Conversion of Lignocellulosic Biomass into Its Molecular Components by Sequential Combination of Organic Acid and Base
Open Access
- Author:
- Noda, Yu
- Graduate Program:
- Energy and Mineral Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 19, 2011
- Committee Members:
- Chunshan Song, Dissertation Advisor/Co-Advisor
Chunshan Song, Committee Chair/Co-Chair
Prof Yongsheng Chen, Committee Member
Caroline Elaine Clifford, Committee Member
Robert Martin Rioux Jr., Committee Member
Prof Yaw D Yeboah, Committee Member - Keywords:
- lignocellulose
biomass
biomass conversion
hydrolysis
acid
base
catalysis
combination
cellulose
hemicellulose
lignin - Abstract:
- The primary objective of this research is to explore a new concept of converting lignocellulosic biomass into liquid organic products via hydrolysis by sequentially combining acid and base treatments. The concept was examined by studying two-step hydrolytic reactions of biomass (spruce) using oxialic acid (OA) and tetramethylammonium hydroxide (TMAH) at moderate reaction temperatures below 200 °C. Different selectivity of C-O bond cleavage of hemicellulose, cellulose, and lignin between the reactions with OA and TMAH was demonstrated, and the sequential combination of OA and TMAH treatments exhibited an enhancing effect on conversion of biomass, which proves the promise of the proposed concept. A similar enhancing effect of combination was further confirmed in the reactions with mineral acid and base. Interestingly, characterization of solid residue from reactions of biomass and further investigation of the reactions of commercial cellulose revealed that the A-B sequence (the first reaction with OA and the second with TMAH) enhanced the conversion of cellulose at the second step with TMAH. It was suggested from the NMR and XRD study of solid residues that this enhancement was caused by the reduction of crystallinity of cellulose by the first reaction with OA. This effect was shown to be an interesting feature of A-B treatment sequence for converting lignocellulosic biomass. To improve the yield of monomeric sugars, the effect of adding organic solvents to the system was also studied. No improvement on sugar yield was observed under the explored conditions. However, it was shown that some furans and phenols can be directly formed from the reactions of biomass in the binary solvent system, which may be beneficial for producing more value-added chemicals from biomass.