Methyl Ketone Production from Municipal Solid Waste/ Biomass Blends by One‐pot Ionic Liquid Pretreatment, Enzymatic Saccharification, and Escherichia coli Fermentation

The conversion of municipal solid waste (MSW) and lignocellulosic biomass blends to methyl ketones (MKs) was investigated by using bioderived ionic liquid (bionic liquid)-based hydrolysates followed by fermentation with an engineered Escherichia coli strain. The hydrolysates were produced by a one-pot process using six types of MSW–biomass blends, choline-based bionic liquids, and commercial enzymes. Based on the sugar yields, one blend (corn stover/MSW=95:5, w/w) and two bionic liquids {cholinium lysinate ([Ch][Lys]) and cholinium aspartate ([Ch][Asp])} were selected for scale-up studies. Maximum yields of 82.3 % glucose and 54.4 % xylose were obtained from the selected blend in the scale-up studies (6 L), which was comparable with 83.6 % glucose and 52.8 % xylose obtained at a smaller scale (0.2 L). Comparable or higher yields of medium-chain (C–C) MKs were achieved by using the MSW–biomass blend-derived hydrolysates, relative to the sugar controls (glucose and xylose) with similar sugar feeding concentrations. Up to 1145 mg L of MKs was produced by using MSW–biomass-derived hydrolysates, and the MK titer decreased to 300 mg L when the bionic-liquid concentration in the hydrolysate increased from 1 to 2 %, indicative of bionic-liquid inhibition. Technoeconomic analysis was conducted to investigate the economic potential of using the selected MSW–biomass blend as a feedstock to produce MKs.