Last modified on: 05/02/2015
Bio-fuels from microalgae—A review of technologies for production, processing, and extractions of bio-fuels and co-products


These days reliance on fossil fuel energy resources is unsustainable, owing to both depleting world reserves and the green house gas emissions associated with their use. Therefore, there are vigorous research initiatives aimed at developing alternative renewable and potentially carbon neutral solid, liquid and gaseous bio-fuels as alternative energy resources. However, alternate energy resources akin to first generation bio-fuels derived from terrestrial crops such as sugarcane, sugar beet, maize and rapeseed place an enormous strain on world food markets, contribute to water shortages and precipitate the destruction of the world's forests. Second generation bio-fuels derived from lignocellulosic agriculture and forest residues and from non-food crop feed-stocks address some of the above problems; however there is concern over competing land use or required land use changes. Therefore, based on current knowledge and technology projections, third generation bio-fuels specifically derived from microalgae are considered to be a technically viable alternative energy resource that is devoid of the major drawbacks associated with first and second generation bio-fuels. Microalgae are photosynthetic microorganisms with simple growing requirements (light, sugars, CO2, N, P, and K) that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both bio-fuels and valuable co-products. Review study undertaken elsewhere on microalgae-to-bio-fuels systems, focusing on the biomass production, harvesting, conversion technologies, and the extraction of useful co-product and microalgae-derived bio-fuels could progressively substitute a significant proportion of the fossil fuels required to meet the growing energy demand



Source: Renewable and Sustainable Energy Reviews; Volume 14, Issue 2, February 2010, Pages 557–577