U.S. patent application number 14/469318 was filed with the patent office on 2015-05-21 for hydroprocess for a hydrocarbon stream from coal tar.
The applicant listed for this patent is UOP LLC. Invention is credited to Paul T. Barger, Maureen L. Bricker, Joseph A. Kocal, Matthew Lippmann.
Application Number | 20150136659 14/469318 |
Document ID | / |
Family ID | 53172217 |
Filed Date | 2015-05-21 |
United States Patent
Application |
20150136659 |
Kind Code |
A1 |
Barger; Paul T. ; et
al. |
May 21, 2015 |
HYDROPROCESS FOR A HYDROCARBON STREAM FROM COAL TAR
Abstract
A coal tar process is described. A coal tar stream is provided,
and the coal tar stream is separated to provide a plurality of
hydrocarbon streams. At least one of the hydrocarbon streams is
hydroprocessed in a fluidized bed hydroprocessing zone with a
catalyst to provide a gaseous volatile product and a solid heavy
hydrocarbon product absorbed onto the catalyst. The gaseous
volatile product is separated from the catalyst. The catalyst is
regenerating by separating the absorbed heavy hydrocarbon product
from the catalyst. The regenerated catalyst is recycled into the
hydroprocessing zone.
Inventors: |
Barger; Paul T.; (Arlington
Heights, IL) ; Bricker; Maureen L.; (Buffalo Grove,
IL) ; Kocal; Joseph A.; (Buffalo Grove, IL) ;
Lippmann; Matthew; (Chicago, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UOP LLC |
Des Plaines |
IL |
US |
|
|
Family ID: |
53172217 |
Appl. No.: |
14/469318 |
Filed: |
August 26, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61905988 |
Nov 19, 2013 |
|
|
|
Current U.S.
Class: |
208/428 ;
208/110; 208/59; 208/60; 208/61; 208/85 |
Current CPC
Class: |
C10G 65/10 20130101;
C10G 65/12 20130101; C10G 67/02 20130101; C10G 47/18 20130101 |
Class at
Publication: |
208/428 ; 208/85;
208/59; 208/60; 208/110; 208/61 |
International
Class: |
C10G 47/18 20060101
C10G047/18; C10G 67/02 20060101 C10G067/02; C10G 65/10 20060101
C10G065/10; C10G 1/04 20060101 C10G001/04; C10G 65/12 20060101
C10G065/12 |
Claims
1. A process comprising: providing a coal tar stream; separating
the coal tar stream to provide a plurality of hydrocarbon streams;
hydroprocessing at least one of the hydrocarbon streams in a
fluidized bed hydroprocessing zone with a catalyst to provide a
gaseous volatile product and a solid heavy hydrocarbon product
absorbed onto the catalyst; separating the gaseous volatile product
from the catalyst; regenerating the catalyst by separating the
absorbed heavy hydrocarbon product from the catalyst; and recycling
the regenerated catalyst into the hydroprocessing zone.
2. The process of claim 1 wherein the hydrocarbon stream has a
minimum boiling point of about 450.degree. C. to about 500.degree.
C.
3. The process of claim 1 wherein the hydrocarbon stream comprises
one or more of a toluene-insoluble stream, a hexane-insoluble
stream, and a tetrahydrofuran-insoluble stream.
4. The process of claim 1 wherein the hydrocarbon stream comprises
a pitch stream.
5. The process of claim 1 wherein the hydroprocessing takes place
at an H.sub.2 partial pressure ranging from about 3.4 MPa (500
psig) to about 17.2 MPa (2500 psig).
6. The process of claim 1 wherein regenerating the catalyst
comprises burning off the absorbed heavy hydrocarbon product from
the catalyst.
7. The process of claim 1 wherein a hydrocarbon stream flow rate
into the hydroprocessing zone is controlled based on a rate of
catalyst withdrawal to reduce buildup of heavy material on the
catalyst.
8. The process of claim 1 further comprising: removing the
separated gaseous volatile product.
9. The process of claim 8 further comprising: processing the
separated gaseous volatile product by one or more of hydrotreating,
hydrocracking, catalytic cracking, deoxygenation, desulfurization,
and hydrogenation.
10. A process comprising: pyrolyzing a coal feed to provide a coal
tar stream and a coke stream; separating the coal tar stream to
provide a plurality of hydrocarbon streams; hydroprocessing at
least one of the hydrocarbon streams in a fluidized bed
hydroprocessing zone with a catalyst to provide a gaseous volatile
product and a solid heavy hydrocarbon product absorbed onto the
catalyst; separating the gaseous volatile product from the
catalyst; regenerating the catalyst by separating the absorbed
heavy hydrocarbon product from the catalyst; and recycling the
regenerated catalyst into the hydroprocessing zone.
11. The process of claim 10 wherein the hydrocarbon stream has a
minimum boiling point of about 450.degree. C. to about 500.degree.
C.
12. The process of claim 10 wherein the hydrocarbon stream
comprises a pitch stream.
13. The process of claim 10 wherein the hydrocarbon stream
comprises one or more of a toluene-insoluble stream, a
hexane-insoluble stream, and a tetrahydrofuran-insoluble
stream.
14. The process of claim 10 wherein the hydroprocessing takes place
at an H.sub.2 partial pressure ranging from about 3.4 MPa (500
psig) to about 17.2 MPa (2500 psig).
15. The process of claim 10 further comprising: removing the
separated gaseous volatile product.
16. The process of claim 15 further comprising: processing the
separated gaseous volatile product by one or more of hydrotreating,
hydrocracking, catalytic cracking, deoxygenation, desulfurization,
and hydrogenation.
17. A process comprising: hydroprocessing a hydrocarbon stream from
a coal tar stream in a fluidized bed hydroprocessing zone with a
catalyst to provide a gaseous volatile product and a solid heavy
hydrocarbon product absorbed onto the catalyst; separating the
gaseous volatile product from the catalyst; regenerating the
catalyst by separating the absorbed heavy hydrocarbon product from
the catalyst; and recycling the regenerated catalyst into the
hydroprocessing zone.
18. The process of claim 17 wherein the hydrocarbon stream
comprises one or more of a toluene-insoluble stream, a
hexane-insoluble stream, and a tetrahydrofuran-insoluble
stream.
19. The process of claim 17 wherein the hydrocarbon stream
comprises pitch.
20. The process of claim 17 wherein the hydrocarbon stream
comprises a coal stream having a minimum boiling point of at least
525.degree. C.
Description
[0001] This application claims the benefit of Provisional
Application Ser. No. 61/905,988 filed Nov. 19, 2013, entitled
Hydroprocess for a Hydrocarbon Stream from Coal Tar.
BACKGROUND OF THE INVENTION
[0002] Many different types of chemicals are produced from the
processing of petroleum. However, petroleum is becoming more
expensive because of increased demand in recent decades.
[0003] Therefore, attempts have been made to provide alternative
sources for the starting materials for manufacturing chemicals.
Attention is now being focused on producing liquid hydrocarbons
from solid carbonaceous materials, such as coal, which is available
in large quantities in countries such as the United States and
China.
[0004] Pyrolysis of coal produces coke and coal tar. The
coke-making or "coking" process consists of heating the material in
closed vessels in the absence of oxygen to very high temperatures.
Coke is a porous but hard residue that is mostly carbon and
inorganic ash, which is used in making steel.
[0005] Coal tar is the volatile material that is driven off during
heating, and it comprises a mixture of a number of hydrocarbon
compounds. It can be separated to yield a variety of organic
compounds, such as benzene, toluene, xylene, naphthalene,
anthracene, and phenanthrene. These organic compounds can be used
to make numerous products, for example, dyes, drugs, explosives,
flavorings, perfumes, preservatives, synthetic resins, and paints
and stains. The residual pitch left from the separation is used for
paving, roofing, waterproofing, and insulation.
[0006] Coal tar hydrocarbon streams, especially heavier hydrocarbon
streams and pitch, can be difficult to crack in hydroprocessing,
resulting in an undesirable ratio of pitch to more valuable
volatile products.
[0007] There is a need for an improved hydroprocessing method for
coal tar streams.
SUMMARY OF THE INVENTION
[0008] One aspect of the invention involves a coal tar process. A
coal tar stream is provided, and the coal tar stream is separated
to provide a plurality of hydrocarbon streams. At least one of the
hydrocarbon streams is hydroprocessed in a fluidized bed
hydroprocessing zone with a catalyst to provide a gaseous volatile
product and a solid heavy hydrocarbon product absorbed onto the
catalyst. The gaseous volatile product is separated from the
catalyst. The catalyst is regenerated by separating the absorbed
heavy hydrocarbon product from the catalyst. The regenerated
catalyst is recycled into the hydroprocessing zone.
[0009] Another aspect of the invention involves a coal tar process.
A coal feed is pyrolyzed to provide a coal tar stream and a coke
stream. The coal tar stream is separated to provide a plurality of
hydrocarbon streams. At least one of the hydrocarbon streams is
hydroprocessed in a fluidized bed hydroprocessing zone with a
catalyst to provide a gaseous volatile product and a solid heavy
hydrocarbon product absorbed onto the catalyst. The gaseous
volatile product is separated from the catalyst, and the catalyst
is regenerated by separating the absorbed heavy hydrocarbon product
from the catalyst. The regenerated catalyst is recycled into the
hydroprocessing zone.
[0010] Another aspect of the invention involves a coal tar process.
A hydrocarbon stream from a coal tar stream is hydroprocessed in a
fluidized bed hydroprocessing zone with a catalyst to provide a
gaseous volatile product and a solid heavy hydrocarbon product
absorbed onto the catalyst. The gaseous volatile product is
separated from the catalyst, and the catalyst is regenerated by
separating the absorbed heavy hydrocarbon product from the
catalyst. The regenerated catalyst is recycled into the
hydroprocessing zone.
BRIEF DESCRIPTION OF THE DRAWING
[0011] The Figure is an illustration of one embodiment of the
process of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The Figure shows one embodiment of a process 5 of the
present invention. A coal feed 10 can be sent to a pyrolysis zone
15 for pyrolyzing. In some example processes, a portion of the coal
feed 10 is sent to a gasification zone (not shown), for instance
the coal feed 10 can be split into two parts and sent to both.
[0013] In some processes, all or a portion of the coal feed 10 is
mixed with oxygen and steam and reacted under heat and pressure in
the gasification zone to form syngas, which is a mixture of carbon
monoxide and hydrogen. The syngas can be further processed using
the Fischer-Tropsch reaction to produce gasoline or using the
water-gas shift reaction to produce more hydrogen.
[0014] In the pyrolysis zone 15, the coal is heated at high
temperature, e.g., up to about 2,000.degree. C. (3600.degree. F.),
in the absence of oxygen to drive off the volatile components.
Coking produces a coke stream 20 and a coal tar stream 25. The coke
stream 20 can be used in other processes, such as the manufacture
of steel.
[0015] The coal tar stream 25 is sent to a fractionation zone 30
for separation. Coal tar comprises a complex mixture of
heterocyclic aromatic compounds and their derivatives with a wide
range of boiling points. The number of fractions and the components
in the various fractions can be varied as is well known in the art.
A typical separation process involves separating the coal tar
stream 25 into four to six streams. For example, there can be a
fraction 35 comprising NH.sub.3, CO, and light hydrocarbons, a
light oil fraction 40 with boiling points between 0.degree. C. and
180.degree. C., a middle oil fraction 45 with boiling points
between 180.degree. C. to 230.degree. C., a heavy oil fraction 50
with boiling points between 230 to 270.degree. C., an anthracene
oil fraction with boiling points between 270.degree. C. to
350.degree. C., and pitch 55.
[0016] The light oil fraction contains compounds such as benzenes,
toluenes, xylenes, naphtha, coumarone-indene, dicyclopentadiene,
pyridine, and picolines. The middle oil fraction contains compounds
such as phenols, cresols and cresylic acids, xylenols, naphthalene,
high boiling tar acids, and high boiling tar bases. The heavy oil
fraction contains creosotes, for example. The anthracene oil
fraction contains anthracene. Pitch is the residue of the coal tar
distillation containing primarily aromatic hydrocarbons and
heterocyclic compounds.
[0017] Preferred processes hydroprocess coal tar streams that are
difficult to crack; e.g. heavy coal tar streams. In an example
embodiment, the fractionation zone 30 separates the coal tar stream
into a fraction comprising NH.sub.3, CO, and light hydrocarbons 35,
light and middle oil fractions 40, 45, and at least one heavy oil
fraction 50 having a minimum boiling point of about 450.degree. C.
to about 500.degree. C. The heavy fraction 50 is introduced to a
fluidized bed hydroprocessing zone 60, with hydrogen co-feed
streams 57 and 58 including fresh hydrogen stream 56 and recycle
stream 82, for hydroprocessing, e.g., hydrocracking, the heavy
fraction 50.
[0018] The hydrocarbon stream that is input to the fluidized bed
hydroprocessing zone 60 can come from other sources. The pitch
stream 55 can be input to the hydroprocessing zone 60. In another
example process, the fractionation zone 30 is replaced with a
solvent extractor (not shown), which extracts a coal tar stream
with a solvent such as toluene, hexane, tetrahydrofuran, or
combinations thereof The solvent extractor outputs a
toluene-insoluble stream, a hexane-insoluble stream, a
tetrahydrofuran stream, or a combination. This output can be
introduced to the hydroprocessing zone 60. In another example
process, a heavy end coal tar stream taken directly from the
pyrolysis zone 15, for example a coal tar stream having a minimum
boiling point of at least 525.degree. C., is input to the
hydroprocessing zone without intermediate separation such as
fractionation or solvent extraction. The coal tar stream can be
obtained from sources other than pyrolyzing the coal feed 10 in the
pyrolysis zone 15, and this coal tar stream can either be separated
and fed to the hydroprocessing zone 60, or a heavy feed coal tar
stream can be directly input into the hydroprocessing zone.
[0019] Hydrocracking is a process in which hydrocarbons crack in
the presence of hydrogen to lower molecular weight hydrocarbons.
Typical hydrocracking conditions may include a temperature of about
290.degree. C. (550.degree. F.) to about 468.degree. C.
(875.degree. F.), a pressure of about 3.5 MPa (500 psig) to about
20.7 MPa (3000 psig), a liquid hourly space velocity (LHSV) of
about 1.0 to less than about 2.5 hr.sup.-1, and a hydrogen rate of
about 421 to about 2,527 Nm.sup.3/m.sup.3 oil (2,500-15,000
scf/bbl). Typical hydrocracking catalysts include amorphous
silica-alumina bases or low-level zeolite bases combined with one
or more Group VIII or Group VIB metal hydrogenating components, or
a crystalline zeolite cracking base upon which is deposited a Group
VIII metal hydrogenating component. Additional hydrogenating
components may be selected from Group VIB for incorporation with
the zeolite base.
[0020] The example fluidized bed hydroprocessing zone 60 includes a
plurality of zones for hydrocracking the hydrocarbon stream, e.g.,
heavy oil fraction 50. An outer, reaction zone 65 includes a
fluidized bed having an active hydrocracking catalyst disposed
therein. The catalyst preferably is powdered. Example active
hydrocracking catalysts include non-noble metals. Preferred
catalysts include Ni--Mo and W--Mo. The catalyst preferably is on a
spray-dried alumina or silica-aluminum base. The catalyst is
circulated internally through the hydroprocessing zone 60. An
example fluidized bed hydroprocessing zone 60 includes one or more
internal riser reactors 70 contained within an outer fluidized
reactor 65. The heavy fraction 50 and hydrogen co-feed stream 57
are mixed to provide a combined hydrocarbon and hydrogen stream 59
which is divided and injected into the bottom of each of the
internal riser reactors 70 with sufficient velocity to lift a
portion of the catalyst within the fluidized bed 65 through the
internal riser to thoroughly mix the hydrocarbon, hydrogen and
catalyst and initiate the hydroprocessing reactions. The second
hydrogen co-feed stream 58 is fed through a distributor to the
bottom of the fluidized bed 65 to provide fluidization. At the top
of the riser reactors 70 the majority of the catalyst and any
adsorbed or liquid-phase hydrocarbon drop down into the fluidized
bed 65 for further hydroprocessing.
[0021] During hydrocracking, hydrogen is provided at a very high
pressure, e.g., an H.sub.2 partial pressure ranging from about 3.4
MPa (500 psig) to about 17.2 MPa (2500 psig). An example
temperature range is between about 350.degree. C. to about
600.degree. C. During hydrocracking, a gaseous volatile product is
produced, as well as a solid heavy hydrocarbon product (e.g.,
pitch) that is absorbed on the catalyst. A feed rate and withdrawal
rate of the hydrocarbon stream into and out of the hydroprocessing
zone 60 can be controlled in relation to reaction activity to
reduce the buildup of heavy material (i.e., the amount of absorbed
pitch) on the catalyst. This limits buildup of solids on the
catalyst and preferably keeps the catalyst in a powder form. A
portion of the circulated catalyst with the adsorbed pitch is
removed as a free-flowing solid 95 from the fluidized bed 65.
[0022] Any unconverted hydrogen and gas phase hydrocarbon from
either the top of the internal riser reactors 70 or the top of the
fluidized bed 65, as well as any entrained catalyst particles and
hydrocarbon aerosol, exit the fluidized bed hydroprocessing zone 60
through a disengaging zone 75, preferably disposed internally to
the reaction zone 60, to separate gaseous volatile products (gas
phase) from the catalyst (solid phase) that includes non-volatile
products. The disengaging zone 75 separates the gas and solid phase
by the use of one or more stages of cyclone separators operating at
about reactor temperature and pressure. The separated gaseous
volatile product 80 is removed as an output of the disengaging zone
75 from the top of the hydroprocessing zone 60. The separated
gaseous volatile product 80 cooled in a condenser 81 to give a
gas-phase product stream 82 consisting primarily of unreacted
hydrogen and a liquid-phase condensed hydrocarbon stream. A portion
of the gas-phase product can be recycled back to the
hydroprocessing reactor via lines 57 and 58, while the remainder is
recovered as a vapor product 84. The condensed hydrocarbon stream
83 can be processed in a processing zone 85 to provide one or more
products 90.
[0023] The separated catalyst 95 is then fed to a regeneration zone
100 for separating the absorbed heavy hydrocarbon product from the
catalyst. The regeneration zone 100 preferably is a separate vessel
from the hydroprocessing zone 60. In the regeneration zone 100, the
absorbed heavy hydrocarbon product is burned off from the catalyst.
For instance, the absorbed heavy hydrocarbon product can be burned
at high temperatures, e.g., 450-800.degree. C., with an air input
97.
[0024] Alternatively, the separated catalyst 95 can be regenerated
by an extraction process such as solvent extraction using a solvent
such as paraffins, aromatics, sulfolane, and other polar aprotic
organic solvents at 100-250.degree. C., a solvent to catalyst
weight ratio of 1:1 to 100:1 and sufficient pressure to maintain
the solvent in the liquid phase at the extraction temperature.
[0025] The burned off or otherwise separated heavy hydrocarbon
product is output via stream 105. The regenerated, solid catalyst
110 is circulated to the fluidized bed 65.
[0026] Example processes for the condensed hydrocarbon stream 83 in
the processing zone include hydrotreating, hydrocracking,
deoxygenation, desulfurization, and hydrogenation. Hydrotreating is
a process in which hydrogen gas is contacted with a hydrocarbon
stream in the presence of suitable catalysts which are primarily
active for the removal of heteroatoms, such as sulfur, nitrogen,
and metals from the hydrocarbon feedstock. In hydrotreating,
hydrocarbons with double and triple bonds may be saturated.
Aromatics may also be saturated. Typical hydrotreating reaction
conditions include a temperature of about 290.degree. C.
(550.degree. F.) to about 455.degree. C. (850.degree. F.), a
pressure of about 3.4 MPa (500 psig) to about 26.7 MPa (4000 psig),
a liquid hourly space velocity of about 0.5 hr-1 to about 4 hr-I,
and a hydrogen rate of about 168 to about 1,011 Nm3/m3 oil
(1,000-6,000 scf/bbl). Typical hydrotreating catalysts include at
least one Group VIII metal, preferably iron, cobalt and nickel, and
at least one Group VI metal, preferably molybdenum and tungsten, on
a high surface area support material, preferably alumina. Other
typical hydrotreating catalysts include zeolitic catalysts, as well
as noble metal catalysts where the noble metal is selected from
palladium and platinum.
[0027] Hydrocracking is a process in which hydrocarbons crack in
the presence of hydrogen to lower molecular weight hydrocarbons.
Typical hydrocracking conditions may include a temperature of about
290.degree. C. (550.degree. F.) to about 468.degree. C.
(875.degree. F.), a pressure of about 3.5 MPa (500 psig) to about
20.7 MPa (3000 psig), a liquid hourly space velocity (LHSV) of
about 1.0 to less than about 2.5 hr.sup.-1, and a hydrogen rate of
about 421 to about 2,527 Nm.sup.3/m.sup.3 oil (2,500-15,000
scfibbl). Typical hydrocracking catalysts include amorphous
silica-alumina bases or low-level zeolite bases combined with one
or more Group VIII or Group VIB metal hydrogenating components, or
a crystalline zeolite cracking base upon which is deposited a Group
VIII metal hydrogenating component. Additional hydrogenating
components may be selected from Group VIB for incorporation with
the zeolite base.
[0028] Deoxygenation is a process for removing oxygen from a
molecule. An example deoxygenation process hydroprocesses a feed by
passing the feed to a hydrotreating unit where the feed is
contacted with a hydrotreating catalyst. The hydrotreating unit can
also be a hydrocracking unit with a hydrocracking catalyst.
Hydrogenation and hydrotreating catalysts are also capable of
catalyzing decarboxylation, decarbonylation, and/or
hydrodeoxygenation of the feed to remove oxygen. Deoxygenation
conditions include a relatively low pressure of about 1724 kPa
absolute (250 psia) to about 10.342 kPa absolute (1500 psia), with
embodiments in the range of 3447 kPa (500 psia) to about 6895 kPa
(1000 psia) or below 4826 kPa (700 psia); a temperature of about
200.degree. C. to about 460.degree. C. with embodiments in the
range of about 288.degree. C. to about 345.degree. C.; and a liquid
hourly space velocity (LHSV) of about 0.25 to about 4 hr .sup.-1
with example embodiments in the range of about 1 to about 4
hr.sup.-1. Since hydrogenation is an exothermic reaction, as the
feedstock flows through a catalyst bed the temperature increases
and decarboxylation, decarbonylation, and hydrodeoxygenation can
occur. Although the hydrogenation reaction is exothermic, some
feedstocks may be highly saturated and not generate enough heat
internally. Therefore, some embodiments may require external heat
input. All the reactions may occur simultaneously in one reactor or
in one bed. Alternatively, the conditions can be controlled such
that hydrogenation primarily occurs in one bed and decarboxylation,
decarbonylation, and/or hydrodeoxygenation occurs in a second or
additional bed(s). If only one bed is used, it may be operated so
that hydrogenation occurs primarily at the front of the bed, while
decarboxylation, decarbonylation and hydrodeoxygenation occur
mainly in the middle and bottom of the bed. Hydrogenation can be
carried out in one reactor, while decarboxylation, decarbonylation,
and/or hydrodeoxygenation can be carried out in a separate reactor.
However, the order of the reactions is not critical.
[0029] Desulfurization is a process for reducing sulfur of
hydrocarbon feedstocks to lower levels. Desulfurization is
typically performed by contacting a hydrocarbon feedstock in a
desulfurization reaction vessel or zone with a suitable
desulfurization catalyst under conditions of elevated temperature
and pressure in the presence of hydrogen to yield a product
containing the desired maximum limits of sulfur. An example
hydrocarbon desulfurization process is disclosed in U.S. Pat. No.
7,108,779.
[0030] Suitable desulfurization catalysts include hydrotreating
catalysts and include those which are comprised of at least one
Group VIII metal, preferably iron, cobalt and nickel, more
preferably cobalt and/or nickel and at least one Group VI metal,
preferably molybdenum and tungsten, on a high surface area support
material, preferably alumina. Other suitable desulfurization
catalysts include zeolitic catalysts, as well as noble metal
catalysts where the noble metal is selected from palladium and
platinum. More than one type of desulfurization catalyst can be
used in the same reaction vessel. The Group VIII metal is typically
present in an amount ranging from about 2 to about 20 weight
percent, preferably from about 4 to about 12 weight percent. The
Group VI metal will typically be present in an amount ranging from
about 1 to about 25 weight percent, preferably from about 2 to
about 25 weight percent. Typical desulfurization temperatures range
from about 204.degree. C. (400.degree. F.) to about 482.degree. C.
(900.degree. F.) with pressures from about 2.1 MPa (300 psig) to
about 17.3 MPa (2500 psig), preferably from about 2.1 MPa (300
psig) to about 13.9 MPa (2000 psig). Operating conditions and
desulfurization catalysts within the desulfurization reactor can be
selected to affect the quality of the desulfurized products.
[0031] Hydrogenation involves the addition of hydrogen to
hydrogenatable hydrocarbon compounds. Alternatively hydrogen can be
provided in a hydrogen-containing compound with ready available
hydrogen, such as tetralin, alcohols, hydrogenated naphthalenes,
and others via a transfer hydrogenation process with or without a
catalyst. The hydrogenatable hydrocarbon compounds are introduced
into a hydrogenation zone and contacted with a hydrogen-rich
gaseous phase and a hydrogenation catalyst in order to hydrogenate
at least a portion of the hydrogenatable hydrocarbon compounds. The
catalytic hydrogenation zone may contain a fixed, ebulated or
fluidized catalyst bed. This reaction zone is typically at a
pressure from about 689 kPa gauge (100 psig) to about 13790 kPa
gauge (2000 psig) with a maximum catalyst bed temperature in the
range of about 177.degree. C. (350.degree. F.) to about 454.degree.
C. (850.degree. F.). The liquid hourly space velocity is typically
in the range from about 0.2 hr.sup.-1 to about 10 hr.sup.-1 and
hydrogen circulation rates from about 200 standard cubic feet per
barrel (SCFB) (35.6 m.sup.3/m.sup.3) to about 10,000 SCFB (1778
m.sup.3/m.sup.3).
[0032] While at least one exemplary embodiment has been presented
in the foregoing detailed description of the invention, it should
be appreciated that a vast number of variations exist. It should
also be appreciated that the exemplary embodiment or exemplary
embodiments are only examples, and are not intended to limit the
scope, applicability, or configuration of the invention in any way.
Rather, the foregoing detailed description will provide those
skilled in the art with a convenient road map for implementing an
exemplary embodiment of the invention. It being understood that
various changes may be made in the function and arrangement of
elements described in an exemplary embodiment without departing
from the scope of the invention as set forth in the appended
claims.
* * * * *