GB1327497A - Propylene oxide - Google Patents

Abstract

1327497 Propylene oxide BP CHEMICALS INTERNATIONAL Ltd 25 May 1972 [23 June 1971] 29395/71 Heading C2C Propylene oxide is produced in a process which comprises reacting propylene and a molecular oxygen containing gas at an elevated temperature in the presence of a catalyst composition comprising elemental silver together with a halide or halides (as hereinafter defined) of one or more metals of Group II of the Periodic Classification due to Mendeleef. The process may be carried out in the vapour phase by passing a gaseous mixture comprising propylene and a molecular oxygen containing gas over the catalyst composition. The gaseous reaction mixture may also contain an inert gaseous diluent, e.g. helium or nitrogen within the range of 0 to 97% by volume of the mixture. The reaction temperature may be in the range 100‹ to 400‹ C. and the pressure range from atmospheric to 20 atmospheres gauge and the contact time may be 0À1 to 60 seconds. The process may also be carried out in the liquid phase by introducing propylene into a reaction zone containing a water-immiscible organic solvent, e.g. benzene or dimethyl phthalate carrying a solid suspension of catalyst composition and thereafter passing a molecular oxygen containing gas, e.g. air, through the solvent to oxidize the propylene. The term "halide" is defined as any inorganic radical containing a halogen atom e.g. chloride, bromide, fluoride, hypochlorite, hypobromite, chlorate and/or bromate. The produced propylene oxide may be recovered from the reaction mixture by, for example, passing the reaction gases into a gas/liquid scrubbing agent, e.g. cooled ethanol, water and esters of ethylene glycol or propylene glycol, to absorb the oxide, followed by distillation.