Green Alternatives for Converting Agricultural Residues into Alkyl Levulinates: A Comparative Approach

Biomass, as a renewable resource, holds significant potential for providing sustainable feedstock for energy and chemicals, particularly to meet the needs of an automotive society. Among the various biomass sources, agricultural waste's high cellulose polysaccharide content has made it an attractive resource, which are essential for pyrolysis processes that produce valuable intermediate chemicals. This research aims to promote sustainable growth by employing greener, more efficient synthetic approaches to produce alkyl levulinate from agricultural waste derivatives, such as corn husk, millet husk and many more agricultural residues. Alkyl levulinate is an important biobased platform chemical, widely used in industries as an additive to improve fuel efficiency in internal combustion engines, as well as a solvent, flavoring, and fragrance substance. Numerous spectroscopic methods, such as nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and UV-visible spectroscopy, will be used to characterize the derived alkyl levulinate products. As a renewable substitute for fossil-derived chemicals, alkyl levulinate contributes significantly to sustainability goals in the chemical industry. This study investigates the production of alkyl levulinate from agricultural residues using a greener methodology, specifically through microwave-assisted synthesis with the use of environmentally friendly solvents and heterogeneous acid catalysts. This approach offers a better yield and simplified downstream processing compared to traditional methods. The comparative analysis of different agricultural wastes, such as corn husk and millet husk, will provide insight into the most efficient and sustainable pathways for alkyl levulinate production.