Catalyst preparation from various naturally available waste materials for biodiesel production: A review

The fossil fuels, which are non-renewable are depleted at a faster rate and leading to the issue of energy crises. Therefore, it is necessary to look for a fuel source that will substitute the fossil fuel and meets the energy requirement. Biodiesel is considered as a promising fuel and can be produced from vegetable oils, naturally available plants and organic waste and also from non-edible oils. The process of biodiesel production from transesterification reduces the issue of dependency on non-renewable resources. The drawbacks associated with the process are higher production cost, final product has to be purified and the process has technical limitations such as operating conditions and the catalyst used. Therefore, the transesterification process has to be modified with respect to the operating conditions and the expensive catalyst. The catalyst required can be produced from naturally available waste materials which reduce the cost of the overall process. The calcium oxide produced from the waste materials can be used as the catalyst for the production of biodiesel. The present study reviews the production of calcium oxide as catalyst from various naturally available waste materials for transesterification process.