Catalytic hydroconversion of Yiwu lignite over solid superacid and solid superbase

Trifluoromethanesulfonic acid supported on attapulgite powder (TFMSA/AP) and Mg 2 Si/γ-Al 2 O 3 were facilely prepared by impregnating TFMSA onto AP and Mg 2 Si onto γ-Al 2 O 3 . The extraction residue from Yiwu lignite (YL ER ) was subjected to non-catalytic hydroconversion (NCHC) and catalytic hydroconversion (CHC) over TFMSA/AP and Mg 2 Si/γ-Al 2 O 3 , respectively. Detailed molecular compositions of the soluble portions from the NCHC (SP NCHC ) and CHC over TFMSA/AP (SP CHC-A ) and Mg 2 Si/γ-Al 2 O 3 (SP CHC-B ) were characterized with a gas chromatograph/mass spectrometer. As a result, the yields of SP CHC-A and SP CHC-B are 19.6% and 17.5%, respectively, which are much higher than that of SP NCHC (1.04%), suggesting that both TFMSA/AP and Mg 2 Si/γ-Al 2 O 3 show excellent activity for the CHC of YL ER . Arenes and arenols are predominant in SP CHC-A and SP CHC-B , respectively, while large amounts of alkanoates were detected in SP NCHC . The results indicate that TFMSA/AP effectively catalyzes the cleavage of C ar –C alk and C alk –O bridged bonds (BBs) in YL ER , while Mg 2 Si/γ-Al 2 O 3 significantly promotes the cleavage of C–O BBs in YL ER . Di(1-naphthyl)methane, 1-methylnaphthalene, oxydibenzene, and benzyloxybenzene were used as coal-related model compounds (CRMCs) for the CHC to further explore the catalysis of TFMSA/AP and Mg 2 Si/γ-Al 2 O 3 . The results show that TFMSA/AP not only releases mobile H + but also heterolytically splits H 2 to form an immobile H − and a mobile H + , leading to the cleavage of C alk –C ar and C alk –O BBs in the CRMCs. In contrast, Mg 2 Si/γ-Al 2 O 3 facilitates heterolytically splitting H 2 to an immobile H + and a mobile H − , resulting in the cleavage of C–O BBs in the CRMCs.