Comparsion of Marine Microalgae Culture Systems for Fuels Production and Carbon Sequestration

70302 Microalgae technologies that not only would produce renewable fuels but also would mitigate greenhouse gases are being developed in the U.S. and abroad. A central R&D issue is the design of the culture systems, which can be of two general types: open ponds and closed photobioreactors. A direct experimental comparison of their attributes is required in order to continue the development of these technologies. In this project, marine microalgae will be cultured on seawater in three different production biosystems to allow a quantitative comparison among the designs for biomass productivities and CO2 utilization. The most suitable system for greenhouse gas mitigation will be identified and applied initially in small-scale aquaculture processes that fix CO2 and yield high-value byproducts. In Phase I, three different microalgae production systems ¿ open shallow raceway ponds, deeper circular tanks, and small diameter tubular photobioreactors ¿ will be operated on seawater with two algal species to compare productivities with CO2 supply. The results will be used to scale-up processes using microalgae for greenhouse gas mitigation. Commercial Applications and Other Benefits as described by the awardee: Microalgae culture systems, both open ponds and closed photobioreactors, are already used in the U.S. for the production of high value animal feeds and nutritional products. Alternative microalgae production systems should have applications for aquaculture feeds and, in the longer-term, wastewater treatment, and other large-scale greenhouse gas mitigation processes.