(477g) Optimization of Woody Biomass Conversion Via Amine-Based Solvent Pretreatment | AIChE

(477g) Optimization of Woody Biomass Conversion Via Amine-Based Solvent Pretreatment


Islam, M. T. - Presenter, Florida Institute of Technology
Pidatala, V., Lawrence Berkeley National Laboratory
Choudhary, H., Sandia National Laboratories
Simmons, B., Lawrence Berkeley National Laboratory
Rodriguez, A., Joint BioEnergy Institute
Gladden, J. M., Joint BioEnergy Institute
The development of scalable and cost-efficient biomass pretreatment methods to enhance the conversion of biomass has been a challenging problem over the past decades. The purpose of this work is to optimize the conversion of woody biomass feedstocks (walnut, almond) to fermentable sugars when subjected to a process using distillable amine-based solvents, as well as demonstrating high solvent recovery and characterizing the resulting biomass fractions. Therefore, pretreatment experiments were performed at a bench-scale using an almond and walnut mix (80/20, w/w) with butylamine, ethanolamine,
ethylenediamine, triethylamine (boiling points; 78, 170, 117, and 89 °C, respectively), and amine-water mixtures at different weight ratios (10-75 wt%). The biomass-solvent ratio was maintained at a fixed value and the pretreatment was performed in a pressure tube reactor for a specified reaction time. The pretreated biomass slurry was processed in three pathways: (1) washed with water, (2) distilled (3) distilled and washed with water. Each of the fractions along with raw untreated biomass were characterized for glucan/xylan composition, CHN content, and sugar release efficacy. The glucan and xylan compositions suggested that the glucan/xylan content were improved by ~18-36 % with decreasing water percentage. Results indicate that pathway-1 showed >90 % sugar release, about 41-43 % higher than pathways-2 or 3. Elemental analysis via CHN analyzer showed that a reduction in C/N ratio follows their boiling point order after distillation. Washing of distilled biomass increases the C/N ratio by 19%, 384%, and 232% for butylamine, ethanolamine, and ethylenediamine, respectively, suggesting washing could hardly remove any butylamine as chemical bonding might be present. In addition, adding water in the amine-based solvent showed higher solid recovery, implying lower sugar release than standalone amine-based solvent. Ongoing solvent recycling experiments suggested promising recovery of these amine-based solvents after lignocellulosic biomass pretreatment.

Keywords: Biomass; Pretreatment; Amine-based solvent, Enzymatic hydrolysis; Sugar;