A Review of Lignin Chemistry and its Biorefining Conversion Technologies

Lignin is potentially an abundant source for the synthesis of energydense fuels, phenolic chemicals, high-performance polymers, carbon fibers and value-added products surrogate to those conventionally obtained from fossil fuels. Low in cost, abundant in existence and product efficiency equivalent to the petroleum-derived products make lignin an excellent naturally occurring feedstock. This review attempts to broadly present the recent advancements in the field of lignin conversion and its applications as an energy resource. The growing popularity of lignin and the comprehensive research that is being conducted on biorefining has led to the inception of compiling this valuable information in the form of a review presented herewith. This review encompasses the vast extensive research towards lignin conversion and the new developments in this field. This paper reviews the chemistry of lignocellulosic biomass and the physicochemical changes occurring during biomass pre-treatment. Several ligninolytic microorganisms responsible for the degradation of lignin are also discussed. In addition, pyrolysis, liquefaction, gasification and microwave treatment for lignin conversion to biofuels and chemicals are elaborated.