Supercritical CO2 Extraction for Algal Biodiesel Production

SC-CO2 is cleaner green technology for extraction of algal lipids/oils for algal biodiesel production. This work offers an optimized method for the direct conversion (One-step) of algal biomass to biodiesel using supercritical CO₂ extraction and supercritical methanol transesterification. SC-CO₂ uses moderate temperature and pressure so that it can be useful for the extraction of thermolabile compounds which may decompose at the temperature at which thermal methods are carried out. This study examines the effects of pressure, temperature and algae to methanol ratio on fatty acid methyl ester (FAME) yield from algal biomass. The extraction with SC-CO2 allows to obtain a higher amount of long chain fatty acids. The algal biomass characterization and algal biodiesel analysis were performed using ATR-FTIR, SEM-EDS, TEM, TGA and GC-MS.