Biodiesel represents a renewable alternative to conventional diesel, offering comparable potential. This paper delves into the production of biodiesel from non-edible oil seeds, emphasizing kernel-based feedstocks for their sustainable qualities. We discuss the critical stages of kernel separation and degumming, offering an in-depth examination of seed distribution, attributes, pretreatment, and oil extraction methodologies. Additionally, the paper considers the status of life cycle assessment (LCA) associated with biodiesel. Furthermore, it outlines the necessary steps toward sustainable biodiesel production and underscores the importance of integrating a sustainable circular bioeconomy in biodiesel synthesis.

In this study, the effect of different modes of cultivation viz., photoautotrophic (AT), heterotrophic (HT) and photomixotrophic (MT), on the growth and biochemical responses of Chlorella sp. isolated from local ponds. The performance of microalgal growth was quantified using nonlinear growth models such as Gompertz, logistic, Baranyi-Roberts, Morgan under different cultivation conditions. The results revealed that microalgae could grow better in MT than in other cultivation modes with a major increase in biochemical responses for carbohydrates, which showed higher accumulation under HT. The maximum biomass concentration was 1.24 g L^-1 (MT), 1.16 g L^-1 (HT), 0.76 g L^-1 (AT) with maximum specific growth rates of 0.0083 h^-1 (HT), 0.0078 h^-1 (MT) and 0.0055 h^-1 (AT) respectively. The biomass concentration was higher in the order of MT>HT>AT for which MT yielded 8.8 fold higher biomass, compared with the initial biomass concentration, at the end of experiments (16 days). Concomitant increases in biochemical responses were observed in the three cultivation conditions. Protein and lipid accumulation in the MT mode was higher (1.2 fold) compared with the initial protein yield as well as the other cultivation modes. However, the carbohydrate yield was higher (1.12 fold) in the heterotrophic mode than in other cultivation conditions.

The quantity of fossil fuel is declining year by year, and the pollutant also released to the environment which insist on the exploration of new alternative fuel. Biodiesel from non-edible seeds is of primary concern for increasing prices of crude oil and thereof preventing greenhouse gas emissions. In the present study, the production of biodiesel by In-situ acid catalyzed transesterification from Sterculia foetida oil and seeds were reported. GC-FID characterization of oil sample revealed the presence of long-chain fatty acids with a higher proportion of sterculic acid (32%). The operating parameters in acid transesterification process viz., the weight of the oil and biomass, solvent volume, acid volume, temperature and time were optimized using Placket-Burman design. The maximum biodiesel yield obtained for sterculia oil and seeds were 91.58% and 95.91% exhibiting volume of oil being the critical factor based on Plackett-Burman design. One-way ANOVA analysis showed that chosen parameters were statistically significant (P < .05) except for temperature. FT-IR analysis confirms the presence of biodiesel (1741 cm^–1) obtained from the transesterification process.

In the present study, Sterculia foetida oil and waste cooking oil (SWO) were blended in a 1:1 ratio and its influence on biodiesel properties was studied. In situ transesterification for biodiesel production from blended oil and the investigational design were accomplished using an acid catalyst. Effects of process variables and operating conditions like sample amount, methanol volume, hexane volume, sulphuric acid, temperature and time were examined using Plackett–Burman design. GCMS revealed the presence of the linolenic acid (20.9%) and palmitic acid (18.3%) in maximum content and the high yield of biodiesel obtained from this blended oil from the experiments was around 95%. Sulphuric acid, temperature, time and hexane volume were found to be important process parameters as per the results obtained from the Plackett–Burman design. ANOVA analysis exhibited all the process parameters were significant except methanol volume and sample amount. The R² value exhibiting 96.37% and R² (adj) 92.02% shows the good fit of the model from the obtained regression equation. After in situ transesterification, the conversion of oil in to biodiesel is confirmed by FTIR analysis by the presence of band at (1741 cm^–1).