(17h) The Formation of Choline-Lignin Complex By Choline Based Ionic Liquid

I would dedicate my efforts to lignin valorization to complement the existing strengths of the department in biotechnology and sustainable energy. Three unique characteristics (abundance, energy density and aromatic structure) allow lignin to have great potentials for industrial application.

Teaching Interests:

Teaching Biofuels and Bioenergy is an incredible challenge, because students may have to deal with systematic problems that not only require interdisciplinary knowledge, but also require a long-term effort. My course will address questions such as: Why bioenergy? How will biofuels be produced? What biofuelsâ?? challenges need to be resolved? I will also teach students chemistry of biomass and lignin and how to collect and analyze data that will be used in their future careers.

The Formation of Choline-Lignin Complex by Choline Based Ionic Liquid

Jijiao Zeng¹, Michael Kent², Jian Sun¹, Feng Xu¹, Tanmoy Dutta¹, Kai Deng¹, Seema Singh¹, Blake Simmons³ and Kenneth L. Sale^1*

(1) Deconstruction Division, Joint BioEnergy Institute / Sandia National Laboratories, Emeryville, CA, (2) Sandia National Laboratories, Albuquerque, NM, (3) Lawrence Berkeley National Laboratories, Berkeley, CA

Abstract

Recently ionic liquids have been extensively studied for biomass pretreatment, as they are capable of selectively solubilizing and isolating cell wall components. The deconstruction division within the Joint BioEnergy Institute (JBEI) is developing cheaper, biocompatible and adaptable ionic liquid technologies for use in current biorefineries. Our work has demonstrated that choline-based ionic liquids are highly effective in removing lignin from herbaceous crops such as switch grass. However, the dissociation mechanism of lignin from different biomass by choline-based ionic liquids is still unclear. In this study, modification of the lignin structure by choline glutamate ([Ch][Glu]) and choline α-ketoglutarate ([Ch][aKg]) was investigated. Interestingly, the results showed that choline-based ionic liquids results in the formation a new phenyl-choline ether (4-O-C) bond. Although the yield of isolated lignin from switch grass was significantly higher than for softwood and hardwood, the newly identified signals were present in all isolated lignins. NMR and MALDI-TOF-MS were used to analyze the mechanisms of generating phenyl-choline ether. It is hypothesized that cholination of lignin is a fingerprint for modification of lignin by choline-based ionic liquids.