Effects of Calcination Temperature on the Physicochemical Behaviour of Catalysts Produced from Eggshell and Rice Husk

Abstract

The production, security, sustainability, and affordability of energy are crucial factors in various industries and physical and chemical processes. To address environmental concerns and promote energy production, solid waste materials can serve as catalysts. This research specifically investigates the influence of different calcination temperatures on the properties of two solid wastes, namely Eggshell and Rice husk, as heterogeneous catalysts in Biodiesel production. The results of the study revealed notable changes in various properties such as color, mass, chemical transformation, crystallinity, and functional groups as the calcination temperatures increased for both raw materials. X-ray diffractometer (XRD) analysis was used to characterize the calcined Eggshells and Rice husks. It was observed that increasing the calcination temperature from 600ºC to 700ºC led to enhanced crystallinity, with the highest average crystal size being 278.0374 nm, and chemical transformation in the eggshells. Conversely, the Rice husks exhibited decreased crystallinity (274.793 nm to 16.723 nm) but increased chemical transformation with higher calcination temperatures increasing from 600ºC to 800ºC. The presence of a small amount of K2O in the calcined Rice husk was attributed to leaching with HCl after roasting and quenching before calcination. Furthermore, the Fourier Transform Infrared Spectroscopy (FT-IR) analysis indicated the formation of desirable functional peaks with increasing calcination temperatures in both materials. Additionally, the presence of CO3-2 was observed in KA and KB due to the incomplete decomposition of CaCO3. Notably, the highest formation of CaO occurred at 700ºC for Eggshell, while the Rice husk calcined at 800ºC exhibited the highest formation of silicon (IV) oxide and lower impurity content (lignin, cellulose, and hemicellulose). Overall, this research provides valuable insights into the effects of calcination temperatures on the properties of Eggshell and Rice husk as catalysts for Biodiesel production. The findings highlight the potential of utilizing solid waste materials as catalysts for energy production while also considering the optimization of calcination temperatures to enhance their performance.