Microwave-assisted biodiesel production using –SO3H functionalized heterogeneous catalyst derived from a lignin-rich biomass

Abstract

The synthesis of biodiesel from renewable resources has immense potential as a sustainable and cost-effective energy alternative. In this work, a reusable –SO3H functionalized heterogeneous catalyst that has a total acid density of 2.06 mmol/g was prepared from walnut (Juglans regia) shell powder by low-temperature hydrothermal carbonization (WNS-SO3H). Walnut shell (WNS) contains more lignin (50.3%), which shows great resistance toward moisture. The prepared catalyst was employed for the effective conversion of oleic acid to methyl oleate by a microwave-assisted esterification reaction. The EDS analysis revealed the significant presence of sulfur (4.76 wt%), oxygen (51.24 wt%), and carbon (44 wt%) content. The results of the XPS analysis confirm the bonding of C–S, C–C, C=C, C–O, and C=O. Meanwhile, the presence of –SO3H (the responsible factor for the esterification of oleic acid) was confirmed by FTIR analysis. Under the optimized conditions (9 wt% catalyst loading, 1:16 oleic acid to methanol molar ratio, 60 min reaction time, and 85 °C temperature), the conversion of oleic acid to biodiesel was found to be 99.01 ± 0.3%. The obtained methyl oleate was characterized by employing 13C and 1H nuclear magnetic spectroscopy. The conversion yield and chemical composition of methyl oleate were confirmed by gas chromatography analysis. In conclusion, it can be a sustainable catalyst because the catalyst preparation controls the agro-waste, a great conversion is achieved due to the high lignin content, and the catalyst was reusable for five effective reaction cycles.

A smart and sustainable pathway for abatement of single and binary mixtures of dyes through magnetically retrievable Ca4Fe9O17 anchored on Biochar matrix

“…1 . In the XRD pattern of SDBC, a broad diffraction peak between 18 to 27° is observed, which is considered to be the amorphous structure of biochar 39 . Its amorphous nature was verified by the XRD pattern, which was characteristically broad, with the prominent peaks being Ca 4 Fe 9 O 17 40 .…”

Advances in biomass derived low-cost carbon catalyst for biodiesel production: preparation methods, reaction conditions, and mechanisms

“…Generally, the esterication reaction follows pseudo-1st order kinetics due to excess of methanol. 4,10,[66][67][68] Following factors should be considered for kinetics of esterication reaction-1. The esterication process is the only responsible in biodiesel production.…”

“…Generally, the esterification reaction follows pseudo-1st order kinetics due to excess of methanol. 4,10,66–68 Following factors should be considered for kinetics of esterification reaction-…”

“…[1][2][3] Biodiesel is a clean, renewable, non-toxic and biodegradable biofuel. 4 A variety of feedstock based on agriculture, wood waste, energy crops, plant-oil based, and aquatic biomass are helpful to produce biodiesel. Numerous major countries have accessibility of prospective bio-resources as feedstock materials such as Calophyllum inophyllum (Malaysia and Australia), Pongamia pinnata (India, Bangladesh, and Australia), Sunower (Argentina, Greece, Turkey, Italy, and Canada), Jatropha curcas (India, Thailand, Malaysia, Tanzania, Mali, Mozambique, Cuba, Peru, and Zimbabwe, Pakistan), rapeseed (Italy, Chile, Canada, Greece, and Turkey, China), oil seed palm (Thailand, Brazil, Iran, Peru, Malaysia, and Mexico), soyabean (Unites States, Italy, Argentina, and Canada), sh residues (Norway) and sh oil (Iran).…”