Effect of catalyst and atmosphere on liquefaction performance of the lignite in optimized two-stage liquefaction process

Since most oxygen containing structures in lignite will break at relatively low temperature and macromolecular structure will pyrolyze at higher temperatures, two-stage liquefaction process is proposed to obtain better liquefaction performance and reduce energy consumption. Different collocations of catalyst and atmosphere were examined and results showed that the total conversion and oil yield could increase with a percentage of 8.12% and 14.04% in maximum. The collocation of CO atmosphere and sodium carbonade had the best adaptability to moisture and a relatively good liquefaction performance. The effect of sodium carbonade on product conversion and feasibility of replacing hydrogen with CO or syngas were discussed. This work is proposing solutions for lignite liquefaction to strengthen the efficient use of low-rank coal resources.