10.2478/s11814-009-0245-0

Abstract

Methods for regenerating H3PW12O40 catalyst in the solvent-free direct preparation of dichloropropanol (DCP) from glycerol and hydrochloric acid gas were investigated. Regenerated H3PW12O40 catalyst was then applied to the solvent-free direct preparation of DCP. In the solvent-free direct preparation of DCP, selectivity for DCP over H3PW12O40 catalyst regenerated by method I (recovery of solid H3PW12O40 catalyst by evaporating homogeneous liquidphase product solution) significantly decreased with increasing recycling run, while that over H3PW12O40 catalyst regenerated by method II (regeneration of H3PW12O40 catalyst by oxidative calcination of solid product recovered by method I) was slightly decreased with no significant catalyst deactivation with respect to recycling run. On the other hand, selectivity for DCP over H3PW12O40 catalyst regenerated by method III (regeneration of H3PW12O40 catalyst by recrystallization and subsequent oxidative calcination of solid product recovered by method II) was the same as that over fresh catalyst without any catalyst deactivation with respect to recycling run. Thus, method III was found to be the most efficient method for the regeneration of H3PW12O40 catalyst.