Trends in the development and utilization of agricultural wastes as heterogeneous catalyst for biodiesel production

Biodiesel is unarguably one of the most considered substitutes for fossil-based liquid fuels. However, the high cost of biodiesel production has been a major inhibitor for its large-scale activity. Apart from the cost of feedstock, catalysts contribute to the high pump price of biodiesel. Wastes derived from agricultural sources have been seen as viable means of synthesizing cost-effective and environmentally friendly catalysts and is an appropriate disposal of wastes. In this study recent trends in converting and utilizing agricultural wastes as heterogeneous catalysts for biodiesel production were reviewed. Agricultural wastes classifications, types of catalysts for biodiesel production, and the effects of conversion and modification techniques on pore size, acidity, surface area, and other fingerprints that enhance the catalytic activity were discussed. The use of characterization methods to test the suitability of solid catalysts was analysed, and some published works on the use of some agricultural wastes-derived catalysts were scrutinized. The paper concludes that catalysts derived from agricultural wastes offer a cheap, readily available, easy to produce, and environmentally benign replacement for the imported commercial ones. Going forward, more target investigations are needed on the suitability of some unexplored agricultural wastes to convert them to green catalysts. Researchers should explore the use of optimization models and statistical tools to determine the appropriate conditions for effective performance of biofuels.

Automated summary

The study reviewed recent trends in using agricultural wastes as catalysts for biodiesel production, discussing the classifications of agricultural wastes, types of catalysts, and the effects of conversion techniques on enhancing catalytic activity. It also analyzed the use of characterization methods for testing solid catalysts and highlighted the potential of agricultural waste-derived catalysts as cheap, environmentally friendly alternatives to commercial ones. Further investigations and optimization models are recommended for effective performance of biofuels.