Process for carbonylation of ethylene
AssigneeImperial Chemical Industries PLC
InventorsJean Margaret Pearson, Raymond Anthony Hadden
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Abstract
A process for the liquid-phase carbonylation of ethylene, according to the equation C2H4+CO+ROH→C2H5CO2R, in the presence of a catalyst system comprising a Group VIII metal or compound thereof, a phosphine ligand and a source of anions, and in the presence of water or a source of organic hydroxyl groups, is carried out in conditions in which the molar ratio of ethylene to carbon monoxide in the gaseous phase of the reactor is greater than 1:1. The higher ratios of ethylene to carbon monoxide are beneficial in increasing the turnover number of the catalyst system.
Claims19
A process for the carbonylation of ethylene in a liquid phase which process comprises
- (i) forming a gaseous phase from an ethylene feed stream and a carbon monoxide feed stream;
- (ii) contacting the gaseous phase with a catalyst system within the liquid phase containing water or a source of organic hydroxyl groups, said catalyst system comprising palladium, or a compound thereof, and a phosphine ligand together with a source of anions;
- and
- (iii) reacting the ethylene with the carbon monoxide in the presence of the source of hydroxyl groups and of the catalyst system;
- wherein the ethylene feed stream and carbon monoxide feed stream provide a molar ratio of ethylene to carbon monoxide in the gaseous phase of the reactor which is greater than 1:1 and the source of anions is derivable from an acid with a pKa measured in aqueous solution of less than 4.
A process for the carbonylation of ethylene in a liquid phase comprising:
- (iii) forming a gaseous phase from an ethylene feed stream and a carbon monoxide feed stream;
- (iv) contacting the gaseous phase with a catalyst system within the liquid phase containing water or a source of organic hydroxyl groups;
- and
- (iii) reacting the ethylene with the carbon monoxide in the presence of the source of hydroxyl groups and of the catalyst system;
- wherein the ethylene feed stream and carbon monoxide feed stream provide a molar ratio of ethylene to carbon monoxide in the gaseous phase of the reactor which is greater than 1:1 and said catalyst system comprises a combination of:
- (a) palladium or a compound thereof;
- (b) a bidentate phosphine represented by the general formula (1)
- wherein
- R0 represents a tertiary carbon atom,
- each of R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11 and R12 independently represents a pendant optionally substituted C1-8 hydrocarbon group which carries a carbon atom through which the group is linked to the respective R0,
- each of L1 and L2 independently represents a linking group selected from an optionally substituted C1-4 alkylene chain connecting the respective phosphorus atom to the group X, and
- X represents a bridging group comprising an optionally substituted aryl moiety to which the phosphorus atoms are linked on available adjacent carbon atoms;
- and
- (c) an anion which is essentially non-coordinating to palladium ions and derivable from an acid with a pKa measured in aqueous solution of less than 4.
A process for the production of methyl propionate comprising the steps of:
- (i) forming a gaseous phase from an ethylene feed stream and a carbon monoxide feed stream;
- (ii) contacting the gaseous phase with a catalyst system within a liquid phase comprising methanol, a solvent and a catalyst system comprising palladium, or a compound thereof, a phosphine ligand and a source of anions;
- and
- (iii) reacting the ethylene with the carbon monoxide in the presence of the methanol and of the catalyst system;
- characterised in that the ethylene feed stream and carbon monoxide feed stream provide a molar ratio of ethylene to carbon monoxide in the gaseous phase which is greater than 1:1.
Dependencies are inferred from the claim text.