title: A novel in situ gas stripping-pervaporation process integrated with acetone-butanol-ethanol fermentation for hyper n-butanol production.
abstract: Butanol is considered as an advanced biofuel, the development of which is restricted by the intensive energy consumption of product recovery. A novel two-stage gas stripping-pervaporation process integrated with acetone-butanol-ethanol (ABE) fermentation was developed for butanol recovery, with gas stripping as the first-stage and pervaporation as the second-stage using the carbon nanotubes (CNTs) filled polydimethylsiloxane (PDMS) mixed matrix membrane (MMM). Compared to batch fermentation without butanol recovery, more ABE (27.5 g/L acetone, 75.5 g/L butanol, 7.0 g/L ethanol vs. 7.9 g/L acetone, 16.2 g/L butanol, 1.4 g/L ethanol) were produced in the fed-batch fermentation, with a higher butanol productivity (0.34 g/L · h vs. 0.30 g/L · h) due to reduced butanol inhibition by butanol recovery. The first-stage gas stripping produced a condensate containing 155.6 g/L butanol (199.9 g/L ABE), which after phase separation formed an organic phase containing 610.8 g/L butanol (656.1 g/L ABE) and an aqueous phase containing 85.6 g/L butanol (129.7 g/L ABE). Fed with the aqueous phase of the condensate from first-stage gas stripping, the second-stage pervaporation using the CNTs-PDMS MMM produced a condensate containing 441.7 g/L butanol (593.2 g/L ABE), which after mixing with the organic phase from gas stripping gave a highly concentrated product containing 521.3 g/L butanol (622.9 g/L ABE). The outstanding performance of CNTs-PDMS MMM can be attributed to the hydrophobic CNTs giving an alternative route for mass transport through the inner tubes or along the smooth surface of CNTs. This gas stripping-pervaporation process with less contaminated risk is thus effective in increasing butanol production and reducing energy consumption.
authors.affiliation: Department of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China. xue.1@dlut.edu.cn.
authors.forename: Chuang
authors.initials: C
authors.lastname: Xue
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, 43210.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, 43210.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, 43210.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Ren
authors.affiliation: Department of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China.
authors.forename: Fengwu
authors.initials: F
authors.lastname: Bai
authors.affiliation: Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, 43210. yang.15@osu.edu.
authors.forename: Shang-Tian
authors.initials: ST
authors.lastname: Yang
mesh_terms: D020001:1-Butanol / Q000302:isolation & purification* / Q000378:metabolism*; D000096:Acetone / Q000378:metabolism*; D004129:Dimethylpolysiloxanes / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005740:Gases; D043942:Nanotubes
chemical_list: D004129:Dimethylpolysiloxanes; D005740:Gases; D000096:Acetone; D000431:Ethanol; C013830:baysilon; D020001:1-Butanol
keywords: ABE fermentation; butanol; carbon nanotube; gas stripping; pervaporation