title: Fermentative hydrogen and methane cogeneration from cassava residues: effect of pretreatment on structural characterization and fermentation performance.
abstract: The physicochemical properties of cassava residues subjected to microwave (or steam)-heated acid pretreatment (MHAP or SHAP) were comparatively investigated to improve fermentative hydrogen and methane cogeneration. The hydrogen yield from cassava residues with MHAP and enzymolysis was higher (106.2 mL/g TVS) than that with SHAP and enzymolysis (102.1 mL/g TVS), whereas the subsequent methane yields showed opposite results (75.4 and 93.2 mL/g TVS). Total energy conversion efficiency increased to 24.7%. Scanning electron microscopy images revealed MHAP generated numerous regular micropores (∼6 μm) and SHAP generated irregular fragments (∼23 μm) in the destroyed lignocellulose matrix. Transmission electron microscopy images showed SHAP generated wider cracks (∼0.2 μm) in delaminated cell walls than MHAP (∼0.1 μm). X-ray diffraction patterns indicated MHAP caused a higher crystallinity index (33.00) than SHAP (25.88), due to the deconstruction of amorphous cellulose. Fourier transform infrared spectroscopy indicated MHAP caused a higher crystallinity coefficient (1.20) than SHAP (1.12).
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Richen
authors.initials: R
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Lingkan
authors.initials: L
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China; Department of Life Science and Engineering, Jining University, Jining 273155, China.
authors.forename: Wenlu
authors.initials: W
authors.lastname: Song
authors.affiliation: Department of Civil and Environmental Engineering, Tohoku University, Sendai 9808579, Japan.
authors.forename: Yuyou
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Junhu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Kefa
authors.initials: K
authors.lastname: Cen
mesh_terms: D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis; D003624:Darkness; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D002365:Manihot / Q000737:chemistry* / Q000648:ultrastructure; D008697:Methane / Q000096:biosynthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D002241:Carbohydrates; D006859:Hydrogen; D008697:Methane
keywords: Cassava residue; Hydrogen; Methane; Microwave-heated acid; Steam-heated acid