An investigation into the feasibility of improving the sustainability of a biogas fueled electricity generator by capturing CO2 exhaust emissions using photosynthetic green microalgae

Abstract

Municipal solid waste landfills release a methane rich biogas, which can be combusted in standalone electricity generators. This work, which measured the exhausted off-gas from a biogas fed generator, which at an average of 526˚C was 5,556 Nm3 /hour and contained 11% CO2. It is hypothesized that this off-gas could be captured and used as a year-round carbon source for photosynthetic microalgae. A pilot plant concept is modeled to be built at later date for a feasibility CO2 capture study. The proposed pilot plant consists of ten 1 m3 tanks (1 seed tank, 3 sets of biological triplicates) and would take 0.34% of the total off-gas. The model produced indicated that it could be operated above 15˚C and 30˚C year-round and has the potential to produce 2.7 kg dry weight microalgae m-3 day-1 of lipid-rich microalgae for research and market analysis purposes.