effluent
stream 130.
[0134] Stream 115 is heated prior to entering the first stage
hydroprocessing unit, vessel 10. Vessel 10 is preferably operated
as a hydrotreater where the hydrocarbonaceous feed's sulfur content
if decreased to very low levels. Preferably, the sulfur content is
less than 100 ppm. More preferred, the sulfur content is less than
50 ppm and most preferred, the sulfur content is less than 20 ppm.
The feed flows downward through at least one or more beds of
catalyst, thereby producing a hydrotreated product.
[0135] The hydrotreated effluent product exits vessel 10 through
stream 120 and is introduced to a second reactor system, a
hydrocracker unit, vessel 15. Vessel 15 is preferably operated at
hydrocracking operating conditions where the effluent's viscosity
index is improved to the viscosity index levels associated with
lubricant oils, preferably from about 98 to about 150. The
hydrotreated effluent product is contacted with a hydrocracking
catalyst, thereby producing a hydrocracked product.
[0136] The hydrocracked effluent product exits vessel 15 through
stream 125 and is flashed in the high pressure separator, vessel
20. This vessel is a simple flash drum, separating the liquid
hydrocarbon from the hydrogen rich recycle gas stream 130. The
recycle gas stream 130 is compressed in the recycle gas compressor
130 and recycled to the hydrotreater reactor 10 inlet.
[0137] The high pressure liquid effluent stream 150 is fed through
valve 35 and reduced in pressure to a low pressure, typically below
60 psig, to form stream 155. Stream 155 is flashed in the low
pressure separator, vessel 40. This vessel is a simple flash drum
separating the liquid hydrocarbon, stream 170, from the product
gases, stream 160.
[0138] The liquid effluent stream 170 is heated and separated into
at least two product streams in stripper 50 in order to separate
the light end gases from those product streams having a higher
boiling point. The separated product streams may include (1) a waxy
base oil, (2) a waxy base oil/diesel stream, (3) jet fuel, stream
195, (4) light end gases, stream 180, and (5) naphtha, stream 190.
Optionally, the jet fuel product stream, stream 195, may either be
stripped in stripper 50 or combined with the waxy base oil/diesel
boiling range material in stream 200.
[0139] The waxy base oil/diesel or the jet/diesel/waxy base oil
stream 200 is pumped to a pressure suitable for hydrogenation
(e.g., 2000-2700 psi) and combined with stream 210, which comprises
make-up hydrogen, and with stream 240, which comprises recycled
hydrogen, to form stream 215. Hydrogen in stream 240 is prepared by
compressing the high pressure separator 70 gas effluent stream
230.
[0140] Stream 215 is heated prior to entering the first stage of
vessel 60. Vessel 60 is preferably operated as an isomerization
de-waxing unit. Preferably the beds in the vessel 60 are charged
with high activity, noble base metal catalysts, where the stream
200 is isomerized to the levels required to set the lubricant base
oil pour point and as a result yields a de-waxed product, a diesel
fuel composition with excellent cold flow properties.
[0141] Applicable catalyst for the isomerization dewaxing unit
comprises noble metals supported over SM-3, SSZ-32 or ZSM-5 or
mixtures thereof supported on alumina, silica, silica alumina or
mixtures thereof.
[0142] Stream 220 is generally cooled prior to entering a second
stage hydrofinishing reaction unit, vessel 65. Vessel 65 is
preferably operated as a hydrogenation unit, preferably charged
with high activity, noble base metal catalysts, where the dewaxed
product's aromatic and olefinic hydrocarbons are hydrogenated to
the levels required to meet diesel fuel specifications, including a
low odor. The feed flows downward through at least one or more beds
of catalyst.
[0143] Applicable catalysts for the hydrofinishing unit comprise of
noble metals, such as platinum, palladium, and, optionally, high
levels of a reduced Group VIII base metal such as nickel, supported
over alumina, silica, silica alumina or mixtures thereof.
[0144] The hydrofinished effluent product stream exits vessel 65
through stream 225 and is flashed in the high pressure separator,
vessel 70. This vessel is a simple flash drum, separating a liquid
hydrocarbon effluent stream from the hydrogen rich recycle gas
stream 230. The recycle gas stream 230 is fed to the recycle gas
compressor 80, where it is compressed and fed to the isomerization
dewaxing reactor.
[0145] The high pressure liquid hydrocarbon effluent stream 250 is
reduced in pressure (valve 85) to a low pressure, typically below
60 psig, to form stream 255. Stream 255 is flashed in the low
pressure separator, vessel 90. This vessel is a simple flash drum
separating liquid hydrocarbon effluent, stream 270, from product
gas effluent, stream 260.
[0146] The liquid hydrocarbon effluent stream 270 is heated and
separated in stripper 95 into a finished lubricating base oil,
stream 320, diesel product stream 310, jet product stream 295,
naptha product stream 290, and light gases stream 280. By removing
the lighter components in the stripper, the flash point is raised
to meet the odorless diesel limitation of greater than 50 degrees
C.
[0147] In one embodiment of the present invention, a
hydrocarbonaceous feedstock having at least 50 ppm sulfur and at
least 7.5 percent by weight aromatic content is fed to a reactor
system (e.g., hydrogenating unit) which contains high activity base
metal catalysts to hydrogenate the hydrocarbonaceous feedstock,
thereby hydrogenating the hydrocarbonaceous feedstock and producing
a hydrogenated product stream. The hydrogenated product stream is
fed to at least one separation unit, thereby separating the
hydrogenated product stream into at least two separate product
streams. Preferably, the hydrogenated product stream is separated
in at least two separation units, one of which includes a
distillation column. Preferably, the hydrogenated product stream is
separated into at least a naphtha product stream, a jet product
stream and a diesel product stream. The diesel product stream has
an aromatic content of less than 7.5 percent by weight, a sulfur
content of less than 10 ppm, and a flash point of greater than 50
degrees C.
[0148] Preferably, the high activity base metal catalysts employed
in this embodiment comprises Group VI base metal and Group VIII
noble metal supported on an alumina, silica, alumina-silica, other
inorganic oxide or zeolite support. Preferably, the catalyst
comprises at least 5 wt % Group VIII and 5 wt % Group VI metals.
More preferred, the catalyst comprises 6 wt % Ni and 19 wt %
Tungsten. Most preferred, the catalyst comprises 20 wt % Ni and 20
wt % Tungsten, and the reactor system has a pressure of at least
1000 psi.
[0149] The hydrogenation component of the catalyst can a base metal
and can be impregnated into the inorganic oxide, the zeolite or
both. In this application, the term "base metal" includes one or
more of nickel, cobalt, tungsten or molybdenum. Usually, a
combination of base metals are used, such as nickel or cobalt in
combination with tungsten or molybdenum, and the base metal is
usually sulfided or presulfided in the catalyst when or before the
catalyst is put on stream. The term "impregnation" shall mean the
addition to a solid of a volume of solution not substantially
greater than that which can be absorbed by the solid, and allowing
the solution to be absorbed by or oil the solid, followed, without
an intermediate washing step, by the drying of the solution onto
the solid.
[0150] FIG. 4 further depicts one embodiment of a process of making
an odorless diesel fuel composition. FIG. 4 illustrates a sulfur
containing hydrocarbonaceous feedstock stream 100 which may be
combined with a recycle diesel stream 310 to from stream 105 which
is then combined with stream 110 which comprises make-up hydrogen
and with stream 140 which comprises recycled hydrogen to form
stream 115. Hydrogen in stream 140 is prepared by compressing the
high pressure separator 20 gas effluent, stream 130.
[0151] Stream 115 is heated prior to entering the first stage
hydroprocessing unit, vessel 10. Vessel 10 is preferably operated
as a hydrotreater for the removal of both feed sulfur and nitrogen
contained in the feedstock.
[0152] Suitable catalysts employed in the hydrotreater comprise
Group VI base metals, Group VIII noble metals, or mixtures thereof
supported on silica, alumina, alumina/silica or mixtures thereof.
Optionally, the catalyst cracking activity may be enhanced by
adding zeolites. Stream 115 is contacted with the aforementioned
catalyst(s), thereby producing a hydrotreated product stream
effluent.
[0153] The hydrotreated product stream effluent exits vessel 10
through stream 120 and enters vessel 20 which is preferably
operated as a hydrogenation unit, thereby producing a hydrogenated
product stream effluent. Preferably, the hydrogenation unit is
charged with relatively high levels of high activity, base metals
catalyst, where the hydrotreated product stream's aromatic content
is saturated to the levels required to make the diesel fuel product
low in odor, (i.e., an aromatic content of less than 7.5 percent by
weight). The feed flows downward through at least one or more beds
of catalyst.
[0154] The hydrogenated product effluent stream exits vessel 20
through stream 125 and is flashed in the high pressure separator,
vessel 30. This vessel is a simple flash drum, separating the
liquid hydrocarbon from the hydrogen rich recycle gas stream 130.
The recycle gas stream 130 is compressed in the recycle gas
compressor and recycled to the hydrogenation reactor.
[0155] The high pressure liquid effluent stream 150 is fed through
valve 35 and is reduced in pressure (valve 35) to a low pressure,
typically below 60 psig to form stream 155. Stream 155 is flashed
in the low pressure separator, vessel 40. This vessel is a simple
flash drum separating a liquid hydrocarbon effluent steam (stream
170) from the product gases (stream 160).
[0156] The liquid hydrocarbon effluent stream 170 is heated and
separated into a diesel product stream or diesel/jet stream product
stream in stripper 50 to remove the light gases (stream 180), a
naphtha product stream (stream 190), jet fuel product stream
(stream 200) and a diesel product stream (Stream 300), having a low
odor. Optionally, a portion of the diesel product stream, stream
310, may be recycled back to the hydrotreater reactor,
hydrogenation reactor or both for improved saturation. By removing
the lighter components in the stripper, the flash point is raised
to meet the odorless diesel limitation of greater than 50 degrees
C.
[0157] In one embodiment of the present invention, a
hydrocarbonaceous feedstock, having less than 100 ppm sulfur and at
least 7.5 percent by weight aromatic content, is fed to a reactor
system (e.g., hydrogenation unit) which contains high activity
noble metal catalysts, thereby hydrogenating the hydrocarbonaceous
feedstock and producing a hydrogenated product. Preferably, the
high activity noble metal catalyst comprises at least one Group
VIII noble metal, such as platinum, palladium or mixtures thereof.
More preferred, the high activity noble metal catalyst comprises
greater than 0.5 wt % of at least one noble metal. Most preferred,
the high activity noble metal catalyst comprises at least 0.5 wt %
platinum, at least 0.5 wt % palladium or mixtures thereof. The
hydrogenated product is separated in at least one separation unit,
thereby producing at least two separated product streams.
Preferably, the hydrogenated product is separated in at least two
separation units, one of which includes a distillation column.
Preferably, the separated product stream is separated into at least
a naphtha product stream, a jet product stream and a diesel product
stream. The diesel product stream has an aromatic content of less
than 7.5 percent by weight, a sulfur content of less than 10 ppm
and a flash point of greater than 50 degrees C.
[0158] Preferably, the high activity noble metal catalysts employed
in this embodiment comprises a noble metal that can be impregnated
into the inorganic oxide, the zeolite or both. In this application,
the term "noble metal" includes one or more of ruthenium, rhodium,
palladium, osmium, iridium or platinum. The term "impregnation"
shall mean the addition to a solid of a volume of solution not
substantially greater than that which can be absorbed by the solid,
and allowing the solution to be absorbed by or on the solid,
followed, without an intermediate washing step, by the drying of
the solution onto the solid.
[0159] FIG. 5 further depicts another embodiment of the process for
making an odorless diesel fuel composition.
[0160] FIG. 5 illustrates a low sulfur hydrocarbonaceous feedstock,
preferably, having a sulfur content of less than 50 ppm. More
preferred, the sulfur content is less than 15 ppm. The feedstock,
stream 100, may be combined with a recycle diesel stream 310 to
form stream 105 which is then combined with stream 110, which
comprises make-up hydrogen, and with stream 140, which comprises of
recycle hydrogen, thereby forming stream 115. Hydrogen in stream
140 is prepared by compressing the high pressure separator 20 gas
effluent stream 130.
[0161] Stream 115 is heated prior to entering a hydrogenation
reactor, vessel 10. Vessel 10 is preferably operated at
hydrogenation operating conditions that are useful for obtaining
aromatic saturation.
[0162] Suitable catalysts for the hydrogenation reactor are noble
base metals supported on supports comprising silica, alumina,
silica alumina or mixtures thereof. The catalyst cracking activity
may be enhanced by adding zeolites, which have been described
herein. The hydrocarbonaceous feedstock is fed to the hydrogenation
reactor over the catalyst, thereby producing a hydrogenated product
effluent stream.
[0163] The hydrogenated product effluent stream exits vessel 10
through stream 120 and is flashed in the high pressure separator,
vessel 30. This vessel is a simple flash drum, separating the
hydrogenated liquid effluent product stream into a hydrocarbon
stream and a hydrogen rich recycle gas stream 130. The recycle gas
stream 130 is compressed in the recycle gas compressor 30 and
recycled to the hydrogenation reactor inlet.
[0164] The high pressure liquid effluent stream 150 is reduced in
pressure (valve 35) to low pressure, typically below 60 psig to
form a low pressure liquid effluent stream, stream 155. Stream 155
is flashed in the low pressure separator, vessel 40. This vessel is
a simple flash drum separating the liquid effluent stream into a
liquid product effluent stream (stream 170) and a product gas
(stream 160).
[0165] The liquid hydrocarbon effluent stream 170 is heated and
separated into a diesel product stream or diesel/jet stream product
stream in stripper 50 to remove the light gases (stream 180), a
naphtha product stream (stream 190), jet fuel product stream
(stream 200) and a diesel product stream (Stream 300), having a low
odor. Optionally, a portion of the diesel product stream, stream
300, may be recycled back to the hydrotreater reactor/hydrogenation
reactor or both for improved saturation. By removing the lighter
components in the stripper, the flash point is raised to meet the
odorless diesel limitation of greater than 50 degrees C.
Odorless Diesel Benefits
[0166] It has also been discovered that use of the odorless diesel
fuel, produced from the processes as described herein, provides
decreased soot in a combustion chamber compared to soot produced in
a combustion chamber when conventional ultra low sulfur diesel is
employed.
[0167] One embodiment of the invention is directed to a method of
reducing soot in an internal combustion engine by employing a
diesel fuel composition produced by the processes described
herein.
[0168] Another embodiment of the present invention is directed to a
method reducing soot in an internal combustion engine by employing
a diesel fuel composition, wherein the diesel fuel composition has
a (1) sulfur content of less than 10 ppm; (2) a flash point of
greater than 50.degree. C.; (3) a UV absorbance, A.sub.total, of
less than 1.5 as determined by the formula comprising
A.sub.total=A.sub.x+10(A.sub.y) [0169] wherein A.sub.x is the UV
absorbance at 270 nanometers; and [0170] wherein A.sub.y is the UV
absorbance at 310 nanometers;
[0171] (4) a naphthene content of greater than 5 percent; (5) a
cloud point of less than -12.degree. C.; (6) a nitrogen content of
less than 10 ppm; and (7) a 5% distillation point of greater than
300 F and a 95% distillation point of greater than 600 F.
[0172] It may be deemed that there is a reduction in particulate
matter when the odorless diesel of the present invention is
employed.
[0173] Other embodiments will be obvious to those skilled in the
art.
[0174] The following examples are presented to illustrate specific
embodiments of this invention and are not to be construed in any
way as limiting the scope of the invention.
EXAMPLES
Example 1
[0175] Example 1 corresponds to FIG. 2. The following process was
followed to produce the odorless diesel as illustrated in FIG. 2. A
hydrocarbonaceous feedstock having 10260 ppm sulfur, a boiling
range of about 257 F to about 759 F and an aromatic content of 31
percent by weight, as measured by SFC (supercritical fluid
chromatography ASTM D5186) method, was fed to a reactor, which
comprised a catalyst system, having a liquid hourly space velocity
(LHSV) of 3.0 l/Hr. The catalyst system comprised hydrotreating
catalysts selected containing a Group VI and Group VIII metals
catalysts, which was promoted with phosphorus, on a large surface
area alumina, non-acidic support. The total metals were 20 wt %.
Specifically, the hydrotreating catalyst comprise nickel and
molybdenum, promoted with phosphorus and supported on alumina. The
temperature of the hydrotreating reactor was 659 F. 320 scf of
hydrogen was consumed. 4700 scfb of hydrogen was recycled to the
hydrotreater. The average pressure of the hydrogen was 860 psi. The
hydrotreated product was then fed to a hydrogenation unit which
comprised a hydrogenation catalyst. The hydrogenation catalyst
comprised platinum/palladium on a silica/alumina support. The
temperature of the hydrogenation reactor was 580 F. 420 scf of
hydrogen was consumed. 2915 scfb was recycled to the hydrogenation
reactor. The average pressure of the hydrogen was 1363 psi.
[0176] As shown in Table 1, the two stage reaction process resulted
in a hydrocarbon product having an odor of less <0.5 and a
non-detectable percent of aromatics in the product stream, which
has a boiling range of from about 403 F to about 768.
TABLE-US-00001 TABLE 1 Two Stage Process, Base Metal for Sulfur
Removal followed by Single Stage Process with High Activity Noble
Metal Catalysts for Aromatic Saturation Hydrogenation Hydrogenation
Hydrotreater Hydrotreater Reactor Feed Reactor Effluent ID: Feed
Conditions Effluent Conditions Conditions Conditions Operating
Conditions Diesel Hydrotreater Diesel Hydrogenation Pressure, psig
950 1600 H2 Pressure Avg. psi 860 1363 LHSV, I/Hr 3.0 3.0 Reactor
Temperature, F. 659 580 Recycle Hydrogen, SCFB 4700 2915 H2
Consumption, SCFB 320 420 Yields: Jet, Vol. % 0.0 3.7 0.0 22.4
Diesel, Vol % 100.0 80.5 100.0 80.5 Odor Scale >5.0 >5.0
>5.0 <0.5 Inspections API Gravity 34.3 38.1 38.1 39.1 Sulfur,
PPM 10260 <6 <6 <6 Viscosity, cSt @ 40 C. 3.709 3.400
3.400 -- Cloud Point, C. -5 -5 -5 -10 UV Absorbance: UV@272 +
10UV@310 12.6567 1.8774 1.8774 0.0038 Cetane Index 52.2 59.1 59.1
60.3 Aromatics, % 31.0 27.3 27.3 -- Mono aromatics 23.9 23.9 23.9
-- Polynuclear Aromatics 6.4 6.4 6.4 -- Flash Point, Calc C. 103 77
77 120 Aniline Point, F. 157 170 170 192 Net Heat of Combustion,
18.460 18.660 18.660 18.742 04529, KBTU/lb Distillation, 02887
IBP/5% 257/416 271/357 271/357 403/455 10/30% 472/547 397/503
397/503 482/542 50% 579 561 561 577 70/90% 617/673 606/684 606/684
618/682 95/EP 698/759 721/759 721/759 711/768 Characterization
Factor, Kw 11.89 12.17 12.17 12.23
Example 2
[0177] Example 2 corresponds to FIG. 3. The following process was
followed to produce the odorless diesel as illustrated in FIG. 3. A
hydrocarbonaceous feedstock was hydrotreated by feeding the
hydrocarbonaceous feedstock into a first reactor which comprised
several catalysts layers dispersed in two reactor beds, thereby
producing hydrotreated product. In the first reactor bed, the first
layer comprised a demetallization catalyst which comprised nickel
and molybdenum and was promoted with phosphorus. The second layer
comprised hydrotreating layer as described in Example 1. The third
layer comprised a hydrotreating/hydrogenation/hydrocracking
catalyst which comprised nickel/molybdenum and was promoted with
phosphorus on an alumina support. The hydrotreated product, which
was the hydrocracking feedstock, had at least 19600 ppm sulfur, a
boiling range of about 594 F to about 971 F. The hydrocracking
feedstock was fed to the second reactor bed reactor, which
comprised a catalyst system, having a liquid hourly space-velocity
(LHSV) of 0.7 l/Hr. In the second reactor bed, the first catalyst
layer comprised a hydrotreating/hydrogenation/hydrocracking
catalyst which comprised nickel/molybdenum and was promoted with
phosphorus oil an alumina support. The second layer comprised a
hydrocracking catalyst which comprised nickel/molybdenum/y-zeolite
on a silica/alumina support. The third layer comprised another
hydrotreating catalyst layer as described herein. The temperature
of the hydrocracking section of the reactor was 724 F. The average
pressure of the hydrogen was 2700 psi. And, the gas recycle rate
was 5000 scfb. The hydrocracked product, which had a boiling point
range of from about 600 F to about 1010 F was separated into two
products: a waxy 220 N product and a waxy 100 N product. The waxy
220 N product had a boiling point range of from about 640 F to
about 1010 F and the waxy 100 N product had a boiling point range
of from about 600 F to about 920 F. The waxy 100 N product was then
fed to the de-waxing reactor which had a temperature of 625 F,
thereby producing a de-waxed product. The de-waxing reactor
comprised a catalyst comprising platinum and 60 wt % SSZ-32 on an
alumina support. The de-waxed product was then fed to a
hydrofinishing reactor which comprised a platinum/palladium
catalyst on a silica/alumina support and had a temperature of 494
F. The hydrofinishing product had a boiling point range of from
about 240 F to about 900 F. The hydrofinishing product was
separated into at least 3 product streams: (1) a 100 N base oil
having a boiling point range of from about 595 F to about 900 F;
(2) a 60 N base oil having a boiling point range of from about 540
F to about 710 F; and (3) an odorless diesel product having a
boiling point range of from about 250 F to about 665 F.
[0178] As shown in Table 2, the
hydrocracker/de-waxing/hydrofinishing reaction process resulted in
hydrocarbon product having an odor of <0.5 and less than 0.5
weight percent of aromatics in the product stream, which has a
boiling range of from about 255 F to about 660.
[0179] The odorless diesel product may be additized with a
lubricity additive dissolved in xylene at a concentration that does
not add odor to the diesel product.
TABLE-US-00002 TABLE 2 Multi-Stage Process for Aromatic Saturation
and Production of Odorless Diesel Operation Hydrocracker
De-waxer/Hydrofinisher Operating Conditions Pressure, psig 2700
2750 LHSV, I/Hr 0.7 1.9 Recycle Gas Rate SCFR 5000 3000
Temperatures, F. 375 Hydrocracker 724 -- IDW -- 625 HF -- 494
Yields, % Odorless Diesel -- 3.2 Lube Oil, 60 N -- 7.5 100 N (Waxy
100) (32) 79.1 Waxy 220 (47) -- Stream: HDC Feed Waxy 220 Waxy 100
100 N Product 60 N Odorless Product Product/ Product Diesel/ DW
Feed Product Inspections: Odor Scale -- -- -- -- -- <0.5 UV@272
+ 10UV@310 -- -- -- -- -- 0.0023 Flash Point, Calc. C. -- -- -- 210
178 81 (78) API Gravity 23.0 32.8 34.4 33.7 32.5 39.0 Sulfur, PPM
19600.000 19 5 <0.5 <0.5 <0.5 Nitrogen, PPM 896 1.1 0.1
0.1 0.1 0.1 Pour Point, C. -- -- -- -14 -20 -37 Cloud Point, C. --
-- -- -12 -25 -45 Cetane Index 34 44 53 52 52 59 Aromatics, % -- --
-- -- -- <0.5 Mono aromatics -- -- -- -- -- <0.5 Polynuclear
Aromatics -- -- -- -- -- <0.5 Viscosity, cSt @ 40 C. -- -- --
20.9 9.4 3.27 @ 100 C. 7.780 5.675 3.625 4.165 -- -- VI 67 120 110
101 60 -- Distillation, D2887 IBP/5% 594/672 649/719 604/650
601/661 545/589 255/366 10/30% 700/756 745/795 671/717 683/728
605/637 404/508 50% 792 829 752 761 656 567 70/90% 825/870 861/905
783/826 791/831 671/686 599/630 95/EP 892/971 826/1006 845/914
848/891 692/703 641/660 K Factor 11.79 12.66 12.53 12.50 12.05
12.18 HDC: Hydrocracker DW: Dewaxing
Example 3
[0180] Examples 3A and 3B correspond to FIG. 4. The following
process, which exemplifies Example 3A, was followed to produce the
odorless diesel as illustrated in FIG. 4. A hydrocarbonaceous
feedstock having 10171 ppm sulfur, a boiling range of about 257 F
to about 759 F and an aromatic content of at least 31 percent by
weight, as measured by SFC (Supercritical Fluid Chromatography,
ASTM D 5186), was fed to a reactor, which comprised a multi-layer
catalyst system, having a liquid hourly space velocity (LHSV) of
0.52 l/Hr. A first layer of the multi-layer catalyst system
comprised a nickel/molybdenum layer promoted by phosphorus on an
alumina support. And, a second layer of the multi-layer catalyst
system comprised a nickel/molybdenum/y-zeolite on a silica/alumina
support. The temperature of the reactor was 673 F. 1660 scb of
hydrogen was consumed. 8640 scfb of hydrogen was recycled to the
reactor. The average pressure of the reactor was 2254 psi. The
feedstock was fed to the reactor over the aforementioned catalysts,
thereby producing a reaction product. The reaction product was
distilled into two streams: (1) a diesel product stream and (2) a
naphtha/jet product stream. The diesel product stream had a sulfur
content of 6 ppm; a total UV absorbance of 0.0052; a boiling point
range of from 328 F to about 692 degrees F.; and a calculated
flashpoint of 72 degrees C. from the front end distillation.
[0181] Example 3B exemplifies a second run of the single stage
process using high activity base metal catalysts to produce
odorless diesel. A hydrocarbonaceous feedstock having 10171 ppm
sulfur, a boiling range of about 257 F to about 759 F and an
aromatic content of at least 31 percent by weight, as measured by
SFC (Supercritical Fluid Chromatography, ASTM D 5186), was fed to a
reactor, which comprised a catalyst system, having a liquid hourly
space velocity (LHSV) of 0.52 l/Hr. The catalyst system comprised a
multi-layer catalyst system comprising four catalyst layers. The
first layer comprised a nickel/molybdenum layer promoted by
phosphorus on an alumina support. And, a second layer comprised a
nickel/molybdenum/y-zeolite catalyst on a silica/alumina support. A
third layer comprised a nickel/tungsten/y-zeolite catalyst on a
silica/alumina support. And, a fourth layer comprised a
nickel/molybdenum layer promoted by phosphorus on an alumina
support. The temperature of the reactor was 673 F. 1710 scfb of
hydrogen was consumed. 8610 scfb of hydrogen was recycled to the
reactor. The average pressure of the reactor was 2254 psi. The
feedstock was fed to the reactor over the aforementioned catalysts,
thereby producing a reaction product. The reaction product was
distilled into two streams: (1) a diesel product stream and (2) a
naphtha/jet product stream. The diesel product stream had a sulfur
content of 6 ppm; a total UV absorbance of 0.0047; a boiling point
range of from 296 degrees F. to about 673 degrees F.; and a
calculated flashpoint of 58 degrees C. from the front end
distillation.
[0182] As shown in Table 3, the single stage reaction process
resulted in a hydrocarbon product having an odor of less <0.5.
The odorless diesel product may be additized with a lubricity
additive dissolved in xylene at a concentration that does not add
odor to the diesel product.
TABLE-US-00003 TABLE 3 Single Stage Process with High Activity Base
Metal Catalysts ID: Feed Example 3A Example 3B Operating Conditions
and Yields Operating Conditions Pressure, psig 2254 2254 H2
Pressure Avg. psi 2058 2060 LHSV, I/Hr 0.52 0.53 Reactor
Temperature, F. 673 673 Recycle Hydrogen, SCFB 8640 8610 H2
Consumption, SCF 1660 1710 Recovery, % -- 103.5 102.6 Yields:
Hydrogen, Wt. % -2.36 -2.76 Hydrogen Sulfide, Wt. % 1.08 1.08
Ammonia, wt. % 0.01 0.01 Methane/Ethane, Wt. % 0.17 0.16
Propane/Butane, Vol. % 16.5 17.3 Lt. Naphtha, C5/C6, Vol % 15.5
13.6 Naphtha/Jet, Vol. % 0.0 42.3 49.1 Diesel, Vol % 100.0 45.1
40.8 Total 100.0 119.4 120.8 Product: Feed Diesel Naphtha/Jet
Diesel Naphtha/Jet Odor Scale >5.0 <0.5 -- <0.5 -- API
Gravity 34.3 42.7 43.4 41.3 41.3 Sulfur, PPM 10171 <6 <6
<6 <6 Total UV Absorbance: 12.6567 0.0052 -- 0.0041 -- UV@272
+ 10UV@310 Flash Point, Calc. C. 103 72 -- 58 -- Product Quality
Inspections: Hydrogen, Wt. % -2.36 -2.76 Hydrogen Sulfide, Wt. %
1.08 1.08 Ammonia, wt. % 0.01 0.01 Methane/Ethane, Wt. % 0.17 0.16
Propane/Butane, Vol. % 16.5 17.3 Lt. Naphtha, C5/C6, Vol % 15.5
13.6 Naphtha/Jet, Vol. % 0.0 42.3 49.1 Diesel, Vol % 100.0 45.1
40.8 Total 100.0 119.4 120.8 Product Feed Diesel Naphtha/Jet Diesel
Naphtha/Jet Yield, Vol. % 100.0 45.1 42.3 40.8 49.1 Odor Scale 5.0
<0.5 -- <0.5 -- API Gravity 34.3 47.4 49.3 Sulfur, PPM 10171
<6 <6 <6 <6 Cloud Point, C. -5 -10 -- -17 -- Aromatics,
% 31.0 -- -- -- -- Mono aromatics 19.9 -- -- -- -- Polynuclear
Aromatics 11.1 -- -- -- -- Total UV Absorbance: 12.6567 0.0052 --
0.0047 -- UV@272 + 10UV@310 Cetane Index 52.2 67 -- 61 -- n-DM
Analysis: Aromatic Carbon, % 16.2 0.0 0.1 0.1 0.0 Naphthenic
Carbon, % 24.0 20.6 38.1 24.7 34.0 Parflinic Carbon, % 59.8 79.4
61.8 75.2 66.0 Flash Point, Calc C. 103 72 -- 58 -- Aniline Point,
F. 157 186 -- 178 -- Net Heat of Combustion, 18.455 18.890 --
18.890 -- D4529, KBTU/lb Distillation, D2887 IBP/5% 257/416 328/345
132/169 296/314 85/149 10/30% 472/547 361/418 193/237 325/370
171/218 50% 579 488 258 429 247 70/90% 617/673 549/600 288/318
516/577 270/293 95/EP 698/759 626/692 328/344 601/673 298/344
Characterization Factar, Kw 11.89 12.45 11.96 12.31 12.08
Example 4
[0183] Examples 4A and 4B correspond to FIG. 5. The following
process, which exemplifies Examples 4A and 4B, was followed to
produce the odorless diesel as illustrated in FIG. 5. A
hydrocarbonaceous feedstock was hydrotreated to decrease the sulfur
content in the feedstock. The hydrotreating method employed was
similar to the method described in Example 1. The hydrotreated
product, which had a sulfur content of less than 6 ppm and a total
UV absorbance of 1.8774, was fed to a catalyst system which
comprised a high activity noble metal catalyst which comprised 0.5
wt % platinum and 0.5 wt % palladium, supported on a silica/alumina
support. The temperature of the reactor was 580 F. 2915 scfb of
recycle hydrogen gas was fed to the reactor. 420 scfb of hydrogen
was consumed. The average pressure of the reactor was 1600 psi. The
feedstock was fed to the reactor over the aforementioned catalyst,
thereby producing a reaction product. The reaction product was
distilled into two streams: (1) a diesel product stream and (2) a
jet product stream. The diesel product stream had a sulfur content
of less than 6 ppm; a total UV absorbance of 0.0038; a boiling
point range of from 403 F to about 768 F; and a calculated
flashpoint of 120 degrees C.
[0184] Example 4B exemplifies a second run of the process using the
same base metal catalysts as in Example 4A to produce odorless
diesel.
[0185] As shown in Table 4, the single stage reaction process
resulted in a hydrocarbon product having an odor of less <0.5.
The odorless diesel product may be additized with a lubricity
additive dissolved in xylene at a concentration that does not add
odor to the diesel product.
TABLE-US-00004 TABLE 4 Base Metals Catalyst used in Hydroprocessing
to Produce Odorless Diesels 4A 4B ID: 4A Feed Product 4B Feed
Product Operating Conditions Pressure, psig 1600 1604 H2 Pressure
Avg, psi 1363 1386 LHSV, I/Hr 3.0 3.0 Reactor Temperature, F. 580
622 Recycle Hydrogen, 2915 3115 SCFB H2 Consumption, SCF 420 475
Yields: Jet, Vol. % 0.0 22.4 0.0 11.9 Diesel, Vol % 100.0 80.5
100.0 90.5 Odor Scale 5.0 <0.5 5.0 <1.5 Inspections API
Gravity 38.1 39.1 38.8 40.1 Sulfur, PPM <6 <6 6.2 <6
Viscosity, cSt @ 40 C. 3.400 -- 2.685 -- Cloud Point, C. -3 -- -10
-- UV Absorbance: UV@272 + 10UV@310 1.8774 0.0038 2.0385 0.0110
Cetane Index 48.8 60.3 56.5 60.0 Aramatics, % 18.6 -- 22.2 -- Mono
aromatics 16.4 -- 20.0 -- Polynuclear Aromatics 2.2 -- 2.0 -- Flash
Point, Calc C. 89 120 59 87 Aniline Point, F. 170 192 160 258 Net
Heat of Combustion, 18.589 18.742 18.620 18.965 04529, KBTU/lb
Distillation, 02887 IBP/5% 283/384 403/455 231/315 334/381 10/30%
412/453 482/542 355/456 405/488 50% 484 577 538 550 70/90% 497/534
618/682 588/657 597/661 95/EP 552/627 711/768 684/750 687/752
Characterization Factor, 11.78 12.23 11.70 12.19 Kw
Example 5
[0186] Example 5 corresponds to FIG. 5. The following process was
followed to produce the odorless diesel as illustrated in FIG. 5. A
hydrocarbonaceous feedstock having 6.2 ppm sulfur, a boiling range
of about 231 F to about 750 F and an aromatic content of 22.2
percent by weight, as measured by SFC (Supercritical Fluid
Chromatography, ASTM D5186), was fed to a reactor, which comprised
a catalyst system, having a liquid hourly space velocity (LHSV) of
2.6 l/Hr. The catalyst system comprised the same high activity
noble metal catalyst employed in Example 4. The temperature of the
reactor was 603 F. 836 scfb of hydrogen was consumed. 3080 scfb of
hydrogen was recycled to the reactor. The average pressure of the
reactor was 1610 psi. The feedstock was fed to the reactor over the
aforementioned catalyst, thereby producing a reaction product,
Intermediate Products A and B. Intermediate Products A and B were
the result of two separate runs. Both Intermediate Products A and B
had a sulfur content of less than 6 ppm; a total UV absorbance of
0.0044 and 0.0031, respectively; a boiling point range of from 165
F to about 750 F and from about 135 to about 736, respectively; and
a calculated flashpoint of 38 degrees C. and 32 degrees C.,
respectively. Intermediate product B was then fed to a distillation
column wherein the distillation range was from about 317 F to about
744 degrees F., thereby producing an odorless diesel product which
had a sulfur content of less than 6 ppm; a total UV absorbance of
0.0047; an aromatic content of less than 1.5; and a net heat of
combustion, as determined by ASTM Method D4529, of 18,875
KBTU/lb.
[0187] The odorless diesel product may be additized with a
lubricity additive dissolved in xylene at a concentration that does
not add odor to the diesel product.
TABLE-US-00005 TABLE 5 Single Stage Process with High Activity
Noble Metal Catalysts Catalyst: Pt/Pd/Silica Alumina Intermediate
ID: Feed Intermediate Product A Product B Distillation Operating
Conditions Pressure, psig 1610 1590 H2 Pressure Avg. psi 1489 1516
LHSV, I/Hr 2.6 1.3 Reactor Temperature, F. 603 603 Recycle
Hydrogen, SCFB 3080 3390 H2 Consumption, SCF 836 911 Yields: Jet,
Vol. % 0.0 0.0 0.0 10.6 Diesel, Vol % 100.0 106.5 106.4 95.8 Odor
Scale 5.0 3.0 2.5 <1.5 Inspections API Gravity 38.8 42.7 43.4
41.3 Sulfur, PPM 6.2 <6 <6 <6 Viscosity, cSt @ 40 C. 2.685
-- -- 2.953 Cloud Point, C. -10 -- -- -9 UV Absorbance: UV@272 +
10UV@310 2.0385 0.0044 0.0031 0.0047 Cetane Index 56.5 60.9 60.5
61.0 Aromatics, % 22.2 -- -- <1.0 Mono aromatics 20.0 -- --
<0.5 Polynuclear Aromatics 2.0 -- -- <0.5 Flash Point, Calc
C. 59 43 38 77 Aniline Point, F. 160 177 177 182 Net Heat of
Combustion, 18.615 18.908 18.923 18.875 D4529, KBTU/lb
Distillation, D2887 IBP/5% 231/315 169/279 135/268 317/357 10/30%
355/456 327/424 312/411 379/468 50% 538 513 499 538 70/90% 588/657
576/646 566/638 587/653 95/EP 684/750 674/740 670/736 680/744
Characterization Factor, K.sub.w 11.70 12.23 12.22 12.23
Example 6
[0188] 19.7 mg of the odorless diesel fuel composition as prepared
in Example 2 was injected into the combustion chamber. The fuel was
injected into the combustion chamber for 7 seconds and then ignited
with a spark plug. At the time of injection the pressure of the
chamber was 1560 bar. The combustion chamber was filled with gas
containing approximately 15% oxygen and the remainder comprises
inert gas. The gas density in the combustion chamber was 22.8
kg/m3. The temperature of the combustion chamber was 1000 K; and
the pressure of the combustion chamber was 60 bar. The combustion
chamber was a one-cylinder version of a 4-stroke diesel engine. The
injector was a second-generation Bosch Common-Rail and had a nozzle
diameter (single hole) of 0.090 mm and a nozzle shape of
KS1.5/0.86.
[0189] Measurements of the soot thickness were made in an optically
accessible section of the combustion chamber. At the end of the
combustion cycle, the odorless diesel fuel composition had the
following results:
TABLE-US-00006 TABLE 6 Soot Thickness Results No. 2 Ultra-Low
Example 2 Sample Sulfur Diesel Odorless Diesel T.sub.10 (.degree.
C.) 211 223 T.sub.90 (.degree. C.) 315 312 Cetane Number 46 59
Aromatics Vol % 27 Less than 5 Soot Optical Thickness, KL @ 20 mm
from nozzle 0 0 @ 30 mm from nozzle 0.4 0.4 @ 40 mm from nozzle 1.8
1.4 @48 mm from nozzle 2.3 2.0 KL: kiloluminaires
[0190] As evidenced in Table 6, the odorless diesel, as prepared in
Example 2, has less soot that results from the combustion of the
odorless diesel than the soot that remains when ultra low sulfur
diesel is combusted. Accordingly, it may be deemed that there is a
reduction in particulate matter when the odorless diesel of the
present invention is employed.
* * * * *