Cosolvent pretreatment in cellulosic biofuel production: effect of tetrahydrofuran-water on lignin structure and dynamics. Issue 5 (13th October 2015)

• Record Type: Journal Article
• Authors: Smith, Micholas Dean; Mostofian, Barmak; Cheng, Xiaolin; Petridis, Loukas; Cai, Charles M.; Wyman, Charles E.; Smith, Jeremy C.
• Is Part Of: Green chemistry. Volume 18:Issue 5(2016)
• Page Start: 1268
• Page End: 1277
• Publication Date: 2015-10-13
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c5gc01952d
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Lignin transitions from a collapsed globular state to a random-coil when in exposed to a tetrahydrofuran and water cosolvent system at CELF pretreatment temperatures. Abstract : The deconstruction of cellulose is an essential step in the production of ethanol from lignocellulosic biomass. However, the presence of lignin hinders this process. Recently, a novel cosolvent based biomass pretreatment method called CELF (Cosolvent Enhanced Lignocellulosic Fractionation) which employs tetrahydrofuran (THF) in a single phase mixture with water, was found to be highly effective at solubilizing and extracting lignin from lignocellulosic biomass and achieving high yields of fermentable sugars. Here, using all-atom molecular-dynamics simulation, we find that THF preferentially solvates lignin, and in doing so, shifts the equilibrium configurational distribution of the biopolymer from a crumpled globule to coil, independent of temperature. Whereas pure water is a bad solvent for lignin, the THF : water cosolvent acts as a "theta" solvent, in which solvent : lignin and lignin : lignin interactions are approximately equivalent in strength. Under these conditions, polymers do not aggregate, thus providing a mechanism for the observed lignin solubilization that facilitates unfettered access of celluloytic enzymes to cellulose.