U.S. patent application number 13/380008 was filed with the patent office on 2012-05-31 for method of use of an ionic liquid and device for sorption of a gas.
This patent application is currently assigned to VTU HOLDING GMBH. Invention is credited to Roland Kalb.
Application Number | 20120134905 13/380008 |
Document ID | / |
Family ID | 42470690 |
Filed Date | 2012-05-31 |
United States Patent
Application |
20120134905 |
Kind Code |
A1 |
Kalb; Roland |
May 31, 2012 |
METHOD OF USE OF AN IONIC LIQUID AND DEVICE FOR SORPTION OF A
GAS
Abstract
A method of use of an ionic liquid for sorption of a gas having
an electric multipole moment is provided, wherein the ionic liquid
comprises an anion and a non-aromatic cation. In particular, the
electric multipole moment may be an electric dipole moment and/or
an electric quadrupole moment. The sorption may be an adsorption or
an absorption. The ionic liquid may be a pure ionic liquid, i.e. a
liquid substantially only containing anions and cations, while not
containing other components, e.g. water. Alternatively a solution
containing the ionic liquid and a solvent or further compound, e.g.
water, may be used.
Inventors: |
Kalb; Roland; (Leoben,
AT) |
Assignee: |
VTU HOLDING GMBH
Grambach
AT
|
Family ID: |
42470690 |
Appl. No.: |
13/380008 |
Filed: |
June 22, 2010 |
PCT Filed: |
June 22, 2010 |
PCT NO: |
PCT/EP10/58856 |
371 Date: |
January 18, 2012 |
Current U.S.
Class: |
423/220 ;
261/119.1; 261/157; 422/120; 422/129; 422/198; 423/210; 95/149;
95/230; 95/231; 95/232; 95/233; 95/235; 95/236; 95/237; 95/240 |
Current CPC
Class: |
Y02C 20/40 20200801;
B01D 53/1493 20130101; B01D 2252/30 20130101; B01D 53/1456
20130101 |
Class at
Publication: |
423/220 ;
423/210; 422/120; 422/129; 422/198; 95/149; 95/231; 95/235; 95/236;
95/233; 95/230; 95/232; 95/237; 95/240; 261/119.1; 261/157 |
International
Class: |
B01D 53/02 20060101
B01D053/02; B01D 53/14 20060101 B01D053/14; B01F 3/04 20060101
B01F003/04; B01D 53/18 20060101 B01D053/18 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 25, 2009 |
EP |
09163831.2 |
Claims
1. A method comprising: using an ionic liquid for sorption of a gas
having an electric multipole moment, wherein the ionic liquid
comprises an anion and a non-aromatic cation.
2. The method according to claim 1, wherein the non-aromatic cation
is an aliphatic cation.
3. The method according to claim 1, wherein the non-aromatic cation
is a quaternary material.
4. The method according to claim 1, wherein the gas is one out of
the group consisting of: H.sub.2O, HCN, H.sub.2S, H.sub.2Se,
H.sub.2Te, CO.sub.2, CO, CS.sub.2, COS, CF.sub.2O, CF.sub.2S,
O.sub.3, NO, NO.sub.2, N.sub.2O, N.sub.2O.sub.3, NOCl, NF.sub.3,
HNO.sub.2, HNO.sub.3, RCOR', RCOH, RCOOH, CF.sub.3SO.sub.3H,
CF.sub.3COOH, RCOOR', ROH, ROR, RSH, RSR, ROCl, ROBr, RONH.sub.2,
RONHR', RONR'R'', RSO.sub.2Cl, RSO.sub.2Br, ROCN, RCON, RCN, HF,
HCl, HBr, HI, SO.sub.2, SO.sub.3, NH.sub.3, NH.sub.2R, NHR'R'',
NR'R''R''', PH.sub.3, PH.sub.2R, PHR'R'', PR'R''R''', BF.sub.3,
BCl.sub.3, BBr.sub.3, B.sub.2H.sub.6, BrF.sub.3, ClF.sub.3,
ClF.sub.5, ClCN, IF.sub.5, AsH.sub.3, CH.sub.3F, CH.sub.3Cl,
CH.sub.3Br, CH.sub.3I, POCl.sub.2, PSCl.sub.2, PF.sub.5, SF.sub.4,
SF.sub.6, SO.sub.2F.sub.2, SO.sub.2Cl.sub.2, SOCl,
H.sub.2C.dbd.CHBr, H.sub.2C.dbd.CHCl and ethylene oxide.
5. The method according to claim 4, wherein at least one of R, R',
R'' and/or R''' is a moiety out of the group consisting of:
C.sub.1-C.sub.8-alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkenyl,
aryl and heteroaryl.
6. The method according to claim 1, wherein the anion comprises a
carbonate, an alkylcarbonate, an arylcarbonate a carboxylate, a
carbanion, and/or an aromatic compound.
7. The method according to claim 1: wherein the ionic liquid
satisfies the generic formula [Q.sup.+][A.sup.-], wherein the anion
is described by one of the following structures: ##STR00004##
8. The method according to claim 1, wherein the ionic liquid
satisfies the generic formula [Q.sup.+].sub.a[A.sup.a-], wherein
[A.sup.a-] with the charge a-, is selected out of the group
consisting of: dialkyl ketones, dialkyl-1,3-diketones,
alkyl-.beta.-keto esters, terminal alkines, linear or cyclic
1,3-thioethers, dialkyl phosphonates, dialkyl malonic acid esters,
.beta.-cyano carbonic acids and their respective alkylesteres,
.beta.-alkoxy carbonic acids and their respective alkylesters,
.beta.-cyano nitriles, cyclopentadiene (substituted if necessary),
trialkylimines, dialkylimines, diaryl ketones, alkyl-aryl-ketones,
diaryl-1,3-diketones, alkyl-aryl-1,3-diketones, .beta.-aryloxy
carbonic acids and their respective alkylesters, .beta.-aryloxy
carbonic acids and their respective arylesters,
aryl-.beta.-ketoesters, diarylphosphonates,
alkyl-aryl-phosphonates, diaryl malonic acid esters,
alkyl-aryl-malonic acid esters, .beta.-cyano carbonic acids
arylesters and arylimines.
9. The method according to claim 1, wherein the ionic liquid
satisfies the generic formula [Q.sup.+].sub.a[A.sup.a-], wherein
[A.sup.a-] is a carbanion formed by deprotonating a chemical
compound out of the group consisting of: acetoacetic ester, malonic
mononitrile, malonic acid dimethylester, malonic acid diethylester,
acetylacetone, malonic acid dinitrile, acetone, diethylketone,
methlethylketone, dibutylketone, 1,3-dithian, acetaldehyde,
benzaldehyde, crotonaldehyde and butyraldehyde.
10. The method according to claim 1, wherein the anion comprises at
least one polar group.
11. The method according to claim 1, wherein the cation is a
quaternary or protonated cation out of the group consisting of:
ammonium, phosphonium, sulfonium, piperidinium, pyrrolidinium, and
morpholinium.
12. The method according to claim 1, wherein the cation is one out
of the group consisting of: trialkylmethylammonium,
tetramethylammonium, triethylmethylammonium,
tributylmethylammonium, trio ctylmethylammonium trialkylammonium,
trimethylammonium, triethylammonium, tributylammonium, and
trioctylammonium.
13. The method according to claim 1, wherein the cation is one out
of the group consisting of: tetramethylammonium,
triethylmethylammonium, tributylmethylammonium, and trio
ctylmethylammonium.
14. The method according to claim 1, wherein the anion is written
in the form [RCO.sub.2.sup.-], wherein [RCO.sub.2.sup.-] is one out
of the group consisting of: carboxylate, formiate, acetate,
propionate, butyrate, benzoate, and salicylate.
15. The method according to claim 1, wherein the anion is written
in the form [RCO.sub.2.sup.-], wherein [RCO.sub.2.sup.-] is a
carboxylate wherein R is a radical out of the group consisting of:
C.sub.1-C.sub.30-alkyl, C.sub.3-C.sub.12-cycloalkyl,
C.sub.2-C.sub.30-alkenyl, C.sub.3-C.sub.12-cycloalkenyl,
C.sub.2-C.sub.30-alkinyl, aryl and heteroaryl.
16. The method according to claim 1, wherein the anion is written
in the form [RCO.sub.2], wherein [RCO.sub.2.sup.-] is a carboxylate
wherein R represents one to three radicals out of the group
consisting of: C.sub.1-C.sub.6-alkyl, aryl, heteroaryl,
C.sub.3-C.sub.7-cycloalkyl, halogen, cyanide, ORc, SRc, NRcRd,
CORc, COORc, CO--NRcRd, wherein Rc and/or Rd, is one of the group
consisting of: hydrogen, C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-halogenalkyl, cyclopentyl, cyclohexyl, phenyl,
tolyl, and benzyl.
17. The method according to claim 1, wherein the gas is
CO.sub.2.
18. The method according to claim 17, wherein CO.sub.2 is sorbed
from a medium which is selected out of the group consisting of:
recovery gas, synthesis gas, water gas, inhaled air, and exhaled
air.
19. A device for sorption of a gas having an electric multipole
moment, the device comprising: a reservoir of an ionic liquid
comprising an anion and a non-aromatic cation.
20. The device according to claim 19, wherein the device is a heat
pump, and wherein the heat pump comprises a circuit including
CO.sub.2 and the ionic liquid comprises an anion and a non-aromatic
cation as working media.
21. A method comprising: using an ionic liquid for sorption of a
gas having an electric multipole moment, wherein the ionic liquid
comprises a carbanion and a cation.
22. The method according to claim 21, wherein the ionic liquid
satisfies the generic formula [Q.sup.+].sub.a[A.sup.a-], wherein
[Q].sup.+ is one out of the group consisting of quaternary ammonium
cation [R.sup.1'R.sup.1R.sup.2R.sup.3N].sup.+, phosphonium
[R.sup.1'R.sup.1R.sup.2R.sup.3P].sup.+, sulfonium
[R.sup.1'R.sup.1R.sup.2S].sup.+ and a hetero aromatic cation.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a method of use of an ionic liquid,
in particular for sorption of a gas or vapor having an electric
multipole moment.
[0002] Further, the invention relates to a device for sorption of a
gas or vapor.
BACKGROUND OF THE INVENTION
[0003] Carbon dioxide (CO.sub.2) is an undesired diluent that is
present in many gas sources. In order to improve the quality of the
gases the CO.sub.2 should be removed to acceptable specifications.
In gas processing industry, various technologies have been employed
for CO.sub.2 removal including chemical solvents, physical
solvents, and membranes. By far, chemical solvents that reversibly
react with CO.sub.2 are most commonly used for CO.sub.2
removal.
[0004] Furthermore, processes for removal of CO.sub.2 from gaseous
streams are known, which comprise the contacting a CO.sub.2
containing gaseous stream with an absorbent comprising from 1 to 20
wt % water and an ionic liquid comprising pyridines or imidazole
cations and an anion, wherein said contacting occurs at absorption
conditions, to absorb at least a portion of the CO.sub.2 from the
CO.sub.2 containing gaseous stream and forming a CO.sub.2-absorbent
complex. Afterwards the gaseous product having a reduced CO.sub.2
content is recovered.
[0005] However, the known processes of removal CO.sub.2 may be
costly.
OBJECT AND SUMMARY OF THE INVENTION
[0006] It may be an objective of the invention to provide a method
of removal of a gaseous or vaporous component and a device for
removal of a gaseous or vaporous component which may be save to use
or less expensive than known methods.
[0007] This object may be solved by a method of use of an ionic
liquid, in particular for sorption of a gas or vapor having an
electric multipole moment and a device for sorption of a gas or
vapor according to the independent claims. Further exemplary
embodiments are described in the dependent claims.
[0008] According to an exemplary aspect of the invention a method
of use of an ionic liquid for sorption of a gas having an electric
multipole moment is provided, wherein the ionic liquid comprises an
anion and a non-aromatic cation. It should be noted that according
to this application the terms "gas" and "gaseous" and "vapor" and
"vaporous", respectively may be interchangeably used, i.e. no
distinction is made between these two terms.
[0009] In particular, the electric multipole moment may be an
electric dipole moment and/or an electric quadrupole moment. The
sorption may be an adsorption or an absorption. The ionic liquid
may be a pure ionic liquid, i.e. a liquid substantially only
containing anions and cations, while not containing other
components, e.g. water. Alternatively a solution containing the
ionic liquid and a solvent or further compound, e.g. water, may be
used. For example, the content of other components than the ionic
liquid may be 35% or less by mass, in particular less than 30% by
mass, less than 20% by mass, less than 10% by mass, or even less
than 5% by mass, wherein for all the above ranges the lower limit
may be about 10 ppm. However, in case of water as the other
component the ranges may be between about 10 ppm and 50% by mass,
in particular between about 10 ppm and 35% by mass, between about
10 ppm and 20% by mass, between about 10 ppm and 10% by mass, or
even between about 10 ppm and 5% by mass. In this context it should
be noted that according to specific embodiments the sorption may be
performed by the ionic liquid itself, e.g. may particularly be a
physical sorption. In general, the ionic liquid may also perform a
chemical sorption, a physical sorption or a combined
chemical-physical sorption. This process has to be distinguished
from a process in which the ionic liquid only forms a solvent for a
compound or component, e.g. a polymer, which then acts as the
sorbent for the gas having an electric multipole moment. That is,
according to specific embodiments of the invention the ionic liquid
may form the sorbent which sorbs the gas having an electric
multipole moment. Consequently a method according to an exemplary
embodiment may comprise the step of sorbing a gas having an
electric multipole moment by an ionic liquid, wherein the ionic
liquid may be a pure or substantially pure ionic liquid or may
include some additives having only few, e.g. less than 35% by mass,
further components. In the most generic form the ionic liquids may
be represented by [Q.sup.+].sub.n[Z.sup.n-], wherein Q represents a
non-aromatic cation and which may be produced by a process as
described for example in WO 2005/021484 which is hereby herein
incorporated by reference.
[0010] According to an exemplary aspect of the invention a device
for sorption of a gas having an electric multipole moment is
provided, wherein the device comprises a reservoir of an ionic
liquid comprising an anion and a non-aromatic cation.
[0011] In particular, the device may comprise an inlet, a container
including the ionic liquid, and optionally an outlet. The device
may be used to sorb gas having an electric multipole moment, e.g.
CO.sub.2, from a medium which is selected out of the group
consisting of recovery gas, synthesis gas, water gas, natural gas,
inhaled air, and exhaled air. In particular, the device may be a
heat pump. The heat pump may comprise a circuit including CO.sub.2
and the ionic liquid which comprises an anion and a non-aromatic
cation as working media. In particular, the usage of a pair of
working media containing CO.sub.2 and an ionic liquid in a heat
pump may be advantageous since CO.sub.2 is not toxic is of less
concern with respect to environmental effect compared to other
vaporizable working substances.
[0012] According to an exemplary aspect of the invention a method
of use of an ionic liquid for sorption of a gas having an electric
multipole moment is provided, wherein the ionic liquid comprises a
carbanion and a cation.
[0013] The use of non-aromatic cations of the ionic liquid may
provide for an ionic liquid which may be cheaper and more secure
than the use of aromatic cations. Such ionic liquids may be a
suitable medium to sorb specific gases, e.g. CO.sub.2, or vapor out
of a mixture of gases and may also be suitable to release these
specific gases or vapor again. The specific gases and the ionic
liquid may form a complex, i.e. the specific gases may be complex
bound. According to some exemplary embodiments it may even be
possible to remove the complex bound in the form of a solid
compound. The uses of such ionic liquids for sorption of gases may
be advantageous since ionic liquids may be used showing no or at
least substantially no vapor pressure, e.g. a non measureable vapor
pressure or even a vapor pressure in the same magnitude of order of
steel. Thus, the gases or mixture of gases may not be contaminated
by vapor of the ionic liquid. Furthermore, the use of non-aromatic
ionic liquids may increase the performance of the sorption process
compared to the case in which aromatic ionic liquids are used. For
example, the removal of CO.sub.2 by using non-aromatic ionic
liquids may exhibit an improved performance even in cases where the
vapor pressure of CO.sub.2 is low.
[0014] However, alternatively it may also be possible to use an
ionic liquid having aromatic cation in case the ionic liquid
comprises a carbanion. That is, when using an ionic liquid
comprising a carbanion the cation may be an aromatic or a
non-aromatic anion.
[0015] Next, further aspects of exemplary embodiments of the method
of use of an ionic liquid for sorption of a gas are described.
However, these embodiments also apply for the device for sorption
of a gas.
[0016] According to an exemplary embodiment of the method of use of
an ionic liquid the non-aromatic cation is an aliphatic cation. The
term "aliphatic cation" may also include cations having aliphatic
side chains.
[0017] Aliphatic cations may be suitable non-aromatic cations for
an ionic liquid which are less expensive and/or less toxic than
typical aromatic cations.
[0018] According to an exemplary embodiment of the method of use of
an ionic liquid the ionic liquid satisfy the generic formula
[Q.sup.+][A.sup.-],
[0019] wherein the anion can be described by one of the following
structures:
##STR00001##
[0020] In particular, the anion may be describable by the resonant
or mesomeric states:
##STR00002##
wherein X and Y may indicate, independently from each other, groups
which may attract electrons due to the inductive effect or the
mesomeric effect and/or which may delocalize and/or stabilize
(localize) electrons. Examples for such groups may be: [0021] --CN,
--NO.sub.2, --NO.sub.3, --CO--R.sup.k, --COOR.sup.k,
--C.dbd.N--R.sup.k, --CO--NR.sup.kR.sup.m, --NR.sup.kR.sup.m, --OH,
--OR.sup.k, --SH, --SR.sup.k, --SO--R.sup.k, --SO.sub.2--R.sup.k,
--SO.sub.2--OR.sup.k, --PO--OR.sup.kOR.sup.m (phosphonate), --I,
--Cl, --Br, --F, --CCl.sub.3, --CCl.sub.2R.sup.k,
--CClR.sup.kR.sup.m, --CF.sub.3, --CF.sub.2R.sup.k,
--CFR.sup.kR.sup.m, --SO.sub.2CF.sub.3, --COOCF.sub.3,
--C.sub.6H.sub.5, --CR.sup.k.dbd.CR.sup.mR.sup.n,
--C.ident.CR.sup.m, CR.sup.k.dbd.CR.sup.m--CN,
--CR.sup.k.dbd.CR.sup.m--NO.sub.2,
--CR.sup.k.dbd.CR.sup.m--CO--R.sup.k,
--CR.sup.k.dbd.CR.sup.m--COOR.sup.k,
--CR.sup.k.dbd.CR.sup.m--C.dbd.N--R.sup.n,
--CR.sup.k.dbd.CR.sup.m--CO--NR.sup.nR.sup.o,
--CR.sup.k.dbd.CR.sup.m--NR.sup.nR.sup.o,
--CR.sup.k.dbd.CR.sup.m--OR.sup.n,
--CR.sup.k.dbd.CR.sup.m--SR.sup.n,
CR.sup.k.dbd.CR.sup.m--SO--R.sup.n,
--CR.sup.k.dbd.CR.sup.m--SO.sub.2--R.sup.n,
--CR.sup.k.dbd.CR.sup.m--SO.sub.2--R.sup.n,
--CR.sup.k.dbd.CR.sup.m--SO.sub.2--OR.sup.n,
--CR.sup.k.dbd.CR.sup.m--CF.sub.3,
--CR.sup.k.dbd.CR.sup.m--SO.sub.2CF.sub.3, wherein R.sup.k,
R.sup.m, R.sup.n, R.sup.o may, independently from each other,
denote hydrogen, C.sub.1- to C.sub.30-alkyl and their aryl-,
heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-,
formyl-, --O--, --CO--, --CO--O-- or --CO--N< substituted
components, like methyl, ethyl, 1-propyl, 2-propyl, 1-butyl,
2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl
(tert.-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl,
3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl,
2,2-dimethyl-1-propyl, 1-hexyl, 2-hexyl, 3-hexyl,
2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl,
2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl,
2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl,
2,3-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl,
2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl,
decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl,
hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, henicosyl,
docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl,
octacosyl, nonacosyl, triacontyl, phenylmethyl (benzyl),
diphenylmethyl, triphenylmethyl, 2-phenylethyl, 3-phenylpropyl,
cyclopentylmethyl, 2-cyclopentylethyl, 3-cyclopentylpropyl,
cyclohexylmethyl, 2-cyclohexylethyl, 3-cyclohexylpropyl, methoxy,
ethoxy, formyl, acetyl or C.sub.nF.sub.2(n-a)+(1-b)H.sub.2a+b
wherein n.ltoreq.30, 0.ltoreq.a.ltoreq.n and b=0 or 1 (e.g.
CF.sub.3, C.sub.2F.sub.5,
CH.sub.2CH.sub.2--C.sub.(n-2)F.sub.2(n-2)+1, C.sub.6F.sub.13,
C.sub.8F.sub.17, C.sub.10F.sub.21, C.sub.12F.sub.25);
[0022] C.sub.3- to C.sub.12-cycloalkyl and their aryl-,
heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-,
formyl-, --O--, --CO-- or --CO--O-substituted components, e.g.
cyclopentyl, 2-methyl-1-cyclopentyl, 3-methyl-1-cyclopentyl,
cyclohexyl, 2-methyl-1-cyclohexyl, 3-methyl-1-cyclohexyl,
4-methyl-1-cyclohexyl or C.sub.nF.sub.2(n-a)-(1-b)H.sub.2a-b
wherein n.ltoreq.0, 0.ltoreq.a.ltoreq.n and b=0 or 1;
[0023] C.sub.2- to C.sub.30-alkenyl and their aryl-, heteroaryl-,
cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, --O--,
--CO-- or --CO--O-substituted components, e.g. 2-propenyl,
3-butenyl, cis-2-butenyl, trans-2-butenyl or
C.sub.nF.sub.2(n-a)-(1-b)H.sub.2a-b wherein n.ltoreq.30,
0.ltoreq.a.ltoreq.n and b=0 or 1;
[0024] C.sub.3- to C.sub.12-cycloalkenyl and their aryl-,
heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-,
formyl-, --O--, --CO-- or --CO--O-substituted components, e.g.
3-cyclopentenyl, 2-cyclohexenyl, 3-cyclohexenyl,
2,5-cyclohexadienyl or C.sub.nF.sub.2(n-a)-3(1=b)H.sub.2a-3b
wherein n.ltoreq.0, 0.ltoreq.a.ltoreq.n and b=0 or 1; and
[0025] aryl or heteroaryl having 2 to 30 carbon atoms and their
alkyl-, aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-,
amino-, carboxy-, formyl-, --O--, --CO-- or --CO--O-substituted
components, e.g. phenyl, 2-methyl-phenyl (2-tolyl), 3-methyl-phenyl
(3-tolyl), 4-methyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl,
4-ethyl-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl,
2,5-dimethyl-phenyl, 2,6-dimethyl-phenyl, 3,4-dimethyl-phenyl,
3,5-dimethyl-phenyl, 4-phenyl-phenyl, 1-naphthyl, 2-naphthyl,
1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridinyl, 3-pyridinyl,
4-Pyridinyl or C.sub.6F.sub.(5-a)H.sub.a wherein
0.ltoreq.a.ltoreq.5,
wherein pairs of the R.sup.k, R.sup.m, R.sup.n, R.sup.o may be
bonded directly to each other or via C.sub.1-C.sub.4, which may be
substituted if necessary, so that a saturated, unsaturated, or
conjugated unsaturated ring may be formed.
[0026] According to an exemplary embodiment of the method of use of
an ionic liquid the ionic liquid satisfy the generic formula
[Q.sup.+].sub.a[A.sup.a-], wherein [A.sup.a-] with the charge a- is
selected out of the group consisting of:
[0027] dialkyl ketones, dialkyl-1,3-diketones, alkyl-.beta.-keto
esters, terminal alkines, linear or cyclic 1,3-thioethers, dialkyl
phosphonates, dialkyl malonic acid esters, .beta.-cyano carbonic
acids and their respective alkylesters, .beta.-alkoxy carbonic
acids and their respective alkylesters, .beta.-cyano nitriles,
cyclopentadiene (substituted if necessary), trialkylimines,
dialkylimines, diaryl ketones, alkyl-aryl-ketones,
diary)-1,3-diketones, alkyl-aryl-1,3-diketones, .beta.-aryloxy
carbonic acids and their respective alkylesters, .beta.-aryloxy
carbonic acids and their respective arylesters,
aryl-.beta.-ketoesters, diarylphosphonates,
alkyl-aryl-phosphonates, diaryl malonic acid esters,
alkyl-aryl-malonic acid esters, .beta.-cyano carbonic acids
arylesters and arylimines.
[0028] According to an exemplary embodiment of the method of use of
an ionic liquid the ionic liquid satisfy the generic formula
[Q.sup.+].sub.a[A.sup.a-],wherein [A.sup.a-] is a carbanion formed
by deprotonating a chemical compound out of the group consisting
of:
[0029] acetoacetic ester, malonic mononitrile, malonic acid
dimethylester, malonic acid diethylester, acetylacetone, malonic
acid dinitrile, acetone, diethylketone, methlethylketone,
dibutylketone, 1,3-dithian, acetaldehyde, benzaldehyde,
crotonaldehyde and butyraldehyde.
[0030] According to an exemplary embodiment of the method of use of
an ionic liquid the ionic liquid satisfy the generic formula
[Q.sup.+].sub.a[A.sup.a-], wherein [A.sup.a-] is a carbanion and
wherein [C].sup.+ is one out of the group consisting of quaternary
ammonium cation [R.sup.1'R.sup.1R.sup.2R.sup.3N].sup.+, phosphonium
[R.sup.1'R.sup.1R.sup.2R.sup.3P].sup.+, sulfonium
[R.sup.1'R.sup.1R.sup.2S].sup.+ and a hetero aromatic cation. In
particular, the carbanion may be formed by deprotonating a chemical
compound out of the group consisting of: acetoacetic ester, malonic
mononitrile, malonic acid dimethylester, malonic acid diethylester,
acetylacetone, malonic acid dinitrile, acetone, diethylketone,
methlethylketone, dibutylketone, 1,3-dithian, acetaldehyde,
benzaldehyde, crotonaldehyde and butyraldehyde.
[0031] In particular:
[0032] R.sup.1, R.sup.1', R.sup.2, R.sup.3 may be alkyl, alkenyl,
alkinyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl which may be
independently substituted, or
[0033] two of the moieties R.sup.1, R.sup.1', R.sup.2, R.sup.3 may
form a ring together with a hetero-atom to which they are bound.
The ring may be saturated, unsaturated, substituted or
unsubstitued. The chain may be interrupted by one or more
hetero-atoms out of the group consisting of O, S, NH or
N--C.sub.1-C.sub.4-alkyl.
[0034] The hetero aromatic cation may be a 5 or 6 membered ring
comprising at least one N and if necessary one 0 and/or one S. The
hetero aromatic cation may be substituted or unsubstituted and/or
annelated. Preferably, the hetero aromatic cation is selected from
the group consisting of:
##STR00003##
[0035] wherein the moieties R may be one of the following:
[0036] R hydrogen, C.sub.1-C.sub.30-alkyl,
C.sub.3-C.sub.12-cycloalkyl, C.sub.2-C.sub.30-alkenyl,
C.sub.3-C.sub.12-cycloalkenyl, C.sub.2-C.sub.30-alkinyl, aryl or
heteroaryl, wherein the latter 7 moieties may have one or more
halogenic moiety and/or 1 to 3 moieties selected from the group
consisting of C.sub.1-C.sub.6-alkyl, aryl, heteroaryl,
C.sub.3-C.sub.7-cycloalkyl, halogen, OR.sup.c, SR.sup.c,
NR.sup.cR.sup.d, COR.sup.c, COOR.sup.c, CO--NR.sup.cR.sup.d,
wherein R.sup.c and R.sup.d may be hydrogen, C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-halogenalkyl, cyclopentyl, cyclohexyl, phenyl,
tolyl or benzyl;
[0037] R.sup.1, R.sup.1', R.sup.2, R.sup.3 may be hydrogen, alkyl,
alkenyl, alkinyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl
which may be independently substituted; or
[0038] two of the moieties R1, R1', R2, R3 may form a ring together
with a hetero-atom to which they are bound. The ring may be
saturated, unsaturated, substituted or unsubstitued. The chain may
be interrupted by one or more hetero-atoms out of the group
consisting of O, S, NH or N--C.sub.1-C.sub.4-alkyl;
[0039] R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8 may be,
independently of each other, hydrogen, halogen, nitro, cyano,
OR.sup.c, SR.sup.c, NR.sup.cR.sup.d, COR.sup.c, COOR.sup.c,
CO--NR.sup.cR.sup.d, C.sub.1-C.sub.30-alkyl,
C.sub.3-C.sub.12-cycloalkyl, C.sub.2-C.sub.30-alkenyl,
C.sub.3-C.sub.12-cycloalkenyl, aryl or heteroaryl, wherein the
latter 6 moieties may comprise one or more halogenic moiety and/or
1 to 3 moieties selected out of the group consisting of
C.sub.1-C.sub.6-alkyl, aryl, heteroaryl,
C.sub.3-C.sub.7-cycloalkyl, halogen, OR.sup.c, SR.sup.c,
NR.sup.cR.sup.d, COR.sup.c, COOR.sup.c, CO--NR.sup.cR.sup.d,
wherein R.sup.c and R.sup.dR.sup.d may be, independently of each
other, hydrogen, C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-halogenalkyl, cyclopentyl, cyclohexyl, phenyl,
tolyl or benzyl; or
[0040] two neighboring moieties of the moieties R, R.sup.4,
R.sup.5, R.sup.6, R.sup.7, R.sup.8, may form, together with an atom
they are bound, a ring which may be unsaturated or aromatic,
unsaturated or saturated, wherein the chain formed by the
respective moieties may be interrupted by one or more hetero-atoms
out of the group consisting of O, S, NH or
N--C.sub.1-C.sub.4-alkyl;
[0041] R.sup.e, R.sup.f, R.sup.g, R.sup.h may be, independently of
each other, hydrogen, C.sub.1-C.sub.6-alkyl, aryl-, heteroaryl-,
C.sub.3-C.sub.7-cycloalkyl, halogen, OR.sup.c, SR.sup.c,
NR.sup.cR.sup.d, COOR.sup.c, CO--NR.sup.cR.sup.d or COR.sup.c,
wherein R.sup.c, R.sup.d, may be, independently of each other,
hydrogen, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.6-halogenalkyl,
cyclopentyl, cyclohexyl, phenyl, tolyl or benzyl; preferably for
hydrogen, halogen, C.sub.1-C.sub.6-alkyl, in particular, hydrogen
or C.sub.1-C.sub.6-alkyl.
[0042] According to an exemplary embodiment of the method of use of
an ionic liquid the non-aromatic cation is a quaternary material.
In particular, the quaternary material may be a quaternary salt.
Alternatively, the non aromatic cation may comprise or may consist
of protonated bases.
[0043] According to an exemplary embodiment of the method of use of
an ionic liquid the gas is one out of the group consisting of:
H.sub.2O, HCN, H.sub.2S, H.sub.2Se, H.sub.2Te, CO.sub.2, CO,
CS.sub.2, COS, CF.sub.2O, CF.sub.2S, O.sub.3, NO, NO.sub.2,
N.sub.2O, N.sub.2O.sub.3, NOCl, NF.sub.3, HNO.sub.2, HNO.sub.3,
RCOR', RCOH, RCOOH, CF.sub.3SO.sub.3H, CF.sub.3COOH, RCOOR', ROH,
ROR (including cyclic ethers like tetrahydrofuran), RSH, RSR
(including cyclic thioethers like tetrahydrothiophen), ROCl, ROBr,
RONH.sub.2, RONHR', RONR'R'', RSO.sub.2Cl, RSO.sub.2Br, ROCN, RCON,
RCN, HF, HCl, HBr, HI, SO.sub.2, SO.sub.3, NH.sub.3, NH.sub.2R,
NHR'R'', NR'R''R''', PH.sub.3, PH.sub.2R, PHR'R'', PR'R''R''',
BF.sub.3, BCl.sub.3, BBr.sub.3, B.sub.2H.sub.6, BrF.sub.3,
ClF.sub.3, ClF.sub.5, ClCN, IF.sub.S, AsH.sub.3, CH.sub.3F,
CH.sub.3Cl, CH.sub.3Br, CH.sub.3I, POCl.sub.2, PSCl.sub.2,
PF.sub.S, SF.sub.4, SF.sub.6, SO.sub.2F.sub.2, SO.sub.2Cl.sub.2,
SOCl, H.sub.2C.dbd.CHBr, H.sub.2C.dbd.CHCl and ethylene oxide. In
general, every gas or vapor having a multipole moment and which may
be classified as an harmful substance, irritant, or toxic
substance, e.g. (strong) acids, (strong) bases, may be sorbed by
using a method according to an exemplary embodiment of the
invention. In particular, the sorption process may be used to
remove these gases or vapors from air which is inhaled or
exhaled.
[0044] According to an exemplary embodiment of the method of use of
an ionic liquid at least one of R, R', R'' and/or R''' is a moiety
out of the group consisting of: C.sub.1-C.sub.8-alkyl, alkenyl,
alkinyl, cycloalkyl, cycloalkenyl, aryl and heteroaryl. In
particular, R, R', R'' and/or R''' may denote a moiety or radical
which may be partially and/or independently substituted. For
clarity reasons it should be mentioned that in this application the
term C.sub.1-C.sub.8-alkyl or similar terms is an abbreviatory
notation for C1-alkyl, C2-alkyl, . . . , up to C8-alkyl or similar
terms.
[0045] According to an exemplary embodiment of the method of use of
an ionic liquid the anion comprises a carbonate, an alkylcarbonate,
an arylcarbonate, alkylcarbonate, carboxylate, a carbanion, and/or
an aromatic compound. In particular, the carbonates may be alkaline
metal carbonates, alkaline earth metal carbonates, quaternary
tetraalkylammonium carbonates, quaternary tetraalkylphosphonium
carbonates, hydrogencarbonate, and/or arylcarbonate, for example.
In particular, the arylcarbonate may be phenylcarbonate or
benzylcarbonate, for example.
[0046] According to an exemplary embodiment of the method of use of
an ionic liquid the anion comprises at least one polar group.
[0047] In particular, the polar group may be formed by an acetate,
a sulfonate, a sulfate, a carbonate, and/or a malonate compound.
Furthermore, it should be noted that the anion may be polar. In
particular, the anion may be formed by a small ion having a high
charge density or by an ion, carrying a functional group with a
heteroatom with a high charge density e.g. O, N, F.
[0048] According to an exemplary embodiment of the method of use of
an ionic liquid the cation is a quaternary or protonated cation out
of the group consisting of ammonium, phosphonium, sulfonium,
piperidinium, pyrrolidinium and morpholinium.
[0049] According to an exemplary embodiment of the method of use of
an ionic liquid the cation is one out of the group consisting of
trialkylmethylammonium, tetramethylammonium,
triethylmethylammonium, tributylmethylammonium, and
trioctylmethylammonium, trialkylammonium, trimethylammonium,
triethylammonium, tributylammonium, and trioctylammonium. In
particular, the trialkylmethylammonium may be a
C.sub.1-C.sub.10-trialkylmethylammonium.
[0050] According to an exemplary embodiment of the method of use of
an ionic liquid the cation is one out of the group consisting of
tetramethylammonium, triethylmethylammonium,
tributylmethylammonium, and trioctylmethylammonium.
[0051] According to an exemplary embodiment of the method of use of
an ionic liquid the anion can be written in the form
[RCO.sub.2.sup.-], wherein [RCO.sub.2.sup.-] is one out of the
group consisting of carboxylate, formiate, acetate, propionate,
butyrate, benzoate, and salicylate.
[0052] According to an exemplary embodiment of the method of use of
an ionic liquid the anion can be written in the form
[RCO.sub.2.sup.-], wherein [RCO.sub.2.sup.-] is a carboxylate and
wherein R is a radical out of the group consisting of
C.sub.1-C.sub.30-alkyl, C.sub.3-C.sub.12-cycloalkyl,
C.sub.2-C.sub.30-alkenyl, C.sub.3-C.sub.12-cycloalkenyl,
C.sub.2-C.sub.30-alkinyl, aryl and heteroaryl. In particular, the
moiety or radical R may comprise or include one or more halogen
radicals.
[0053] According to an exemplary embodiment of the method of use of
an ionic liquid the anion can be written in the form
[RCO.sub.2.sup.-], wherein [RCO.sub.2] is a carboxylate wherein R
represents one to three radicals out of the group consisting of,
C.sub.1-C.sub.6-alkyl, aryl, heteroaryl,
C.sub.3-C.sub.7-cycloalkyl, halogen, cyanide, ORc, SRc, NRcRd,
CORc, COORc, CO--NRcRd, wherein Rc and/or Rd, is one of the group
consisting of hydrogen, C.sub.1-C.sub.6-alkyl,
C.sub.1-C.sub.6-halogenalkyl, cyclopentyl, cyclohexyl, phenyl,
tolyl, and benzyl.
[0054] According to an exemplary embodiment of the method of use of
an ionic liquid the gas is CO.sub.2.
[0055] Summarizing, according to an exemplary aspect of the
invention, a method of use is provided which uses an ionic liquid
having a non-aromatic cation to sorb gases having an electric
multipole moment. The gas may in particular be CO.sub.2 while the
ionic liquid may be an organic salt having a melting temperature of
below 200.degree. C., preferably below 100.degree. C. The organic
salts may be quaternary salts having a generic formula of:
[K.sup.+][RCO.sub.2]. The described method of use may be in
particular useful for all processes in which CO.sub.2 shall be
removed as pure substance or from a gas or vapor mixture
independent of whether CO.sub.2 is a main or secondary component, a
process gas, or a working medium. Some exemplary applications may
be the use in a heat pump or refrigerator based on ionic
liquid/CO.sub.2 as working media, or removing of CO.sub.2 out of
recovery gas, synthesis gas, water gas, inhaled air, and exhaled
air. The removing out of inhaled/exhaled air may be in particular
useful in the field of aerospace, submarines, or building services
engineering wherein the very low vapor pressure if the ionic liquid
may be advantageous since the ionic liquid may not evaporate into
the air. Furthermore, it may be possible to use ionic liquids which
selectively remove CO.sub.2 while do not remove water or water
vapor, i.e. hydrophobic ionic liquids may be used. Another possible
application may be the purification of CO.sub.2 and/or
non-pressurized storing of CO.sub.2, since the ionic liquid forms a
complex bound with the quadrupolaric CO.sub.2 which complex bound
may be broken by heating, microwave, ultrasonic wave, or by adding
bipolar solvents, e.g. water, alcohol, etc. In general, every gas
or vapor having a multipole moment and which may be classified as
an harmful substance, irritant, or toxic substance, e.g. (strong)
acids, (strong) bases, may be sorbed by using a method according to
an exemplary embodiment of the invention. In particular, the
sorption process may be used to remove these gases or vapor from
air which is inhaled or exhaled, e.g. for purifying breathable
air.
[0056] The aspects defined above and further aspects of the
invention are apparent from the examples of embodiment to be
described hereinafter and are explained with reference to these
examples of embodiment. It should be noted that features described
in connection with one exemplary embodiment or exemplary aspect may
be combined with other exemplary embodiments and other exemplary
aspects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0057] The invention will be described in more detail hereinafter
with reference to examples of embodiment but to which the invention
is not limited.
[0058] FIG. 1 schematically illustrates a heat pump.
[0059] FIG. 2 schematically illustrates a test arrangement for
measuring a gas sorption.
[0060] FIG. 3 schematically illustrates a test arrangement for
measuring equilibrium curves.
[0061] FIG. 4 illustrates equilibrium curves for
monoethanolamine.
[0062] FIG. 5 illustrates equilibrium curves for choline
carbonate.
DESCRIPTION OF EMBODIMENTS
[0063] The illustration in the drawing is schematically.
[0064] FIG. 1 schematically shows a heat pump which may use a
process according to an exemplary embodiment, i.e. a process which
may be based on pair of working media comprising CO.sub.2 and an
ionic liquid comprising a non-aromatic ionic liquid.
[0065] In particular, FIG. 1 shows a heat pump 100 having an
absorber 101, including the pair of working media, e.g. CO.sub.2
and the ionic liquid, wherein the ionic liquid acts as a sorbent
and CO.sub.2 is the sorbat. The mixture is transmitted via a pump
102 to a heat exchanger 103a in which the mixture absorbs heat or
releases heat. After the heat exchanger the mixture is transmitted
to a settler 104 in which at least a partially seperation of the
mixture into a sorbent rich phase and a sorbat rich phase is
performed. The sorbant rich phase is transferred to transferred
trough a second heat exchanger 103b and a restrictor 105a into a
evaporizer 106. In the evaporizer 106 the sorbat at least partially
evaporates out of the sorbat rich phase which is then introduced
back into the absorber 101. Optionally, the sorbat rich phase may
be passed through another heat exchanger, e.g. heat exchanger 103b,
before it is introduced into the absorber. The sorbent richt phase
is transferred from the settler 104 to the absorber 101 via a
second restrictor 105b in which it is brought back to the pressure
level of the absorber 100. Optionally the sorbent rich phase may be
passed through another heat exchanger, e.g. heat exchanger 103a,
before it is introduced into the second restrictor 105b.
[0066] The described heat exchanger is only an example for a device
using a method of use according to an exemplary embodiment of the
invention. A plurality of embodiments may become apparent for a
person skilled in the art. For example, a ionic liquid having a
non-aromatic cation may be used in a open device, i.e. a device
which does not include the ionic liquid in a closed loop, in order
to enable the sorption of a gas having an electric multipole
moment.
[0067] In the following some experimental results are described
showing the ability of ionic liquid to absorb CO.sub.2.
[0068] FIG. 2 schematically shows a fluid tank 200 used as a heat
reservoir in order to provide a constant temperature selectable in
the range between 25.degree. C. and 80.degree. C. A vessel or vial
201 having a volume of about 20 ml is placed in the tank, wherein
the vial is filled with CO.sub.2 at a partial pressure of the
enviromental pressure, e.g. atmospheric pressure of about 1000 hPa.
Additionally, a CO.sub.2 sorbing fluid is injected 202 into the
vial. The sorption of the CO.sub.2 is determined by measuring the
decrease of the pressure in the vial by a digital manometer 203
which is connected to a computer. The speed of the pressure
decrease is an indicator of the reaction kenetics and the total
decrease of the pressure is an indicator for the total CO.sub.2
sorption. The tests were performed at two temperatures 25.degree.
C. and 80.degree. C., wherein at the higher temperature a smaller
amount of CO.sub.2 may be desirable since this may be an indicator
for an estimation of the ability of the fluid to release the
CO.sub.2. For testing several ionic liquids are injected and
compared to a reference sample, wherein an aqueous solution (30%)
of monoethanolamine is used. In particular, the resulting parameter
was the equilibrium concentration at constant reduced pressure,
i.e. the pressure reached in the vial, and at the set temperature,
wherein the result was calculated in mol.sub.gas per mol.sub.IL,
wherein the index gas denotes CO.sub.2 and the index IL denotes
ionic liquid. The equilibrium concentration were calculated by the
following formular:
pressure decrease [ hPa ] 0.02145 [ l ] 83.145 temp [ K ] / mass of
CO 2 [ g ] molar mass [ g / mol ] ##EQU00001##
wherein 0.02145 is the volume of the vial and 83.145 is the gas
constant in the used units.
[0069] The following results were achieved:
TABLE-US-00001 pressure conc. T decrease time charging name solvent
[%] [.degree. C.] [hPa] [min] [mol.sub.CO2/mol.sub.IL] TBMP- 100 25
332 4000 0.08 acetate TBMP- 100 80 342 3160 0.08 acetate TEMA-
H.sub.2O 70 25 495 2400-5000 0.1 acetate TEMA- H.sub.2O 70 80 130
2400 0.03 acetate TOMA- 100 25 448 2500 0.19 acetate TOMA- 100 80
122 1000 0.05 acetate MEA H.sub.2O 30 25 679 250 0.12 MEA H.sub.2O
30 80 440 130 0.08 wherein: TBMP denotes tributyl methyl
phosphonium, TEMA denotes triethyl methyl ammonium, TOMA denotes
trioctyl methyl ammonium, and MEA denotes monoethanolamine.
[0070] As can be seen the acetate anion may be responsible for a
high CO.sub.2 sorption, while similar sorption amounts may be
achievable by cations having different structures.
[0071] FIG. 3 schematically illustrates a test arrangement 300 for
measuring equilibrium curves. In particular, FIG. 3 shows an
equilibrium cell comprising three vessels 301, 302 and 303 each
closed by a respective frit in order to ensure a good mass transfer
between the gas, e.g. CO.sub.2 and the sorbing fluid. The vessels
are interconnected by flexible plastic tubes 304 and 305 having
non-return valves. The vessels are placed in a heat reservoir 306
to ensure a constant temperature which can be controlled by using
an electric heating 307. The heat reservoir is covered by a cover
or lid 308 in order to ease the temperature control. A container or
condenser 309 including silica gel is implemented downstream of the
equilibrium cell wherein the silica gel is used to dry the
generated gas which is then analyzed. Additionally, an input amount
or volume to the equilibrium cell is controlled or regulated by
using a rotameter 310.
[0072] FIG. 4 illustrates equilibrium curves for monoethanolamine.
In particular, FIG. 4 shows the partial pressure p.sub.CO2 versus
the CO.sub.2 loading for 60.degree. C. and 80.degree. C. for an
aqueous solution (30%) of monoethanolamine. For each temperature a
respective curve is approximated based on measurements, wherein a
first curve 401 approximates the equilibrium curve for 80.degree.
C. while a second curve 402 approximates the equilibrium curve for
60.degree. C. The values generated for MEA are comparable with the
data published in literature, known to the expert.
[0073] FIG. 5 illustrates equilibrium curves for choline carbonate.
In particular, FIG. 5 shows values for the partial pressure
p.sub.CO2 versus the CO.sub.2 loading for six different
temperatures 40.degree. C., 60.degree. C., 80.degree. C.,
90.degree. C., 100.degree. C., and 110.degree. C. for an aqueous
solution (60%) of choline carbonate. Additionally, to the measured
values fits for the different temperatures are shown in FIG. 5 as
well. In particular, graph 501 shows the fit for 40.degree. C.,
graph 502 shows the fit for 60.degree. C., graph 503 shows the fit
for 80.degree. C., graph 504 shows the fit for 90.degree. C., graph
505 shows the fit for 100.degree. C., and graph 506 shows the fit
for 110.degree. C.
[0074] Furthermore, an experiment concerning the influence of water
on the CO.sub.2 sorption was performed. TEMA acetate having a water
amount of 10% was used as an ionic liquid. TEMA acetate was
introduced for four days into a CO.sub.2 atmosphere having a
pressure of 600 hPa at a temperature of 80.degree. C. In one case
the TEMA acetate comprised included a surplus of water while in the
other case no water was added. The water content of the sample
including water increased from 10% to 35% while the sample without
water increased only from 10% to 15%. After the four days acid was
added to the two samples which lead to a clear generation of foam
or gas in the sample without water, while the reaction of the probe
with water was less intense. Thus, the water may lead to a reduced
CO.sub.2 sorption of the ionic liquid.
[0075] In the following two examples will be described wherein
trioctylmethylammonium (TOMA)-acetylacetonate or -acetate is used
to sorp a gas having an electric multipole moment.
Example 1
Sorption of Hydrogen Sulphide
[0076] The experiment was performed at room temperature and a vapor
pressure equilibrium of 338 hPa. A beaded bottle is flushed with
120 ml of hydrogen sulphide by using two needles. One of the
needles is connected to a manometer having a resolution of 1 hPa.
Subsequently 1 ml of TOMA-acetate is injected into the bottle by
using one of the needles, wherein the TOMA-acetate was preheated by
a hairdryer in order to reduce the viscosity. After 30 minutes of
stirring by using a magnetic stir bar a constant reduction of the
pressure of 622 hPa was observed. This pressure reduction
corresponds to a molar ratio of 0.26 moI.sub.H2S/mol.sub.IL at an
equilibrium pressure of 338 hPa. For comparison, a 30% aqueous
solution of monoethanolamine provides, under the same conditions, a
pressure reduction of 651 hPa which corresponds to a molare ratio
of 0.11 mol.sub.H2S/mol.sub.L at an equilibrium pressure of 309
hPa.
Example 2
Sorption of Carbon Dioxide
[0077] The experiment was performed at room temperature and a vapor
pressure equilibrium of 523 hPa. A beaded bottle is flushed with
120 ml of carbon dioxide by using two needles. One of the needles
is connected to a manometer having a resolution of 1 hPa.
Subsequently 1 ml of TOMA-acetylacetonate is injected into the
bottle by using one of the needles, wherein the
TOMA-acetylacetonate was preheated by a hairdryer in order to
reduce the viscosity. After 30 minutes of stirring by using a
magnetic stir bar a constant reduction of the pressure of 437 hPa
was observed. This pressure reduction corresponds to a molar ratio
of 0.18 mol.sub.CO2/mol.sub.IL at an equilibrium pressure of 523
hPa. For comparison, a 30% aqueous solution of monoethanolamine
provides, under the same conditions, a pressure reduction of 670
hPa which corresponds to a molare ratio of 0.12
mol.sub.CO2/mol.sub.L at an equilibrium pressure of 290 hPa.
[0078] Finally, it should be noted that the above-mentioned
embodiments illustrate rather than limit the invention, and that
those skilled in the art will be capable of designing many
alternative embodiments without departing from the scope of the
invention as defined by the appended claims. In the claims, any
reference signs placed in parentheses shall not be construed as
limiting the claims. The word "comprising" and "comprises", and the
like, does not exclude the presence of elements or steps other than
those listed in any claim or the specification as a whole. The
singular reference of an element does not exclude the plural
reference of such elements and vice-versa. In a device claim
enumerating several means, several of these means may be embodied
by one and the same item of software or hardware. The mere fact
that certain measures are recited in mutually different dependent
claims does not indicate that a combination of these measures
cannot be used to advantage.
* * * * *