Ammonolysis of ethanol on pure and zinc oxide modified HZSM-5 zeolites

Abstract

Reaction between ethanol and ammonia have been studied on various zinc oxide modified HZSM-5 (Si/Al=225) catalysts under various conditions of temperature, C/N ratio of the reactants and their WHSV. Two pure zinc oxides were taken for the study.One was a highly active acidic form ZI and the other was a stoichiometric non acidic zinc oxide Z(2). The activity of the catalysts for ammonolysis reaction followed the order Z(2)much less thanZ(1)much less than HZSM-5. However, for composite catalysts containing 10-40 percent Z(1) on HZSM-5, the activity increased synergistically and became maximum (similar to 81 percent conversion of alcohol) for the catalyst 40 percent Z(1)/HZSM-5 and about 50 percent conversion for the catalyst 40 percent Z(2)/HZSM-5. The products formed were mainly N-heterocycles.Some novel high molar mass N-heterocycles were also detected. The catalytic activity and product selectivity was crucially affected by the reaction conditions, particularly the effect of temperature; the optimum yield of the products was obtained at the catalyst temperature of 723 K. C/N ratio 0.3892 and WHSV of 2.5 h(-1).