摘要:
A process for the epoxidation of olefins which includes i) reacting an olefin with hydrogen peroxide in presence of an epoxidation catalyst and an alcoholic solvent; ii) separating product olefin oxide and unreacted olefin from the reaction product of step i); iii) recovering a stream comprising the alcoholic solvent; and iv) subjecting the recovered stream of step iii) to hydrogenation.
摘要:
A continuous process for the epoxidation of olefins with hydrogen peroxide in the presence of a heterogeneous catalyst promoting the epoxidation reaction, whereby the aqueous reaction mixture contains i) an olefin; ii) hydrogen peroxide; iii) less than 100 wppm of alkali metals, earth alkali metals, both irrespective whether in ionic, complex or covalently bonded form, bases or cations of bases having a pkB of less than 4.5, or combinations thereof; and, iv) at least 100 wppm of bases or cations of bases having a pkB of at least 4.5 or combinations thereof, whereby the wppm are based on the total weight of hydrogen peroxide in the reaction mixture.
摘要:
A process for the continuous epoxidation of propene with hydrogen peroxide in the presence of a titanium silicalite catalyst and a methanol solvent, wherein the catalyst is periodically regenerated by washing with a methanol solvent at a temperature of at least 100° C. and the epoxidation reaction is carried out for periods of more than 300 h between two regeneration steps.
摘要:
A process for the catalytic epoxidation of olefins in the presence of a titanium containing zeolite catalyst and a polar solvent whereby the deactivation of the catalyst upon recycling of the solvent has been considerably reduced. In the process one or more nitrogen containing compounds are introduced at some stage, a solvent stream is recovered, treated to contain less than 50 wppm nitrogen in the form of organic nitrogen compounds and at least a part of it is recycled to the epoxidation step. Also disclosed is a process for the catalytic epoxidation of propene which integrates the treatment and recycle of the solvent into the workup of the reaction mixture.
摘要:
An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkB of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.
摘要:
An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkB of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.
摘要:
An aqueous hydrogen peroxide solution containing i) less than 50 wppm alkali metals, alkaline earth metals or combinations thereof in total, irrespective whether the alkali or alkaline earth metals are present in cationic or complex form; ii) less than 50 wppm of amines having a pkB of less than 4.5 or the corresponding protonated compounds in total; and iii) at least 100 wppm anions or compounds that can dissociate to form anions in total, where the wppm are based on the weight of hydrogen peroxide and the concentration of hydrogen peroxide is more than 50% by weight based on the total weight of the hydrogen peroxide solution. A process for preparation of said hydrogen peroxide solution and the use of said solution in a process for epoxidation of olefins is also disclosed.
摘要:
The invention relates to a process for increasing the selectivity of the hydrogenation of 4,4′-diaminodiphenylmethane (4,4′-MDA) to diaminodicyclohexylmethane (4,4′-HMDA) by catalytic hydrogenation of a mixture containing 4,4′-MDA as the main component and its mono-N-methyl derivative as a secondary component. According to the invention, the hydrogenation is terminated before a conversion of 4,4′-MDA to 4,4′-HMDA of 99% is achieved. Under these conditions, a substantially smaller proportion of the N-methyl-4,4′-MDA is hydrogenated to N-methyl-4,4-HMDA.
摘要:
The invention relates to a process for increasing the selectivity of the hydrogenation of 4,4′-diaminodiphenylmethane (4,4′-MDA) to diaminodicyclohexylmethane (4,4′-HMDA) by catalytic hydrogenation of a mixture containing 4,4′-MDA as the main component and its mono-N-methyl derivative as a secondary component. According to the invention, the hydrogenation is terminated before a conversion of 4,4′-MDA to 4,4′-HMDA of 99% is achieved. Under these conditions, a substantially smaller proportion of the N-methyl-4,4′-MDA is hydrogenated to N-methyl-4,4-HMDA.
摘要:
The invention relates to a process for hydrogenating an aromatic amine that has at least one amino group bound to an aromatic nucleus with hydrogen in the presence of a supported catalyst that contains at least ruthenium as active metal. The catalyst support has a BET surface area in the range from greater than 30 m2/g to less than 70 m2/g and more than 50% of the pore volume of the catalyst support is formed by macropores having a pore diameter of greater than 50 nm and less than 50% are mesopores having a pore diameter of 2 to 50 nm.