Byproduct lignins, sources

Various pulping technologies for wood and other biomass have been used for centuries to produce fiber, primarily for paper production. These processes effecbvely separate and clean the cellulose for use as fiber. However, the hemicellulose and lignin byproducts are not typically used for chemical products. The depolymerized hemicellulose in pulping liquor is a large source of biomass carbohydrate that could potentially be used for chemical producbon. 

Ferulic acid is ubiquitously present in plants, mainly as part of the cell walls esterified to polysaccharides such as arabinoxylans. It is also an intermediate in the secondary metabolism of phenylalanine and tyrosine. It can be conveniently isolated from corn hulls, rice bran, and sugar beet. Biocatalytic processes using cinnamoyl esterases and glycosyl hydrolases have been developed for this purpose [32]. Another potentially interesting source is lignin, since ferulic acid is one of the prominent byproducts of its degradation. 

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