George S. Dodos

Biodiesel production by ethanolysis of various vegetable oils using calcium ethoxide as a solid base catalyst.

In this study, fatty acid ethyl esters (FAEE) were produced from four different vegetable oils (sunflower, cotton seed, olive oil, and used frying oil) using calcium ethoxide as a heterogeneous solid base catalyst. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transterification were an ethanol/oil molar ratio of 12:1, catalyst amount (3.5%), and 80°C temperature, whereas the maximum yield of ethyl esters reached 80.5%. In the second stage, the yield of ethyl esters showed signs of improvement of 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. Property analysis of prepared ethyl ester samples was done, in order to examine their quality parameters. The results obtained showed that the density, viscosity, and calorific value of the produced ethyl esters had values close to those of a no. 2 diesel. On the contrary, the cold filter plugging points were higher than the conventional diesel fuel.

Methanolysis of sunflower oil and used frying oil using LiNO3/CaO as a solid base catalyst

The conversion of sunflower oil and used frying oil to methyl esters (biodiesel) was studied using lithium nitrate loaded on calcium oxide as heterogeneous catalyst. Reaction parameters such as catalyst concentration, methanol to oil ratio, reaction time and agitation speed on the conversion of sunflower and used frying oil were investigated. The catalyst loaded LiNO3 of 35% m/m on CaO, after being calcined at 750°C for 6 h, was found to be the optimum catalyst. The quality of the methyl esters was tested according to the European Standard ELOT EN 14214. The two types of biodiesel produced, seemed to meet all the parameters of the European Standard except the oxidation stability, acid value and the glycerol content for the used frying oil methyl ester only.

The Introduction of Biofuels in Marine Sector

Sulphur and emissions related limits which are imposed on marine fuels drive the maritime industry to look on alternative fuels. The maximum sulphur content of the fuel has already decreased in the ECAs SOx (Sulphur Emission Control Areas) from 1.5% to 1% from 1 July 2010, and to 0.1% from 1 January 2015. Globally, the highest permitted sulphur content of fuel will be reduced, as from 1 January 2020 to 0.5%. Increasing demand of low sulphur fuel is anticipated, leading to a substantial mitigation of marine fuels from residual to distillate ones. Biodiesel or else Fatty Acid Methyl Esters (FAME), and mixtures of it with conventional petroleum fuels, constitute alternative energy source for the maritime industry. The International Standard EN ISO 8217 specifies the requirements of petroleum fuels for use in marine diesel engines. According to the previous version of EN ISO 8217:2012 distillate fuels should comply with the “de minimis level” of approximately 0.1% v/v FAME. Nevertheless with the latest revision of EN ISO 8217 standard in 2017, the incorporation of FAME up to 7% v/v is allowed in specific marine distillate grades (DF). Marine distillates can also include hydrocarbons from synthetic or renewable sources, similar to the composition of petroleum distillate fuels.