Optimization of component yields and thermal properties by organosolv fractionation of loblolly pine (Pinus taeda) using response surface design
Bozell, J. J., A. Astner, T. M. Young, and T. G. Rials.  2018.  Bioenergy Research, 11(3):1-13.

Abstract:
Lignin, a low value by-product of biomass fractionation, is of current particular interest for the production of value added materials such as carbon fibers within a biorefinery. Accordingly, we have isolated lignin, hemicellulose, and cellulose by organosolv fractionation of loblolly pine (Pinus taeda) under the influence different fractionation severities (2.503.31). A designed experimental matrix targeted maximum lignin and pulp yields and lignin glass transition temperature (Tg) as a function of several process parameters. Optimal fractionation conditions were estimated from an enhanced regression model of the statistically significant variables generated using response surface design (RSD). The most significant factor influencing lignin and pulp yields was solvent composition (p-value < 0.0001). A maximum lignin yield of 94.71 wt% and maximum cellulose yield of 74.96 wt% were determined at combined severities of 3.21 and 2.63, respectively. The lowest Tg of 132.83 C was found at a combined severity of 2.82.