COMPARISON OF VANADIUM-OXIDE CATALYSTS FOR SYNTHESIS OF BENZENE - BENZENE PURITY, YIELDS AND RECONDITIONING METHODS

This study compares vanadium oxide catalysts from three different sour ces: Noakes (N), Harshaw Chemical (H) and Kh. Arslanov at the St. Pete rsburg State University, Russia(R). The catalysts are used to convert acetylene to benzene in the last step of benzene synthesis. The organi c 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 9 4.3%. (N) averaged 92.6%, (H) averaged 91.1% and (R) averaged 92.0%. A conversion residue in the catalysts was analyzed for delta(13)C and f ound to be isotopically lighter relative to acetylene by -2.2 parts pe r thousand for (N) and (H) and -3.9 parts per thousand for (R). Benzen e yields were studied on different reconditioning methods applied to a ll catalysts: heating to 400 degrees C in air averaged 92.3%; the same temperature with a half and half mixture of O-2 and Ar averaged 91.9% , adding a half and half mixture of H-2 and Ar at 200 degrees C to the end of this treatment averaged 91.8%. Based on this research, the obv ious difference seen between the catalysts is in their trace by-produc ts.