Abstract

Lignin is primarily used to produce energy in the pulp and paper industry. However, given its phenolic structure and the presence of varied functional groups (phenolic hydroxyl, aliphatic hydroxyl, carboxyl, methoxyl and carbonyl), lignin could be a valuable raw material for the production of carbon fibers, active carbon, epoxy resins, phenolic adhesives, emulsifiers, and several other compounds. A novel, selective chemo-enzymatic process to generate epoxide structures was developed. A lipase (Candida antarctica lipase B, Novozyme 435 R (EC 3.1.1.3)) catalyzed the formation of peroxyacids from fatty acids in the presence of hydrogen peroxide. The peroxyacids were then reacted with unsaturated vegetable oils for the formation of oxirane rings through of the epoxidation of the C=C bond. Similar protocols were applied to a lignin degradation model compound (vanillic acid) and to processed lignin in order to generate epoxide structures.