Catalytic Hydroconversion of Runbei Lignite over a Highly Active Solid Superacid

Abstract

A highly active solid superacid, denoted as TFMSA/CNOFW, was prepared by calcining Ni-organic framework (NOFW) to get calcined NOFW (CNOFW), into which trifluoromethanesulfonic acid (TFMSA) was impregnated. It was used to catalyze the hydroconversions of both oxybis(methylene)dibenzene (OBMDB) and the extraction residue (ER RL ) from Runbei lignite (RL). The results show that over TFMSA/CNOFW, OBMDB was hydrocracked to toluene as the main product, indicating that TFMSA/CNOFW can heterolytically spit H 2 to relatively mobile H + and immobile H À attached on TFMSA/CNOFW. The addition of H + to the oxygen atom (OA) in OBMDB produces phenylmethylium (PM I ) and phenylmethanol (PM II ). Toluene was yielded by the following 2 reactions: (1) the abstraction of H À by PM I from the TFMSA/CNOFW surface and (2) H + addition to the OA in PM II , subsequent dehydration to form PM I , and the abstraction of H À by PM I from the TFMSA/CNOFW surface. In the similar mechanism, ER RL was hydrocracked to acetonesoluble portion in the yield of 78.6% over TFMSA/CNOFW under 4 MPa of initial hydrogen pressure at 310 °C for 4 h.