Process to afford gamma butyrolactone and tetrahydrofuran

Abstract

A process for production of tetrahydrofuran and gamma butyrolactone by hydrogenation of maleic anhydride recovered from a process of conversion of a n-butane. The process consists essentially of the following steps: A) converting n-butane to maleic anhydride by catalytic vapor phase oxidation; B) recovering maleic anhydride from the effluent gases of butane oxidation by selective absorption in gamma butyrolactone, forming a maleic anhydride-gamma butyrolactone mixture; C) removing water from the maleic anhydride-gamma butyrolactone mixture in a stripper under the action of a gas and/or under vacuum conditions, producing a maleic anhydride-gamma butyrolactone mixture with minimum water and maleic acid content; D) recovering gamma butyrolactone contained in the exhaust gases leaving the maleic anhydride absorber, by absorption in water; E) dehydrating the recovered gamma butyrolactone and recycling it to the maleic anhydride absorber; F) hydrogenating the dewatered maleic anhydride-gamma butyrolactone mixture, over suitable catalyst (s), under conditions favouring the formation of tetrahydrofuran and gamma butyrolactone; G) separating by distillation tetrahydrofuran, gamma butyrolactone and the by-products from the resulting hydrogenation mixture; H) recycling a gamma butyrolactone rich stream to the selective absorption of maleic anhydride.