Research on renewable biomass resource-lignin.

Lignin is an abundant natural aromatic renewable resource on earth.A 180-years long history has been past from the discovery of lignin to the determination of lignin aromatic compounds,and its basic types of functional groups and chemical structure.However,the speed of lignin research is slowed down due to the complexity and variability of lignin structure.The author describes the formation of lignin and their chemistry research system,reviews the development of lignin study,analyzes the characteristics and difficulties of lignin research,and highlights future research direction and hot topics.