| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: invention relates to an improved method of producing alkane diol and dialkyl carbonate, involving: (a) reaction of source alkylene carbonate and alkanol in a first reaction zone in re-esterification conditions to obtain a mixture of products containing dialkyl carbonate, unconverted alkanol, alkane diol, unconverted alkylene carbonate and alkane diol dimers; (b) separating dialkyl carbonate and alkanol from the mixture of products to obtain a stream of a bottom product containing alkane diol, unconverted alkylene carbonate and alkane diol dimers; (c) extracting dialkyl carbonate; and (d) separating alkane diol from the stream of bottom product to leave a recirculated stream containing unconverted alkylene carbonate and alkane diol dimers; wherein the method further involves (e) passing at least a portion of the recirculated stream into a second reaction zone wherein alkane diol dimers are converted to high-boiling alkane diol oligomers by reacting dimers with alkylene oxide or alkylene carbonate to obtain an effluent stream containing oligomers; (f) separating the high-boiling oligomers from the effluent stream containing oligomers to obtain a remaining stream containing alkylene carbonate; and (g) recirculating the remaining stream containing alkylene carbonate to the first reaction zone. ^ EFFECT: method enables to cut loss of unconverted alkylene carbonate and remove the undesirable by-product - dimer. ^ 17 cl, 1 dwg |
