U.S. patent application number 13/276403 was filed with the patent office on 2013-04-25 for catalyst composition for selective hydrogenation with improved characteristics.
The applicant listed for this patent is Richard Fischer, Frank Grossmann, Alfred Hagemeyer, Hongyi C. Hou, David Michael Lowe, Claus Lugmair, Mingyong Sun, Normen Szesni, Michael Urbancic. Invention is credited to Richard Fischer, Frank Grossmann, Alfred Hagemeyer, Hongyi C. Hou, David Michael Lowe, Claus Lugmair, Mingyong Sun, Normen Szesni, Michael Urbancic.
Application Number | 20130102819 13/276403 |
Document ID | / |
Family ID | 48136503 |
Filed Date | 2013-04-25 |
United States Patent
Application |
20130102819 |
Kind Code |
A1 |
Szesni; Normen ; et
al. |
April 25, 2013 |
CATALYST COMPOSITION FOR SELECTIVE HYDROGENATION WITH IMPROVED
CHARACTERISTICS
Abstract
This invention relates to heterogeneous catalysts useful for
selective hydrogenation of unsaturated hydrocarbons, comprising
palladium and optionally a promoter, supported on a substrate,
having an uncoated BET surface area of .ltoreq.9 m.sup.2/g, the
surface being coated with an ionic liquid. Also described are
methods of making the catalysts and methods of selective
hydrogenation of acetylene and/or dienes in front-end mixed olefin
feed streams.
Inventors: |
Szesni; Normen; (Rosenheim,
DE) ; Hagemeyer; Alfred; (Bad Aibling, DE) ;
Grossmann; Frank; (Munchen, DE) ; Fischer;
Richard; (Bad Aibling, DE) ; Urbancic; Michael;
(Louisville, KY) ; Lugmair; Claus; (San Jose,
CA) ; Sun; Mingyong; (Louisville, KY) ; Hou;
Hongyi C.; (San Jose, CA) ; Lowe; David Michael;
(Sunnyvale, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Szesni; Normen
Hagemeyer; Alfred
Grossmann; Frank
Fischer; Richard
Urbancic; Michael
Lugmair; Claus
Sun; Mingyong
Hou; Hongyi C.
Lowe; David Michael |
Rosenheim
Bad Aibling
Munchen
Bad Aibling
Louisville
San Jose
Louisville
San Jose
Sunnyvale |
KY
CA
KY
CA
CA |
DE
DE
DE
DE
US
US
US
US
US |
|
|
Family ID: |
48136503 |
Appl. No.: |
13/276403 |
Filed: |
October 19, 2011 |
Current U.S.
Class: |
585/275 ;
502/164; 502/328; 502/329; 502/330; 502/331; 502/333; 502/339 |
Current CPC
Class: |
B01J 31/0277 20130101;
B01J 35/1009 20130101; B01J 23/44 20130101; B01J 23/50 20130101;
B01J 37/024 20130101; B01J 23/58 20130101; C07C 2523/50 20130101;
C10G 2400/20 20130101; B01J 23/62 20130101; B01J 2531/824 20130101;
B01J 23/626 20130101; B01J 37/0201 20130101; B01J 2231/645
20130101; C07C 2523/44 20130101; B01J 21/04 20130101; B01J 23/6447
20130101; B01J 35/1038 20130101; B01J 37/16 20130101; B01J 35/008
20130101; C10G 45/40 20130101; B01J 23/60 20130101; C07C 7/167
20130101; C07C 11/06 20130101; C07C 7/167 20130101; B01J 23/628
20130101; B01J 23/52 20130101; B01J 23/8926 20130101; C07C 7/167
20130101; B01J 31/0279 20130101; B01J 31/0284 20130101; Y02P 20/52
20151101; C07C 11/04 20130101 |
Class at
Publication: |
585/275 ;
502/339; 502/330; 502/329; 502/328; 502/331; 502/333; 502/164 |
International
Class: |
C07C 5/09 20060101
C07C005/09; B01J 23/50 20060101 B01J023/50; B01J 23/52 20060101
B01J023/52; B01J 31/02 20060101 B01J031/02; B01J 23/62 20060101
B01J023/62; B01J 23/89 20060101 B01J023/89; B01J 23/644 20060101
B01J023/644; B01J 23/58 20060101 B01J023/58; B01J 23/44 20060101
B01J023/44; B01J 23/60 20060101 B01J023/60 |
Claims
1. A catalyst comprising palladium supported on a substrate, said
catalyst further comprising at least one ionic liquid, wherein said
substrate has a BET surface area of less than 9 m.sup.2/g prior to
the addition of said at least one ionic liquid.
2. The catalyst of claim 1, wherein said BET surface area is
preferably within a range of 2 to 8 m.sup.2/g, and more preferably
within a range of 3 to 5 m.sup.2/g.
3. The catalyst of claim 1, wherein the palladium-supported
catalyst further comprises a promoter selected from the group
consisting of Ag, Au, Zn, Sn, Cd, Pb, Cu, Bi, K, Ga, and mixtures
thereof.
4. The catalyst of claim 3, wherein the promoter comprises Ag.
5. The catalyst of claim 1, having a Pd loading of 10 to 1000
ppm.
6. The catalyst of claim 3, having a ratio of Pd:promoter of
1:5-3:1.
7. The catalyst of claim 1, wherein the ionic liquid comprises a
compound of the formula: [A].sub.n.sup.+[Y].sub.n.sup.-, wherein:
n=1 or 2; [Y].sub.n.sup.- is selected from the group consisting of
tetrafluoroborate ([BF.sub.4].sup.-) hexafluorophosphate
([PF.sub.6].sup.-), dicyanamide ([N(CN).sub.2].sup.-), halides
(Cl.sup.-, Br.sup.-, F.sup.-, I.sup.-), hexafluoroantimonate
([SbF.sub.6].sup.-), nitrate ([NO.sub.3].sup.-), nitrite
([NO.sub.2].sup.-), anionic metal complexes such as for example
[CuCl.sub.4].sup.2-, [PdCl.sub.4].sup.2- or [AuCl.sub.4].sup.-,
acetate ([CH.sub.3COO].sup.-), trifluoracetate
([F.sub.3CCOO].sup.-), hexafluoroarsenate ([AsF.sub.6].sup.-),
sulfate ([SO.sub.4]2.sup.-), hydrogen sulfate
([R'--SO.sub.4].sup.-), alkyl sulfate ([R'--SO.sub.4].sup.-),
tosylate ([C.sub.7H.sub.7SO.sub.3].sup.-), triflate
([CF.sub.3SO.sub.3].sup.-), nonaflate
([C.sub.4F.sub.9SO.sub.3].sub.-), triperfluoroethylene
trifluorophosphate ([PF.sub.3(C.sub.2F.sub.5).sub.3].sup.-),
tricyanomethide ([C(CN).sub.3].sup.-), tetracyanoborate
([B(CN).sub.4].sup.-, thiocyanate ([SCN].sup.-), carbonate
([CO.sub.3].sub.2.sup.-), carboxylate ([R'--COO].sup.-), sulfonate
([R'SO.sub.3].sup.-), dialkylphosphate ([R'PO.sub.4R''].sup.-),
alkyl phosphonate ([R'HPO.sub.3].sup.-) and bissulfonylimide
([(R'-SO.sub.2).sub.2N].sup.-), such as
bis(trifluormethylsulfonyl)imide, wherein R' and R'' are the same
or different, and each represent a linear or branched 1 to 12
carbon atom-containing aliphatic or alicyclic alkyl group or a
C.sub.5-C.sub.18-aryl, C.sub.5-C.sub.18-aryl-C.sub.1-C.sub.6-alkyl
or C.sub.1-C.sub.6-alkyl-C.sub.5-C.sub.18-aryl group that can be
substituted with halogen atoms; [A].sup.+ is selected from the
group consisting of quaternary ammonium cations with the formula
[NR.sup.1R.sup.2R.sup.3R].sup.+, phosphonium cations with the
formula [PR.sup.1R.sup.2R.sup.3R].sup.+, sulfonium cations with the
formula [SR.sup.1R.sup.2R].sup.+, guadinium cations with the
formula ##STR00010## imidazolium cations with the formula
##STR00011## wherein the imidazole core can also be substituted
with one or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups, pyridinium
cations with the formula ##STR00012## wherein the pyridine core can
also be substituted with one or more groups selected from
C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6-alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.5-C.sub.12-aryl and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups, pyrazolium
cations with the formula ##STR00013## wherein the pyrazole core can
also be substituted with one or more groups selected from
C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6-alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.5-C.sub.12-aryl or
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups, and triazolium
cations with the formula ##STR00014## wherein the triazole core can
also be substituted with one or more groups selected from
C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6-alkoxy,
C.sub.1-C.sub.6-aminoalkyl, C.sub.5-C.sub.12-aryl or
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups, wherein
R.sup.1, R.sup.2, R.sup.3 are selected independently from each
other from the group consisting of: hydrogen; linear or branched,
saturated or unsaturated, aliphatic or alicyclic alkyl groups with
1 to 20 carbon atoms; heteroaryl groups with 3 to 8 carbon atoms
and at least one hetero atom selected from N, O and S, wherein the
heteroaryl group can be substituted with one or more groups
selected from C.sub.1-C.sub.6-alkyl groups and halogen atoms;
heteroaryl-C.sub.1-C.sub.6-alkyl groups with 3 to 8 carbon atoms
and at least one hetero atom selected from N, O and S in the
heteroaryl moiety, wherein the heteroaryl moiety can be substituted
with at least one group selected from C.sub.1-C.sub.6-alkyl groups
and halogen atoms; polyethers with the formula
[--CH.sub.2CH.sub.2O].sub.nR.sup.a with n=1 to 50,000, wherein
R.sup.a is selected from the group consisting of linear or
branched, saturated or unsaturated, aliphatic or alicyclic alkyl
groups with 1 to 20 carbon atoms; aryl groups with 5 to 12 carbon
atoms, which may be substituted with one or more
C.sub.1-C.sub.6-alkyl groups and/or halogen atoms;
aryl-C.sub.1-C.sub.6-alkyl groups with 5 to 12 carbon atoms in the
aryl moiety, which may be substituted with one or more
C.sub.1-C.sub.6-alkyl groups and/or halogen atoms, and wherein R is
selected from the group consisting of: linear or branched,
saturated or unsaturated, aliphatic or alicyclic alkyl groups with
1 to 20 carbon atoms; heteroaryl-C.sub.1-C.sub.6-alkyl groups with
4 to 8 carbon atoms and at least one hetero atom selected from N, O
and S in the heteroaryl moiety, which can be substituted with one
or more C.sub.1-C.sub.6-alkyl groups and/or halogen atoms; and
aryl-C.sub.1-C.sub.6-alkyl groups with 4 to 12 carbon atoms in the
aryl moiety, which may be substituted with one or more
C.sub.1-C.sub.6-alkyl groups and/or halogen atoms.
8. The catalyst of claim 7, wherein the ionic liquid comprises one
or more selected from the group consisting of
1-butyl-3-methylimidazolium triflate, 1-ethyl-3-methylpyridinium
ethylsulfate, 1-butyl-1-methylpyrrolidinium triflate,
1-butyl-2,3-dimethylimidazolium triflate,
1-butyl-3-methylimidazolium tricyanomethane,
1-butyl-3-methylimidazolium methylsulfate,
1-butyl-3-methylimidazolium octylsulfate,
1-butyl-3-methylimidazolium tetrafluoroborate,
1-ethyl-3-methylimidazolium ethylsulfate,
1-ethyl-3-methylimidazolium methylphosphonate,
1-ethyl-3-methylimidazolium triflate, 1-butyl-1-methylpyrrolidinium
bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium
tetracyanoborate, 1-butyl-1-methylpyrrolidinium
tris(pentafluoroethyl)trifluorophosphate,
1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide,
1-butyl-3-methylimidazolium tricyanomethane,
1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide,
1-ethyl-3-methylimidazolium tetracyanoborate,
1-ethyl-3-methylimidazolium
tris(pentafluoroethyl)trifluorophosphate,
1-methyl-3-octylimidazolium triflate,
ethyldimethyl-(2-methoxyethyl)ammonium
tris(pentafluoroethyl)trifluorophosphate, tributylmethylammonium
dicyanamide, tricyclohexyltetradecylphosphonium
tris(pentafluoroethyl)trifluorophosphate,
1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and
mixtures thereof.
9. The catalyst of claim 7, wherein [A].sub.n.sup.+ is selected
from the group consisting of 1-butyl-1-methylpyrrolidinium,
1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium,
1-ethyl-3-methylimidazolium, 1-ethyl-3-methylpyridinium,
1-methyl-3-octylimidazolium,
ethyldimethyl-(2-methoxyethyl)ammonium, tributylmethylammonium,
tricyclohexyltetradecylphosphonium, and mixtures thereof, and
wherein [Y].sub.n.sup.- is selected from the group consisting of
bis(trifluoromethylsulfonyl)imide, dicyanamide, ethylsulfate,
methylphosphonate, methylsulfate, octylsulfate, tetracyanoborate,
tetrafluoroborate, tricyanomethane, triflate,
tris(pentafluoroethyl)trifluorophosphate, and mixtures thereof.
10. The catalyst of claim 1, having an ionic liquid loading of
0.01% to 10% by weight, and more preferably of 0.1% to 5% by
weight.
11. The catalyst of claim 1, having a cleanup temperature of less
than 80.degree. C. and an operating window of greater than
25.degree. C. when tested with a simulated de-ethanizer feed
containing 0.35 mol % acetylene, 20 mol % hydrogen, 0.02 mol % CO,
45 mol % ethylene, and balance methane being passed over a 25 ml
catalyst bed at 500 psig (35.5 bar) in total pressure and 7000
h.sup.-1 in Gas Hourly Space Velocity (GHSV), while the bed
temperature is gradually increased from about 35.degree. C., the
"clean up temperature" is defined as the temperature at which the
outlet reaches <25 ppm acetylene, the runaway temperature is
defined as the temperature at which the outlet ethane concentration
is >2% and the operation window is defined as the difference
between the runaway temperature and the clean up temperature.
12. The catalyst of claim 1, wherein the integral pore volume of
the catalyst without the presence of said at least one ionic liquid
is in the range of 0.005 to 0.07 ml/g, preferably in the range of
0.007 to 0.04 ml/g and more preferably within a range of 0.009 to
0.02 ml/g.
13. The catalyst of claim 1, having a selectivity of >25% at
clean up temperature, when tested with a simulated de-ethanizer
feed containing 0.35 mol % acetylene, 20 mol % hydrogen, 0.02 mol %
CO, 45 mol % ethylene, and balance methane being passed over a 25
ml catalyst bed at 500 psig (35.5 bar) in total pressure and 7000
h.sup.-1 in Gas Hourly Space Velocity (GHSV), while the bed
temperature is gradually increased from about 35.degree. C., the
"clean up temperature" being defined as the temperature at which
the outlet reaches <25 ppm acetylene.
14. A method of making a coated catalyst, comprising the steps of:
(a) providing a catalyst having a BET surface area less than or
equal to 9 m.sup.2/g and comprising palladium supported on a
substrate and optionally further comprising a promoter; (b) coating
the catalyst in (a) with a mixture of an ionic liquid and a
solution agent; and (c) removing the solution agent during or after
the coating in (b).
15. The process of claim 14, further comprising the step of
reducing the catalyst before step (b) or after step (c).
16. The process of claim 14, wherein step (b) comprises a fluidized
bed coating or an impregnation with a solution or suspension.
17. A method of selective hydrogenation of acetylene in front-end
mixed olefin feed streams, comprising catalyzing said hydrogenation
with a catalyst comprising palladium supported on a substrate, the
catalyst having an uncoated BET surface area of less than 9
m.sup.2/g, said catalyst further comprising at least one ionic
liquid.
18. The method of claim 17, wherein the selective hydrogenation
occurs in a gas phase.
19. The method of claim 17, wherein the selective hydrogenation
occurs in a liquid phase.
Description
FIELD OF THE INVENTION
[0001] The present invention is related to a catalyst composition
for selective hydrogenations, for example for the selective
hydrogenation of acetylene in the gaseous phase, comprising a
heterogeneous catalyst with a BET surface area of .ltoreq.9
m.sup.2/g and an ionic liquid applied to the surface of the same.
The catalyst composition has improved characteristics such as, for
example, improved selectivity in favor of the desired product and
better thermal stability.
BACKGROUND OF THE INVENTION
[0002] Ethylene and propylene are important monomers for the
production of plastics, such as for example polyethylene or
polypropylene. Ethylene and propylene are primarily derived from
petroleum and petroleum products by means of thermal or catalytic
cracking of hydrocarbons. The ethylene or propylene derived with
the aid of the cracking process does, however, contain an
undesirably high proportion of acetylenic compounds such as
acetylene or methyl acetylene (propyne), which can negatively
influence downstream ethylene or propylene polymerization.
Therefore prior to polymerization the ethylene or propylene must be
freed from acetylenic compounds as far as possible.
[0003] Typically for the polymerization of ethylene the acetylene
concentration must, for example, be reduced to a value of below 1
ppm. For this the acetylene is selectively hydrogenated into
ethylene. High requirements are placed on the catalyst and the
hydrogenation process. On the one hand, the acetylene must be
removed as completely as possible by transformation into ethylene,
while the hydrogenation of ethylene into ethane must be prevented,
hence the term "selective hydrogenation". In order to ensure this
result, the hydrogenation is carried out within a temperature range
that is delimited by the so-called "clean-up" temperature and the
so-called "run-away" temperature. In the present context the
"clean-up" temperature is understood as the temperature from which
an appreciable hydrogenation of acetylene into ethylene is
observed, while "run-away" temperature is understood as the
temperature at which an appreciable hydrogenation of ethylene into
ethane commences. The said temperatures can be determined in that
the hydrogen consumption of a defined gas mixture containing
acetylene, ethylene, and hydrogen is, for example, measured
depending on the temperature.
[0004] Palladium shell catalysts, often using silver as a promoter,
are primarily used as commercial catalysts for the selective
hydrogenation of acetylene into ethylene in hydrocarbon streams.
The palladium and the silver are supported on an inert,
temperature-resistant substrate. The production of these catalysts
is carried out in such a way that suitable salts of palladium and
silver, for example palladium nitrate and silver nitrate, are
applied to a substrate in form of an aqueous solution
(impregnation). The impregnation can take place during separate
steps with a palladium compound solution and a silver compound
solution. It is, however, also possible to apply the solution of
palladium compounds and the solution of silver compounds to the
substrate simultaneously during a single impregnation step. The
impregnated substrate is then calcined to transform the silver into
silver oxide, or the palladium into palladium oxide, and is then
subjected to a reduction in order to transfer the catalyst into the
active form. During the reaction the silver and palladium are
assumed to be transferred into the oxidation state "zero".
[0005] DE 31 19 850 A1 describes a method for the selective
hydrogenation of a diolefin with at least 4 carbon atoms in a
hydrocarbon mixture. Hydrogenation takes place with hydrogen on a
catalyst containing palladium and silver. The silver/palladium
weight ratio of the catalyst is 0.7:1 to 3:1. The production of the
catalyst is by way of co-impregnation of a substrate with an
aqueous solution of palladium and silver salts.
[0006] U.S. Pat. No. 5,648,576 A describes a method for the
selective gaseous phase hydrogenation of acetylenic hydrocarbons
(C.sub.2-C.sub.3) into the corresponding ethylenic hydrocarbons.
The production of the catalyst is realized by co-impregnating the
substrate with an aqueous solution of the respective metal
salts.
[0007] EP 0 064 301 A1 offers a catalyst for the selective gaseous
phase hydrogenation of acetylene. The production of the catalyst is
realized by means of a two-step application of palladium and
silver.
[0008] EP 0 780 155 A1 describes the production of hydrogenation
catalysts, whereby solutions of palladium nitrate and silver
nitrate in a nitrogenous acid are used for the impregnation of the
substrate.
[0009] Apart from the Pd/Ag catalysts described above, a number of
further palladium based catalyst are described, which also provide
improved selectivity and sometimes also improved activity; the same
include Pd/Zn, Pd/Cd, Pd/Ga and Pd/Au. The latter catalyst family
is characterized primarily by a high "run-away" temperature.
[0010] According to the definition of Wasserscheid and Keim in
"Angewandte Chemie" 2000, 112, pages 3926-3945, ionic liquids are
salts, i.e. compounds of anions and cations that are externally
neutral, which melt at low temperatures, usually at temperatures of
below 100.degree. C. Ionic liquids are therefore already liquid at
low temperatures. In addition they are generally not flammable and
have an extremely low vapor pressure. Due to the high variation
range of the structure of their cations and anions, their physical
and chemical characteristics can be varied over a broad range.
[0011] The concept of coating heterogeneous catalysts with small
quantities of an ionic liquid has already been described by Jess et
al. and Claus et al. [U. Kernchen, B. Etzold, W. Korth, A. Jess,
Chem. Eng. Technol. 2007, 30, 985-994; J. Arras, M. Steffan, Y.
Shayeghi, P. Claus, Chem. Commun. 2008, 4058-4060]. In both cases
an improved selectivity towards the desired product in the target
reaction of the hydrogenation of citral or the hydrogenation of
diolefins could be achieved than is possible with the uncoated
catalyst. This catalyst family has also been named as SCILL--Solid
Catalyst with Ionic Liquid Layer--catalysts by the authors.
[0012] US 2008/0269533 A1 describes the selective
mono-hydrogenation of conjugated dienes with the aid of supported
Pd nanoparticles coated with ionic liquids.
[0013] International patent application WO2007/124 896 relates to
heterogeneous catalysts having a BET surface area of preferably 10
to 300 m.sup.2/g. These catalysts may be covered with an ionic
liquid and are used for the selective hydrogenation of unsaturated
cyclic compounds.
[0014] A catalyst system for the selective hydrogenation of
acetylene in the simultaneous presence of ethylene comprising a
heterogeneous catalyst coated with ionic liquid has also already
been described [M. Ruta, G. Laurenczy, P. J. Dyson, L.
Kiwi-Minsker, J. Phys. Chem. C 2008, 112, 17814-17819]. However,
these catalysts are prepared with support materials that are not
suitable for industrial use, as the production of the same is too
costly. The described turnovers are also far from realizable.
[0015] With all of the examples described so far support materials
with a high specific surface area and a suitable pore volume were
used. In order to achieve an even coating of the entire catalyst
surface, and thus the best possible effect (selectivity increase
etc.) a relatively large quantity of ionic liquid is required
(10-17 wt. % in relation to the initial weight of the heterogeneous
catalyst). This often results in a substantial pore filling of the
catalyst and the reduced activity connected with the same. Ionic
liquids are also expensive, which results in substantial additional
costs for the overall catalyst formulation.
SUMMARY OF THE INVENTION
[0016] There remains a need for further improving the selectivity
of Pd/promoter catalysts for the hydrogenation of acetylenic
hydrocarbons, while maintaining or even increasing catalyst
activity.
[0017] It is therefore the object of this invention to provide a
catalyst with high selectivity and activity for the hydrogenation
of acetylenic hydrocarbons.
[0018] Surprisingly it has been found that conventional
heterogeneous catalysts with a BET surface area of .ltoreq.9
m.sup.2/g which are coated with a small amount of an ionic liquid
have improved characteristics, such as improved selectivity in the
hydrogenation of unsaturated hydrocarbons while retaining high
activity.
[0019] With the catalyst system of the invention, known
pre-formulated catalysts for the transformation of acetylene into
ethylene with a BET surface area of .ltoreq.9 m.sup.2/g are coated
with one (or more) ionic liquid(s). The resulting catalyst
formulations have a very high selectivity during the hydrogenation
of acetylene in ethylene rich gas streams and are further
surprisingly characterized by a higher "run-away" temperature. The
catalyst formulations of the invention further may use very small
quantities of ionic liquid (in the range of 3% by weight of the
catalyst) to achieve these advantageous effects. The loss of
catalyst activity is very small.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The pre-formulated catalysts used for coating are, as
already described above, supported palladium shell catalysts which
preferably comprise at least one further promoter such as for
example silver, gold, zinc, tin, lead, gallium, cadmium, copper,
bismuth, or potassium. Preferred promoters are Ag, Au and Zn.
Preferred metal or metal-alloy shell thicknesses are between 100
and 500 .mu.m. The Pd metal content in relation to the total weight
of the catalyst is between 10 and 1000 ppm, preferably between 50
and 500 ppm. For the desired target reaction the catalysts are used
either as shaped bodies such as for example tablets, rings,
tri-holes, extrudates etc., or as a granulate or powder. The mass
ratio of palladium to promoter metal for example lies within a
range of 1:5 to 3:1, preferably within a range of 1:4 to 2:1, and
particularly preferably within a range of 1:3 to 1:1.
[0021] Suitable carrier substrates are Al.sub.2O.sub.3, SiO.sub.2,
alumo silicates, TiO.sub.2, ZrO.sub.2, ZnO, MgO, Fe.sub.2O.sub.3
and CeO.sub.2, or mixtures thereof. In order to increase activity
or selectivity the substrates can further be doped with at least
one of the following elements: Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr
and/or Ba. Na, K and/or Ca are particularly suitable.
[0022] The BET surface area of the uncoated catalyst is .ltoreq.9
m.sup.2/g, and more preferably .ltoreq.8 m.sup.2/g, particularly
preferably .ltoreq.6 m.sup.2/g. The determination of the surface
area may be carried out in accordance with ASTM D3663, Standard
Test Method for Surface Area of Catalysts and Catalyst
Carriers.
[0023] The integral pore volume of the catalyst (determined
according to DIN 66134 of February 1998 (N.sub.2 adsorption))
without the IL-coating preferably is in the range of 0.005 to 0.07
ml/g, more preferably in the range of 0.007 to 0.04 ml/g and
particularly preferably within a range of 0.009 to 0.02 ml/g.
[0024] Suitable pre-formulated catalysts for use in preparing
supported ionic liquid phase catalyst compositions of the invention
include any commercially-available supported Pd or Pd/Ag catalysts
supplied by, for example Sud-Chemie, AG, Munich, Germany, BASF,
Johnson-Mathey, etc.
[0025] For the production of a catalyst composition of the
invention a pre-formulated catalyst is loaded with ionic liquid.
The ionic liquid to be used for this is not particularly
restricted, and in principle, all known ionic liquids suitable for
this purpose can be used. Preferred ionic liquids for use with this
invention are compounds with the formula (I):
[A].sub.n.sup.+[Y].sub.n.sup.- (I),
[0026] wherein:
[0027] n=1 or 2;
[0028] [Y].sub.n.sup.- is selected from the group consisting of
tetrafluoroborate ([BF.sub.4].sup.-), hexafluorophosphate
([PF.sub.6].sup.-), dicyanamide ([N(CN).sub.2].sup.-), halides
(Cl.sup.-, Br.sup.-, F.sup.-, I.sup.-), hexafluoroantimonate
([SbF.sub.6].sup.-), nitrate ([NO.sub.3].sup.-), nitrite
([NO.sub.2].sup.-), anionic metal complexes such as for example
[CuCl.sub.4].sup.2-, [PdCl.sub.4].sup.2- or [AuCl.sub.4].sup.-,
acetate ([CH.sub.3COO].sup.-), trifluoracetate ([F3CCOO].sup.-),
hexafluoroarsenate ([AsF.sub.6].sup.-), sulfate
([SO.sub.4].sub.2.sup.-), alkyl sulfates ([R'--SO.sub.4].sup.-),
tosylate ([C.sub.7H.sub.7SO.sub.3].sup.-), triflate
([CF.sub.3SO.sub.3].sup.-), nonaflate
([C.sub.4F.sub.9SO.sub.3].sup.-), triperfluoroethylene
trifluorophosphate ([PF.sub.3(C.sub.2F.sub.5).sub.3].sup.-),
tricyanomethide ([C(CN).sub.3].sup.-), tetracyanoborate
([B(CN).sub.4].sup.-, thiocyanate ([SCN].sup.-), carbonate
([CO.sub.3].sub.2.sup.-), carboxylates ([R'--COO].sup.-),
sulfonates ([R'SO.sub.3].sup.-), dialkylphosphates
([R'PO.sub.4R''].sup.-), alkyl phosphonates ([R'HPO.sub.3].sup.-)
and bissulfonylimides ([(R'--SO.sub.2).sub.2N].sup.-), such as
bis(trifluormethylsulfonyl)imide,
[0029] wherein R' and R'' are the same or different, and each
represents a linear or branched, 1 to 12 carbon atom-containing
aliphatic or alicyclic alkyl group or a C.sub.5-C.sub.18-aryl,
C.sub.5-C.sub.18-aryl-C.sub.1-C.sub.6-alkyl, or
C.sub.1-C.sub.6-alkyl-C.sub.5-C.sub.18-aryl group that can be
substituted with halogen atoms; and
[0030] [A].sup.+ is selected from the group consisting of
quaternary ammonium cations with the formula
[NR.sup.1R.sup.2R.sup.3R].sup.+, phosphonium cations with the
formula [PR.sup.1R.sup.2R.sup.3R].sup.+, sulfonium cations with the
formula [SR.sup.1R.sup.2R].sup.+, guadinium cations with the
formula (II):
##STR00001##
[0031] imidazolium cations with the formula (III)
##STR00002##
wherein the imidazole core may additionally be substituted with one
or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl, and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups,
[0032] pyridinium cations with the formula (IV)
##STR00003##
wherein the pyridine core may additionally be substituted with one
or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl, and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups,
[0033] pyrazolium cations with the formula (V)
##STR00004##
wherein the pyrazole core may additionally be substituted with one
or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl, and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups,
[0034] triazolium cations with the formula (VI)
##STR00005##
wherein the triazole core may additionally be substituted with one
or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl, and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups,
[0035] and pyrrolidinium cations with the formula (VII)
##STR00006##
wherein the pyrrolidinium core may additionally be substituted with
one or more groups selected from C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-alkoxy, C.sub.1-C.sub.6-aminoalkyl,
C.sub.5-C.sub.12-aryl, and
C.sub.5-C.sub.12-aryl-C.sub.1-C.sub.6-alkyl groups,
[0036] wherein R.sup.1, R.sup.2, and R.sup.3 are selected
independently from each other from the group consisting of:
hydrogen; linear or branched, saturated or unsaturated, aliphatic
or alicyclic alkyl groups with 1 to 20 carbon atoms, which may be
interrupted by one or two of NH, O and/or S; heteroaryl groups with
3 to 8 carbon atoms and at least one hetero atom selected from N, O
and S, wherein the heteroaryl groups can be substituted with one or
more groups selected from C.sub.1-C.sub.6-alkyl groups and halogen
atoms; heteroaryl-C.sub.1-C.sub.6-alkyl groups with 3 to 8 carbon
atoms and at least one hetero atom selected from N, O and S in the
heteroaryl portion, wherein the heteroaryl portion can be
substituted with at least one group selected from
C.sub.1-C.sub.6-alkyl groups and halogen atoms; polyethers with the
formula [--CH.sub.2CH.sub.2O].sub.nR.sup.a with n=1 to 50,000,
wherein R.sup.a is selected from the group consisting of linear or
branched, saturated or unsaturated, aliphatic or alicyclic alkyl
groups with 1 to 20 carbon atoms; aryl groups with 5 to 12 carbon
atoms, which may be substituted with one or more
C.sub.1-C.sub.6-alkyl groups and/or halogen atoms;
aryl-C.sub.1-C.sub.6-alkyl groups with 5 to 12 carbon atoms in the
aryl portion, which may be substituted with one or more
C.sub.1-C.sub.6-alkyl groups and/or halogen atoms, and
[0037] wherein R is selected from the group consisting of: linear
or branched, saturated or unsaturated, aliphatic or alicyclic alkyl
groups with 1 to 20 carbon atoms; heteroaryl-C.sub.1-C.sub.6-alkyl
groups with 4 to 8 carbon atoms and at least one hetero atom
selected from N, O and S in the heteroaryl portion, which may be
substituted with one or more C.sub.1-C.sub.6-alkyl groups and/or
halogen atoms; and aryl-C.sub.1-C.sub.6-alkyl groups with 4 to 12
carbon atoms in the aryl portion, which may be substituted with one
or more C.sub.1-C.sub.6-alkyl groups and/or halogen atoms.
[0038] Further preferred ionic liquids for use with this invention
are compounds with the formula (I):
[A].sub.n.sup.+[Y].sub.n.sup.- (I),
wherein:
[0039] n and [Y].sub.n.sup.- are as defined above, and
[0040] [A].sup.+ is selected from the group consisting of
quaternary ammonium cations with the formula
[NR.sup.1R.sup.2R.sup.3R].sup.+, imidazolium cations with the
formula (III)
##STR00007##
pyridinium cations with the formula (IV)
##STR00008##
and pyrrolidinium cations with the formula (VII)
##STR00009##
[0041] wherein R, R.sup.1, R.sup.2 and R.sup.3 are selected
independently from each other from the group consisting of
hydrogen; linear or branched C.sub.1-C.sub.12-alkyl groups; linear
or branched (C.sub.1-C.sub.6-alkyloxy)-C.sub.1-C.sub.6-alkyl
groups; and aryl-C.sub.1-C.sub.6-alkyl groups with 5 to 12 carbon
atoms in the aryl portion, which may be substituted with one or
more C.sub.1-C.sub.6-alkyl groups and/or halogen atoms.
[0042] More preferred ionic liquids for preparing supported ionic
liquid phase catalysts of the invention include
1-butyl-3-methylimidazolium triflate, 1-ethyl-3-methylpyridinium
ethylsulfate, 1-butyl-1-methylpyrrolidinium triflate,
1-butyl-2,3-dimethylimidazolium triflate,
1-butyl-3-methylimidazolium tricyanomethane,
1-butyl-3-methylimidazolium methylsulfate,
1-butyl-3-methylimidazolium octylsulfate,
1-butyl-3-methylimidazolium tetrafluoroborate,
1-ethyl-3-methylimidazolium ethylsulfate,
1-ethyl-3-methylimidazolium methylphosphonate,
1-ethyl-3-methylimidazolium triflate, 1-butyl-1-methylpyrrolidinium
bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium
tetracyanoborate, 1-butyl-1-methylpyrrolidinium
tris(pentafluoroethyl)trifluorophosphate,
1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide,
1-butyl-3-methylimidazolium tricyanomethane,
1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide,
1-ethyl-3-methylimidazolium tetracyanoborate,
1-ethyl-3-methylimidazolium
tris(pentafluoroethyl)trifluorophosphate,
1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide,
1-methyl-3-octylimidazolium triflate,
ethyldimethyl-(2-methoxyethyl)ammonium
tris(pentafluoroethyl)trifluorophosphate, tributylmethylammonium
dicyanamide, tricyclohexyltetradecylphosphonium
tris(pentafluoroethyl)trifluorophosphate,
1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and
mixtures thereof.
[0043] More preferred ionic liquids further include those of the
formula (I), wherein [A].sub.n.sup.+ is selected from the group
consisting of 1-butyl-1-methylpyrrolidinium,
1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium,
1-ethyl-3-methylimidazolium, 1-ethyl-3-methylpyridinium,
1-methyl-3-octylimidazolium,
ethyldimethyl-(2-methoxyethyl)ammonium, tributylmethylammonium,
tricyclohexyltetradecylphosphonium, and mixtures thereof, and
wherein [Y].sub.n.sup.- is selected from the group consisting of
bis(trifluoromethylsulfonyl)imide, dicyanamide, ethylsulfate,
methylphosphonate, methylsulfate, octylsulfate, tetracyanoborate,
tetrafluoroborate, tricyanomethane, triflate,
tris(pentafluoroethyl)trifluorophosphate, and mixtures thereof.
[0044] For the production of catalyst compositions of the
invention, the ionic liquid or mixtures of several ionic liquids
are dissolved or suspended in a solution agent suitable for the
purpose, such as for example water, alcohols, acetone etc., or in a
solution agent mixture, and applied continuously onto the already
pre-formed catalyst inside a reaction chamber with the aid of a
nozzle. For this the solution agent is continuously removed from
the reaction chamber during the process. In order to achieve an
even coating of the substrate, the substrate material is
continuously fluidized through a process gas in a process known as
fluidized bed coating. Further suitable coating processes are dip
coating or spray application with a spray pistol or a spray drying
pistol.
[0045] Apart from the application of ionic liquid by means of
coating technologies, the same can also be applied by impregnating
with a solution or suspension. For this the ionic liquid or
mixtures of several ionic liquids are dissolved or suspended in a
suitable solution agent (mixture) and subsequently brought into
contact with the pre-formed catalyst. The solution agent is then
removed under vacuum or at an increased temperature (or both), by
resting in air, or by means of a gas stream. The quantity of
solution agent used can be equal to or smaller or greater than the
pore volume of the catalyst used.
[0046] The quantity of ionic liquid used is equal to or smaller
than the pore volume of the catalyst used. After the application of
the ionic liquid, one is left with an externally dry solid body
coated with the desired quantity of ionic liquid. The pore volume
of the resulting catalyst composition is reduced by the volume of
the ionic liquid. Related to the total weight of the catalyst 0.1-5
wt. %, preferably 0.2-3 wt. %, and particularly preferably 0.3-1.5
wt. % of ionic liquid is used. The distribution of ionic liquid on
the macroscopic substrate form body, granulate or powder is freely
adjustable by selecting the coating conditions. Depending on the
selection of the conditions, a formation of a so-called eggshell,
egg-white, egg-yolk, or a uniform distribution of the ionic liquid
may result on the substrate. In addition, any concentration
gradient of ionic liquid can be created on the substrate. The ionic
liquid is preferably applied to the substrate surface as a thin
shell. The shell thickness of the ionic liquid on the substrate
surface of this invention usually lies within a range of 10 to 2000
.mu.m, preferably within a range of 20 to 1000 .mu.m, and
particularly preferably within a range of 50 to 250 .mu.m.
[0047] The resulting catalyst can be used without restricting the
target reaction. The reduction of metal particles required for
activating the catalyst can either take place prior to a coating
with the ionic liquid or following the same.
[0048] The catalyst can for example be reduced prior to coating
with an ionic liquid. The methods to be used for the same are known
to the expert, and can for example include wet chemical methods
through reduction such as for example NaBH.sub.4, LiAlH.sub.4,
hydrazine (hydrate), hypophosphite, formic acid, or salts of the
same (formates). In addition a reduction can be brought about in
the gaseous phase with hydrogen (in all mixtures with an inert gas;
preferably 5% in N.sub.2) within a temperature range of
50-200.degree. C., preferably at 80-120.degree. C.
[0049] The reduced metal particles obtained in this way usually
have a diameter within a range of 1 to 30 nm, preferably within a
range of 1 to 10 nm, and particularly preferably within a range of
2 to 8 nm.
EXAMPLES
Example 1
[0050] Sample A contains 0.017 wt % Pd on 1-2 mm alumina spheres
with a BET surface area of 4.0 m.sup.2/g. In order to make Sample
A, 1100 g Alpha Alumina was added to 1075 mL PdCl.sub.2 solution
(0.178 mg Pd/mL) heated at 70.degree. C. After the carrier was
soaked in the solution for 1 hour, the solution was drained and
then the catalyst was washed 10 times using 5 minute soak times
with room temperature deionized water. After final wash, the
catalyst was calcined in a muffle oven in air at 565.degree. C. for
4 hours.
[0051] Sample A1 was made by adding 0.5 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample A1, Sample A (516.0 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (232 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0052] Sample A2 was made by adding 0.5 wt % of BMIM[OTf]
(1-butyl-3-methylimidazolium triflate) on Sample A. In order to
make Sample A2, Sample A (476.3 mg) was impregnated with an aqueous
solution of 1-butyl-3-methylimidazolium triflate (214 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 80.degree.
C. for 16 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0053] Sample A3 was made by adding 0.5 wt % of BMPr[OTf]
(1-butyl-1-methylpyrrolidinium triflate) on Sample A. In order to
make Sample A3, Sample A (499.7 mg) was impregnated with an aqueous
solution of 1-butyl-1-methylpyrrolidinium triflate (225 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0054] Sample A4 was made by adding 0.5 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample A. In order to
make Sample A4, Sample A (528.8 mg) was impregnated with an aqueous
solution of 1-Butyl-2,3-dimethylimidazolium triflate (238 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0055] Sample A5 was made by adding 0.5 wt % of BMIM[BF.sub.4]
(1-butyl-3-methylimidazolium tetrafluoroborate) on Sample A. In
order to make Sample A5, Sample A (508.2 mg) was impregnated with
an aqueous solution of 1-butyl-3-methylimidazolium
tetrafluoroborate (229 .mu.L, 11.11 mg/mL) by incipient wetness.
The catalyst was dried at 80.degree. C. for 16 hours and reduced at
100.degree. C. in 5% H.sub.2/N.sub.2 for 1 hour.
[0056] Sample A6 was made by adding 0.5 wt % of BMIM[MeSO.sub.4]
(1-butyl-3-methylimidazolium methylsulfate) on Sample A. In order
to make Sample A6, Sample A (511.8 mg) was impregnated with an
aqueous solution of 1-butyl-3-methylimidazolium methylsulfate (230
.mu.L, 11.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0057] Sample A7 was made by adding 0.5 wt % of
BMIM[C.sub.8H.sub.17SO.sub.4] (1-butyl-3-methylimidazolium
octylsulfate) on Sample A. In order to make Sample A7, Sample A
(485.7 mg) was impregnated with an aqueous solution of
1-butyl-3-methylimidazolium octylsulfate (218 .mu.L, 11.11 mg/mL)
by incipient wetness. The catalyst was dried at 80.degree. C. for
16 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2 for 1
hour.
[0058] Sample A8 was made by adding 0.5 wt % of EMIM[OTf]
(1-ethyl-3-methylimidazolium triflate) on Sample A. In order to
make Sample A8, Sample A (509.9 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium triflate (229 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 80.degree.
C. for 16 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0059] Sample A9 was made by adding 0.5 wt % of EMPy[EtSO.sub.4]
(1-ethyl-3-methylpyridinium ethylsulfate) on Sample A. In order to
make Sample A9, Sample A (504.0 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylpyridinium ethylsulfate (227 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0060] Sample A10 was made by adding 0.5 wt % of EMIM[MePO.sub.3]
(1-ethyl-3-methylimidazolium methylphosphonate) on Sample A. In
order to make Sample A10, Sample A (517.1 mg) was impregnated with
an aqueous solution of 1-ethyl-3-methylimidazolium
methylphosphonate (233 .mu.L, 11.11 mg/mL) by incipient wetness.
The catalyst was dried at 80.degree. C. for 16 hours and reduced at
100.degree. C. in 5% H.sub.2/N.sub.2 for 1 hour.
[0061] Sample A11 was made by adding 0.5 wt % of BMIM[C(CN).sub.3]
(1-butyl-3-methylimidazolium tricyanomethane) on Sample A. In order
to make Sample A11, Sample A (504.0 mg) was impregnated with a
solution of 1-butyl-3-methylimidazolium
bis(trifluoromethylsulfonyl)imide in 2-butanone (227 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0062] Sample A12 was made by adding 0.5 wt % of BMIM[NTf.sub.2]
(1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) on
Sample A. In order to make Sample A12, Sample A (513.4 mg) was
impregnated with a solution of 1-butyl-3-methylimidazolium
bis(trifluoromethylsulfonyl)imide in 2-butanone (231 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0063] Sample A13 was made by adding 0.5 wt % of MOIM[OTf]
(1-methyl-3-octylimidazolium triflate) on Sample A. In order to
make Sample A13, Sample A (502.1 mg) was impregnated with a
solution of 1-methyl-3-octylimidazolium triflate in 2-butanone (226
.mu.L, 11.11 mg/mL) by incipient wetness. The catalyst was dried at
60.degree. C. for 4 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0064] Sample A14 was made by adding 0.5 wt % of EMIM[NTf.sub.2]
(1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) on
Sample A. In order to make Sample A14, Sample A (490.3 mg) was
impregnated with a solution of 1-ethyl-3-methylimidazolium
bis(trifluoromethylsulfonyl)imide in 2-butanone (220 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0065] Sample A15 was made by adding 0.5 wt % of EMIM[B(CN).sub.4]
(1-ethyl-3-methylimidazolium tetracyanoborate) on Sample A. In
order to make Sample A15, Sample A (504.8 mg) was impregnated with
a solution of 1-ethyl-3-methylimidazolium tetracyanoborate in
2-butanone (227 .mu.L, 11.11 mg/mL) by incipient wetness. The
catalyst was dried at 60.degree. C. for 4 hours and reduced at
100.degree. C. in 5% H.sub.2/N.sub.2 for 1 hour.
[0066] Sample A16 was made by adding 0.5 wt % of
EMIM[PF.sub.3(C.sub.2F.sub.5).sub.3] (1-ethyl-3-methylimidazolium
tris(pentafluoroethyl)trifluorophosphate) on Sample A. In order to
make Sample A16, Sample A (514.4 mg) was impregnated with a
solution of 1-ethyl-3-methylimidazolium
tris(pentafluoroethyl)trifluorophosphate in 2-butanone (231 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
60.degree. C. for 4 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0067] Sample A17 was made by adding 0.5 wt % of EMPy[NTf.sub.2]
(1-ethyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide) on
Sample A. In order to make Sample A17, Sample A (531.6 mg) was
impregnated with a solution of 1-ethyl-3-methylpyridinium
bis(trifluoromethylsulfonyl)imide in 2-butanone (239 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0068] Sample A18 was made by adding 0.5 wt % of BMPr[NTf.sub.2]
(1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide)
on Sample A. In order to make Sample A18, Sample A (512.5 mg) was
impregnated with a solution of 1-butyl-1-methylpyrrolidinium
bis(trifluoromethylsulfonyl)imide in 2-butanone (230 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0069] Sample A19 was made by adding 0.5 wt % of
BMPr[PF.sub.3(C.sub.2F.sub.5).sub.3] (1-butyl-1-methylpyrrolidinium
tris(pentafluoroethyl)trifluorophosphate) on Sample A. In order to
make Sample A19, Sample A (510.3 mg) was impregnated with a
solution of 1-butyl-1-methylpyrrolidinium
tris(pentafluoroethyl)trifluorophosphate in 2-butanone (229 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
60.degree. C. for 4 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0070] Sample A20 was made by adding 0.5 wt % of BMPr[B(CN).sub.4]
(1-butyl-1-methylpyrrolidinium tetracyanoborate) on Sample A. In
order to make Sample A20, Sample A (516.0 mg) was impregnated with
a solution of 1-butyl-1-methylpyrrolidinium tetracyanoborate in
2-butanone (232 .mu.L, 11.11 mg/mL) by incipient wetness. The
catalyst was dried at 60.degree. C. for 4 hours and reduced at
100.degree. C. in 5% H.sub.2/N.sub.2 for 1 hour.
[0071] Sample A21 was made by adding 0.5 wt % of TBMA[N(CN).sub.2]
(tributylmethylammonium dicyanamide) on Sample A. In order to make
Sample A21, Sample A (474.2 mg) was impregnated with a solution of
tributylmethylammonium dicyanamide in 2-butanone (213 .mu.L, 11.11
mg/mL) by incipient wetness. The catalyst was dried at 60.degree.
C. for 4 hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2
for 1 hour.
[0072] Sample A22 was made by adding 0.5 wt % of
{EtMe.sub.2(MeOEt)}N[PF.sub.3(C.sub.2F.sub.5).sub.3]
(ethyldimethyl-(2-methoxyethyl)ammonium
tris(pentafluoroethyl)trifluorophosphate) on Sample A. In order to
make Sample A22, Sample A (477.6 mg) was impregnated with a
solution of ethyldimethyl-(2-methoxyethyl)ammonium
tris(pentafluoroethyl)trifluorophosphate in 2-butanone (215 .mu.L,
11.11 mg/mL) by incipient wetness. The catalyst was dried at
60.degree. C. for 4 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
Example 2
[0073] Sample B1 was made by adding 0.001 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample B1, Sample A (485.8 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (219 .mu.L,
0.022 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0074] Sample B2 was made by adding 0.007 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample B2, Sample A (505.1 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (227 .mu.L,
0.16 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0075] Sample B3 was made by adding 0.025 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample B3, Sample A (512.8 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (231 .mu.L,
0.56 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0076] Sample B4 was made by adding 0.05 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample B4, Sample A (468.0 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (210 .mu.L,
1.11 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0077] Sample B5 was made by adding 0.1 wt % of EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample E. In order to
make Sample B5, Sample A (497.3 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (224 .mu.L,
2.22 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0078] Sample B6 was made by adding 0.25 wt % of EMIM[EtSO4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample A. In order to
make Sample B6, Sample A (480.9 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (216 .mu.L,
5.56 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
Comparative Example 3
[0079] Comparative Sample C contains 0.019 wt % Pd on 1-2 mm
alumina spheres with a BET surface area of 50 m.sup.2/g. In order
to make Comparative Sample C, 10 g alumina was added to 11.4 mL
PdCl.sub.2 solution (0.1667 mg Pd/mL) heated at 70.degree. C. After
the carrier was soaked in the solution for 1 hour, the solution was
withdrawn and then the catalyst was washed 10 times using 5 minute
soak times with room temperature deionized water. After the final
washing step, the catalyst was calcined in muffle oven in air at
565.degree. C. for 4 hours.
[0080] Comparative Sample C1 was made by adding 0.5 wt % of
EMIM[EtSO.sub.4] (1-ethyl-3-methylimidazolium ethylsulfate) on
Comparative Sample C. In order to make Comparative Sample C1,
Comparative Sample C (502.1 mg) was impregnated with an aqueous
solution of 1-ethyl-3-methylimidazolium ethylsulfate (316 .mu.L,
7.94 mg/mL) by incipient wetness. The catalyst was dried at
80.degree. C. for 16 hours and reduced at 100.degree. C. in 5%
H.sub.2/N.sub.2 for 1 hour.
[0081] Comparative Sample C2 was made by adding 0.5 wt % of
BMIM[OTf] (1-butyl-3-methylimidazolium triflate) on Comparative
Sample C. In order to make Comparative Sample C2, Comparative
Sample C (484.4 mg) was impregnated with an aqueous solution of
1-butyl-3-methylimidazolium triflate (305 .mu.L, 7.94 mg/mL) by
incipient wetness. The catalyst was dried at 80.degree. C. for 16
hours and reduced at 100.degree. C. in 5% H.sub.2/N.sub.2 for 1
hour.
Example 4
[0082] Sample A, Samples A1-A22, Samples B1-B6, and Comparative
Samples C, C1 and C2 were tested as prepared in a microreactor test
unit at typical front-end hydrogenation conditions. In the test, a
simulated de-propanizer feed containing 0.35 mol % acetylene, 15
mol % hydrogen, 0.02 mol % CO, 47 mol % ethylene, and balance
nitrogen was passed over a 260 .mu.l catalyst bed at 478 psig (34
bar) in total pressure and 7000 h.sup.-1 in Gas Hourly Space
Velocity (GHSV), while the bed temperature was gradually increased
from about 45.degree. C. The acetylene concentration at the reactor
outlet was monitored with an on-line gas chromatograph (GC). The
acetylene concentration at reactor outlet continued decreasing with
increasing temperature until reaching <25 ppm. The temperature
at this point was defined as the "clean up temperature" (T1).
Catalyst bed temperature was further increased until 125.degree. C.
(the maximum temperature the test unit could reach) or a certain
temperature (T2), at which the outlet ethane concentration was
>2% due to the increased non-selective reaction of hydrogen with
ethylene. The temperature range between T1 and T2 is called the
"operation window". Test results of Sample A, Samples A1 to A22,
Samples B1-B6, as well as of Comparative Sample C, C1-C2 are listed
in the table below. For catalysts that did not run away at the
maximum temperature the test unit could reach, T2 was calculated by
fitting the data at temperatures above complete acetylene
conversion with a first order kinetic model.
TABLE-US-00001 Test Results of Samples A, A1 to A22, B1 to B6, and
Comparative Samples C and C1 to C2 Operation Selectivity Ethane T1
T2 Window at Make at [.degree. C.] [.degree. C.] [.degree. C.] T1
[%] [125.degree. C.] Sample A 63 84 21 92.8 10.439 Sample A1 68 176
108 96.1 0.429 Sample A2 68 137 69 96.9 0.714 Sample A3 61 113 52
89.0 3.316 Sample A4 62 113 51 85.6 3.228 Sample A5 69 164 95 94.5
0.462 Sample A6 68 167 99 97.6 0.390 Sample A7 68 157 89 95.5 0.594
Sample A8 65 141 76 96.2 1.139 Sample A9 65 100 35 95.8 9.45 Sample
A10 82 188 106 90.1 0.194 Sample A11 68 157 89 90.0 0.637 Sample
A12 61 100 39 89.5 4.668 Sample A13 67 115 48 66.1 3.005 Sample A14
60 110 50 99.8 3.477 Sample A15 71 149 78 90.6 0.821 Sample A16 67
145 78 90.1 1.199 Sample A17 62 86 24 93.0 10.23 Sample A18 64 101
37 88.9 4.836 Sample A19 62 120 58 74.8 2.382 Sample A20 69 150 81
98.9 0.906 Sample A21 65 153 88 85.2 0.982 Sample A22 66 122 56
93.2 2.315 Sample B1 62 82 20 47.3 10.444 Sample B2 63 101 38 69.0
8.691 Sample B3 60 113 53 96.3 9.122 Sample B4 61 119 58 95.5 5.378
Sample B5 65 121 56 98.4 3.838 Sample B6 67 123 56 100 2.428
Comparative 56 76 20 91.1 10.506 Sample C Comparative 68 99 31 81.3
5.725 Sample C1 Comparative 65 98 33 96.1 6.878 Sample C2
The operation window as well as the selectivity markedly increase
with decrease in BET surface area (Samples A1 and A2 compared to
Comparative Samples C1 and C2).
Example 5
[0083] Sample D is a commercial selective hydrogenation catalyst
that is supplied by Sud-Chemie AG under trade name OleMax.RTM. 251.
It contains 0.019 wt % Pd and 0.05 wt % Ag on 4.times.4 mm alumina
tablets with a BET surface area of about 4.0 m.sup.2/g.
[0084] Sample D1 was made by adding 0.5 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample D. In order to
make Sample D1, 0.6 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
D is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0085] Sample D2 was made by adding 1.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample D. In order to
make Sample D2, 1.2 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
D is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0086] Sample D3 was made by adding 2.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample D. In order to
make Sample D3, 2.4 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
D is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0087] Sample D4 was made by adding 3.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample D. In order to
make Sample D4, 3.6 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
D is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0088] Sample D1' was made by impregnation of Sample D with a
BMMIM[OTf] (1-Butyl-2,3-dimethylimidazolium triflate) solution
containing 0.5 g of BMMIM[OTf] in 38 ml deionized water. The clear
solution is added to 120 g of dry Sample D. The mixture is then
mixed at room temperature for approx. 60 minutes. The catalyst
formulation is then dried at 80.degree. C. for 16 h to finally
obtain Sample D1'.
Example 6
[0089] Samples prepared in Example 5 were tested as prepared in a
bench scale test unit at typical front-end hydrogenation
conditions. In the test, a simulated de-ethanizer feed containing
0.35 mol % acetylene, 20 mol % hydrogen, 0.02 mol % CO, 45 mol %
ethylene, and balance methane was passed over a 25 ml catalyst bed
at 500 psig (35.5 bar) in total pressure and 7000 h.sup.-1 in Gas
Hourly Space Velocity (GHSV), while the bed temperature was
gradually increased from about 35.degree. C. The acetylene
concentration at the reactor outlet was monitored with an on-line
gas chromatograph (GC). The acetylene concentration at reactor
outlet continued decreasing with increasing temperature until
reaching <25 ppm. The temperature at this point was defined as
the "clean up temperature" (T1). Catalyst bed temperature was
further increased until 105.degree. C. (the maximum temperature the
water bath could reach) or a certain temperature (T2), at which the
outlet ethane concentration was >2% due to the increased
non-selective reaction of hydrogen with ethylene. The temperature
range between T1 and T2 is called the "operation window". Test
results of Sample D and Samples D1 to D4 and D1' are listed in the
table below.
TABLE-US-00002 Front End Deethanizer Feed Test Results Operation
Selectivity T1 T2 Window at T1 [.degree. C.] [.degree. C.]
[.degree. C.] [%] Sample D 52 57 5 -1 Sample D1 61 97 36 52 Sample
D2 61 105 44 61 Sample D3 69 >105 >36 48 Sample D4 73 >105
>32 56 Sample D1' 67 99 32 38
[0090] The operation window as well as the selectivity markedly
increase with increasing BMMIM[OTf] content. The optimum BMMIM[OTf]
loading seems to be 0.5-1%. At higher loading, the runaway
temperature continued to increase at the expense of a higher T1
temperature. Adding BMMIM[OTf] onto Sample D can be realized by
coating or wet impregnation; and both methods can generate a new
catalyst with significantly improved operation window.
Example 7
[0091] Sample E is a commercial front end selective hydrogenation
catalyst that is supplied by Sud-Chemie AG under the trade name
OleMax.RTM. 250. It contains 0.018 wt % Pd on 4.times.4 mm alumina
tablets with a BET surface area of about 4.0 m.sup.2/g.
[0092] Sample E1 was made by adding 1.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample E. In order to
make Sample E1, 1.2 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
E is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0093] Sample E2 was made by adding 2.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample E. In order to
make Sample E2, 2.4 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
E is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
[0094] Sample E3 was made by adding 3.0 wt % of BMMIM[OTf]
(1-Butyl-2,3-dimethylimidazolium triflate) on Sample E. In order to
make Sample E3, 3.6 g of the ionic liquid BMMIM[OTf] were dissolved
in 150 ml deionized water. At the same time 120 g of the dry Sample
E is fluidized in a reaction chamber with synthetic air as the
process gas. The solution of BMMIM[OTf] in water was introduced
into the reaction chamber at a flow rate of 5 ml/min via a feed
pump and sprayed onto the solid catalyst via a spray nozzle at a
temperature of 80.degree. C. Once the entire solution has been
applied and the substrate is dry, the catalyst formulation is
further dried at 80.degree. C. for 2 hours.
Example 8
[0095] Sample E, Sample E1, Sample E2 and Sample E3 were tested
after in-situ reduction at 94.degree. C. for 1 hour in a bench
scale test unit at typical front-end hydrogenation conditions. In
the test, a simulated de-ethanizer feed containing 0.35 mol %
acetylene, 20 mol % hydrogen, 0.02 mol % CO, 45 mol % ethylene, and
balance methane was passed over a 25 ml catalyst bed at 500 psig
(35.5 bar) in total pressure and 7000 h.sup.-1 in Gas Hourly Space
Velocity (GHSV), while the bed temperature was gradually increased
from about 35.degree. C. The acetylene concentration at the reactor
outlet was monitored with an on-line gas chromatograph (GC). The
acetylene concentration at reactor outlet continued decreasing with
increasing temperature until reaching <25 ppm. The temperature
at this point was defined as the "clean up temperature" (T1).
Catalyst bed temperature was further increased until 105.degree. C.
(the maximum temperature the water bath could reach) or a certain
temperature (T2), at which the outlet ethane concentration was
>2% due to the increased non-selective reaction of hydrogen with
ethylene. The temperature range between T1 and T2 is called the
"operation window". Test results of Sample E and Samples E1 to E3
are listed in the table below.
TABLE-US-00003 Test Results of Sample E and Samples El to E3
Operation Selectivity T1 T2 Window at T1 [.degree. C.] [.degree.
C.] [.degree. C.] [%] Sample E 53 62 9 58 Sample E1 53 69 16 65
Sample E2 52 81 29 74 Sample E3 62 92 30 78
[0096] Upon addition of BMMIM[OTf] onto the Pd/alumina catalyst,
the operation window increases linearly up to a loading of 2% and
then stays constant at 30.degree. C. At higher loading, both T1 and
operation window increased.
Example 9
[0097] Comparative Sample F is a commercial selective hydrogenation
catalyst that is supplied by Sud-Chemie AG under trade name
OleMax.RTM. 201. It contains 0.03 wt % Pd and 0.18 wt % Ag on 2-4
mm alumina spheres with a BET surface area of about 35
m.sup.2/g.
[0098] Comparative Sample F1' was made by adding 0.5 wt % of
EMIM[EtSO.sub.4] (1-ethyl-3-methylimidazolium ethylsulfate) onto
Sample F by incipient wetness impregnation method. The
EMIM[EtSO.sub.4] solution contains 0.5 g of EMIM[EtSO.sub.4] in 60
ml deionized water. The clear solution was added to 100 g of
Comparative Sample F and mixed for about 5 min. The catalyst
formulation is then dried at 80.degree. C. for 16 hr to obtain the
final product.
[0099] Comparative Sample F2' was made by adding 1.0 wt % of
EMIM[EtSO.sub.4] (1-ethyl-3-methylimidazolium ethylsulfate) onto
Sample F by incipient wetness impregnation method. The
EMIM[EtSO.sub.4] solution contains 1 g of EMIM[EtSO.sub.4] in 60 ml
deionized water. The clear solution was added to 100 g of
Comparative Sample F and mixed for about 5 min. The catalyst
formulation is then dried at 80.degree. C. for 16 hr to obtain
final product.
[0100] Sample D2' was made by adding 0.5 wt % EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample D by incipient
wetness impregnation. The EMIM[EtSO.sub.4] solution contains 0.5 g
of EMIM[EtSO.sub.4] in 24 ml deionized water. The clear solution
was added to 100 g of Sample D and mixed for about 5 min. The
catalyst formulation is then dried at 80.degree. C. for 16 hr to
obtain final product.
[0101] Sample D3' was made by adding 1 wt % EMIM[EtSO.sub.4]
(1-ethyl-3-methylimidazolium ethylsulfate) on Sample D by incipient
wetness impregnation. The EMIM[EtSO.sub.4] solution contains 1 g of
EMIM[EtSO.sub.4] in 24 ml deionized water. The clear solution was
added to 100 g of Sample D and mixed for about 5 min. The catalyst
formulation is then dried at 80.degree. C. for 16 hr to obtain
final product.
Example 10
[0102] Samples and Comparative Samples prepared in Example 9 were
tested as prepared in a bench scale test unit at typical front-end
hydrogenation conditions. In the test, a simulated de-ethanizer
feed containing 0.35 mol % acetylene, 20 mol % hydrogen, 0.02 mol %
CO, 45 mol % ethylene, and balance methane was passed over a 25 ml
catalyst bed at 500 psig (35.5 bar) in total pressure and 7000
h.sup.-1 in Gas Hourly Space Velocity (GHSV), while the bed
temperature was gradually increased from about 35.degree. C. The
acetylene concentration at the reactor outlet was monitored with an
on-line gas chromatograph (GC). The acetylene concentration at
reactor outlet continued decreasing with increasing temperature
until reaching <25 ppm. The temperature at this point was
defined as the "clean up temperature" (T1). Catalyst bed
temperature was further increased until 105.degree. C. (the maximum
temperature the water bath could reach) or a certain temperature
(T2), at which the outlet ethane concentration was >2% due to
the increased non-selective reaction of hydrogen with ethylene. The
temperature range between T1 and T2 is called the "operation
window". Test results of Sample F2' and F3' did not run away at the
maximum temperature the test unit could reach: the ethane make was
0.35% at 102.degree. C. for both catalysts. Their T2's for 2%
ethane make were calculated by fitting the data at temperatures
above complete acetylene conversion with a first order kinetic
model.
TABLE-US-00004 Front End Deethanizer Feed Test Results Selectivity
Ethane T1 T2 T2-T1 at T1 Make at [.degree. C.] [.degree. C.]
[.degree. C.] [%] 102.degree. C. [%] Sample F 51 53 2 -5 Not
operable Sample F1' 54 75 21 76 Not operable Sample F2' 59 80 21 86
Not operable Sample D 52 57 5 -1 Not operable Sample D2' 65 148 83
91 0.35 Sample D3' 66 149 83 94 0.35
It appears that EMIM[EtSO.sub.4] has much lower impact on Sample F
than on Sample D.
* * * * *