Directed construction of W/HZSM-5 catalyst exhibiting high selectivity for benzene compounds in coal tar

The heavy fractions produced during low-rank coal pyrolysis exhibit high molecular weights and strong polarity, posing significant challenges for upgrading. Among these, light aromatic compounds hold high added value. Among the upgrading methods attempted, catalytic pyrolysis technology represents a key pathway for upgrading coal tar. This study employed a hydrothermal method to prepare W/HZSM-5 catalysts, featuring W-loaded molecular sieve HZSM-5 as the support, for the catalytic upgrading of coal pyrolysis tar. Experimental results demonstrate that W/HZSM-5 significantly promotes the formation of benzene compounds in tar. Compared to HZSM-5 alone, W/HZSM-5 exhibits outstanding catalytic performance, increasing the total yield of light components by 50%. It demonstrates high selectivity toward aromatic compounds, boosting the aromatic content in the resulting tar by 97% and alkylbenzene content by 200.1%, while significantly reducing the content of medium-weight biphenyl compounds. Additionally, it markedly enhances the catalyst’s resistance to coking. The output of high-value-added products is boosted, and the yield of light fractions is also improved with the aid of this catalyst offering a viable pathway for the high-value utilization of low-rank coal pyrolysis tar.