Biodiesel synthesis from various kinds of oils and fats

Abstract

During the last years, the need to find alternative fuels has increased due to the exhaustion of this energy source. Its consumption also generates high energy dependence for non-producer countries. Biodiesel can be a good alternative thanks to its similar characteristics as fossil fuels which are used nowadays. Moreover, automobiles could be adapted easily. The usual biodiesel’s process production consists on triglycerides transesterification using an excess of methanol and doing a downstream process that consists in a distillation column to recover the methanol with the energy consume that it produces. The alternative process proposed by García Jurado et al (2013) consists in an hybrid column with two areas, a reactive-extractive area and another only extractive. In this column the reactant flow in countercorrent and the glycerine produced is used to recover the methanol, saving energy. Another advantage is the possibility to work in stoichiometric methanol conditions with the consequent saving that produces. Using an hybrid reactive-extractive column, in this project, it has been simulated biodiesel production using different pure oils and also mixes of them simulating the composition of different oils. The oils used as a raw material don’t compete with the production of foods. For example, Jatropha curcas oil which is a non-edible plant or some microalgae oil which could allow a higher production of biodiesel with less cultivated areas. Other oils as used frying oil or oil from animal fats also have been simulated in order to obtain biodiesel. Moreover, it will help to reduce the impact that these wastes can generate finding a way to reuse them. In the simulation of pure oils, it has been possible to obtain biodiesel with an hybrid column with 5 reactive-extractive stages and 9 extractive stages. As more double bonds the triglyceride has, less conversion has been obtained. In the simulation of mixes of pure oils, an important amount of triglycerides have appeared, the 8,75% in the Tolypothrix microalgae oil, but using a 10% more of methanol the problem has been overcome.