C.E AKHABUE

This study explored the optimization of the microwave aided biodiesel production from neem oil with a bio-waste catalyst derived from cow bones and rice bran using central composite design, an experiment analysis on response surface model. The bio-waste catalyst was synthesized by the carbonization and sulphonation of rice bran to produce an acid precursor, while cow bones was calcined and treated with KOH to create the basic precursor. Both precursors were then impregnated using the wet-impregnation method. Also, a model was developed to simulate the process and examine the interactive effect of process input variables on neem oil biodiesel yield using the central composite approach. These inputs generated about 50 runs to be carried out with the catalyst using methanol under optimal conditions. In this study, we aimed to optimize biodiesel production from neem oil using a microwave- assisted process with a bifunctional heterogeneous catalyst synthesized from cow bones and rice bran. Oil characterization was carried out according to the ASTM standards, the catalyst failed to facilitate the transesterification reaction resulting in no biodiesel formation. Biodiesel production was carried out using sodium hydroxide which proved the viability of the oil and this outcome underscores the critical importance of proper catalyst synthesis and activation in biodiesel production. Additionally, the presence of impurities or moisture during catalyst preparation could have led to deactivation, further inhibiting the reaction. Fresh catalyst samples have been impregnated and are awaiting analysis results

Fatty acid alkyl esters are produced by subjecting vegetable or animal fats to a transesterification process with a low molecular weight alcohol, using a suitable catalyst. This process creates biodiesel, often referred to as 'green fuel', due to its numerous advantages such as biodegradability, renewability, reduced toxicity, higher cetane number, and flash point. Consequently, biodiesel has gained recognition as a potential substitute for conventional petroleum-based diesel (Baig and Ng 2010). In the majority of current biodiesel production methods, which employ homogeneous catalysis, refined vegetable oils serve as the primary raw materials. However, these refined oils come at a considerable expense. The cost of these feedstocks significantly affects the economic aspects of biodiesel production, as highlighted in a review conducted by Marchetti and Gebremariam, (Akhabue et al. 2020) discovered that the economics of biodiesel production are notably affected by the expense of feedstocks. Studies have indicated that the expenditure on raw materials for biodiesel production may make up as much as 88% of the total production expenses. Therefore, a substantial rduction in the production cost of biodiesel can be achieved through the utilization of non-edible oils or waste cooking oil (Haas et al. 2016). The elevated levels of free fatty acids (FFA) in waste cooking oil and various non-edible oils lead to saponification by the alkali catalyst, resulting in a r duced biodiesel yield due to the challenge of separating the product. Moreover, the purification process generates waste water, causing environmental pollution concerns, which require the treatment of waste water before disposal or reuse (Daud et al. 2015). This, in turn, adds to the cost of biodiesel production