Abstract: Disclosed is a method of recovering and purifying 3,4-epoxy-1-butene (epoxybutene) from a reaction product gas, obtained by the vapor phase catalytic partial oxidation of 1,3-butadiene with oxygen over a silver catalyst. The recovery and purification comprises absorption of the epoxybutene into a water-miscible solvent followed by separation of the absorbed epoxybutene from the absorbent by extraction into a water-immiscible solvent. A method of recovering and purifying epoxybutene from the extraction solvent and other reaction by-products by a novel combination of distillation and decantation steps also is disclosed.

Abstract: Disclosed is a process for the efficient removal of carbon dioxide from a gas recycle system generated in an epoxidation process wherein 1,3-butadiene is selectively oxidized to 3,4-epoxy-1-butene. Carbon dioxide at low partial pressure is absorbed into an alkanolamine solution from a low pressure recycle gas stream containing high levels of oxygen. Also disclosed is a means for reclaiming the alkanolamine from a solution of a carbon dioxide-alkanolamine salt or adduct formed in the carbon dioxide removal process.

Abstract: A process for recovering 3,4-epoxy-1-butene from a vapor phase catalytic oxidation reactor effluent where 1,3-butadiene is reacted with oxygen over a silver catalyst, the process includes the steps of contacting the reactor effluent with an absorbent in an absorber and vaporizing in the absorber an effective amount of a non-reactive coolant to cool the absorber to a temperature of less than about 40.degree. C. and a pressure of less than about 4 bar. Advantageously, the vaporization of the non-reactive coolant proximate to the absorber allows the absorber to be operated at lower temperatures and pressures than heretofore possible and provides a further advantage of allowing higher O.sub.2 concentrations in the feed to the epoxidation reactor.