Electrical power plants are responsible for over one-third of the U.S. emissions (2001) or about 2.2x10^9 t carbon dioxide (CO2) per year. Power-plant flue gas can serve as a source of CO2 for microalgae cultivation, and the algae can be cofired with coal. The study objective was to conduct a life cycle assessment (LCA) to quantify the environmental benefits of recycling CO2 from power plants for microalgae production. Specifically, electricity production via coal firing versus coal/algae cofiring was compared.  FIND ARTICLE HERE

Algae are an attractive source of biomass energy since they do not compete with food crops and have higher energy yields per area than terrestrial crops. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from a life cycle perspective. In this work, the impacts associated with algae production were determined using a stochastic life cycle model and compared with switchgrass, canola, and corn farming. The results indicate that these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location. Only in total land use and eutrophication potential do algae perform favorably. The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO2 and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae. To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus. Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops.  FIND ARTICLE HERE

This paper provides an analysis of the potential environmental impacts of biodiesel production from microalgae. High production yields of microalgae have called forth interest of economic and scientific actors but it is still unclear whether the production of biodiesel is environmentally interesting and which transformation steps need further adjustment and optimization. A comparative LCA study of a virtual facility has been undertaken to assess the energetic balance and the potential environmental impacts of the whole process chain, from the biomass production to the biodiesel combustion. Two different culture conditions, nominal fertilizing or nitrogen starvation, as well as two different extraction options, dry or wet extraction, have been tested. The best scenario has been compared to first generation biodiesel and oil diesel. The outcome confirms the potential of microalgae as an energy source but highlights the imperative necessity of decreasing the energy and fertilizer consumption. Therefore control of nitrogen stress during the culture and optimization of wet extraction seem to be valuable options. This study also emphasizes the potential of anaerobic digestion of oilcakes as a way to reduce external energy demand and to recycle a part of the mineral fertilizers.  FIND ARTICLE HERE

The U.S. Department of Energy initiated The Aquatic Species Program (ASP) in 1978 as a direct response to the energy crisis of the early 1970's. The research program focused primarily on the use of aquatic plants as potential sources of hydrogen and biodiesel. In 1995 funding for the program was redirected towards research in bioethanol, and the ASP was terminated. This report serves to summarize and consolidate all of the findings into one document. Most of the work was conducted at the National Renewable Energy Laboratory in Golden, Colorado, however some work was subcontracted to research centers in New Mexico, California, and Hawaii. This report serves as the de facto resource on the science behind energy derived from algalculture, and is a must read for any who wish to understand the technology.  FIND ARTICLE HERE

This report provides an independent assessment of the applications and potential contributions to greenhouse gas (GHG) abatement of microalgae biofixation processes. It is intended as a strategic tool for R&D personnel and managers, policy makers, and others who need to broadly evaluate the various technology options for GHG abatement, as well as related environmental and sustainability issues. This assessment, carried out on both regional and global scale, is based on technology plausibly available in the near- to mid-term (2010 to 2020) for practical applications of microalgae to biofuels production. The most plausible immediate applications are in conjunction with advanced wastewater treatment processes, for removal and recovery of nitrogen and phosphorous, thus allowing the re-use of the plant nutrients in agriculture.  FIND ARTICLE HERE