Abstract: The present invention is an improved process for separating alcohols from ethers and/or hydrocarbon raffinate in an etherification process. The excess alcohol reactant, which forms azeotrope mixtures with the product ethers and C.sub.4 -C.sub.7 raffinate, is removed by passing the liquid azeotrope mixture over a pervaporation membrane which effectively breaks the azeotrope and permeates the alcohol with high flux and high selectivity. In a typical etherification process, one or more pervaporation membrane units can be located ahead of the ether/raffinate distillation step, in conjunction with the distillation step with a liquid side draw, after the distillation step, or a combination of any of the above. The present invention also provides an improved process for separating alcohols from ethers and/or hydrocarbon raffinate in an ether decomposition process for the production of high purity iso-alkene products.

Abstract: A process is described for producing ethylene and propylene in high selectivity from feed streams containing ethane and propane. The process involves separating the feed into ethane and propane fractions and subsequently cracking the ethane fraction to produce ethylene and dehydrogenating the propane fraction to produce propylene. The fractions are then combined and purified, and the ethylene and propylene products are recovered. Any unreacted ethane or propane is recycled back to the cracking or dehydrogenation units respectively.