Pyrolysis of lignin following ionic liquid pretreatment at low temperature

A new and effective lignin pyrolysis method is presented for increasing the total volatiles and the tar yield by pretreating the lignin with ionic liquid 1-butyl-3-methyl-imidazolium chloride (BMIC) at low temperature. The pretreatment of lignin involves the dissolution of lignin with BMIC firstly, and then precipitated with water. The effect of BMIC pretreatment on the yield and distribution of pyrolysis products is mainly investigated. It is found that the total liquid yield and phenolic yield for lignin pretreated with BMIC at 50 °C increase by 1.27 times and 11 times, respectively, as compared with that of the untreated lignin. The pretreatment temperature plays a key role in the increase of the total liquid yield and phenolic content in tar.