Production of aromatic hydrocarbons from Mae-Moh lignite

Lignite from Mae-Moh basin in Thailand was used as raw feed to produce value-added chemicals, especially aromatic hydrocarbons. It was found that the hydropyrolysis of Mae-Moh lignite in atmospheric pressure of hydrogen gas is suitable for aromatic hydrocarbon production. For the hydropyrolysis of Mae-Moh lignite at 600 °C and the heating rate of 15 °C/s, 15 wt.% (dry, ash-free basis; daf) of benzene, toluene and xylenes (BTX) and decalin, tetralin and naphthalene (DTN) was produced. To enhance the yield of aromatic fractions, the upgrading of coal volatile over HY zeolite at 500 °C was investigated. The yield of BTX and DTN was 14 wt.% (daf). The attempt was made to convert aliphatic hydrocarbons to aromatic products by reforming of aliphatic products from the above hydropyrolysis/upgrading process over H-ZSM-5 zeolite. The calculated yield of BTX and DTN after this treatment was 20 wt.% (daf).