Biogas upgrading by microalgae: Strategies and future perspectives

Dillirani Nagarajan, Duu Jong Lee, Jo Shu Chang

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Citation (Scopus)

Abstract

Microalgae are being increasingly considered as a potential biomass feedstock for various biofuels, biodiesel in particular. Microalgal biomass for biofuel production purposes can be derived by cultivation using several waste resources, such as wastewater or flue gases, due mainly to the absence of the stringent regulations usually applied for food grade health supplements from microalgae. Anaerobic digestion and dark fermentation, the two highly used biomass digestion processes, generate biogas (a mixture of CH4, CO2 and other gases) and a COD (chemical oxygen demand)-rich effluent with leftover organic acids from the fermentation process. Microalgae can utilize the CO2 present in the biogas stream, thus increasing the methane content and improving the fuel properties of biogas. Several reports indicate that certain microalgae are highly tolerant to the high concentrations of methane present in the biogas stream and can effectively utilize the CO2 in photoautotrophic/mixotrophic mode of cultivation to obtain microalgal biomass. The organic acids of the effluent can also be used as a carbon source for mixotrophic/heterotrophic mode of microalgal cultivation, thus providing a cleanup of both the liquid and gaseous effluents of the fermentation process. This chapter describes in detail the capability of microalgae for carbon capture from biogas and their efficiency in the utilization of organic acids from various effluent streams. A biorefinery concept, integrating anaerobic digestion and microalgal cultivation is proposed, and the future perspectives are discussed.

Original languageEnglish
Title of host publicationMicroalgae Biotechnology for Development of Biofuel and Wastewater Treatment
PublisherSpringer Singapore
Pages347-395
Number of pages49
ISBN (Electronic)9789811322648
ISBN (Print)9789811322631
DOIs
Publication statusPublished - 2019 Apr 30

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All Science Journal Classification (ASJC) codes

  • Medicine(all)
  • Health Professions(all)
  • Immunology and Microbiology(all)
  • Engineering(all)
  • Environmental Science(all)

Cite this

Nagarajan, D., Lee, D. J., & Chang, J. S. (2019). Biogas upgrading by microalgae: Strategies and future perspectives. In Microalgae Biotechnology for Development of Biofuel and Wastewater Treatment (pp. 347-395). Springer Singapore. https://doi.org/10.1007/978-981-13-2264-8_15