Hydrogenation of Maleic Anhydride by Nickel-Kieselguhr Catalyst

Abstract

A kinetic study of the hydrogenation of maleic anhydride over nickelcatalyst supported on kieselguhr was carried out, in order to elucidate the reaction mechanism and the reason why tetrahydrofuran or r-butyrolactone can not be obtained in high yield. The reactions were carried out batchwise under the following conditions temperature 180.y300C, pressure 120A 150 kg/cm2, and catalyst concentration 10 Wt%. Reactions of suecinic anhydride and succinic acid were alsostudied to con relementary processes.Reactions from maleic anhydride and succinic anhydride appear to proceed through different reaction schemes above 2500C, At low temperatures, the production of succinic acid is thermodynamically favorabie, but succinic acid was not hydrogenated to 7-butyrolactone. On the other hand, at high temperatures, the production of polymeric residue was predominant owing to the double bond of maleic anhydride.When the two-step hydrogenation method was applied, the yield of r-butyrolactone from maleic anhydride becameas high as in the case of the reaction of succinic anhydride. How, .ever, the tetrahydrofuran yield was very low even in this case.