Study on the liquefaction of Shengli lignite with NaOH/methanol

The behavior of liquefaction of Shengli (SL) lignite with NaOH–methanol was studied. Based on high content of water in lignite and the economy of the process (amounts of NaOH used), the effects of NaOH concentration, methanol content and water content on the liquefaction behavior of SL lignite were preliminarily investigated. The results show that SL lignite has a good reaction activity, and its conversion and product yield reach 98% and 99% at 300 °C for 1 h respectively, when the ratio of SL lignite, NaOH and methanol is for 1 g:1 g:10 ml. NaOH participates in the reaction. The increase of the amount of NaOH significantly increases the amount of tetrahydrofuran soluble (THFS) fraction. Methanol plays a promotion role in the liquefaction, which makes the product yield increase for about 16–23%. Water content has little effect on the SL lignite conversion, product yield and the product distribution. Solvent-extraction components of liquefaction products of SL lignite with NaOH–methanol are mainly THFS, toluene soluble (TS), hexane soluble (HS) and water soluble fractions (WS). The FTIR analyses of solvent-extraction components show that all of the fractions contain OH group, aromatic structure, carbonyl group and aromatic ether oxygen group.