Influencing factors on the amount of fuel for waste incineration
The process of thermal neutralization and disposal of waste is carried out with constant or temporal use of fuel. Waste incineration is also possible without the use of fuel under conditions of constant continuous supply of waste to the main chamber. In this paper we’re going to find out what factors effect on fuel consumption and the functional mode of burners.
The first factor is what type of fuel will be used. There are several types of fuel used for waste incineration: diesel, gas, waste oils, fuel oil, etc. The calorific value of one type of fuel will be different from another. For instance, natural gas is more calorific compared to diesel, which means that gas consumption will be less than diesel consumption.
The second factor affecting the amount of fuel consumption is the calorific value of the waste. The higher the calorific value of the waste, the less fuel will be required for combustion (high-calorific waste is capable of sustaining self-combustion). To minimize or reduce to zero the consumption of fuel required for evaporation of water in the waste, heating to set temperatures and the cost of heat loss, possibly by the heat released by the waste. For example, the calorific value of contaminated plastic is more than 6000 kcal/kg, the calorific value of food waste is about 800 kcal/kg. So, unlike food waste, plastic can be burned without using fuel.
The third factor is the amount of air supplied to the main and secondary chambers. If the air is supplied without preheating, i.e., taken directly from the environment, that requires a significant amount of heat to heat it up to the preset temperatures. Consequently, the more air oxygen is required to burn the waste, the greater the fuel consumption for heating it. The more organic compounds in the composition of the waste, the more amount of air for waste incineration will be required. For example, the burning of 1 kg of contaminated plastic requires stoichiometrically about 9 kg of air, the burning of 1 kg of food waste requires about 2 kg of air. However, plastic is more calorific and the heat released during its combustion is sufficient to compensate the temperature loss.
The fourth factor is the size of equipment for thermal treatment and disposal of waste. The larger the unit, the more fuel will be needed to heat up the main and secondary chambers. For instance, there will be 4 kg/h of fuel consumption because of heat losses on the pressure vessel walls of the HURIKAN 150 incinerator, and 15 kg/h for the HURIKAN 1000 incinerator. At the same time, when the incinerator enters the operating mode, i.e., full heating and maintaining of a constant continuous supply of waste to the main chamber, the effect of size of equipment on the amount of fuel consumption is reduced due to different productivity: the more waste is burned per unit of time, the more heat is released, therefore, a more productive plant generates more heat.
Thus, the amount of fuel consumption for waste incineration is variable, and depends on a number of factors. The fuel consumption can also be minimized or reduced to zero.