Psidium guajava (guava) leaves derived functional activated carbon as a heterogeneous catalyst for conversion of Jatropha curcas oil to biodiesel

• Published in: Journal of analytical and applied pyrolysis 2024-08, Vol.181, p.106636, Article 106636
• Main Authors: Das, Arpita, Jati, Aditya Prasad, Selvaraj, Manickam, Kataki, Rupam, Baskar, Gurunathan, Halder, Gopinath, Rokhum, Samuel Lalthazuala
• Format: Article
• Language: English
• Subjects: 4-benzenediazoniumsulfonate (4-BDS); activated carbon; Biochar; Biodiesel; catalysts; cost estimates; guavas; Jatropha curcas; Jatropha curcas oil (JCO); Kinetics and thermodynamics; methanol; nuclear magnetic resonance spectroscopy; oils; Psidium guajava; pyrolysis; sulfonates; sulfur; surface area; Transesterification
• ISSN: 0165-2370
• DOI: 10.1016/j.jaap.2024.106636

Herein, we report the development of a highly efficient activated porous acid catalyst using Psidium guajava (guava) leaves as the precursor. The synthesis involved chemical activation with ZnCl2 and sulfonation with 4-benzenediazonium sulfonate, resulting in the AC-X-PhSO3H catalyst, optimized by varying ZnCl2 ratios (X = 1, 2, 3). Comparative characterization using BET, SEM, XRD, FT-IR, and TGA revealed that AC-2-PhSO3H, pyrolyzed at 500 °C, exhibited exceptional efficiency with a maximum surface area of 492.97 m²/g and a sulfur density of 4.23 wt%. Using AC-2-PhSO3H as the catalyst, we achieved a remarkable Jatropha curcas oil (JCO) conversion (98.3 ± 0.3 %) to biodiesel under optimized reaction conditions (20:1 methanol to oil molar ratio, 10 wt% catalyst loading, 100 °C, 50 min) and FAME content of 98.04 %, as confirmed by ¹H NMR spectroscopy. The estimated cost of biodiesel production was $0.87 per litre, largely due to the notable reusability of the catalyst (82.9 ± 0.2 % JCO conversion in the 6th run) without additional treatments, indicating significant commercial applicability and enhanced stability. [Display omitted] •Highly efficient Psidium guajava leaves-derived acid catalyst for biodiesel synthesis.•Optimal AC-2-PhSO3H catalyst with high porosity and SBET of 492.97 m²/g.•Microwave-assisted transesterification exhibits high JCO conversion (98.3 ± 0.3 %).•Notable reusability over six cycles (82.9 ± 0.2 % JCO conversion) validating high stability.•Life cycle cost analysis estimated biodiesel production cost to be $0.87 L–1.