BIOFUELS.

Biogenic fuels can be of plant origin or a product of fermentation or digestion of organic material. The chemical and physical properties vary considerably depending on the fuel. Some substances are solid at room temperature, others are liquid or gaseous.

Typical biofuels are:

• Rapeseed oil

• Soybean oil

• Palm oil

• Biodiesel

• Biogas

• Bio natural gas

• Sewage gas

• Gas from biomass gasification

• Wood dust

All of these fuels have a high calorific value of more than 15 MJ/kg (15 MJ/m³) and a neutral CO2 balance when burned. If sewage gas or biogas was previously released uncontrolled, thermal utilization can reduce the impact on the climate even further: these gases contain a lot of climate-damaging methane, which is converted into CO2 during combustion.

Even though the combustion of rapeseed oil, soybean oil, or biodiesel works largely in the same way as the use of light or heavy oil, each individual fuel poses a particular challenge for combustion: All substances differ in terms of calorific value, pour point, viscosity, and ignitability. Because palm oil is solid at room temperature, it must be preheated to a greater or lesser extent, depending on the burner used, in order to be able to convey and atomize it. In addition, most biogenic liquids contain a certain amount of free fatty acids, which are highly corrosive. In this case, all parts that come into contact with the fuel must be made of stainless steel.