The use of waste cooking oil (WCO) from extended household and restaurants was considered as a suitable feedstock for biodiesel production in this paper. The paper also focuses to showcase the qualities of biodiesel produced from WCO compared to that of other virgin oil. The oil that was supposed to be disposed, at times indiscriminately was de-odoured and purified using appropriate solvents. The purified oil was characterized and used for biodiesel production. The physical and fuel properties such as density, viscosity, cloud point, pour point, cetane number etc were determined according to ASTM standards. The properties obtained were not only comparable with that of others but also within standard limits.
Biodiesel, a renewable fuel made by trans-esterification of vegetable oil with alcohol, is becoming more readily available for blending with conventional diesel fuel for use in transportation applications. Fossil fuels such as petroleum, coal and natural gas, which have been used to meet the energy needs of mankind are associated with negative environmental impacts such as global warming . Similarly, the fossil fuels accumulated over series of geological activities are irreversibly consumed at a rate more than million times faster than they were formed . This has left us in a precarious position especially for petroleum products. The hike in price of petroleum and its products, both in national and international scenes is frequent for two reasons; the mounting demands and fast depletion of reserves the duo of which call for alternative source of energy. Similarly in developing countries, the price paid for petrol, diesel and petroleum products now dominates over all other expenditures and forms a major part of country’s import bill. Biofuel/Biodiesel made from natural oils and fats is being considered as a promising substitute for petrol diesel. Although biodiesel cannot entirely replace fossil fuel, the following reasons however further justify its development.
• It provides a market for excess production of vegetable oils.
• It decreases the dependence on imported petroleum.
. It does not contribute to global warming due to its closed carbon cycle.
. The exhaust emissions of carbon monoxide, unburned hydrocarbons and particulate emissions from biodiesel are lower than fossil fuel .
Though much has been done in the area of biodiesel production especially with the use of various feed stock; soya bean oil, corn oil, peanut oil, olive oil, cotton seed oil, safflower, rape seed oil/canola, line seed oil, sunflower, coconut oil, palm kernel oil, jatropha seed oil etc as further evidenced in the report but still, few research has been carried out on the use of WCO for biodiesel production.
The conversion of vegetable oil carried out by under optimized conditions in presence of co-solvent (n-hexane) obtained with solid base catalyst Na/NaOH/γ-Al2O3 is comparable to that obtained with conventional homogeneous NaOH catalyst. Heterogeneous solid oxide catalysts of the type (Al2O3)4 (SnO) and (Al2O3)4 (ZnO), have been examined by for the transesterification of vegetable oil using different chain length alcohols. The highest yield of 84% was observed with methanol. Also, found that calcined Mg-Al hydrotalcite at 400ºC was most effective catalyst for the transesterification of jatropha oil, obtaining conversion of jatropha oil of 96%.Sathivel ultimately feels that biodiesel production from waste salmon oil holds promise because the biofuel represents a use of a currently under-utilized resource-and salmon oil biodiesel burns more cleanly and efficiently than pure salmon oil . Recently, report in the literature showed that satisfactory result was obtained when the mixture of canola oil and used cooking oil was used as feedstock for biodiesel production . Biodiesel production with biocatalyst produced biodiesel with a very high degree of purity . Different lipases, such as Candida antarctica , Pseudomonas cepacia and Thermomyces lanuginosus have been employed as biocatalysts in the production of biodiesel from vegetable oil.