U.S. patent application number 12/847313 was filed with the patent office on 2012-02-02 for hydrodechlorination of ionic liquid-derived hydrocarbon products.
This patent application is currently assigned to Chevron U.S.A. Inc.. Invention is credited to Russell Cooper, Zunqing He, Hye Kyung Timken, Bi-Zeng Zhan.
Application Number | 20120024750 12/847313 |
Document ID | / |
Family ID | 45525618 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120024750 |
Kind Code |
A1 |
Zhan; Bi-Zeng ; et
al. |
February 2, 2012 |
HYDRODECHLORINATION OF IONIC LIQUID-DERIVED HYDROCARBON
PRODUCTS
Abstract
Processes for the hydrodechlorination of one or more hydrocarbon
products derived from ionic liquid catalyzed hydrocarbon conversion
reactions provide a dechlorinated product and an HCl-containing
off-gas. The dechlorinated product provides liquid fuel or
lubricating base oil, and the HCl may be recovered from the off-gas
for recycling to the ionic liquid catalyzed hydrocarbon conversion
reaction as a catalyst promoter.
Inventors: |
Zhan; Bi-Zeng; (Albany,
CA) ; Timken; Hye Kyung; (Albany, CA) ; He;
Zunqing; (San Rafael, CA) ; Cooper; Russell;
(Fairfield, CA) |
Assignee: |
Chevron U.S.A. Inc.
|
Family ID: |
45525618 |
Appl. No.: |
12/847313 |
Filed: |
July 30, 2010 |
Current U.S.
Class: |
208/56 ;
208/49 |
Current CPC
Class: |
C10G 45/04 20130101;
C10G 2400/10 20130101; C10G 2400/08 20130101; C10G 2300/1088
20130101; C07C 7/12 20130101; C10G 2300/1081 20130101; C10G 50/00
20130101; C10G 2400/04 20130101; C10G 2400/02 20130101; C10G 29/205
20130101; C10G 2300/207 20130101 |
Class at
Publication: |
208/56 ;
208/49 |
International
Class: |
C10G 65/04 20060101
C10G065/04 |
Claims
1. An integrated hydrocarbon conversion process, comprising: a)
contacting at least one hydrocarbon reactant with an ionic liquid
catalyst in a hydrocarbon conversion zone under hydrocarbon
conversion conditions to provide at least one hydrocarbon product
comprising at least one halogenated component; and b) contacting
the at least one hydrocarbon product with a hydrodechlorination
catalyst in the presence of hydrogen in a hydrodechlorination zone
under hydrodechlorination conditions to provide: i) at least one
dechlorinated product and ii) an off-gas comprising HCl, wherein a
first chloride content of the at least one hydrocarbon product is
greater than 50 ppm and a second chloride content of the
dechlorinated product is less than 50 ppm.
2. The process according to claim 1, wherein the first chloride
content of the at least one hydrocarbon product is greater than
about 100 ppm, and a second chloride content of the at least one
dechlorinated product is less than about 10 ppm.
3. The process according to claim 1, further comprising: c)
separating the at least one dechlorinated product from the off-gas;
d) contacting the off-gas with an adsorbent under HCl adsorbing
conditions such that the HCl is adsorbed by the adsorbent to
provide an HCl-free off-gas; and e) after step d), recovering the
HCl from the adsorbent.
4. The process according to claim 1, wherein the at least one
hydrocarbon reactant comprises a C.sub.4-C.sub.10 isoparaffin and a
C.sub.2-C.sub.10 olefin.
5. The process according to claim 1, wherein the at least one
hydrocarbon product is selected from the group consisting of
alkylate gasoline, diesel fuel, jet fuel, base oil, and mixtures
thereof.
6. The process according to claim 1, further comprising: f) prior
to step b), feeding the at least one hydrocarbon product to a
distillation unit to provide at least one distilled hydrocarbon
product, and wherein the at least one hydrocarbon product contacted
with the hydrodechlorination catalyst in step b) comprises the at
least one distilled hydrocarbon product.
7. The process according to claim 1, further comprising: g) after
step b), feeding the at least one dechlorinated product to a
distillation unit.
8. The process according to claim 1, wherein the at least one
dechlorinated product comprises alkylate gasoline having a chloride
content less than 50 ppm.
9. The process according to claim 1, wherein the ionic liquid
catalyst comprises a chloroaluminate ionic liquid, and the
hydrodechlorination catalyst comprises an element selected from the
group consisting of elements of Groups 6, 8, 9, 10, and 11, and
their mixtures, present as metals, oxides, or sulfides.
10. The process according to claim 1, wherein the adsorbent is
selected from the group consisting of a molecular sieve, a
refractory oxide, activated carbon, and combinations thereof.
11. The process according to claim 1, wherein step b) comprises
contacting the hydrocarbon product with the hydrodechlorination
catalyst at a temperature in the range from about 300.degree. F. to
750.degree. F., a pressure in the range from about 100 to 5000
psig, a liquid hourly space velocity (LHSV) feed rate in the range
from about 0.1 to 50, and a hydrogen supply in the range from about
50 to 8000 standard cubic feet per barrel (SCFB) of the at least
one hydrocarbon product.
12. The process according to claim 3, further comprising: h)
feeding the HCl from step e) to the hydrocarbon conversion
zone.
13. The process according to claim 3, wherein the HCl-free off-gas
comprises H.sub.2, and the process further comprises: i) recycling
the HCl-free off-gas from step d) to the hydrodechlorination
zone.
14. The process according to claim 3, wherein the process is
performed under anhydrous conditions.
15. A hydrodechlorination and hydrogen chloride recovery process,
comprising: a) contacting at least one hydrocarbon product with a
hydrodechlorination catalyst in the presence of hydrogen under
hydrodechlorination conditions to provide: i) an off-gas comprising
an HCl and ii) a dechlorinated product; b) separating the
dechlorinated product from the off-gas; c) contacting the off-gas
with an adsorbent under HCl adsorbing conditions such that the HCl
is adsorbed by the adsorbent; and d) after step c), recovering the
HCl from the adsorbent.
16. The process according to claim 15, wherein the
hydrodechlorination conditions comprise a reaction temperature in
the range from about 300.degree. F. to 750.degree. F., a reaction
pressure in the range from about 100 to 5000 psig, a liquid hourly
space velocity (LHSV) feed rate in the range from about 0.1 to 50,
and a hydrogen supply in the range from about 50 to 8000 standard
cubic feet per barrel (SCFB) of the at least one hydrocarbon
product.
17. The process according to claim 15, wherein the
hydrodechlorination catalyst comprises an element selected from the
group consisting of elements of Groups 6, 8, 9, 10, and 11, and
their mixtures, present as metals, oxides or sulfides.
18. The process according to claim 15, wherein: step b) comprises
separating the dechlorinated product, as a liquid, at a temperature
in the range from about 50.degree. F. to 600.degree. F., and step
d) comprises contacting the adsorbent with a recovery carrier gas,
wherein the HCl is desorbed from the adsorbent.
19. The process according to claim 15, wherein the adsorbent is
selected from the group consisting of a molecular sieve, a
refractory oxide, activated carbon, and combinations thereof.
20. The process according to claim 15, wherein the adsorbent
comprises a molecular sieve selected from the group consisting of
3A, 4A, 5A, 13X, 13Y, USY, ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-48,
MCM-22, MCM-35, MCM-58, SAPO-5, SAPO-11, SAPO-35, and VPI-5.
21. The process according to claim 15, wherein the at least one
hydrocarbon product is selected from the group consisting of
alkylate gasoline, diesel fuel, jet fuel, base oil, and mixtures
thereof obtained by contacting at least one hydrocarbon reactant
with an ionic liquid catalyst in a hydrocarbon conversion zone
under hydrocarbon conversion conditions, wherein a first chloride
content of the at least one hydrocarbon product is greater than 50
ppm, and a second chloride content of the dechlorinated product is
less than about 10 ppm.
22. A hydrocarbon conversion and hydrodechlorination process,
comprising: a) contacting at least one hydrocarbon reactant with an
ionic liquid catalyst in a hydrocarbon conversion zone under
hydrocarbon conversion conditions to provide used ionic liquid
combined with a conjunct polymer; b) regenerating at least a
portion of the used ionic liquid in a catalyst regeneration zone to
provide reactivated ionic liquid catalyst and a free conjunct
polymer; c) after step b), separating the free conjunct polymer
from the ionic liquid catalyst; and d) after step c), contacting
the free conjunct polymer with a hydrodechlorination catalyst in
the presence of hydrogen in a hydrodechlorination zone under
hydrodechlorination conditions to provide a dechlorinated
product.
23. The process according to claim 22, wherein the dechlorinated
product comprises middle distillate fuel having a chloride content
less than about 10 ppm.
24. The process according to claim 22, wherein the dechlorinated
product comprises diesel fuel having a chloride content less than
about 10 ppm.
25. The process according to claim 22, wherein the dechlorinated
product comprises base oil having a chloride content less than
about 10 ppm.
26. The process according to claim 22, wherein the
hydrodechlorination catalyst comprises an element selected from the
group consisting of elements of Groups 6, 8, 9, 10, and 11, and
their mixtures, present as metals, oxides, or sulfides.
27. The process according to claim 22, wherein step d) comprises
contacting the conjunct polymer with the hydrodechlorination
catalyst to further provide an off-gas comprising HCl, and the
process further comprises: e) contacting the off-gas with an
adsorbent in an HCl adsorption zone wherein the HCl is adsorbed by
the adsorbent to provide an HCl-free off-gas; and f) after step e),
recovering the HCl from the adsorbent.
28. The process according to claim 27, wherein the HCl-free off-gas
comprises H.sub.2, and the process further comprises: g) recycling
the HCl-free off-gas from step e) to the hydrodechlorination zone.
Description
TECHNICAL FIELD
[0001] The present invention relates to hydrodechlorination of
ionic liquid derived hydrocarbon products.
BACKGROUND
[0002] The conversion by refining industries of light paraffins and
light olefins to more valuable cuts has been accomplished by the
alkylation of paraffins with olefins and by the polymerization of
olefins. Such processes, which have been used since the 1940's,
continue to be driven by the increasing demand for high quality and
clean burning high-octane gasoline, distillate and lubricating base
oil.
[0003] Conventional alkylation processes use vast quantities of
H.sub.2SO.sub.4 or HF as catalyst. The quest for an alternative
catalytic system to replace the conventional catalysts has been
researched by various groups in both academic and industrial
institutions. Unfortunately, thus far, no viable replacement to the
conventional processes has been commercialized.
[0004] Recently there has been considerable interest in metal
halide ionic liquid catalysts as alternatives to conventional
catalysts. As an example, the ionic liquid catalyzed alkylation of
isoparaffins with olefins is disclosed in U.S. Pat. No. 7,432,408
to Timken et al. U.S. Pat. No. 7,572,943 to Elomari et al.
discloses the ionic liquid catalyzed oligomerization of olefins and
the alkylation of the resulting oligomers(s) with isoparaffins to
produce alkylated olefin oligomers. The presence of HCl as a
co-catalyst with an ionic liquid provides an increased level of
catalytic activity, for example, as disclosed by the '408 patent.
Typically, anhydrous HCl or organic chloride may be combined with
the ionic liquid feed to attain the desired level of catalytic
activity and selectivity (see, e.g., U.S. Pat. No. 7,495,144 to
Elomari, and U.S. Pat. No. 7,531,707 to Harris et al.). When
organic chloride is used as the co-catalyst with the ionic liquid,
HCl may be formed in situ in the reactor during the hydrocarbon
conversion process.
[0005] Hydrocarbon product(s) of ionic liquid catalyzed hydrocarbon
conversions, such as alkylate or distillate or base oil, typically
contain substantial amounts of organic chloride components that are
produced during the reaction. The removal of organic chloride
components from such hydrocarbon product(s) may be desirable, e.g.,
to prevent the formation of unwanted by-products during combustion
of liquid fuels (see, for example, U.S. Pat. No. 7,538,256 to
Driver et al., the disclosure of which is incorporated by reference
herein in its entirety).
[0006] There is a need for processes for the efficient
dechlorination of hydrocarbon products derived from ionic liquid
catalyzed hydrocarbon conversion reactions. There is a further need
for the removal of HCl from hydrodechlorination off-gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A represents a scheme for a combined hydrocarbon
conversion, hydrodechlorination, and hydrogen chloride recovery
process, according to an embodiment of the present invention;
[0008] FIG. 1B represents a scheme for a combined hydrocarbon
conversion, hydrodechlorination, and hydrogen chloride recovery
process, according to another embodiment of the present
invention;
[0009] FIG. 2 shows the boiling point distribution of a
hydrodechlorinated alkylate product, as compared with a chlorinated
alkylate feed, according to an embodiment of the present invention;
and
[0010] FIG. 3 shows an HCl breakthrough curve by contacting an
HCl-containing off-gas from the hydrodechlorination of an alkylate
distillate with an adsorbent comprising zeolite 4A.
SUMMARY
[0011] The present invention provides processes for the
hydrodechlorination of hydrocarbon products derived from ionic
liquid catalyzed hydrocarbon conversion reactions. The present
invention also provides processes for the recovery of HCl obtained
from hydrodechlorination off-gas. The present invention further
provides an integrated hydrocarbon conversion, hydrodechlorination,
and HCl recovery process, wherein HCl that is recovered from
dechlorination processes may be used as a catalyst promoter for the
ionic liquid catalyzed hydrocarbon conversion reactions.
[0012] According to one aspect of the present invention there is
provided an integrated hydrocarbon conversion process comprising
contacting at least one hydrocarbon reactant with an ionic liquid
catalyst in a hydrocarbon conversion zone under hydrocarbon
conversion conditions to provide at least one hydrocarbon product
comprising at least one halogenated component; and contacting the
at least one hydrocarbon product with a hydrodechlorination
catalyst in the presence of hydrogen in a hydrodechlorination zone
under hydrodechlorination conditions to provide: i) a dechlorinated
product, and ii) an off-gas comprising HCl. A first chloride
content of the at least one hydrocarbon product may be greater than
50 ppm, the chloride content of the dechlorinated product is lower
than the feed, to be less than 50 ppm, and typically less than 10
ppm.
[0013] In an embodiment, the present invention also provides a
hydrogen chloride recovery process comprising contacting at least
one hydrocarbon product with a hydrodechlorination catalyst in the
presence of hydrogen under hydrodechlorination conditions to
provide: i) an off-gas comprising HCl, and ii) a dechlorinated
product; separating the dechlorinated product from the off-gas;
contacting the off-gas with an adsorbent under HCl adsorbing
conditions such that the HCl is adsorbed by the adsorbent; and,
after the prior step, recovering the HCl from the adsorbent. The
dechlorinated product may comprise alkylate gasoline, jet fuel,
diesel fuel, base oil, or a combination thereof.
[0014] In another embodiment, the present invention further
provides a hydrocarbon conversion and hydrodechlorination process
comprising contacting at least one hydrocarbon reactant with an
ionic liquid catalyst in a hydrocarbon conversion zone under
hydrocarbon conversion conditions to provide used ionic liquid
combined with conjunct polymer; regenerating at least a portion of
the used ionic liquid in a catalyst regeneration zone to provide
reactivated ionic liquid catalyst and free conjunct polymer; after
the prior step, separating the conjunct polymer from the ionic
liquid catalyst; and after the prior step, contacting the separated
conjunct polymer with a hydrodechlorination catalyst in the
presence of hydrogen in a hydrodechlorination zone under
hydrodechlorination conditions to provide a dechlorinated
product.
[0015] As used herein, the terms "comprising" and "comprises" mean
the inclusion of named elements or steps that are identified
following those terms, but not necessarily excluding other unnamed
elements or steps.
DETAILED DESCRIPTION
[0016] Ionic liquid catalysts may be useful for a range of
hydrocarbon conversion processes, including paraffin alkylation,
paraffin isomerization, olefin isomerization, olefin dimerization,
olefin oligomerization, olefin polymerization and aromatic
alkylation. Applicants have now discovered that products and
by-products from ionic liquid catalyzed hydrocarbon conversion
processes may be efficiently dechlorinated by contact with a
hydrodechlorination catalyst in a hydrodechlorination zone in the
presence of hydrogen at relatively low pressure, to provide
HCl-containing off-gas and a dechlorinated product, wherein the
chloride content of the dechlorinated product is low enough to
allow the product to be used for blending into refinery products.
Applicants have further discovered that the HCl may be recovered
from the dechlorination off-gas, to provide HCl for recycling to
the ionic liquid catalyzed hydrocarbon conversion process.
[0017] The term "Periodic Table" as referred to herein is the IUPAC
version of the Periodic Table of the Elements dated Jun. 22, 2007,
and the numbering scheme for the Periodic Table Groups is as
described in Chemical and Engineering News, 63(5), 27 (1985).
Ionic Liquid Catalysts
[0018] In an embodiment, processes according to the present
invention may use a catalytic composition comprising at least one
metal halide and at least one quaternary ammonium halide and/or at
least one amine halohydride. The ionic liquid catalyst can be any
halogen aluminate ionic liquid catalyst, e.g., comprising an alkyl
substituted quaternary amine halide, an alkyl substituted
pyridinium halide, or an alkyl substituted imidazolium halide of
the general formula N.sup.+R.sub.4X.sup.-. As an example, an ionic
liquid useful in practicing the present invention may be
represented by general formulas A and B,
##STR00001##
wherein R.dbd.H, methyl, ethyl, propyl, butyl, pentyl or hexyl, and
X is a halide, and R.sub.1 and R.sub.2.dbd.H, methyl, ethyl,
propyl, butyl, pentyl or hexyl, wherein R.sub.1 and R.sub.2 may or
may not be the same. In an embodiment, X is chloride.
[0019] An exemplary metal halide that may be used in accordance
with the present invention is aluminum chloride (AlCl.sub.3).
Quaternary ammonium halides which can be used in accordance with
the present invention include those described in U.S. Pat. No.
5,750,455, the disclosure of which is incorporated by reference
herein.
[0020] In an embodiment, the ionic liquid catalyst may be a
chloroaluminate ionic liquid prepared by mixing AlCl.sub.3 and an
alkyl substituted pyridinium halide, an alkyl substituted
imidazolium halide, a trialkylammonium hydrohalide, or a
tetraalkylammonium halide, as disclosed in commonly assigned U.S.
Pat. No. 7,495,144, the disclosure of which is incorporated by
reference herein in its entirety.
[0021] In a sub-embodiment, the ionic liquid catalyst may comprise
N-butylpyridinium heptachlorodialuminate ionic liquid, which may be
prepared, for example, by combining AlCl.sub.3 with a salt of the
general formula A, supra, wherein R is n-butyl and X is chloride.
The present invention does not need to be limited to particular
ionic liquid catalyst compositions.
Feedstocks for Ionic Liquid Catalyzed Processes
[0022] In an embodiment, feeds for the present invention may
comprise various streams in a petroleum refinery, a gas-to-liquid
conversion plant, a coal-to-liquid conversion plant, or in naphtha
crackers, middle distillate cracker or wax crackers, FCC offgas,
FCC light naphtha, coker offgas, coker naphtha, hydrocracker
naphtha, and the like. Such streams may contain isoparaffin(s)
and/or olefin(s). Such streams may be fed to the reactor of a
hydrocarbon conversion system of the present invention via one or
more feed dryer units (not shown).
[0023] Examples of olefin containing streams include FCC offgas,
coker gas, olefin metathesis unit offgas, polyolefin gasoline unit
offgas, methanol to olefin unit offgas, FCC light naphtha, coker
light naphtha, Fischer-Tropsch unit condensate, and cracked
naphtha. Some olefin containing streams may contain two or more
olefins selected from ethylene, propylene, butylenes, pentenes, and
up to C.sub.10 olefins.
[0024] The olefin containing stream can be a fairly pure olefinic
hydrocarbon cut or can be a mixture of hydrocarbons having
different chain lengths thus a wide boiling range. The olefinic
hydrocarbon can be terminal olefin (an alpha olefin) or can be an
internal olefin (having an internal double bond). The olefinic
hydrocarbon chain can be either straight chain or branched or a
mixture of both. In one embodiment of the present invention, the
olefinic feed may comprise a mixture of mostly linear olefins from
C.sub.2 to about C.sub.30. The olefins may be mostly, but not
entirely, alpha olefins. In another embodiment of the present
invention, the olefinic feed can comprise 50% of a single alpha
olefin species. In another embodiment of the present invention, the
olefinic feed can comprise at least 20% of alpha olefin
species.
[0025] In an embodiment, olefins in the feed may also undergo
oligomerization when contacted with an ionic liquid catalyst in the
hydrocarbon conversion reactor. Ionic liquid catalyzed olefin
oligomerization may take place under the same or similar conditions
as ionic liquid catalyzed olefin-isoparaffin alkylation. As a
result, in an embodiment of the present invention, both olefin
oligomerization and olefin-isoparaffin alkylation may take place in
a single reaction zone of the hydrocarbon conversion reactor. In an
embodiment, olefin oligomerization and olefin-isoparaffin
alkylation may take place in an oligomerization zone 110a and an
alkylation zone 110b, respectively, of hydrocarbon conversion
reactor 110 (see, for example, FIG. 1B). In an embodiment of the
present invention, an oligomeric olefin produced in oligomerization
zone 110a may be subsequently alkylated by reaction with an
isoparaffin in alkylation zone 110b to provide a distillate, and/or
lubricant component or base oil product. Ionic liquid catalyzed
olefin oligomerization and olefin-isoparaffin alkylation is
disclosed, for example, in commonly assigned U.S. Pat. Nos.
7,572,943 and 7,576,252 both to Elomari et al., the disclosures of
which are incorporated by reference herein in their entirety.
[0026] Examples of isoparaffin containing streams include, but are
not limited to, FCC naphtha, hydrocracker naphtha, coker naphtha,
Fisher-Tropsch unit condensate, and cracked naphtha. Such streams
may comprise a mixture of two or more isoparaffins. In a
sub-embodiment, a feed for an ionic liquid catalyzed process of the
invention may comprise isobutane, which may be obtained, for
example, from a hydrocracking unit or may be purchased.
Reaction Conditions for Ionic Liquid Catalyzed Hydrocarbon
Conversions
[0027] Due to the low solubility of hydrocarbons in ionic liquids,
hydrocarbon conversion reactions in ionic liquids (including
isoparaffin-olefin alkylation reactions) are generally biphasic and
occur at the interface in the liquid state. The volume of ionic
liquid catalyst in the reactor may be generally in the range from
about 1 to 70 vol %, and usually from about 4 to 50 vol %.
Generally, vigorous mixing (e.g., stirring or Venturi nozzle
dispensing) is used to ensure good contact between the reactants
and the ionic liquid catalyst. The reaction temperature may be
generally in the range from about -40.degree. F. to +480.degree.
F., typically from about -4.degree. F. to +210.degree. F., and
often from about +40.degree. F. to +140.degree. F. The reactor
pressure may be in the range from atmospheric pressure to about
8000 kPa. Typically, the reactor pressure is sufficient to keep the
reactants in the liquid phase.
[0028] Residence time of reactants in the reactor may generally be
in the range from a few seconds to hours, and usually from about
0.5 min to 60 min. In the case of ionic liquid catalyzed
isoparaffin-olefin alkylation, the reactants may be introduced in
an isoparaffin:olefin molar ratio generally in the range from about
1 to 100, more typically from about 2 to 50, and often from about 2
to 20. Heat generated by the reaction may be dissipated using
various means well known to the skilled artisan.
[0029] In the case of olefin oligomerization, e.g., in
oligomerization zone 110a (FIG. 1B), oligomerization conditions for
the present invention may include a temperature in the range from
about 30.degree. F. to about 300.degree. F., typically from about
30.degree. F. to about 210.degree. F., and usually from about
30.degree. F. to about 120.degree. F.
Ionic Liquid Catalyzed Hydrocarbon Conversion Systems and
Processes
[0030] In FIG. 1A, systems within the scheme may be represented by
em dash lines (-- -- --); while optional or alternative lines,
conduits, units, or steps may be represented by en dash lines ( ).
With reference to FIG. 1A, an ionic liquid catalyzed hydrocarbon
conversion system 100 according to an embodiment of the present
invention may include a hydrocarbon conversion reactor 110, a
catalyst/hydrocarbon separator 120, a catalyst regeneration unit
130, a distillation unit 140, and a conjunct polymer (CP)
extraction unit 150.
[0031] During an ionic liquid catalyzed hydrocarbon conversion
process of the instant invention, dry feeds may be introduced into
reactor 110. Reactor 110 may also be referred to herein as a
hydrocarbon conversion zone. The dry feeds may include at least one
hydrocarbon reactant, which may be introduced into reactor 110 via
one or more reactor inlet ports (not shown). In an embodiment, the
at least one hydrocarbon reactant may comprise a first reactant
comprising a C.sub.4-C.sub.10 isoparaffin and a second reactant
comprising a C.sub.2-C.sub.10 olefin.
[0032] Ionic liquid catalyst may be introduced into reactor 110 via
a separate inlet port (not shown). The feeds to reactor 110 may
further include a catalyst promoter, such as anhydrous HCl or an
alkyl halide. In an embodiment, the catalyst promoter may comprise
a C.sub.2-C.sub.6 alkyl chloride. In a sub-embodiment, the catalyst
promoter may comprise n-butyl chloride or t-butyl chloride. Reactor
110 may be vigorously mixed to promote contact between reactant(s)
and ionic liquid catalyst. Reactor conditions may be adjusted to
optimize process performance for a particular hydrocarbon
conversion process of the present invention.
[0033] During hydrocarbon conversion processes of the invention,
reactor 110 may contain a mixture comprising ionic liquid catalyst
and a hydrocarbon phase. The hydrocarbon phase may comprise at
least one hydrocarbon product of the ionic liquid catalyzed
reaction. The ionic liquid catalyst may be separated from the
hydrocarbon phase via catalyst/hydrocarbon separator 120, wherein
the hydrocarbon and ionic liquid catalyst phases may be allowed to
settle under gravity, by using a coalescer, or by a combination
thereof. The use of coalescers for liquid-liquid separations is
described in US Publication Number 20100130800A1, the disclosure of
which is incorporated by reference herein in its entirety. The
hydrocarbon phase may be fed from catalyst/hydrocarbon separator
120 to distillation unit 140. At least a portion of the ionic
liquid phase may be recycled directly to reactor 110.
[0034] With continued operation of hydrocarbon conversion system
100, the ionic liquid catalyst may become partially deactivated or
spent. Catalyst deactivation is associated with the formation of
conjunct polymer in the ionic liquid phase, for example, as
disclosed in commonly assigned U.S. Pat. No. 7,674,739, the
disclosure of which is incorporated by reference herein in its
entirety. In order to maintain the catalytic activity, at least a
portion of the ionic liquid phase may be fed to regeneration unit
130 for regeneration of the ionic liquid catalyst. In an
embodiment, the portion of the ionic liquid phase fed to
regeneration unit 130 may be generally in the range from about 1%
to 95%, and typically from about 5% to 75%.
[0035] In an embodiment, the ionic liquid catalyst may be
regenerated by treatment with a regeneration metal. As an example,
a process for the regeneration of ionic liquid catalyst by
treatment with Al metal is disclosed in U.S. Pat. No. 7,674,739,
incorporated by reference herein. In another embodiment, the ionic
liquid may be regenerated by treatment, in the presence of H.sub.2,
with a hydrogenation catalyst (see, for example, U.S. Pat. No.
7,691,771 to Harris et al., the disclosure of which is incorporated
by reference herein in its entirety).
[0036] In an embodiment of the present invention, fresh ionic
liquid catalyst may be introduced into reactor 110 during a
hydrocarbon conversion process. The catalytic activity of reactor
110 may be maintained under steady state conditions by monitoring
the catalytic activity, and by adjusting process parameters, such
as the degree of catalyst regeneration, the amount of catalyst
drainage, the amount of fresh ionic liquid introduced, and
combinations thereof, according to the monitored catalytic
activity. The catalytic activity may be gauged, for example, by
monitoring the concentration of conjunct polymer in the ionic
liquid catalyst phase.
[0037] The conjunct polymer that has combined with the used ionic
liquid may be released from the ionic liquid during ionic liquid
catalyst regeneration. The free conjunct polymer may then be
separated from the regenerated ionic liquid catalyst in a conjunct
polymer (CP) extraction unit 150. The conjunct polymer may be
extracted from the used ionic liquid, e.g., using a
C.sub.4-C.sub.15 hydrocarbon (e.g., alkane), and typically a
C.sub.4-C.sub.10 alkane, such as isobutane or alkylate gasoline.
The regenerated ionic liquid catalyst may be fed from the conjunct
polymer extraction unit 150 to reactor 110.
[0038] The hydrocarbon phase from catalyst/hydrocarbon separator
120 may be fed to distillation unit 140. Distillation unit 140 may
represent or comprise a plurality of distillation columns. In an
embodiment, distillation unit 140 may comprise one (1), two (2),
three (3), four (4), or more distillation columns. Distillation
unit 140 may be adjusted, e.g., with respect to temperature and
pressure, to provide at least one hydrocarbon product from the
hydrocarbon phase under steady state distillation conditions.
[0039] In an embodiment of the present invention, a hydrocarbon
product obtained from distillation unit 140 may comprise at least
one halogenated component. As an example only, the hydrocarbon
product may have an organic chloride content generally greater than
about 50 ppm, typically greater than 100 ppm, and often greater
than 200 ppm. In an embodiment, a hydrocarbon product from
distillation unit 140 may have an organic chloride content
generally in the range from about 50 ppm to 5000 ppm, typically
from about 100 ppm to 4000 ppm, and often from about 200 ppm to
3000 ppm.
[0040] The hydrocarbon product(s), which may include at least one
halogenated component, may be fed, e.g., from distillation unit 140
to hydrodechlorination unit 210 for hydrodechlorinating the
hydrocarbon product(s) by contacting the at least one hydrocarbon
product with a hydrodechlorination catalyst in the presence of
hydrogen in a hydrodechlorination zone under hydrodechlorination
conditions to provide: i) at least one dechlorinated product and
ii) an off-gas comprising HCl, as described herein below. In
general, a first chloride content of the at least one hydrocarbon
product prior to hydrodechlorination according to the present
invention is greater than 50 ppm, and typically much greater than
50 ppm; while after hydrodechlorination according to the present
invention, a second chloride content of the dechlorinated
product(s) is less than 50 ppm, and typically less than about 10
ppm.
[0041] With reference to FIG. 1B, an ionic liquid catalyzed
hydrocarbon conversion and hydrodechlorination system 400 according
to another embodiment of the present invention may include a
hydrocarbon conversion reactor 110, a catalyst/hydrocarbon
separator 120, a hydrodechlorination unit 210, a catalyst
regeneration unit 130, a gas/liquid separator 220, an HCl recovery
unit 310, and a distillation unit 140.
[0042] During an ionic liquid catalyzed hydrocarbon conversion
process of the instant invention, dry feeds may be introduced into
reactor 110. Reactor 110 may also be referred to herein as a
hydrocarbon conversion zone. In an embodiment, reactor 110 may
include an oligomerization zone 110a and an alkylation zone 110b.
The dry feeds may include at least one hydrocarbon reactant, e.g.,
substantially as described herein above with reference to FIG. 1A.
Reaction conditions for ionic liquid catalyzed hydrocarbon
conversions are described herein above. Reactor conditions within
each of oligomerization zone 110a and alkylation zone 110b may be
adjusted to optimize process performance, e.g., for particular
hydrocarbon feeds or desired products.
[0043] Hydrocarbon product(s) from reactor 110 may be separated
from the ionic liquid via catalyst/hydrocarbon separator 120, as
described with reference to FIG. 1A. The hydrocarbon product(s),
which may include at least one chlorinated component, may be fed,
e.g., from catalyst/hydrocarbon separator 120 to
hydrodechlorination unit 210 for hydrodechlorinating the
hydrocarbon product(s). Such hydrodechlorination may be performed
by contacting the at least one hydrocarbon product with a
hydrodechlorination catalyst in the presence of hydrogen in a
hydrodechlorination zone under hydrodechlorination conditions to
provide: i) at least one dechlorinated product and ii) an off-gas
comprising HCl, as described herein below. In general, a first
chloride content of the at least one hydrocarbon product prior to
hydrodechlorination according to the present invention is greater
than 50 ppm, and typically much greater than 50 ppm. In contrast,
as a result of hydrodechlorination according to the present
invention, a second chloride content of the dechlorinated
product(s) is less than 50 ppm, and typically less than about 10
ppm.
Hydrodechlorination of Ionic Liquid Catalyzed Hydrocarbon
Conversion Products
[0044] With further reference to FIGS. 1A and 1B, at least one
hydrocarbon product, e.g., derived from an ionic liquid catalyzed
alkylation reaction, may be fed together with hydrogen into a
hydrodechlorination unit 210. In an embodiment, the at least one
hydrocarbon product may comprise a distilled hydrocarbon product
from distillation unit 140 (see, e.g., FIG. 1A). In an embodiment,
the at least one hydrocarbon product may comprise alkylate
gasoline, diesel fuel, jet fuel, base oil, or a combination
thereof.
[0045] In another embodiment of the present invention, the at least
one hydrocarbon product may comprise a plurality of hydrocarbon
products, which may be fed to hydrodechlorination unit 210, e.g.,
en masse, from catalyst/hydrocarbon separator 120 before undergoing
fractionation (see, for example, FIG. 1B).
[0046] Hydrodechlorination unit 210 may contain a
hydrodechlorination catalyst. The hydrodechlorination unit 210 may
also be referred to herein as a hydrodechlorination zone. The
hydrodechlorination catalyst may comprise an element selected from
elements of Groups 6, 8, 9, 10, and 11 of the Periodic Table, and
their mixtures, present as metals, oxides, or sulfides. In a
sub-embodiment, the hydrodechlorination catalyst may comprise an
element selected from Pd, Pt, Au, Fe, Ni, Co, Mo, and W, and their
mixtures, present as metals, oxides, or sulfides.
[0047] The hydrodechlorination catalyst may further comprise a
support. The support may comprise an inorganic porous material,
such as a refractory oxide, or an activated carbon. Examples of
refractory oxide support materials include alumina, silica,
titania, alumina-silica, and zirconia, or the like, and
combinations thereof. In an embodiment, the hydrodechlorination
catalyst may comprise a noble metal on a refractory oxide support.
In a sub-embodiment, the hydrodechlorination catalyst may comprise
Pd, e.g., in the range from about 0.05 to 3.0 wt % Pd.
[0048] Within hydrodechlorination unit 210, the at least one
hydrocarbon product may be contacted with the hydrodechlorination
catalyst in the presence of hydrogen under hydrodechlorination
conditions to provide: i) a dechlorinated product and ii) an
off-gas comprising HCl. In an embodiment, the dechlorinated product
may comprise dechlorinated alkylate gasoline, dechlorinated jet
fuel, dechlorinated diesel fuel, or dechlorinated base oil. The
dechlorinated product may be separated from the off-gas via a
gas/liquid separator 220. The hydrodechlorination system 200
upstream from gas/liquid separator 220 may be above ambient
pressure, and gas/liquid separator 220 may also be referred to
herein as a high pressure separator.
[0049] In an embodiment, gas/liquid separator 220 may be operated
at a temperature generally in the range from about 50.degree. F. to
600.degree. F., typically from about 100.degree. F. to 550.degree.
F., and often from about 100.degree. F. to 500.degree. F. In an
embodiment, gas/liquid separator 220 may be operated at a maximum
liquid level typically not more than about 85%, usually not more
than about 75%, and often not more than about 65% of the total
height or volume of gas/liquid separator 220. As a non-limiting
example, a major portion of the HCl can be constrained in the gas
phase, for subsequent recovery therefrom, when gas/liquid separator
220 is operated at a suitable temperature within the range cited
hereinabove and at a liquid level equal to or less than about
65%.
[0050] The hydrodechlorination conditions within the
hydrodechlorination zone may comprise a reaction temperature
generally in the range from about 300.degree. F. to 750.degree. F.,
and typically from about 400.degree. F. to 650.degree. F. The
hydrodechlorination conditions may include a reaction pressure
generally in the range from about 100 to 5000 psig, and typically
from about 200 to 2000 psig. A liquid hourly space velocity (LHSV)
feed rate to the hydrodechlorination zone may be generally in the
range from about 0.1 to 50, and typically from about 0.2 to 10. A
hydrogen supply to the hydrodechlorination zone may be generally in
the range from about 50 to 8000 standard cubic feet per barrel
(SCFB) of hydrocarbon product, and typically from about 100 to 5000
SCFB.
[0051] The hydrocarbon product feed to hydrodechlorination unit 210
may typically have a much higher chloride content as compared with
that of the dechlorinated product obtained from hydrodechlorination
unit 210. In an embodiment, a first chloride content of at least
one hydrocarbon product fed to hydrodechlorination unit 210 may be
greater than about 50 ppm. In an embodiment, the hydrocarbon
product feed to hydrodechlorination unit 210 may have an organic
chloride content generally in the range from about 50 ppm to 5000
ppm, typically from about 100 ppm to 4000 ppm, and often from about
200 ppm to 3000 ppm. In contrast, the chloride content of the
dechlorinated product is lower than that of the feed, typically
less than 50 ppm, and usually less than about 10 ppm.
[0052] With further reference to hydrodechlorination system 200 of
FIG. 1A, in an embodiment the dechlorinated product obtained from
gas/liquid separator 220 may comprise alkylate gasoline, having
similar or substantially the same octane number and boiling point
distribution as compared with the alkylate feed, while the chloride
content is greatly decreased. Typically, a dechlorinated product,
such as alkylate gasoline, provided by processes of the present
invention may have a chloride content less than 50 ppm, and often
equal to or less than about 10 ppm. Analogous results will be
obtained when the present invention is practiced using catalyst
systems based on halides other than chlorides.
[0053] In an embodiment, the dechlorinated product may be fed to a
stripper unit 230 for removing any residual off-gas components. As
an example, such stripping may be performed using a counter-current
stream of dry nitrogen gas. In an embodiment wherein gas/liquid
separator 220 is operated under suitable temperature and other
conditions, the dechlorinated product from gas/liquid separator 220
may have a chloride content (e.g., <10 ppm chloride) and other
specifications well within acceptable ranges, and therefore a
stripping procedure may optionally be omitted.
[0054] The off-gas produced by hydrodechlorination unit 210 may
comprise substantial amounts of H.sub.2, in addition to HCl. The
off-gas produced in hydrodechlorination unit 210 may further
comprise from about 0.1 to 20 vol % C.sub.1-C.sub.5 hydrocarbons.
The off-gas produced in hydrodechlorination unit 210 may still
further comprise C.sub.5+ hydrocarbons.
[0055] The off-gas from hydrodechlorination unit 210 may be fed to
an HCl recovery system 300 (see, e.g., FIG. 1A) for removing the
HCl from the off-gas and for recovering the HCl, as described
herein below. The off-gas from hydrodechlorination unit 210 may be
fed to an HCl scrubber 250 for HCl removal from the off-gas. Then
the HCl-free off-gas, which may comprise predominantly H.sub.2 gas,
can be recycled back to hydrodechlorination unit 210.
Hydrodechlorination of Conjunct Polymer Feed
[0056] While not being bound by any theory, the formation of
by-products known as conjunct polymer during ionic liquid catalyzed
hydrocarbon conversion reactions can be associated with ionic
liquid catalyst deactivation. Conjunct polymer may comprise a
mixture of polyunsaturated acyclic, cyclic, and polycyclic
molecules that may include one or a combination of 4-, 5-, 6- and
7-membered rings in their skeletons. Some examples of the likely
polymeric species were reported by Miron et al. (Journal of
chemical and Engineering Data, 1963) and Pines (Chem. Tech, 1982).
The accumulation of conjunct polymer can deactivate chloroaluminate
ionic liquid catalysts by weakening the acid strength of the
catalyst through the formation of complexes of conjunct polymers
with AlCl.sub.3.
[0057] Applicants have now discovered that conjunct polymer, e.g.,
that may be released during catalyst regeneration, may provide a
valuable feedstock for liquid fuel production processes. In an
embodiment, used ionic liquid catalyst may be regenerated by
treatment with a regeneration metal. The regeneration metal may be,
e.g., Al, Ga, In, and Zn. The metals may be in the form of fine
particles, granules, sponges, gauzes, etc. An effective amount of
metal, say aluminum, used for the regeneration of used ionic liquid
catalyst may be determined by the amount (concentration) of
conjunct polymer in the used ionic liquid.
[0058] The particular regeneration metal to be used may be selected
based on the composition of the ionic liquid catalyst, e.g., to
prevent the contamination of the catalyst with unwanted metal
complexes or intermediates that may form and remain in the catalyst
phase. As an example, aluminum metal will be the metal of choice
for the regeneration when the catalyst system is a chloroaluminate
ionic liquid-based catalyst.
[0059] With further reference to FIG. 1A, the regenerated ionic
liquid may be sent to conjunct polymer extraction unit 150, in
which free conjunct polymer that is released from the ionic liquid
during catalyst regeneration may be extracted with a hydrocarbon,
e.g., a C.sub.3-C.sub.10 alkane. In an embodiment, the hydrocarbon
solvent used for extracting the conjunct polymer may comprise
isobutane. After phase separation, the organic phase may be sent to
a stripper to separate the extracted conjunct polymer from the
solvent. A process for ionic liquid catalyst regeneration in which
released conjunct polymer is separated from the catalyst phase, is
disclosed in commonly assigned U.S. Pat. No. 7,732,364, the
disclosure of which is incorporated by reference herein in its
entirety.
[0060] A conjunct polymer feed, e.g., obtained from conjunct
polymer extraction unit 150, may have an organic chloride content
generally in the range from about 50 ppm to 5000 ppm, typically
from about 100 ppm to 4000 ppm, and often from about 200 ppm to
3000 ppm. The conjunct polymer feed, may be dechlorinated
substantially as described hereinabove for the dechlorination of
alkylate distillate. In an embodiment, a first chloride content of
the conjunct polymer feed may greater than about 50 ppm or greater,
and the chloride content of the dechlorinated product is lower than
that of the feed, generally the chloride content of the
dechlorinated product being less than 50 ppm, and typically the
chloride content of the dechlorinated product being less than 10
ppm.
[0061] When using conjunct polymer as feed to hydrodechlorination
unit 210, at least about 90% of the dechlorinated product derived
from the conjunct polymer feed may have a boiling point range
generally from about 200.degree. F. to 1000.degree. F., and often
from about 200.degree. F. to 800.degree. F. In an embodiment, the
dechlorinated product may comprise base oil, or a middle distillate
fuel, such as jet fuel or diesel fuel, wherein the dechlorinated
product may have a chloride content generally less than about 50
ppm, and more typically less than about 10 ppm.
HCl Capture, Recovery, and Recycle
[0062] According to an aspect of the present invention, the off-gas
from hydrodechlorination unit 210 may be fed from gas/liquid
separator 220 to HCl recovery system 300 for removing the HCl from
the off-gas and for recovering the HCl. The off-gas may be fed
through HCl recovery unit 310 to capture the HCl. The off-gas may
comprise H.sub.2 and C.sub.1-C.sub.5 hydrocarbons in addition to
HCl.
[0063] HCl recovery unit 310 may contain an adsorbent for adsorbing
the HCl present in the off-gas. The HCl recovery unit 310 may also
be referred to herein as an HCl adsorption zone. The off-gas may be
contacted with the adsorbent under HCl adsorbing conditions such
that the HCl is adsorbed by the adsorbent. In an embodiment, the
off-gas may be fed through HCl recovery unit 310 at about ambient
temperature and a pressure in the range from about atmospheric
pressure to the pressure of the gas/liquid separator 220 to capture
the HCl. The adsorbent may be selective, such that HCl is
selectively adsorbed, while H.sub.2 and light hydrocarbons flow
through the absorbent to provide HCl-free off-gas.
[0064] The adsorbent within HCl recovery unit 310 may comprise a
material selected from a molecular sieve, a refractory oxide, an
activated carbon, or combinations thereof. In an embodiment, the
adsorbent may comprise a refractory oxide selected from alumina,
silica, titania, silica-alumina, and zirconia, or the like, and
combinations thereof. In an embodiment, the adsorbent may comprise
a molecular sieve, including 8-, 10-, and 12-ring zeolites, and
combinations thereof, wherein the zeolites may have a Si/Al ratio
in the range from 1 to .infin.. Some examples of molecular sieves
that may be used as adsorbents in practicing the present invention
include the following: 3A, 4A, 5A, 13X, 13Y, USY, ZSM-5, ZSM-22,
ZSM-23, ZSM-35, ZSM-48, MCM-22, MCM-35, MCM-58, SAPO-5, SAPO-11,
SAPO-35, and VPI-5. In a sub-embodiment, the adsorbent may comprise
zeolite 4A. In another sub-embodiment, the adsorbent may comprise
zeolite 13X. Zeolites and molecular sieves are well known in the
art (see, for example, Zeolites in Industrial Separation and
Catalysis, By Santi Kulprathipanja, Pub. Wiley-VCH, 2010).
[0065] In an embodiment, HCl recovery unit 310 may include two
adsorption beds )not shown) which may be arranged in parallel to
faclitate the HCl adsorption/desorption cycles. The feed to HCl
recovery unit 310 may be controlled, e.g., via a valve, whereby
after the first adsorbent bed is saturated with HCl from the
off-gas, the flow of off-gas to HCl recovery unit 310 can be turned
to the second adsorbent bed. The adsorbed HCl on the first
adsorbent bed may be recovered from the adsorbent, e.g., by feeding
a recovery carrier gas through the spent adsorbent bed. In an
embodiment, the recovery carrier gas may comprise dry N.sub.2. In
another embodiment, the recovery carrier gas may comprise a
C.sub.3-C.sub.8 alkane, such as isobutane. Desorption of the HCl
from the adsorbent may be completed at the ambient temperature and
the system pressure, or may be promoted by heating the adsorbent
via the recovery carrier gas, or by operating HCl recovery unit 310
at a pressure lower than the adsorption pressure. In an embodiment,
the adsorbent may be heated to a temperature in the range from
about 100.degree. F. to 1000.degree. F., and typically from about
200.degree. F. to 800.degree. F. to promote desorption of the HCl
from the adsorbent. The desorption pressure may be generally in the
range from about 0 to 500 psig, and typically from about 20 to 300
psig.
[0066] In an embodiment, the HCl recovered from the adsorbent may
be recycled to hydrocarbon conversion reactor 110 (see, e.g., FIGS.
1A and 1B). Since HCl serves as a promoter of ionic liquid
catalyzed hydrocarbon conversion reactions, the required amount of
fresh HCl or organic halide promoter is thereby decreased, thus
providing a substantial economic benefit to the overall hydrocarbon
conversion process of the invention.
[0067] Due to the presence of HCl in the hydrocarbon conversion,
hydrodechlorination, and HCl recovery systems of the present
invention, processes of the present invention may be performed
entirely under anhydrous conditions.
[0068] HCl recovery system 300 may further include an HCl scrubber
320, such that the off-gas may be fed to scrubber 320 for HCl
removal from the off-gas. As an example, HCl scrubber 320 may serve
as a contingency or back-up capability, e.g., in the event that HCl
recovery unit 310 may be temporarily inoperative or unavailable. In
an embodiment, HCl recovery system 300 may include one or more
additional HCl recovery units (not shown), one or more of which may
be operated in parallel with HCl recovery unit 310, whereby a first
HCl recovery unit may be operated in adsorption mode while a second
HCl recovery unit may be operated in desorption mode. The HCl-free
off-gas from HCl recovery system 300, which may comprise mostly
H.sub.2 gas, may be recycled back to the hydrodechlorination unit
210 to minimize the consumption of H.sub.2.
[0069] The following examples are illustrative of the present
invention, but are not intended to limit the invention in any way
beyond what is contained in the claims which follow.
EXAMPLES
Example 1
Ionic Liquid Catalyst Comprising Anhydrous Metal Halide
[0070] Various ionic liquid catalysts comprising metal halides such
as AlCl.sub.3, AlBr.sub.3, GaCl.sub.3, GaBr.sub.3, InCl.sub.3, and
InBr.sub.3 may be used for practicing the catalytic processes of
the present invention. N-butylpyridinium heptachlorodialuminate
(C.sub.5H.sub.5NC.sub.4H.sub.9Al.sub.2Cl.sub.7) ionic liquid
catalyst is an example of such a catalyst. The catalyst has the
following composition.
TABLE-US-00001 Wt % Al 12.4 Wt % Cl 56.5 Wt % C 24.6 Wt % H 3.2 Wt
% N 3.3
[0071] N-butylpyridinium heptachlorodialuminate may be prepared,
e.g., according to Example 1 of U.S. Pat. No. 7,432,408, or may be
purchased (Alfa Aesar, Ward Hill, Mass.).
Example 2
Preparation of Alkylate Distillate
[0072] A chlorinated alkylate was prepared by reacting isobutane
with C.sub.3-C.sub.4 olefins at an isobutane to olefin molar ratio
of 8 in the presence of N-butylpyridinium heptachlorodialuminate (6
vol %) as catalyst and n-butyl chloride as catalyst promoter. The
alkylation reaction was conducted at 95.degree. F. and 190 psig
with vigorous stirring. After phase separation, the hydrocarbon
phase provided a chlorinated alkylate ("feed") having the boiling
point distribution as shown in FIG. 2, and a C.sub.8 composition as
shown in Table 1.
Example 3
Preparation of Hydrodechlorinated Alkylate Product
[0073] The alkylate prepared according to Example 2 was
hydrodechlorinated over a Pd/alumina catalyst containing 0.5 wt %
Pd, as follows. The hydrodechlorination catalyst was first reduced
in flowing hydrogen at 450.degree. F., 500 psig for two hours.
Then, hydrodechlorination of the alkylate prepared according to
Example 2 was performed at an average catalyst temperature of
500.degree. F., a pressure of 500 psig, a LHSV of 1.0 hr.sup.-1,
and a H.sub.2 feed rate of 1000 SCFB.
[0074] The hydrodechlorinated alkylate product had the boiling
characteristics as shown in FIG. 2. It can be seen that
hydrodechlorination according to the present invention did not
substantially alter the boiling characteristics of the alkylate
"feed" prepared according to Example 2.
Example 4
C.sub.8 Composition of Alkylate Feed and Hydrodechlorination Whole
Liquid Product
[0075] The alkylate feed of Example 2 and the dechlorinated whole
liquid product obtained using the hydrodechlorination procedure of
Example 3 were each subjected to C.sub.8 composition analysis by
GC, and the results are shown in Table 1. The dechlorinated product
had a trimethylpentane content of about 83.3% and a
trimethylpentane to dimethylhexane (TMP/DMH) ratio of about 5.32.
These values are comparable to those for the alkylate feed: 83.5%
and 5.39, respectively (Table 1).
TABLE-US-00002 TABLE 1 Comparison of C.sub.8 composition for
alkylate feed and dechlorinated product Alkylate Dechlorinated Feed
product.sup..dagger. C.sub.8 composition C.sub.8 in WLP, % 60.5
61.7 TMP/DMH 5.39 5.32 TMP in C.sub.8, % 83.5 83.3 Chloride content
(ppm) 4048 <3 .sup..dagger.Hydrodechlorination conditions as for
Example 3; liquid product recovery was >95%.
[0076] It can be seen that hydrodechlorination according to the
present invention did not substantially alter the percent of
trimethylpentane in the total C.sub.8 hydrocarbon fraction, nor the
trimethylpentane to dimethylhexane (TMP/DMH) ratio of the
dechlorinated product, as compared with the alkylate feed prepared
according to Example 2.
Example 5
Quantitative Analysis of Alkylate Feed and Hydrodechlorinated Whole
Liquid Product for Organic Chloride
[0077] The chloride content of the alkylate prepared according to
Example 2 and of the hydrodechlorinated whole liquid product
(Example 3) was determined using a bench-top XOS Clora chloride
analyzer (X-Ray Optical Systems, Inc., East Greenbush, N.Y.). It
can be seen from Table 1 that following hydrodechlorination the
chloride content was decreased to <10 ppm.
Example 6
Preparation of Conjunct Polymer
[0078] A chlorinated conjunct polymer was prepared by regenerating
a deactivated ionic liquid catalyst with aluminum metal followed by
extraction with isobutane. The conjunct polymer was separated from
the organic phase by distillation.
Example 7
Preparation of Hydrodechlorinated Conjunct Polymer
[0079] The conjunct polymer prepared according to Example 6 was
hydrodechlorinated over a Pd/alumina catalyst containing 0.5 wt %
Pd under the following conditions: 500.degree. F. average catalyst
bed temperature, 450 psig total pressure, 1.0 LHSV, and 3000
SCF/B.
[0080] Table 2 shows that hydrodechlorination process can
significantly remove chloride impurity from the feed, by decreasing
the chloride content from 301 ppm in the conjunct polymer feed to
2.9 ppm in the dechlorinated product. The hydrodechlorination
process also hydrogenates unsaturated components in the conjunct
polymer as indicated by the reduction of bromine number from 179
g-Br/100 g conjunct polymer of the feed to <1 g-Br/100 g of the
dechlorinated product, thus improving diesel properties such as API
and cetane index. The hydrodechlorination process also lowers the
sulfur content of the conjunct polymer. The sulfur content in the
conjunct polymer was reduced from 29.7 ppm to 7.8 ppm.
TABLE-US-00003 TABLE 2 Comparison of conjunct polymer feed and
dechlorinated product Conjunct Polymer Dechlorinated Feed ID Feed
Product API gravity 34.1 35.4 S, wt ppm 29.7 7.8 Bromine number,
g-Br/100 g 179 <1 Cl, ppm 301 2.9 Simdist, .degree. F. 0.5 wt %
226 212 10 wt % 342 340 50 wt % 492 500 90 wt % 703 723 99.5 wt %
953 988
Example 8
HCl Capture from Hydrodechlorination Processes
[0081] A HCl-containing off-gas from a hydrodechlorination process
using alkylate distillate feed was fed directly to a HCl recovery
unit (see, e.g., FIG. 1A) using zeolite 4A as adsorbent at a
temperature of 100.degree. F. The HCl concentration in the off-gas
before and after contacting with adsorbent was periodically
monitored and measured by HCl-selective Draeger tubes. FIG. 3 shows
the HCl concentration measured in the off-gas as the % of the feed
HCl concentration as a function of time. It can be seen from FIG. 3
that the HCl in the off-gas was selectively removed by the
absorbent for about 7 hours. HCl breakthrough occurred at 7 hours
of time on stream. Even after the breakthrough, 70% of the HCl was
captured by the adsorbent for a further extended period of time
(7-12 hours).
[0082] There are numerous variations on the present invention which
are possible in light of the teachings and supporting examples
described herein. It is therefore understood that within the scope
of the following claims, the invention may be practiced otherwise
than as specifically described or exemplified herein.
* * * * *