Bioethanol Production from Mixed Temple Floral Waste and Pomegranate Peel using Alkaline Pretreatment and Oxalic Acid Hydrolysis

In the present study, the sustainable production of bioethanol from mixed temple floral waste and pomegranate peel was successfully achieved by using sodium hydroxide pretreatment, oxalic acid hydrolysis, and microbial fermentation using Saccharomyces cerevisiae. Biodegradable temple and fruit processing wastes are potential sources of lignocellulosic feedstocks that can be utilized for generating renewable energy in an environmentally sustainable way and also for tackling the challenges of organic waste disposal. The pH analysis, proximate analysis, FTIR, and SEM were used for preliminary characterization and confirmed that the 1:1 mixed biomass had optimum physicochemical properties for biochemical conversion and ethanol production.   Sodium hydroxide pretreatment was found to be effective in loosening the lignocellulosic structure, thus facilitating the accessibility of cellulose for hydrolysis in the absence of lignin and hemicellulosic barriers. The subsequent hydrolysis in the presence of oxalic acid performed under autoclave-assisted conditions helped convert biomass polysaccharides to fermentable entities. By using activated Saccharomyces cerevisiae, ethanol was successfully produced using fermentation, and the final ethanol yield was 30 mL/60g mixed biomass, which is 0.5 mL/g biomass. This was further verified by FTIR analysis and K₂Cr₂O₇ assay.   The results obtained from the present study indicate that the temple floral waste and pomegranate peels have great potential as low-cost and renewable substrates for second-generation bioethanol production. Integrated waste biomass utilization as renewable fuel helps in sustainable waste management, decrease of environmental pollution, and development of a circular bioeconomy. Further investigations based on advanced analytical characterization and reducing sugar estimation, large-scale process optimization, and techno-economic assessment are needed for improving industrial feasibility and commercialization potential. In conclusion, the study illustrates that eco-friendly pretreatment and hydrolysis processes to valorize lignocellulosic biomass could be an effective way for sustainable production of renewable energy sources and future green biofuels.

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