Biodiesel synthesis from low cost biomass wastes and its cost assessment inducing process optimization

This study employed low-cost biomass wastes for the synthesis of biodiesel that is cost-effective and environmentally friendly. The major raw material (oil) was obtained by steam distillation (SD) from Croton heliotropiifolius Kunth leaf (CHKL) and was characterized for its aptness for biodiesel production. Dwarft green coconut husk ash (DGCHA) was used as a bio-adsorbent for acid value reduction of Croton heliotropiifolius Kunth leaves oil (CHKLO). A novel, highly potassium-based catalyst was derived from Karpuravalli banana peels (KBP), calcined, and characterized using TGA, ZETA, FTIR, SEM-EDX, XRF-FS, and BET analysis. Biodiesel was synthesized using a microwave-assisted method, characterized, and compared with the recommended standard. The catalytic strength of the calcined Karpuravalli banana peel powder (CKBPP) was tested using a reusability test, and the cost evaluation of production was estimated. Results showed that the CHKL was rich in oil (43% wt./wt.), and the oil is highly acidic (5.23 mg KOH/g oil). At high particle size, the dwarf green coconut husk ash (DGCHA) bagasse reduced the acid value to a minimum (1.4 mg KOH/g oil) at 3 days. The developed novel catalyst from CKBPP indicated high potassium-calcium contents for base transesterification. Process optimization indicated that the predicted response data of 95.285% (wt./wt.) at T₁ = 90 min, T₂ = 60 ^oC, T₃ = 4.5% (wt.), and T₄ = 9 (vol./vol.) was validated in triplicate, and the average data value of 95.10% (wt./wt.) was established. Dataset on the quality of biodiesel showed that the produced biodiesel properties were in line with recommended standards. Economic appraisal data showed that the cost of producing 20 L of CHKLOB (biodiesel) was $4.73 at 1,500 to $1. The study concluded that the production of biodiesel from waste can be cost-effective and environmentally friendly if wastes are harness.

Graphical Abstract