摘要:
The present invention relates to a method for the transesterification of a hydroxylated oil including two consecutive transesterification steps performed in the presence of a light alcohol (methanol or ethanol) and a basic catalyst under temperature, pressure and alcohol/oil weight ratio conditions enabling the nearly total conversion of the hydroxylated oil into fatty acid esters. Characteristically, a resulting directly from the first transestrefication step in order to obtain a reaction mixture including, in particular, hydroxylated fatty acid esters and glycerol. Said reaction mixture is subjected to a separation step that makes it possible to obtain a less dense phase predominantly consisting of fatty esters and a denser phase predominantly consisting of glycerol and water and fatty acid soaps. The second transesterification step is performed on the less dense phase, with said light alcohol and said basic catalyst are added thereto.
摘要:
The present invention relates to a process for the preparation of dimethylketene (DMK) and then of polydimethylketene (PDMK) by polymerization of DMK. More specifically, the DMK is obtained by pyrolysis by isobutyric anhydride (IBAN), the latter decomposing under the effect of heat (pyrolysis) to give isobutyric acid (IBA) and DMK. One mole of pyrolyzed IBAN gives one mole of IBA and one mole of DMK.
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 consists in 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 consists in continuously extracting from the esterification reaction medium a near-azeotropic water/ethanol gas mixture; then in dehydrating said gas mixture directly using molecular sieves, then 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:
The present invention relates to a method for the transesterification of a hydroxylated oil including two consecutive transesterification steps performed in the presence of a light alcohol (methanol or ethanol) and a basic catalyst under temperature, pressure and alcohol/oil weight ratio conditions enabling the nearly total conversion of the hydroxylated oil into fatty acid esters. Characteristically, a resulting directly from the first transestrefication step in order to obtain a reaction mixture including, in particular, hydroxylated fatty acid esters and glycerol. Said reaction mixture is subjected to a separation step that makes it possible to obtain a less dense phase predominantly consisting of fatty esters and a denser phase predominantly consisting of glycerol and water and fatty acid soaps. The second transesterification step is performed on the less dense phase, with said light alcohol and said basic catalyst are added thereto.
摘要:
The present invention relates to a process for the continuous preparation of selected organic peroxides using plate exchangers having a high heat exchange capacity.
摘要:
The present invention relates to a process for the continuous preparation of selected organic peroxides using plate exchangers having a high heat exchange capacity.
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.