Chromium-free catalysts for selective vapor phase hydrogenation of maleic anhydride to γ-butyrolactone

✍ Scribed by Gian Luca Castiglioni; Maria Ferrari; Alberto Guercio; Angelo Vaccari; Rosa Lancia; Carlo Fumagalli

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 473 KB
• Volume: 27
• Category: Article
• ISSN: 0920-5861
• DOI: 10.1016/0920-5861(95)00209-x

✦ Synopsis

The replacement of chromite catalysts in the selective vapor phase hydrogenation of maleic anhydride (MA) to y-butyrolactone (GBL), useful intermediate in the production of chlorine-free solvents, was investigated. In order to avoid the interferences related to physical dishomogeneity of the precursors, Cu/Zn/M catalysts (38:38:24, atomic ratio percent, where M = Cr, A1 or Ga) obtained by thermal decomposition of hydrotalcite-type anionic clays were used. The Al-containing catalyst exhibited better performances than the Cr-containing catalyst, while with gallium no significant differences in comparison to aluminum were observed, capable of justifying the significantly higher cost. Cu/Zn/AI catalysts showed complete MA conversion and high yields in GBL, with maximum values when the Al-content was about 17% (as atomic ratio) and the Cu/Zn ratio fell between 0.5 and 1.0. Furthermore, better carbon balances were observed for these last catalysts, which may be attributed to lower light hydrocarbon synthesis and tar formation.