On the role of devolatilization in fossil fuel combustion

At the initial stage of liquid or solid fuel combustion volatiles are released, then tar decomposes, and finally carbonic residue burns out. In connection with this, vaporization and burning of a fuel oil droplet on the hot surface and the processes of volatile release and carbonic residue burning are analyzed. Most part of fuel caloricity is related to volatiles, and this is the initial combustion stage on which further fuel combustion depends. On the basis of the experience of heavy fuel oil combustion in different boilers, we summarize how to use the initial volatile combustion in order to reduce the residue of soot, nitrogen oxides, and CO. Wider use of biofuel is related to gasification of this fuel. Manufacturing of synthetic gas differs for wood, which is comprised of aliphatic spirits, from that of fuel oil or tires, where there are plenty of aromatic hydrocarbons and their conglomerates, such as naphtenes. The pyrolysis process depends on temperature, the amount of oxygen existent in the environment, and chemical composition of fuel, and all this will be revealed by research of used tires and glycerol gasification. The theoretical combustion process and numerical modeling of volatile assessment are discussed in general.