Comparison of vanadium oxide catalysts for synthesis of benzene; benzene purity, yields and reconditioning methods.

Abstract

This study compares vanadium oxide catalysts from three different sources: Noakes (N), Harshaw Chemical (H) and Kh. Arslanov at the St. Petersburg State University, Russia (R). The catalysts are used to convert acetylene to benzene in the last step of benzene synthesis. The organic purity of benzene in all three catalysts is high; 99.91-99.93% for (N) and (H) and 99.87% for (R). The benzene yields range from 90.0 to 94.3%. (N) averaged 92.6%, (H) averaged 91.1% and (R) averaged 92.0%. A conversion residue in the catalysts was analyzed for delta (super 13) C and found to be isotopically lighter relative to acetylene by -2.2 per mil for (N) and (H) and -3.9 per mil for (R). Benzene yields were studied on different reconditioning methods applied to all catalysts: heating to 400 degrees C in air averaged 92.3%; the same temperature with a half and half mixture of O (sub 2) and Ar averaged 91.9%, adding a half and half mixture of H (sub 2) and Ar at 200 degrees C to the end of this treatment averaged 91.8%. Based on this research, the obvious difference seen between the catalysts is in their trace by-products.