In recent decades, the concern over depletion of the world׳s petroleum reserves and environmental pollution has increased the demand to develop a renewable and environmental friendly fuel. Biodiesel, which mainly consists of Fatty Acid Methyl Esters (FAME) is one of the best substitutes for diesel fuel. Currently, vegetable oils, edible or non-edible, are the main resources of biodiesel. This review aims at providing comprehensive information and analyzes on biodiesel produced from edible and non-edible vegetable oils, their composition and specifications. Accordingly, the Fatty Acid (FA) profiles of 28 edible vegetable oils and 40 non-edible vegetable oils were collected. Their main specifications including sulfur content, density, viscosity, flash point, cloud point, pour point, cold filter plugging point, cetane number, iodine number, heating value, acid value and carbon residual before and after transesterification (vegetable oil and biodiesel, respectively) were analyzed in detail. Many researchers have developed prediction models to quantify biodiesel specifications to optimize its manufacturing and obtain biodiesel with the best specifications. Three factors that are especially influential are the fatty acids profiles, the degree of unsaturation within the FA structures and molecular weight. Accordingly, many models have been constructed on these features. There are also models that quantify the relationship between the biodiesel specifications and its thermodynamic properties or other specifications. Accordingly, the second part of this work was conducted on the existing prediction models. All the models were discussed along with their deviation in prediction.

A comprehensive review on properties of edible and non-edible vegetable oil-based biodiesel: Composition, specifications and prediction models

State of the art and prospective of lipase-catalyzed transesterification reaction for biodiesel production

This paper discusses about the importance of animal fats for power generation particularly from waste chicken fat, advantages of using chicken fat for biodiesel production, different ways of oil extraction from chicken fat and various biodiesel production techniques. A detailed review has been done on the use of novel heterogeneous catalysts for transesterification process such as metal based catalysts and organic catalysts. The factors influencing transesterification parameters like molar ratio, catalyst weight percentage, reaction time and temperature has been collected from several research articles were presented in detail. In addition, the transesterification reaction is studied at different co solvents employed to increase the methyl ester conversion. Also, analyses of relative optimization techniques implementing for transesterification process parameters have been discussed thoroughly. The physico-chemical properties of chicken fat methyl ester such as kinematic viscosity, density, pour, cloud, flash and cold filter plugging point, calorific value and fatty acid compositions of chicken fat methyl ester were compared with different animal fat methyl esters. The study reveals that biodiesel produced from waste chicken fat would be a suitable replacement of edible vegetable oils due to its low cost, ease of availability and the properties of chicken fat methyl ester were within the limits of ASTM D 6751 biodiesel standards. Furthermore, the research work has to be carried out for the improvement of cycles of catalyst reusability, biodiesel purity and cost-effectiveness of biodiesel production process in future.

P. Kathkar

Papers

Co-solvents transesterification of cotton seed oil into biodiesel: Effects of reaction conditions on quality of fatty acids methyl esters