Abstract:
PROBLEM TO BE SOLVED: To obtain the subject compound with high selectivity and at high yield without using much catalyst by reacting an oxirane with CO and H2 in the presence of a catalyst i.e., a transition metal modified with a specified ligand. SOLUTION: This compound is (E) a β-hydroxyaldehyde and is obtained by reacting (B) a 1,2-oxirane with (C) carbon monoxide and (D) hydrogen in the presence of (A) a transition metal modified with a phosphorus-oxygen-ligand or nitrogen-oxygen-ligand and working as a catalyst. A cobolt-carbonyl-catalyst combined with phosphine oxide is preferably used as the component A and the ratio of oxygen based on phosphorus in the phosphine oxide is preferably 0.5-2.0. High yield is expectable thereby without using any accelerant.
Abstract:
The invention relates to a process for the production of hydrogen peroxide by the anthraquinone process, comprising a hydrogenation stage, an oxidation stage and an extraction stage. According to the invention, catalytic hydrogenation of anthraquinone derivatives dissolved in a working solution is carried out in the presence of added molecular oxygen. Per mol hydrogen, 0.1 to 10 mmol oxygen is preferably introduced into the hydrogenation stage with the hydrogenating gas, in mixture with an inert gas and/or dissolved and/or dispersed in the working solution. This increases the residence time of the catalyst.
Abstract:
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.
Abstract:
The invention relates to a method for catalytically hydrating an organic compound, especially an unstable organic compound, in the presence of a supported catalyst that is provided with a coating that contains ruthenium as the active metal and a total of 0.01 to 30 % by weight of active metals. The aim of the invention is to increase stereoselectivity and catalyst service life. To this end, a supported catalyst is used whose oxide-, carbide-, nitride- or silicate-containing support material, prior to being charged with at least one active metal, has a BET(N2) surface of less than 10 m /g, preferably 0.1 to 5 m /g, with the exception of diatomaceous earth with a BET(N2) surface of greater 2 m /g, and whose ruthenium content constitutes at least 50 % by weight, preferably at least 99 % by weight, of the active metals. The invention further relates to the aforementioned supported catalysts. The method and catalysts according to the invention are especially suitable for hydrating polyfunctional compounds such as hydroxycarbonyl compounds and aromatic amines.
Abstract:
In a process for the epoxidation of propene, comprising the steps: reacting propene with hydrogen peroxide in the presence of a titanium silicalite catalyst and a methanol solvent; separating non-reacted propene and propene oxide from the resulting reaction mixture to provide a solvent mixture comprising methanol and water in a combined amount of at least 90 % by weight; and feeding this solvent mixture as a feed stream to a continuously operated methanol distillation column at a feed point in the middle section of said column to provide an overhead product comprising at least 90 % by weight methanol and a bottoms product comprising at least 90 % by weight water; the addition of a liquid defoamer, having a solubility in the feed stream of less than 10 mg/kg at 25 °C and a surface tension at the liquid air interface of less than 22 mN/m at 20 °C, at or above the feed point in an amount exceeding the solubility of the liquid defoamer in the feed stream suppresses foam formation in the methanol distillation column.
Abstract:
The invention is directed to an improved 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 DEG C and the epoxidation reaction is carried out for periods of more than 300 h between two regeneration steps.
Abstract:
The invention is directed to an improved 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 DEG C and the epoxidation reaction is carried out for periods of more than 300 h between two regeneration steps.