Biodiesel

ABSTRACT

Biofuels are presented as an alternative to partial or total replacement of those petroleumbased

fuels. They are defined as renewable energy source that are generated directly or

indirectly from biomass. One such example biodiesel, a fuel produced from the reaction of

vegetable oil and fat with alcohol in presence of a catalyst.

In a search of new crops for biodiesel production, Jatropha Curcas has advantages of not

compete with species for food purposes and have high oil content in seeds. On the another

hand, water deficit and low temperatures resistance are two problems to solve for the success

of this plant in a specific area.

Laboratory analytic technique of laboratory in oil extraction, transesterification, product

quality analysis, use of sub-products and waste treatment, with this thesis aims to contribute in

a development of the production process of biodiesel from Jatropha Curcas. Three samples of

Jatropha Curcas seeds from Yuto (Jujuy province, Argentina) were used, classified according to

the period of harvest and ripeness of the fruit.

The Oil extraction process can be optimized by dehulled, grinding and heat treatment of the

seeds. With these operations, the oil content is around 40-50% in relation to the mass

processed. Acid value, Iodine number and fatty acid composition were changing in function of

sample. This behaviour must be evaluated over the subsequent years of crops.

Meal form de-hulled seeds, after oil extraction, have 50% of brute protein. Forbol esters,

lecithin, saponins and trypsin inhibitors must be eliminated to used this meal for food.

The biodiesel production process will depend on the fatty acid content (%AG) present in the

oil. Two pre-treatment are possible: esterification (for oils with %AG>8) and neutralization with

glycerine phase from the transesterification reactor. (for oils whose %AG is between 2 and 8).

For the transesterification reaction, methanol is used in 6:1 molar ratio to oil and sodium

methoxide as a catalyst. The quality parameters of the final product are according with national

and international standards.

The shells of nuts and seed shells can be used in energy generation process (combustion

and pirolysis) that’s why the high calorific power they possess. Meal and glycerine are treated

by anaerobic process, generating biogas and liquid effluents rich in nutrients, especially

nitrogen. The volume of biogas production is 490 ml/g SV (volatile solids) when using meal from

4

dehulled seed and 240 ml/g SV when used meal from completed seeds. An increase of

glycerine in input flow increased biogas production, but produces negative changes in control

parameters, mainly on the acidity and alkalinity

...