International Journal of Scientific Engineering and Science Volume 7, Issue 4, pp. 5-13, 2023. ISSN (Online): 2456-7361 5 http://ijses.com/ All rights reserved Performance Evaluation of Waste Chicken Eggshell and Waste Seashell as a Heterogeneous Catalyst for Biodiesel Production K.A. Viraj Miyuranga 1 , Udara S.P.R. Arachchige* ,1 , Parami P. R. Hettiarachchi 1 , Randika A. Jayasinghe 1 , Nuwan A. Weerasekara 1 , Gamunu Samarakoon 2 1 Department of Civil and Environmental Technology, University of Sri Jayewardenepura, Sri Lanka 2 Department of Process, Energy and Environmental Technology, University of South-Eastern Norway, Norway Email address: *udara@sjp.ac.lk Abstract— Due to their reusability, heterogeneous catalysts for biodiesel production have gained popularity. If the commercial-grade heterogeneous catalyst could be replaced with CaO generated from eggshells (which is a waste product) and seashells (which is abundantly available in Sri Lanka) would be beneficial for the sustainability of the process and circular economy. This work em-phasizes and summarizes the derivation of CaO from eggshell and seashell, the investigation of the produced catalyst using a scanning electron microscope, and the comparison of the two by powder X-ray diffraction. CaO produced from eggshell, and seashell exhibited slight differences in its surface structure. However, there are larger voids in the seashell-derived catalyst due to the release of CO2 during calcination. The derived catalyst and commercial CaO were both employed to produce biodiesel under identical operating circumstances, including a 12: 1 Methanol-to-oil molar ratio, 60 °C operating temperature, 120min reaction time, 600 rpm, and a 5 wt.% catalyst concentration. The biodiesel yield was computed and compared for all three scenarios involving catalyst recycling. Commercial grade CaO produced the highest yield, followed by seashell- and eggshell-derived CaO. Both derived catalysts are less pure than commercial CaO, as they were produced with CaCO3 in addition to CaO. Keywords— Biodiesel, Catalyst, CaO, Eggshell, Hetergenous, Renewable energy, Seashell, Transesterification, Waste cooking oil. I. INTRODUCTION As a consequence of industrialization and population growth, energy supply instability has been a challenge for several decades. Due to the alarming rates of global warming and environmental pollution, the worldwide community has identified the development of sustainable energy sources as a top research priority [1]. Multiple causes are re-sponsible for environmental pollution such as industrialization, globalization, vehicle emission, population [2-4]. The combustion of fossil fuels for power generation and transportation accounts for a greater proportion of air pollution [5,6]. The research of worldwide energy consumption patterns indicated that automobiles fueled by fossil fuels account for more than 70 % of all CO emissions and 19 % of all CO2 emissions [7]. There-fore, Biodiesel production and implementation widely discussing worldwide to reduce the fossil fuel combustion and to confirm the energy security. Biodiesel has multiple benefits such as, high combustion efficiency, biodegradable nature, lubricity, less environmental pollution, and clean sustainable energy source [8]. Biodiesel is produced by the reaction of triglycerides with simple alcohols such as Methanol, Ethanol, Propanol and Butanol and with the presence of catalyst [9]. The overall reaction of the biodiesel production is transesterification reaction (Fig. 1). The most widely used catalyst for biodiesel production is homogeneous alkaline catalyst such as potassium hydroxide or sodium hydroxide due to its availability and ease of operation [11]. These catalysts are present in same phase during the reaction [12, 13]. However, heterogeneous catalyst has also gain broader attention recently due to reusability of the catalyst and the availability [14, 15]. Fig. 1. A schematic representation of the Transesterification Reaction [10] By considering the advantages of heterogeneous catalysts, they are easily separated from the product by filtration, and they can be recycled several rounds for the biodiesel production without depleting the yield significantly [16]. As an examples for heterogeneous catalysts, calcium oxide (CaO), magnesium oxide (MgO), barium oxide (BaO), zinc oxide (ZnO), barium hydroxide (Ba(OH) 2) can be considered [12, 17]. CaO is one of the most popular catalysts because to its abundance in nature, high activity, and inexpensive cost [18]. Further, CaO base catalyst impregnated with metal oxide will boost reactivity by overcoming separation difficulties when CaO is used alone in the reaction media [15, 16]. numerous studies have been conducted to determine the efficiency of CaO catalyst obtained from eggshell waste and CaO derived from seashells. Some of the researchers were generating eggshell derived CaO catalysts [16, 19-25] to optimize the biodiesel process. Several studies have also used