公开(公告)号：US20230114770A1

公开(公告)日：2023-04-13

申请号：US17914395

申请日：2021-03-26

Applicant: BASF SE

Inventor： Andrey KARPOV ,  Christian WALSDORFF ,  Thorsten JOHANN ,  Christian ALMER ,  Daniela RIECK ,  Christian BARTOSCH ,  Mauricio GROBYS ,  Tobias WEINLAND ,  Holger BORCHERT

IPC: B01J23/68 ,  B01J37/02 ,  B01J37/14 ,  B01J37/16 ,  C07D301/10

Abstract: A process for producing a silver-based epoxidation catalyst, comprising i) impregnating a particulate porous refractory support with a first aqueous silver impregnation solution comprising silver ions and an aminic complexing agent selected from amines, alkanolamines and amino acids; ii) converting at least part of the silver ions impregnated on the refractory support to metallic silver by heating while directing a stream of a first gas over the impregnated refractory support to obtain an intermediate catalyst, wherein the first gas comprises at least 5 vol.-% oxygen; iii) impregnating the intermediate catalyst with a second aqueous silver impregnation solution comprising silver ions, an aminic complexing agent selected from amines, alkanolamines and amino acids, and one or more transition metal promoters, in particular rhenium; and iv) converting at least part of the silver ions impregnated on the intermediate catalyst to metallic silver by heating while directing a stream of a second gas over the impregnated intermediate catalyst to obtain the epoxidation catalyst, wherein the second gas comprises at most 2.0 vol.-% oxygen, wherein the impregnated refractory support and the impregnated intermediate catalyst are each heated to a temperature of 200 to 800° C. The process of the invention surprisingly allows for obtaining a catalyst with high selectivity in a cost-efficient manner. The invention also relates to a silver-based epoxidation catalyst obtainable by such a process, and to a process for producing an alkylene oxide by gas-phase oxidation of an alkylene, comprising reacting an alkylene and oxygen in the presence of a silver-based epoxidation catalyst obtainable by the above process.

公开(公告)号：US20210039074A1

公开(公告)日：2021-02-11

申请号：US16968548

申请日：2019-02-06

Applicant: BASF SE

Inventor： Andrey KARPOV ,  Andreas LEHR ,  Daniela RIECK ,  Holger BORCHERT ,  Tobias WEINLAND ,  Marco BOSCH ,  Christian WALSDORFF ,  Christian BARTOSCH ,  Juergen ZUEHLKE

IPC: B01J23/50 ,  B01J35/10 ,  B01J35/02 ,  B01J37/02 ,  B01J37/08 ,  C07D301/02

Abstract: A method for preparing a silver impregnation solution comprises (a) charging a neutralization reactor R1 with an aqueous organic amine; (b) adding oxalic acid powder through a first feeding conduit to the neutralization reactor R1 to obtain an aqueous oxalic acid-organic amine solution; (c) directing the aqueous oxalic acid-organic amine solution from the neutralization reactor to a complexation reactor R2; (d) adding particulate silver oxide through a second feeding conduit to the complexation reactor R2 to obtain a silver impregnation solution; and, optionally, (e) subjecting the silver impregnation solution to filtration. The silver impregnation solution is used for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide. The method allows for the preparation of a silver impregnation solution in an efficient and occupationally and environmentally safe way. Security hazards which can occur when oxalic acid and silver oxide are added to an aqueous amine solution using the same powder feeding equipment or the same reactor are avoided.