Nonenzymatic Sugar Production from Biomass Using Biomass-Derived γ-Valerolactone

Abstract

Widespread production of biomass-derived fuels and chemicals will require cost-effective processes for breaking down cellulose and hemicellulose into their constituent sugars. Here, we report laboratory-scale production of soluble carbohydrates from corn stover, hardwood, and softwood at high yields (70 to 90%) in a solvent mixture of biomass-derived γ-valerolactone (GVL), water, and dilute acid (0.05 weight percent H2SO4). GVL promotes thermocatalytic saccharification through complete solubilization of the biomass, including the lignin fraction. The carbohydrates can be recovered and concentrated (up to 127 grams per liter) by extraction from GVL into an aqueous phase by addition of NaCl or liquid CO2. This strategy is well suited for catalytic upgrading to furans or fermentative upgrading to ethanol at high titers and near theoretical yield. We estimate through preliminary techno-economic modeling that the overall process could be cost-competitive for ethanol production, with biomass pretreatment followed by enzymatic hydrolysis.

A lignocellulosic ethanol strategy via nonenzymatic sugar production: Process synthesis and analysis

“…Nonenzymatic sugar production Luterbacher et al (2014) proposed a two-stage dilute acid reaction system (Fig. 1) for the chemical hydrolysis of hemicellulose and cellulose to C 5 and C 6 sugars.…”

“…Cellulose and hemicellulose components of the lignocellulosic biomass are hydrolyzed to 5-carbon (C 5 ) and 6-carbon (C 6 ) sugars either by acids (Luterbacher et al, 2014) or enzymes . The sugars are then co-fermented or fermented separately either by yeast (Kádár et al, 2007) or bacteria (Olsson and HahnHägerdal, 1996) to produce ethanol.…”

“…Recently, Luterbacher et al (2014) developed a novel chemical hydrolysis process for sugar production at high yields using c-valerolactone (GVL) and water as a solvent containing dilute sulfuric acids (SA) as a catalyst. They reported that the sugars could be recovered and effectively concentrated by extraction using liquid CO 2 from the GVL/water solution.…”

Improving Heterogeneous Catalyst Stability for Liquid-phase Biomass Conversion and Reforming

“…[7] Lignin deconstruction processes are much less mature, and most exploratory processes include the hydrogenolysis or oxidation to syringyl and guaicyl derivatives. [7,8] These main routes for the deconstruction of biomass into platform molecules usually occur in water using various combinations of acids, [9,10] bases, [11] solvents [12][13][14] or ionic liquids. [15,16] All these methods typically produce soluble biomass-derived molecules at fairly low concentrations (<20 g/L) in aqueous or solvent solutions, [7] though some carbohydrate solutions can reach 100-220 g/L using solvent pretreatment and enzymatic hydrolysis [17][18][19] or solvent systems.…”

“…[15,16] All these methods typically produce soluble biomass-derived molecules at fairly low concentrations (<20 g/L) in aqueous or solvent solutions, [7] though some carbohydrate solutions can reach 100-220 g/L using solvent pretreatment and enzymatic hydrolysis [17][18][19] or solvent systems. [13,14] Therefore, biomass-derived platform molecules are often produced in solution at fairly low concentrations.…”