摘要:
A method of separating propylene oxide from a mixture (M) comprising propylene oxide and methanol, said method comprising: (i) introducing said mixture (M) into an extractive distillation column; (ii) additionally introducing an extracting solvent into said extractive distillation column; (iii) distilling propylene oxide overhead from said extractive distillation column as top stream; (iv) withdrawing a bottoms stream from said extractive distillation column; (v) compressing the top stream obtained overhead in (iii) by means of at least one compressor to give a compressed vapor.
摘要:
The present invention relates to a process for separating at least one propylene glycol from a mixture (M) comprising water and said propylene glycol, said process comprising (I) evaporating the mixture in at least two evaporation and/or distillation stages at decreasing operating pressures of the evaporators and/or distillation columns obtaining mixture (M′) and mixture (M″); (II) separating the mixture (M′) obtained in (I) in at least one further distillation step, obtaining a mixture (M-I) comprising at least 70 wt.-% of water and a mixture (M-II) comprising less than 30 wt.-% of water.
摘要:
A method of separating propylene oxide from a mixture (M) comprising 5 to 50 percent by weight propylene oxide and 50 to 85 percent by weight methanol, said method comprising (i) introducing said mixture (M) into an extractive distillation column; (ii) additionally introducing a polar solvent into said extractive distillation column; (iii) distilling propylene oxide overhead from said extractive distillation column at a bottoms temperature of from 40 to 70° C. and at a pressure of from 300 to 750 mbar.
摘要:
The present invention relates to a method of separating an olefin from a gas stream, said gas stream comprising the olefin and at least one other component, said method comprising (i) compressing and cooling the gas stream; (ii) separating the olefin from the gas stream by absorbing the olefin in an absorbent; (iii) separating the olefin from the absorbent by desorption; wherein compressing or cooling or compressing and cooling in (i) is carried out at least twice.
摘要:
A process for producing epoxides, the process including: (a) feeding at least one aqueous alkali and at least one halohydrin to a reactive distillation column, wherein the reactive distillation column includes a feed zone, a top zone disposed above the feed zone, and a bottom zone disposed below the feed zone; (b) concurrently in the reactive distillation column: (i) reacting at least a portion of the halohydrin with the alkali to form an epoxide; and (ii) stripping water and the epoxide from a basic aqueous residue; (c) recovering the water and the epoxide from the reactive distillation column as an overheads fraction; (d) condensing and phase separating the overheads fraction to form an organic overheads fraction including the epoxide and an aqueous overheads fraction including water; and (e) maintaining a liquid holdup per plate in the feed zone at a residence time of 10 seconds or less.
摘要:
The invention relates to a process for the epoxidation of an olefin comprising (a) reacting the olefin with hydrogen peroxide in the presence of methanol as solvent in at least two reaction stages to obtain a mixture (M-a) comprising olefin oxide, unreacted olefin, methanol and water, wherein between at least two reaction stages, olefin oxide is separated by distillation; (b) separating unreacted olefin from the mixture (M-a) by distillation to obtain a mixture (M-bi) comprising at least 80 wt.-% of olefin and a mixture (M-bii) comprising methanol, water and at least 7 wt.-% of olefin oxide; (c) separating olefin oxide from the mixture (M-bii) in at least one distillation stage to obtain a mixture (M-ci) comprising at least 99 wt.-% of olefin oxide and a mixture (M-cii) comprising water and at least 55 wt.-% of methanol; (d) separating methanol from the mixture (M-cii) in at least one distillation stage to obtain a mixture (M-di) comprising at least 85 wt.-% of methanol and up to 10 wt.-% of water, and a mixture (M-dii) comprising at least 90 wt.-% of water; wherein a vapor top stream (Td) obtained from at least one distillation column used in (d), said vapor top stream (Td) comprising at least 85 wt.-% methanol, is used to operate at least partially at least one vaporizer used in at least one distillation column used in at least one of stages (a), (b) and (c).
摘要:
A process for producing epoxides, the process including: (a) feeding at least one aqueous alkali and at least one halohydrin to a reactive distillation column, wherein the reactive distillation column includes a feed zone, a top zone disposed above the feed zone, and a bottom zone disposed below the feed zone; (b) concurrently in the reactive distillation column: (i) reacting at least a portion of the halohydrin with the alkali to form an epoxide; and (ii) stripping water and the epoxide from a basic aqueous residue; (c) recovering the water and the epoxide from the reactive distillation column as an overheads fraction; (d) condensing and phase separating the overheads fraction to form an organic overheads fraction including the epoxide and an aqueous overheads fraction including water; and (e) maintaining a liquid holdup per plate in the feed zone at a residence time of 10 seconds or less.
摘要:
A method of separating propylene oxide from a mixture (M) comprising 5 to 50 percent by weight propylene oxide and 50 to 85 percent by weight methanol, said method comprising (i) introducing said mixture (M) into an extractive distillation column; (ii) additionally introducing a polar solvent into said extractive distillation column; (iii) distilling propylene oxide overhead from said extractive distillation column at a bottoms temperature of from 40 to 70° C. and at a pressure of from 300 to 750 mbar.
摘要:
A method of separating propylene oxide from a mixture (M) comprising propylene oxide and methanol, said method comprising (i) introducing said mixture (M) into an extractive distillation column; (ii) additionally introducing an extracting solvent into said extractive distillation column; (iii) distilling propylene oxide overhead from said extractive distillation column as top stream; (iv) withdrawing a bottoms stream from said extractive distillation column; (v) compressing the top stream obtained overhead in (iii) by means of at least one compressor to give a compressed vapor.