Tracing Sweetgum Lignin's Molecular Properties through Biorefinery Processing.

Changes to the molecular properties of lignin over the course of biorefinery processing were investigated by using sweetgum as a feedstock. Hydrothermal pretreatment has been used because it is an economically attractive, green process. Three representative biorefinery lignin preparations were obtained, with about 70 % yield based on raw lignin.

Lignocentric analysis of a carbohydrate-producing lignocellulosic biorefinery process.

A biologically-based lignocellulosic biorefinery process for obtaining carbohydrates from raw biomass was investigated across six diverse biomasses (three hardwoods & three nonwoods) for the purpose of decoding lignin's influence on sugar production. Acknowledging that lignin could positively alter the economics of an entire process if valorized appropriately, we sought to correlate the chemical properties of lignin within the process to the traditional metrics associated with carbohydrate production-cellulolytic digestibility and total sugar recovery. Based on raw carbohydrate, enzymatic recovery ranged from 40 to 64% w/w and total recovery ranged from 70 to 87% w/w.

Biomass pretreatments capable of enabling lignin valorization in a biorefinery process.

Recent techno-economic studies of proposed lignocellulosic biorefineries have concluded that creating value from lignin will assist realization of biomass utilization into valuable fuels, chemicals, and materials due to co-valorization and the new revenues beyond carbohydrates. The pretreatment step within a biorefinery process is essential for recovering carbohydrates, but different techniques and intensities have a variety of effects on lignin. Acidic and alkaline pretreatments have been shown to produce diverse lignins based on delignification chemistry.