Thesis Abstract

Abstract
Biodiesel production has gained significant attention as an alternative renewable fuel source due to environmental concerns and limited fossil fuel resources. In this study, the optimization of biodiesel production from yellow oleander and castor oils was investigated, along with the assessment of their fuel properties. Yellow oleander and castor oils were selected as feedstocks due to their high oil content and potential for biodiesel production. The transesterification process was optimized using response surface methodology (RSM) to maximize biodiesel yield. The effects of methanol/oil molar ratio, reaction temperature, and catalyst concentration on biodiesel yield were studied. The optimal conditions for yellow oleander oil transesterification were found to be a methanol/oil molar ratio of 61, a reaction temperature of 60°C, and a catalyst concentration of 1% w/w, resulting in a biodiesel yield of 94.7%. For castor oil, the optimized conditions were a methanol/oil molar ratio of 51, a reaction temperature of 55°C, and a catalyst concentration of 0.8% w/w, yielding 97.3% biodiesel. The produced biodiesel samples were characterized for their fuel properties according to ASTM standards. The biodiesel samples from yellow oleander and castor oils met the specifications for key parameters such as kinematic viscosity, density, flash point, and cetane number. The biodiesel properties were within the acceptable range set by international standards, indicating their potential as viable alternative fuels. Furthermore, the thermal stability and oxidation stability of the biodiesel samples were evaluated using thermogravimetric analysis (TGA) and Rancimat methods, respectively. The results indicated good thermal and oxidation stability for both yellow oleander and castor oil biodiesel, demonstrating their suitability for long-term storage and use. Overall, the study successfully optimized the biodiesel production process from yellow oleander and castor oils, achieving high yields of quality biodiesel. The comprehensive characterization of the biodiesel samples confirmed their compliance with international fuel standards and highlighted their potential as sustainable alternative fuels. The findings contribute to the growing body of research on biodiesel production from non-edible feedstocks and underscore the importance of studying fuel properties for assessing biodiesel quality and performance.

Thesis Overview

1.0 INTRODUCTION

The world energy sector depends on the petroleum, coal and natural gas reservoirs to fulfill its energy requirements (Meher et al., 2006). Nigeria is traditionally an energy-deficient country which exports above 70% of its crude oil production. The country is dependent upon import of petroleum products to sustain its growth. Diesel fuel plays an essential function in the industrial economy of Nigeria. The fuel is used in heavy trucks, city transport buses, electric generators, farm equipment etc. (Anjana, 2000). However, diesel engine also emits various forms of pollutants into the environment which can endanger human health and damage the ecological environment (Antolin et a.l, 2002). It is therefore essential that the world extend its interest towards new sources of energy. A relatively new alternative that is currently booming worldwide is fuel obtained from renewable resources or biofuel. Biofuels are well suited for decentralized development i.e can be utilised to meet the needs for social and economic progress, especially in rural communities where fossil fuels may be difficult or expensive to obtain (Nwafor and Nwafor, 2000; Ezeanyananso et al., 2010).

Amongst the various alternative fuels which could match the combustion features of diesel oil and can be easily adapted for use in existing engine technologies with or without any major modifications is biodiesel. Biodiesel fuel produced from vegetable oils (both edible and non edible) or animal fats is one of the promising possible sources that can be substituted for conventional diesel fuel and produces favourable effects on the environment. Biodiesel is recommended for use as a substitute for petroleum diesel

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mainly because it is a renewable, domestic resource with an environmentally friendly emission profile and is readily available and biodegradable (Zhang et al., 2003).

The research and use of biodiesel fuel as an alternative started in the 1980?s and the reason was the diesel crisis caused by the reduction of petroleum production by the Organization of Petroleum Exporting Countries (OPEC) and the resultant price hike. The biodiesel produced from locally available resources offer a great promise for future application in Nigeria as it can help in attaining much needed energy security and being environment friendly, will help to conform to stricter emission norms (Ezeanyananso, 2010).

Castor plant (Ricininus communis)

Ricinus communis (Plate I) is a species that belongs to the Euphorbiaceae family and it is commonly known as castor oil plant, and Palma christi. Castor oil is possibly the plant oil industry?s most underappreciated asset. It is one of the most versatile of plant oils, being used in over ten diverse industries.

Owing to its unique chemical composition and structure, castor oil can be used as the starting material for producing a wide range of end-products such as biodiesel, lubricants and greases, coatings, personal care and detergent, surfactants, oleo chemicals e.t.c. Compared to many other crops, castor crop requires relatively fewer inputs such as water, fertilizers and pesticides. The crop can also be grown on marginal land, thus providing an excellent opportunity for many regions of the world to utilize their land resources more productively (Dokwadanyi, 2011). The plant prefers well-drained moisture relative clay or sandy loan in full sun requires a rich soil and day time temperature above 20oC for