Hydro-liquefaction of thermal dissolution soluble fraction of Shenfu subbituminous coal and reusability of catalyst on the hydro-liquefaction

The thermal dissolution (TD) of a Chinese sub-bituminous coal was carried out with different solvents, and five thermal dissolution soluble fractions (TDSFs) with different thermal dissolution soluble yield (TDSY) were obtained. The catalytic hydro-liquefactions of the five TDSFs suggested that the TDSFs obtained have higher liquefaction activity compared to that of raw coal. There is no relation between the liquefaction activity of TDSF and its TDSY. The TDSF with high content of polycyclic aromatic (PCA) ring systems gives lower liquefaction activity. The reusability of a solid acidic catalyst BF3/SBA-15 used in the hydro-liquefaction of TDSF was measured. The results suggested that the reused catalyst has higher catalytic hydro-liquefaction activity compared to that of fresh catalyst. Carbon deposition in the reused catalyst slowly takes place, and the catalyst used in the catalytic liquefaction of TDSF has a good reusability. The recycled use of catalyst for the liquefaction of TDSF is capable at least 4 times. Therefore, it supplies a new pathway to realize high-efficiency coal liquefaction in economy due to the use of recycled high efficient catalyst in the liquefaction of TDSF.