Opinion Sur Joven

In an article by the specialist Ricardo Carlstein published in www.biodiesel-uruguay.com, he explains that the energy of this biofuel is 5% lower than gas oil’s, but its high lubricity compensates such difference, so the energetic yield of both fuels is essentially the same.

Its lubricity is outstanding; it doubles the useful life of the engines using it. This is why it’s used in a mix with low sulfur diesel; to improve the latter’s lubricity. Mixing them also enhances the cetane number of fossil gas oil.

Biodiesel manufacture is simple and does not require economies of scale: it’s based on a vegetable oil, which is entered into a process called transesterification. As a result, biodiesel and a sub-product which is generically known as glycerol are obtained. The latter has more than 1,600 uses in agriculture, industry, medicine, cosmetics and food.

Transesterification may be performed at ambient temperature by mechanically mixing one alcohol, one alkali and the vegetable oil. After some time of mixture and a rest period, biodiesel and glycerol are separated through decantation. The alcohol is used in a 15 to 20% proportion, and the alkali is less than 1% of the initial mixture. The alcohol proportion used is similar to the glycerol proportion obtained as a sub-product. A part of the alcohol used throughout the process may be recovered, but this is not recommended because it adds oxygenating properties to the biodiesel. The obtained biodiesel only requires previous filtering before being used. Unlike fossil gas oil, since it’s not degraded in time it may be simply and economically stored.

Net emissions of carbon dioxide (CO2) and sulfur dioxide (SO2) are 100% reduced with it. Carbon soot emission is reduced from 40 to 60%, and hydrocarbon (HC) emissions 10 to 50%. Carbon monoxide emission (CO) is reduced from 10 to 50%. Emissions of polycyclic aromatic hydrocarbon (PAH) and particularly of other carcinogenic derivates are equally reduced.