Abstract:
A continuous process for preparing propylene oxide proceeds by (a) reacting propene with hydrogen peroxide in a reaction apparatus in the presence acetonitrile as solvent, obtaining a stream S0 containg propylene oxide, acetonitrile, water, at least one further componen B; (b) separating propylene oxide from S0, obtaining stream S1 containing acetonitrile, water and B; (c) dividing Sa into streams S2 and S3; (d) subjects S3 to vapor-liquid fractionation in a first fractionation unit, obtaining vapor fraction stream S4a being depleted, relative to S3, of at least one of B and obtaining liquid bottoms stream S4b, and subjecting at least part of vapor fraction stream S4a to vapor-liquid fractionation in a second fractionation unit, obtaining vapor fraction stream S4c and liquid bottoms stream S4 being depleted, relative to S4a, of at least one of B; (e) recycling at least a portion of S4 to (a).
Abstract:
The present invention relates to A process for the production of a molding, comprising (I) providing a zeolitic material; (II) mixing the zeolitic material provided in step (I) with one or more binders; (III) kneading of the mixture obtained in step (II); (IV) molding of the kneaded mixture obtained in step (III) to obtain one or more moldings; (V) drying of the one or more moldings obtained in step (IV); and (VI) calcining of the dried molding obtained in step (V); wherein the zeolitic material provided in step (I) displays a water adsorption ranging from 1 to 15 wt.-% when exposed to a relative humidity of 85%, as well as to a molding obtainable or obtained according to the inventive process in addition to a molding per se and to their respective use.
Abstract:
A continuous process for the preparation of propylene oxide, comprising (i) providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, water, optionally propane, and at least one dissolved potassium salt; (ii) passing the feed stream provided in (i) into an epoxidation reactor comprising a catalyst comprising a titanium zeolite of structure type MWW, and subjecting the feed stream to epoxidation reaction conditions in the epoxidation reactor, obtaining a reaction mixture comprising propylene oxide, acetonitrile, water, the at least one potassium salt, optionally propene, and optionally pane; (iii) removing an effluent stream from the epoxidation reactor, the effluent stream comprising propylene oxide, acetonitrile, water, at least a portion of the at least one potassium salt, optionally propene, and optionally propane.
Abstract:
In a first aspect, the present invention relates to a shutdown method for a process for preparing an olefin oxide comprising a normal run stage, wherein the normal run stage comprises providing olefin, hydrogen peroxide and organic solvent into an epoxidation zone comprising an heterogeneous epoxidation catalyst, so that a reaction mixture comprising olefin, hydrogen peroxide and organic solvent is formed and subjecting the reaction mixture to epoxidation reaction conditions in the epoxidation zone, thereby obtaining a mixture comprising olefin oxide and organic solvent; wherein the shutdown method comprises (a) providing olefin and organic solvent for a period of time t1 to the epoxidation zone, so that a mixture is formed, which is essentially free of hydrogen peroxide; (b) contacting the mixture from (a) over t1 under epoxidation reaction conditions in the epoxidation zone with the heterogeneous epoxidation catalyst; (c) removing during t1 an effluent stream from the epoxidation zone, the effluent stream comprising olefin and organic solvent. In a second aspect, the present invention relates to a process for preparing an olefin oxide comprising a normal run stage and a shutdown stage, wherein the normal run stage comprises (A) providing olefin, hydrogen peroxide, water and organic solvent into an epoxidation zone comprising an heterogeneous epoxidation catalyst, so that a reaction mixture comprising olefin, hydrogen peroxide, water and organic solvent is formed; (B) subjecting the reaction mixture from (I) to epoxidation reaction conditions in the epoxidation zone, thereby obtaining a mixture comprising olefin oxide, water and organic solvent; (C) removing an effluent stream from the epoxidation zone, comprising olefin oxide, water and organic solvent; wherein the shutdown stage comprises steps (a), (b) and (c) as described with respect to the first aspect.
Abstract:
The present invention relates to a process for purification of a mixture comprising water, N-alkyl-hydroxylammonium salts and some byproducts wherein from the mixture water and byproducts are distilled off until the purity of N-alkyl-hydroxylammonium salts in the residue is 95% or higher and additionally keeping the water content during and after the distillation ≥40 wt.-% according to the residue.
Abstract:
A molding, comprising a zeolitic material having framework type MFI wherein from 98 to 100 weight-% of the zeolitic material consist of Ti, Si, O, and H, and wherein the zeolitic material having framework type MFI exhibits a type IV nitrogen adsorption/desorption isotherm, the molding further comprising a silica binder, wherein the molding has a pore volume of at least 0.8 mL/g.
Abstract:
A process for preparing a molding comprising zinc and a titanium-containing zeolitic material having framework type MWW, comprising (i) providing a molding comprising a titanium-containing zeolitic material having framework type MWW; (ii) preparing an aqueous suspension comprising a zinc source and the molding comprising a titanium-containing zeolitic material having framework type MWW prepared in (i); (iii) heating the aqueous suspension prepared in (ii) under autogenous pressure to a temperature of the liquid phase of the aqueous suspension in the range of from 100 to 200° C., obtaining an aqueous suspension comprising a molding comprising zinc and a titanium-containing zeolitic material having framework type MWW; (iv) separating the molding comprising zinc and a titanium-containing zeolitic material having framework type MWW from the liquid phase of the suspension obtained in (iii).
Abstract:
The present invention relates to a process for the regeneration of a catalyst comprising a titanium-containing zeolite, said catalyst having been used in a process for the preparation of an olefin oxide and having phosphate deposited thereon, said process for the regeneration comprising the steps: (a) separating the reaction mixture from the catalyst, (b) washing the catalyst obtained from (a) with liquid aqueous system; (c) optionally drying the catalyst obtained from (b) in a gas stream comprising an inert gas at a temperature of less than 300° C.; (d) calcining the catalyst obtained from (c) in a gas stream comprising oxygen at a temperature of at least 300° C.
Abstract:
A continuous process for the preparation of propylene oxide, comprising (i) providing a liquid feed stream comprising propene, hydrogen peroxide, acetonitrile, water, optionally propane, and at least one dissolved potassium salt of a phosphorus oxyacid wherein the molar ratio of potassium relative to phosphorus in the at least one potassium salt of a phosphorus oxyacid is in the range of from 0.6 to 1.4; (ii) passing the liquid feed stream provided in (i) into an epoxidation reactor comprising a catalyst comprising a titanium zeolite of structure type MVVW comprising zinc, and subjecting the liquid feed stream to epoxidation reaction conditions in the epoxidation reactor, obtaining a reaction mixture comprising propylene oxide, acetonitrile, water, the at least one dissolved potassium salt of a phosphorus oxyacid, optionally propene, and optionally propane; (iii) removing an effluent stream from the epoxidation reactor, the effluent stream comprising propylene oxide, acetonitrile, water, at least a portion of the at least one dissolved potassium salt of a phosphorus oxyacid, optionally propene, and optionally propane.
Abstract:
The present invention relates to an electrolyte composition (A) containing (i) at least one aprotic organic solvent; (ii) at least one conducting salt; (iii) at least one compound of formula (I) and (iv) optionally at least one further additive.