title: Biodiesel production from lipids in wet microalgae with microwave irradiation and bio-crude production from algal residue through hydrothermal liquefaction.
abstract: A cogeneration process of biodiesel and bio-crude was proposed to make full use of wet microalgae biomass. High-grade biodiesel was first produced from lipids in wet microalgae through extraction and transesterification with microwave irradiation. Then, low-grade bio-crude was produced from proteins and carbohydrates in the algal residue through hydrothermal liquefaction. The total yield (40.19%) and the total energy recovery (67.73%) of the cogenerated biodiesel and bio-crude were almost equal to those of the bio-oil obtained from raw microalgae through direct hydrothermal liquefaction. Upon microwave irradiation, proteins were partially hydrolyzed and the hydrolysates were apt for deaminization under the hydrothermal condition of the algal residue. Hence, the total remaining nitrogen (16.02%) in the cogenerated biodiesel and bio-crude was lower than that (27.06%) in the bio-oil. The cogeneration process prevented lipids and proteins from reacting to produce low-grade amides and other long-chain nitrogen compounds during the direct hydrothermal liquefaction of microalgae.
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.forename: Rui
authors.initials: R
authors.lastname: Huang
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Junhu
authors.initials: J
authors.lastname: Zhou
authors.forename: Kefa
authors.initials: K
authors.lastname: Cen
mesh_terms: D056804:Biofuels / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods*; D045424:Complex Mixtures / Q000378:metabolism*; D004602:Elements; D008401:Gas Chromatography-Mass Spectrometry; D008055:Lipids / Q000737:chemistry*; D058086:Microalgae / Q000187:drug effects / Q000378:metabolism*; D008872:Microwaves; D009821:Oils / Q000378:metabolism; D013696:Temperature; D014867:Water / Q000494:pharmacology*
chemical_list: D056804:Biofuels; D045424:Complex Mixtures; D004602:Elements; D008055:Lipids; D009821:Oils; D014867:Water
keywords: Bio-crude; Biodiesel; Hydrothermal liquefaction; Microalgae; Microwave