Investigation on chlorella Sp. HS2 microalgae growth using CO2 from engine exhaust to study carbon sequestration

A functional method of exploiting engine exhaust waste has been explored in current investigation. In experimentation, a direct injection (DI) 4-stroke diesel engine has been considered. The engine was operated at varying injection pressures and injection timings. The exhaust emissions such as CO2, NO, HC, and CO were determined at different engine load conditions. To capture CO2 emissions at an optimal temperature desired for microalgae cultivation within a designed photobioreactor (PBR) tank, a shell and tube type heat exchanger was designed and operated to cool exhaust gases. Highest volume of CO2 produced through the engine exhaust was used to cultivate Chlorella sp. HS2 microalgae. The results of biomass productivity and growth rate were compared for photobioreactor tanks, one with CO2 supplementation and the other without any external CO2 supply. The results derived in this study depict the effective usage of exhaust gases to harness CO2 in the form of microalgae.