Effect of calcination temperature of alumina supports on the wax hydrocracking performance of Pd-loaded mesoporous alumina xerogel catalysts for the production of middle distillate

Selective production of middle distillate (C-10-C-20) from synthesis gas (CO + H-2) through wax hydrocracking was carried out in a dual-bed reactor. Co/TiO2 catalyst was used in the first-bed reactor to produce wax (C21+) from synthesis gas, and Pd-loaded mesoporous alumina xerogel (denoted as Pd/XA) catalysts were used in the second-bed reactor to produce middle distillate through wax hydrocracking. The effect of calcination temperature of mesoporous alumina xerogel supports on the wax hydrocracking performance of Pd/XA catalysts was investigated. The increment of middle distillate selectivity increased with increasing medium acidity of Pd/XA catalyst. Among the Pd/XA catalysts, the I'd catalyst loaded on mesoporous alumina xerogel support calcined at 800 degrees C retained the highest medium acidity, and at the same time, showed the best catalytic performance in the hydrocracking of wax. (C) 2008 Elsevier B.V. All rights reserved.