Algal oil extraction-cum-biodiesel conversion in a novel batch reactor and its compatibility analysis in IC engine at various CRs

Abstract

Pollution is one of the major tricky issues in the world due to the negative impact of vehicle population and industrialization. Transport sector is still struggling to control the pollution in spite of making many initiatives to keep it in control. Researchers have successfully claimed that biodiesel could be a possible solution due to its closed carbon cycle. In this scenario, microalgal biodiesel has the potential resource to reduce the vehicle pollution as an alternative fuel source. In this work, microalgae cultivated in open raceway ponds in optimized composite media were harvested with low cost filters, dried and oil extracted using solvent method. Two step conversion processes was employed to convert algal oil into biodiesel using optimized process parameters. Naturally available sea shell was used as the catalyst in the transesterification process. A new comprehensive bioreactor was designed and fabricated for oil extraction, esterification, transesterification and distillation process to produce 10 l of biodiesel in a batch. The biodiesel was then tested in the internal combustion (IC) engine test rig for various blends to analyse the performance and emission at different compression ratios (CRs). The brake thermal efficiency (BTE) of 27.42% at specific fuel consumption (SFC) of 0.225 kg/kWh was obtained for B30 blend at CR of 19. The emission characteristics were also found to be low at CR 19, which is the rated CR of the engine for diesel fuel.