Comparative Techno-economic Analysis of Biodiesel Production from Microalgae via Transesterification Methods

Microalgae, which hold great potential for carbon neutral biofuels production, is regarded as one of the most viable options to serve as sustainable feedstock for biodiesel production. This paper analyses two processes for biodiesel production from microalgae (Chlorella Protothecoides). The analysis showed that the energy efficiency of the supercritical transesterification process is 52.85% with the most energy (75.55%) used in the separation step of the process. The alkali-catalysed process has 49.67% energy efficiency with 35.25% used in the biodiesel purification step. The supercritical process requires higher capital cost, the alkali-catalysed process requires slightly higher production cost due to higher number of unit operations and processing steps. It was found that technically, the non-catalytic supercritical transesterification method has higher energy efficiency, but the unit price of the biodiesel is slightly lower via the alkali-catalysed transesterification method.