Lignin
Background
Lignin is a complex and heterogeneous polymer found in wood. It composed of aromatics crosslinked with carbohydrates. If is the second largest component of biomass on Earth and has many applications. Lignin is difficult to decompose in the wild and a dense source of energy when combusted. Lignin may be an a source of aromatic compounds for OSE.
OSE context
Aromatics from lignin
Phenols and benzenes can be produced from lignin using catalytic hydrocracking, high heat with a hydrogen feed.
US patent 4,647,704 issued to Engel et al on March 3, 1987 describes a method of hydrocracking lignin using a tungsten/nickel catalyst supported on a mildly acidic base, notably alumina. The product is a cresol, a methyl phenol, a benzene with a hydroxyl and methyl substitution. The process is conducted in a reactor under a hydrogen atmosphere at pressures of 500 - 3500 psig and temperatures of 300-450 C. Yield is improved with the use of a low weight aliphatic alcohol, namely methanol. A solvent of methanol/water (3:1) is found to have optimal yields and additional process improvements include the inclusion of a lewis acid/friedel-crafts catalyst, namely AlCl3.
http://www.google.com/patents/US3105095
http://www.cellulosechemtechnol.ro/pdf/CCT9(2010)/P.353-363.pdf