Process for stripping carbamate from ion exchange resin
AssigneeEco-Tec Limited
InventorMichael A. Sheedy
Life of this patent
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Abstract
In a preferred embodiment, there is provided a process for separating an amine compound or a conjugate acid thereof and a carbamate compound or a conjugate acid thereof from a mixture having the amine compound, the carbamate compound, carbon dioxide and at least one anionic contaminant salt using an anionic exchange column, the process including passing the mixture through the column to obtain a first effluent and passing through the column an extraction fluid to obtain a second effluent, where the extraction fluid most preferably includes carbonic acid.
Claims22
A process for separating an amine compound or a conjugate acid thereof and a carbamate compound or a conjugate acid thereof from a mixture having the amine compound, the carbamate compound, carbon dioxide and at least one anionic contaminant salt using an anionic exchange column having a plurality of anion exchange sites,
- the amine compound being an optionally substituted piperazine or having formula (1) of R3−xN(R1-Q-R1—OH)x and the carbamate compound being an optionally substituted piperazine carbamate or piperazine dicarbamate, or having formula (2) of (HO—R1-Q-R1)yNH2−yC(O)O−, wherein at least a portion of the carbamate compound is present in the mixture from a reversible reaction between the amine compound and the carbon dioxide to produce the carbamate compound and a hydrogen atom or the conjugate acid of the amine compound, wherein x and y are independently of each other 1 or 2, R is a hydrogen atom or optionally substituted straight or branched C1-C8 alkyl, R1 is nothing or optionally substituted straight or branched C1-C4 alkylene, and Q is nothing, O or S, and wherein the optionally substituted piperazine comprises at least one ring nitrogen atom bonded to a hydrogen atom, at least one R is a hydrogen atom, and at least R1 in each said formulas (1) and (2) is optionally substituted straight or branched C1-C4 alkylene;
- wherein the process comprises:
- passing the mixture through the column to effect attachment to the at least one anionic contaminant salt to the anion exchange sites, and collecting from the column a first effluent comprising at least the amine compound or the conjugate acid thereof;
- passing through the column an extraction fluid at a pressure between 6 atm and 15 atm to obtain a second effluent, the extraction fluid comprising carbonic acid, to effect removal of the carbamate compound attached to the anion exchange sites, wherein the second effluent comprises at least the carbamate compound, the conjugate acid of the carbamate compound or a decomposition product thereof, said decomposition product comprising the amine compound and the carbon dioxide;
- and
- passing through the column a regeneration fluid to regenerate the column, the regeneration fluid comprising an anionic regeneration compound selected to replace the anionic contaminant salt attached to the anion exchange sites,
- wherein the first and second effluents are collected to obtain a separated mixture comprising at least the amine compound or the conjugate acid thereof and the carbamate compound or the conjugate acid thereof.
A process for separating an amine compound or a conjugate acid thereof and a carbamate compound or a conjugate acid thereof from a mixture having the amine compound, the carbamate compound, carbon dioxide and at least one anionic contaminant salt using an anionic exchange column having a plurality of anion exchange sites,
- the amine compound being an optionally substituted piperazine or having formula (1) of R3−xN(R1-Q-R1—OH)x and the carbamate compound being an optionally substituted piperazine carbamate or piperazine dicarbamate, or having formula (2) of (HO—R1-Q-R1)yNH2−yC(O)O−, wherein x and y are independently of each other 1 or 2, R is a hydrogen atom or optionally substituted straight or branched C1-C8 alkyl, R1 is nothing or optionally substituted straight or branched C1-C4 alkylene, and Q is nothing, O or S, and wherein the optionally substituted piperazine comprises at least one ring nitrogen atom bonded to a hydrogen atom, at least one R is a hydrogen atom, and at least R1 in each said formulas (1) and (2) is optionally substituted straight or branched C1-C4 alkylene;
- wherein the process comprises:
- passing the mixture through the column to effect attachment of the at least one anionic contaminant salt to the anion exchange sites, and collecting from the column a first effluent comprising at least the amine compound or the conjugate acid thereof;
- passing through the column an extraction fluid at a pressure between 6 atm and 15 atm to obtain a second effluent, the extraction fluid comprising carbonic acid, to effect removal of the carbamate compound attached to the anion exchange sites, wherein the second effluent comprises at least the carbamate compound, the conjugate acid of the carbamate compound or a decomposition product thereof, said decomposition product comprising the amine compound and the carbon dioxide;
- and
- passing through the column a regeneration fluid to regenerate the column, the regeneration fluid comprising an anionic regeneration compound selected to replace the anionic contaminant salt attached to the anion exchange sites,
- wherein the first and second effluents are collected to obtain a separated mixture comprising at least the amine compound or the conjugate acid thereof and the carbamate compound or the conjugate acid thereof.
Dependencies are inferred from the claim text.