| 摘要 |
Processes for the synthesis of polyol fatty acid polyester by transesterification of a polyol comprise reacting polyol with a first portio n of fatty acid lower alkyl ester to provide a first step reaction product in which substantially all of the polyol is reacted with at least one fatty aci d lower alkyl ester. The process then employs a multistage column for further transesterification of the first step reaction product. Partially esterified polyol, a second portion of fatty acid lower alkyl ester and catalyst are fe d to the column to form a mixture and cause further transesterification of the partially esterified polyol and fatty acid lower alkyl ester, with lower alk yl alcohol being formed as a by product. The resulting liquid mixture of reactants and product is passed in a first direction between adjacent stages through the column for further reaction of partially esterified polyol with fatty acid lower alkyl ester. An inert sparging gas is fed through the colum n in a second direction between adjacent stages, counter current to the flow o f the liquid mixture between adjacent stages in the first direction. The inert gas is directed through the liquid mixture to provide gas induce turbulence, such that the column reactor has a column ratio of at least 0.4/hour.</SDOAB >
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