Power generation from biomass


Biodiesel, (formally) also known as either methyl-ester or ethylester, is the product of a trans-esterification process in which vegetable oils or animal fats are reacted with a monohydric alcohol in presence of a catalyst. In the most commonly used transesterification method (base-catalyzed ransesterification), the triglyceride of oils or fats are converted to methyl (or ethyl) esters; alcohol reacts with the oil to release three “ester chains” from the glycerin backbone of each triglyceride. The reaction requires heat and a strong base catalyst to achieve complete conversion of the vegetable oil into the separated esters and glycerol, the co-product.

Biodiesel is produced from a variety of vegetable oils, as well as from restaurant grease, various animal fats, and soapstock. Since the carbon in the oil or fat is mostly originated from the carbon dioxide in the air, biodiesel is considered to contribute much less to global warming than fossil fuels.

Biodiesel’s advantages compared to petroleum diesel include superior emissions properties, support for domestic agriculture, compatibility with existing engines and distribution infrastructure, and ease of manufacture. It can be refined under normal atmospheric temperature and pressure, and it can be economically produced across a variety of places and scales: from urban to rural, small to commercial.

Biodiesel has chemical and physical characteristics very similar to fossil diesel: it presents a slightly lower heating value (LHV) in comparison to diesel fuel (around 32.6 MJ/l, instead of 36.5 MJ/l); its kinematic viscosity, in general, varies between 1.9 and 6 cSt. This parameter does not differ significantly from diesel fuel (1.3 and 4.1 cSt). Its density is in the range of 0.86-0.90 ton/m3 at 15 °C and the flash point is above 120 °C, which is higher than the value for diesel fuel, whose flash point varies between 60 and 80 °C. The flash point makes biodiesel safer to manipulate and to transport. Cetane Number of biodiesel (> 51) is slightly higher than that for diesel fuel (45-55).

Within the framework of the Bioliquids-CHP Project, Biodiesel from various source will be tested in an adapted Micro Gas Turbine (MGT) and various Diesel Engines (DEs). Full and partial load test will be carried out to asses performance, efficiency, reliability and flue gas emission.