Abstract:
A continuous process for the preparation of propylene oxide, comprising (i) providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, water, dissolved potassium dihydrogen phosphate, and optionally propane; (ii) passing the liquid feed stream provided in (i) into an epoxidation reactor comprising a catalyst comprising a titanium zeolite of structure type MWW, and subjecting the liquid feed stream to epoxidation reaction conditions; (iii) removing an effluent stream from the epoxidation reactor; wherein the concentration of the dissolved potassium dihydrogen phosphate in the liquid feed stream is at least 10% of the solubility limit of the potassium dihydrogen phosphate in the liquid feed stream.
Abstract:
The invention relates to methods for continuously producing chlorine by reacting hydrogen chloride with oxygen in the presence of a heterogeneous catalyst. To this end, the reaction of hydrogen chloride is limited to a level ranging from 15 to 90 % with a single pass through the reactor.
Abstract:
A continuous process for the preparation of propylene oxide, comprising a start-up stage and normal run stage, wherein the normal run stage comprises (i) continuously providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, a formate salt, water and optionally propane, wherein in the liquid feed stream, the molar amount of the formate salt relative to the molar amount of hydrogen peroxide at a given point of time during the normal run stage is aN(Fo/H2O2); (ii) continuously passing the liquid feed stream provided in (i) into an epoxidation zone comprising a catalyst comprising a titanium zeolite having framework type MWW, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation zone, obtaining a reaction mixture comprising propylene oxide, acetonitrile, water, the formate salt, optionally propene, and optionally propane; (iii) continuously removing an effluent stream from the epoxidation zone, the effluent stream comprising propylene oxide, acetonitrile, water, at least a portion of the formate salt, optionally propene, and optionally propane; wherein the normal run stage is characterized in an average rate of change of aN(Fo/H2O2) of less than 0 h−1.
Abstract:
A continuous process for the preparation of propylene oxide, comprising (i) providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, water, dissolved potassium dihydrogen phosphate, and optionally propane; (ii) passing the liquid feed stream provided in (i) into an epoxidation reactor comprising a catalyst comprising a titanium zeolite of structure type MWW, and subjecting the liquid feed stream to epoxidation reaction conditions; (iii) removing an effluent stream from the epoxidation reactor; wherein the concentration of the dissolved potassium dihydrogen phosphate in the liquid feed stream is at least 10% of the solubility limit of the potassium dihydrogen phosphate in the liquid feed stream.
Abstract:
The invention relates to a method for producing butadine from n-butenens, consisting of the following steps: A) a feed gas flow (a) containing n-butenes is provided; B) the feed gas flow (a) containing n-butenes and an oxygen-containing gas is fed to at least one dehydrogenation area and is oxidatively dehydrogenated from n-butenes to form butadiene; a product gas flow (b) containing butadiene, unreacted n-butenes, water vapour, oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases is obtained; C) the product gas flow (b) is cooled and compressed in at least compression step; at least one condensate flow (c1) containing water and a gas flow (c2) containing butadiene, n-butenes, water vapour, oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases is obtained; D) non-condensable and low-boiling gas component parts containing oxygen, low-boiling hydrocarbons, optionally carbon oxides and optionally inert gases are separated from the gas flow (c2) by Da) absorbing C4-hydrocarbons containing butadiene and n-butenes in absorption means boiling at a high temperature, wherein an absorption agent flow charged with C4-hydrocarbons and the gas flow (d2) are obtained, Db) the oxygen is removed from the absorption agent flow charged with the C4-hydrocarbon by stripping with the inert gas, and Dc) the C 4 hydrocarbons are desorbed from the charged absorption agent flow and a C 4 -product gas flow (d1), which consists essentially of C 4 -hydrocarbons and has less that 100ppm oxygen, is obtained. E) the C4-product flow (d1) is separated by extractive distillation using a selected solvent for butadiene in a butadiene and the material flow (e1) containing the selective solvent and a material flow (e2) containing n-butenes; F) the butadiene and the material flow (e1) containing the selective solvent is distilled in a material flow (f1) consisting essentially of the selective solvent and a material flow (f2) containing a butadiene.
Abstract:
The present invention relates to a micropowder, wherein the particles of the micropowder have a Dv10 value of at least 2 micrometer and the micropowder comprises mesopores which have an average pore diameter in the range of from 2 to 50 nm and comprise, based on the weight of the micropowder, at least 95 weight-% of a microporous aluminum-free zeolitic material of structure type MWW containing titanium and zinc.