摘要:
The invention concerns a continuous method for preparing ethyl lactate by esterifying lactic acid with ethanol, in the presence of a catalyst which comprises reacting said lactic acid with ethanol in an initial ethanol/lactic acid mol ratio not less than 2.5, in the presence of a catalyst, at a reflux of the reaction medium of about 100° C. under absolute pressure ranging between 1.5 to 3 bars. Said method is characterized in that it comprises continuously extracting from the esterification reaction medium a near-azeotropic water/ethanol gas mixture: than dehydrating said gas mixture directly using molecular sieves, than recuperating from said dehydration an ethanol gas stream capable of being recycled to the esterification reaction medium and a flow consisting of water and ethanol which is subjected to distillation wherefrom is obtained water and an azeotropic water/ethanol mixture which is injected into the distillation column head of the gas mixture extracted from the esterification reaction medium; then in continuously extracting crude ethyl lactate which is subjected to purification wherefrom are obtained high purity ethyl lactate and heavy products.
摘要:
This invention relates to a continuous process for the manufacture of &bgr;-isophorone by isomerization under homogeneous catalysis of &agr;-isophorone. The process consists of introducing &agr;-isophorone and a solution of an alkaline hydroxide into a reaction region at a temperature ranging from 150° C. to 216° C., simultaneously removing by distillation a fraction comprising an amount by weight of &bgr;-isophorone ranging from 30% to 90%, drawing off the heavy products and then rectifying the fraction removed from the reaction mixture by distillation.
摘要:
The present invention relates to a process for obtaining a solid catalyst of general formula (I): [(Mg2+)1−x(Al3+)x(OH−)2]x+[(OH−)x]x−(H2O)n (I) with 0.20≦x≦0.33 and n
摘要:
For the continuous manufacture of &bgr;-isophorone by isomerization under homogeneous catalysis of &agr;-isophorone, the steps of introducing the &agr;-isophorone and a solution of an alkaline hydroxide into a reaction region, bringing the reaction mixture to reflux at a temperature at least equal to 150° C. under a equal P1 of less than or equal to atmospheric pressure, continuously and simultaneously removing from the reaction mixture: &bgr;-isophorone vapor, by distillation under a pressure P2 less than P1 and at a temperature at most equal to 150° C., and heavy products, at a rate, so that their content by weight is at most equal to 7% in the reaction mixture, and continuous returning the distillation to the reaction region.