Overcoming difficulties with microalgae-based biodiesel by improving lipid production in Chlorococcum littorale ABI83580.1 by using photobioreactor upscale production and optimising biotic and nutritional conditions

The commercialisation of microalgae-based biodiesel is impeded by strain selection, high production costs, and low productivity. To completely replace the current fossil diesel with biodiesel made from microalgae strains, the aforementioned problems must be resolved immediately. This study focuses on offering solutions to the problems plaguing the microalgae-based biodiesel sector. This is accomplished by designing and building a new 20-l tubular photobioreactor for upscale production, choosing a strain with potential for producing biodiesel, identifying the ideal biotic and nutritional parameters for increased lipid production, and characterising the biodiesel produced. A standard procedure was used for determining biotic and nutritional parameters. Upscale production was done in a 20-l tubular photobioreactor. Biomass, lipid extraction, and quantification were determined using filtration, solvent extraction, and gravimetric methods. Transesterification and biodiesel analysis were achieved using sulphuric acid and gas chromatography-mass spectroscopy. Photoperiod (24:0 h L:D), growth medium (BBM), temperature (30 °C), salinity (50 PSU), nitrogen (sodium nitrate), sodium nitrate (0.4 g/L), carbon source (glucose), glucose concentration (6 g/L), pH (7), iron (0.045 g/L), agitation speed (200 rpm), and phosphorus (0.001 g/L) were the best conditions for lipid production. The microalgae strain produced greater biomass (11.25 ± 0.03 g/L), lipid content (76.17 ± 0.03%), volumetric lipid productivity (1713.83 ± 0.21 gL−1d−1 Lc x1000/100), and biodiesel output (99.81 ± 0.02%) after five days in a 20-l tubular photobioreactor. The biodiesel contains 50.85% saturated, 33.90% monounsaturated, and 15.25% polyunsaturated fatty acids. The biodiesel meets the international standard satisfactorily. Chlorococcum littorale produced more lipids in the built photobioreactor, and biodiesel is a promising, high-quality, and reasonably priced fuel.