Patent ID: 7138534

Claim:
A process for the continuous preparation of an olefinic oxide by direct oxidation of an olefin with hydrogen peroxide, which comprises: (a) feeding into a reaction zone containing an epoxidation catalyst the olefin, the hydrogen peroxide, and a buffer and a reaction solvent; (b) feeding the product of the reaction zone into a distillation zone to obtain a head product comprising olefinic oxide and unreacted olefin, and a tail product comprising unreacted hydrogen peroxide, reaction by-products and water and reaction solvent; (c) feeding the tail product of the distillation zone and an aqueous basic solution into a decomposition zone containing a decomposition catalyst to decompose hydrogen peroxide in the tail product; (d) feeding the mixture leaving the decomposition zone comprising oxygen, water and solvent, optionally together with an inert gas, into a phase separation zone to obtain at the top a gaseous phase containing oxygen, traces of solvent and optionally an inert gas, and at the bottom a liquid phase comprising water and reaction by-products and solvent,; (e) feeding the gaseous phase leaving the phase separation zone into a condensation zone to recover the residual solvent, and discharging the uncondensable compounds; (f) feeding the liquid phase leaving the phase separation zone and the solvent leaving the condensation zone into a further distillation zone to obtain at the top a solvent which is recycled into the reaction zone in step (a), and a tail product comprising water, the reaction by-products and the traces of solvent, which tail product is discarded; (g) feeding the head product from the distillation zone in step b), together with the vent products from the reactor zone in step a) into a further distillation zone to obtain a head product comprising unreacted olefin, which is recycled into the reaction zone in step a), and a tail product comprising the olefinic oxide; (h) feeding the tail product from the distillation zone in step g) into a purification zone to recover the residual olefin, which is recycled into the reaction zone in step a), a liquid phase comprising solvent, which is recycled into the distillation zone in step b) and the olefinic oxide.