Sustainability of direct biodiesel synthesis from microalgae biomass: A critical review. (June 2019)

• Record Type: Journal Article
• Authors: Goh, Brandon Han Hoe; Ong, Hwai Chyuan; Cheah, Mei Yee; Chen, Wei-Hsin; Yu, Kai Ling; Mahlia, Teuku Meurah Indra
• Is Part Of: Renewable & sustainable energy reviews. Volume 107(2019)
• Page Start: 59
• Page End: 74
• Publication Date: 2019-06
• Subjects: Biofuel -- Microalgae -- Oil extraction -- Biodiesel conversion -- Alternative energy; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.rser.2019.02.012
• Languages: English
• ISSNs: 1364-0321

Abstract

Abstract: Microalgae has been identified as a potential feedstock for biodiesel production since its cultivation requires less cropland compared to conventional oil crops and the high growth rate of microalgae. Research on microalgae oils often are focused on microalgae oil extraction and biomass harvesting techniques. However, energy intensive and costly lipid extraction methods are the major obstacles hampering microalgae biodiesel commercialisation. Direct biodiesel synthesis avoids such problems as it combines lipid extraction techniques and transesterification into a single step. In this review, the potential of direct biodiesel synthesis from microalgae biomass was comprehensively analysed. The various species of microalgae commonly used as biodiesel feedstock was critically assessed, particularly on high lipid content species. The production of microalgae biodiesel via direct conversion from biomass was systematically discussed, covering major enhancements such as heterogeneous catalysts, the use of ultrasonic and microwave- techniques and supercritical alcohols that focus on the overall improvement of biodiesel production. In addition, this review illustrates the cultivation conditions for biomass growth and lipid productivity improvement, the available harvesting and lipid extraction technologies, as well as the key challenges and future prospect of microalgae biodiesel production. This review serves as a basis for future research on direct biodiesel synthesis from modified microalgae biomass to improve profitability of microalgae biodiesel. Graphical abstract: fx1 Highlights: Microalgae lipid enhancement techniques were compared. Harvesting and extraction technologies were evaluated. Factors impacting direct biodiesel synthesis were discussed. Challenges and prospects for microalgae industrial application were proposed.