Valuable Products from Thermal Degradation of Industrial Waste Lignin in the Presence of Chemical Additives

Abstract

Pulp and paper industries produce lignin as waste material in very large quantities, and it causes a great disposal problem which poses an environmental burden. The structure of lignin shows a three-dimensional branched polymer with aromatic phenolic units with various functional groups; it degrades slowly and has the potential to produce valuable chemicals. In this study, the waste lignin obtained from Simplex Paper Mills, Gondia, Maharashtra, India, was purified and characterized by CHN analysis, FTIR spectroscopy, and thermal studies. The degradation of this waste lignin was carried out at 400–500°C without and with the chemical additives such as ZnCl2 and K2CO3 separately in N2 atmosphere. The degradation of lignin yielded gaseous products, distillate, tarry material, and highly porous carbonaceous material. The distillate was analyzed through GC-MS studies, and it showed the presence of various phenolic compounds having immense industrial applications. The influence of the chemical additives used on the formation of phenolic compounds was studied. Thus, this study indicated that industrial waste lignin (IWL) has the potential to produce valuable chemicals when subjected to thermal degradation.