title: Assessment of Shock Pretreatment of Corn Stover Using the Carboxylate Platform.
abstract: Corn stover was pretreated with lime and shock, a mechanical process that uses a shockwave to alter the biomass structure. Two pretreatments (lime-only and lime + shock) were evaluated using enzymatic hydrolysis, batch mixed-culture fermentations, and continuous countercurrent mixed-culture fermentation. In a 120-h enzymatic hydrolysis, shock pretreatment increased the glucan digestibility of submerged lime pretreatment (SLP) corn stover by 3.5 % and oxidative lime pretreatment (OLP) corn stover by 2.5 %. The continuum particle distribution model (CPDM) was used to simulate a four-stage continuous countercurrent mixed-culture fermentation using empirical rate models obtained from simple batch experiments. The CPDM model determined that lime + shock pretreatment increased the total carboxylic acids yield by 28.5 % over lime-only pretreatment in a countercurrent fermentation with a volatile solids loading rate (VSLR) of 12 g/(L/day) and liquid retention time (LRT) of 30 days. In a semi-continuous countercurrent fermentation performed in the laboratory for 112 days with a VSLR of 1.875 g/(L day) and LRT of 16 days, lime + shock pretreatment increased the total carboxylic acid yield by 14.8 %. The experimental results matched closely with CPDM model predictions (4.05 % error).
authors.affiliation: Department of Chemical Engineering, Texas A&M University, 3122 TAMU Room 626, College Station, TX, 77843-3122, USA. pratik.darvekar@gmail.com.
authors.forename: Pratik
authors.initials: P
authors.lastname: Darvekar
authors.affiliation: Department of Chemical Engineering, Texas A&M University, 3122 TAMU Room 626, College Station, TX, 77843-3122, USA.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Holtzapple
mesh_terms: D018533:Biomass; D002264:Carboxylic Acids / Q000737:chemistry*; D005285:Fermentation; D008956:Models, Chemical; D010084:Oxidation-Reduction; D003313:Zea mays / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids
keywords: Continuum particle distribution modeling (CPDM); Enzymatic hydrolysis; Lignocellulose; Mixed-culture fermentations; Shock pretreatment