Abstract:
Disclosed herein is a process for purifying propylene oxide, including the steps of: (i) providing a stream S0 containing propylene oxide, acetonitrile, water, and an organic compound containing a carbonyl group —C(═O)—; and (ii) separating propylene oxide from the stream S0 by subjecting the stream S0 to distillation conditions in a distillation column to obtain a gaseous top stream S1c which is enriched in propylene oxide compared to the stream S0, a liquid bottoms stream S1a which is enriched in acetonitrile and water compared to the stream S0, and a side stream S1b containing propylene oxide which is enriched in the carbonyl compound compared to the stream S0.
Abstract:
The present invention is related to a process for preparing propylene oxide, comprising (i) providing a stream comprising propene, hydrogen peroxide or a source of hydrogen peroxide, water, and an organic solvent; (ii) passing the liquid feed stream provided in (i) into an epoxidation zone comprising an epoxidation catalyst comprising a titanium zeolite, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propene, propylene oxide, water, and the organic solvent; (iii) removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, water, organic solvent, and propene; (iv) separating propene from the effluent stream by distillation, comprising (iv.1) subjecting the effluent stream to distillation conditions in a distillation unit, obtaining a gaseous top stream S0 enriched in propene compared to the effluent stream subjected to distillation conditions, and a liquid bottoms stream S01 enriched in propylene oxide, water and organic solvent compared to the effluent stream subjected to distillation conditions; (iv.2) returning a condensed portion of the stream S0 to an upper part of the distillation unit.
Abstract:
The present invention relates to a process for the regeneration of a catalyst comprising a titanium-containing zeolite, said catalyst having been used in a process for the preparation of an olefin oxide and having phosphate deposited thereon, said process for the regeneration comprising the steps: (a) separating the reaction mixture from the catalyst, (b) washing the catalyst obtained from (a) with liquid aqueous system; (c) optionally drying the catalyst obtained from (b) in a gas stream comprising an inert gas at a temperature of less than 300° C.; (d) calcining the catalyst obtained from (c) in a gas stream comprising oxygen at a temperature of at least 300° C.
Abstract:
A continuous process for the preparation of propylene oxide, comprising(a) reacting propene, optionally admixed with propane, with hydrogen peroxide in a reaction apparatus in the presence of acetonitrile as solvent, obtaining a stream S0 containing propylene oxide, acetonitrile, water, at least one further component B, optionally propene and optionally propane, wherein the normal boiling point of the at least one component B is higher than the normal boiling point of acetonitrile and wherein the decadic logarithm of the octanol-water partition coefficient (log K ow ) of the at least one component B is greater than zero; (b) separating propylene oxidefrom S0, obtaining a stream S1 containing acetonitrile, water and the at least one further component B; (c) dividing S1 into two streams S2 and S3;(d) subjecting S3 to a vapor-liquid fractionation in a fractionation unit, obtaining a vapor fraction stream S4 being depleted of the at least one component B; (e) recycling at least a portion of S4, optionally after work-up, to (a).
Abstract:
The invention relates to a process for workup of a stream (1) comprising butene and/or butadiene, butane, hydrogen and/or nitrogen and carbon dioxide, comprising the following steps: (a) absorption of the stream (1) comprising butene and/or butadiene, butane, hydrogen and/or nitrogen, with or without carbon dioxide, with a mixture (5) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to obtain a stream (9) comprising N-methylpyrrolidone, water, butene and/or butadiene, and butane, with or without carbon dioxide, and a stream (7) comprising hydrogen and/or nitrogen and butane, (b) extractive distillation of the stream (9) comprising N-methylpyrrolidone, water, butene and/or butadiene, and butane, with or without carbon dioxide, with a stream (13) comprising 80 to 97% by weight of N-methylpyrrolidone and 3 to 20% by weight of water to separate the stream (9) comprising N-methylpyrrolidone, water, butene and/or butadiene, and butane, with or without carbon dioxide, into a stream (17) comprising N-methylpyrrolidone, water, butene and/or butadiene, and a stream (15) comprising essentially butane, with or without carbon dioxide, (c) distillation of the stream (17) comprising N-methylpyrrolidone, water, butene and/or butadiene into a stream (23) comprising essentially N-methylpyrrolidone and water, and a stream (21) comprising butene and/or butadiene.