Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alt...Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production.展开更多
Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other...Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other energy crops. To meet up all these criteria, we have developed a continuous outdoor micro-algal raceway pond reactor(RPR) and a lab scale indoor tubular photo bioreactor(PBR) for biofuel production. An attempt to utilise indigenous sources of nutrients to improve the economics also revealed that micro-algal culturing can also be used as a mode of nutrient removal and water treatment. The photosynthetic rate and lipid production were enhanced by arresting daytime cell division and promoting night-time cell division. A 50% lipid improvement was observed for the particular algal consortia. Microscopic studies revealed that temporal phase separation could be achieved by adjusting nutrient distribution pattern. To monitor temporal phase separation, it is required to know DNA multiplication model. Quantification of g DNA in RPR confirmed that cell division happens during the night which positively affects the photosynthetic efficiency and lipid productivity of microalgae.展开更多
基金Supported by the Ministry of Higher Education,Malaysia(FRGS with cost center015AB-L25)Universiti Teknologi PETRONAS(YUTP-FRG with cost center 0153AAH46)
文摘Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production.
基金part of CSIR-NMITLI project“Biofuel from marine microalgae”,at NIIST by Dr.Ajit Haridas
文摘Microalgae have been recommended as superior candidate for fuel production because of their advantages of higher photosynthetic efficiency, biomass & lipid productivity, and faster growth rate as compared to other energy crops. To meet up all these criteria, we have developed a continuous outdoor micro-algal raceway pond reactor(RPR) and a lab scale indoor tubular photo bioreactor(PBR) for biofuel production. An attempt to utilise indigenous sources of nutrients to improve the economics also revealed that micro-algal culturing can also be used as a mode of nutrient removal and water treatment. The photosynthetic rate and lipid production were enhanced by arresting daytime cell division and promoting night-time cell division. A 50% lipid improvement was observed for the particular algal consortia. Microscopic studies revealed that temporal phase separation could be achieved by adjusting nutrient distribution pattern. To monitor temporal phase separation, it is required to know DNA multiplication model. Quantification of g DNA in RPR confirmed that cell division happens during the night which positively affects the photosynthetic efficiency and lipid productivity of microalgae.
