Microalgae as Sustainable Renewable Energy Feedstock for Biofuel Production

Abstract

The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.

Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

“…Liquid biofuels are currently produced using oil crops, including corn and soy, or from sugar cane; however, their adoption on a global scale seems to be unsustainable in terms of required cultivated area and transformation yield [7,11,12]. The large amount of storable lipids and CO 2 absorption, in addition to the high growth rate without creating competition for arable land, make microalgae the best candidates for biofuel production [7,13,14] or at least economically interesting for compounds such as astaxanthin, vitamins, polyunsaturated fatty acids and pharmaceuticals [15]. The model organism for green algae is Chlamydomonas reinhardtii as its genome has already been sequenced and characterized.…”

Cultivation of Nannochloropsis for eicosapentaenoic acid production in wastewaters of pulp and paper industry

“…Algae might provide an economically and environmentally sustainable way of utilizing the nutrients. Unfortunately, it is not economically feasible to use wastewaters for cultivation of algal biomass for low-value end products like biodiesel oil (Medipally et al, 2015). However, the cultivation might become profitable if the biomass contains a high-value component like a polyunsaturated fatty acid.…”

Production of biodiesel from microalgae through biological carbon capture: a review

“…If the influential factors like irradiation, mixing, media constituents are well optimized then the production cost could be reduced to 0.68 € per kg. At this price microalgae could become a promising feedstock for biofuel production (Medipally et al 2015).…”