Biodiesel via in situ wet microalgae biotransformation: Zwitter-type ionic liquid supported extraction and transesterification

• Published in: ACS Sustainable Chemistry & Engineering
• Main Authors: Bauer, Gerald, Lima, Serena, Chenevard, Jean, Sugnaux, Marc, Fischer, Fabian
• Other Authors: Fischer, Fabian*
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Chemical Society 2017
• Subjects: Chlorella zofingiensi; Direct transesterification; Immobilized CALB (Novozyme 435); Zwitter ionic liquid; Chemistry (all); Environmental Chemistry; Chemical Engineering (all); Renewable Energy; Sustainability and the Environment; Settore ING-IND/25 - Impianti Chimici; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10447/308779; https://doi.org/10.1021/acssuschemeng.6b02665

The production of biodiesel derived from microalgae is among the most forthcoming technologies that provide an ecologic alternative to fossil fuels. Herein, a method was developed that enables the direct extraction and conversion of algal oil to biodiesel without prior isolation. The reaction occurs in aqueous media catalyzed by immobilized Candida antarctica lipase B (Novozyme 435). Zwitter-type ionic liquids were used as cocatalyst to improve the selectivity and reactivity of the enzyme. In a model reaction with sunflower oil, 64% biodiesel was obtained. Applying this method to a slurry of whole-cell Chlorella zof ingiensis in water resulted in 74.8% of lipid extraction, with 27.7% biotransformation products and up to 16% biodiesel. Factors that reduced the lipase activity with whole-cell algae were subsequently probed and discussed. This "in situ" method shows an improvement to existing methods, since it integrates the oil extraction and conversion into an one-pot procedure in aqueous conditions. The extraction is nondisruptive, and is a model for a greener algae to biodiesel process.