ENITECNOLOGIE RD PROJECT ON MICROALGAE BIOFIXATION OF CO_2: OUTDOOR COMPARATIVE TESTS OF BIOMASS PRODUCTIVITY USING FLUE GAS CO_2 FROM A NGCC POWER PLANT

摘要

Microalgae mass cultures could contribute to the mitigation of greenhouse gas (GHG) emissions by enabling the direct utilization of fossil CO_2 streams from concentrated sources and the production from algal biomass of renewable biofuels and fossil fuel-sparing products. EniTecnologie, the R&D arm of the Italian oil & gas company Eni, is focused on demonstrating and improving the achievable biomass productivities of outdoor microalgal mass cultures. We evaluated the feasibility of fixing flue gas CO_2 from a natural gas combined cycle (NGCC) power plant to produce renewable methane fuel to replace a fraction of the input fossil methane. Initial experiments compared the productivity of the marine microalga, Tetraselmis suecica, mass cultured in an outdoor scale-down system that simulates large-scale production systems and comprises both open ponds and closed photobioreactors. Results indicated that closed and open systems have similar productivities, and that in open ponds the areal values are close to the maximal productivities so far reported under outdoor operating conditions and significantly higher than those using flue gas CO_2 in similar scale-down systems. This activity is a constituent project of the International Network on Biofixation of CO_2 and GHG Abatement with Microalgae, an initiative that operates under the auspices of the IEA GHG R&D Programme.