Power generation by waste incineration is the work of introducing waste incineration plants and waste incineration equipment, digesting and absorbing and innovating. Dioxin in the flue gas of municipal solid waste incineration is a common concern in the world in recent years. Toxic dioxins do great harm to the environment. Effectively controlling the generation and diffusion of dioxins is directly related to the popularization and application of garbage incineration and garbage power generation technology.
principle of operation
The sources of dioxins produced in incinerators are petroleum products and chlorine-containing plastics, which are the precursors of dioxins. The power generation mode is mainly combustion power generation. Domestic waste contains a lot of sodium chloride, KCl and so on. However, there are often S elements in incineration, which are produced. And chlorine-containing salts react in the presence of oxygen to generate HCl. CuO reaction between HCl and Cu oxidation. It is found that the most important catalyst for dioxin production is element C (calculated by CO).
The gas-controlled pyrolysis incinerator divides the incineration process into two combustion chambers, and the temperature of the first combustion chamber used for thermal decomposition of garbage is controlled within 700℃, so that the garbage can be decomposed at low temperature under anoxia. At this time, copper, iron, aluminum and other metal elements will not be oxidized, so they will not be produced, which will greatly reduce the amount of dioxins. At the same time, because the formation of HCl is affected by the concentration of residual oxygen, anoxic combustion will reduce the formation of HCl; And is difficult to generate in large quantities in a self-reducing atmosphere. Because the gas-controlled garbage incinerator is a solid bed, it will not produce smoke and dust, and there will be no unburned residual carbon entering the secondary combustion chamber. Combustible components in garbage are decomposed into combustible gas, which is introduced into the second combustion chamber with enough oxygen for combustion. The temperature of the secondary combustion chamber is about 1000℃, and the flue length makes the flue gas residence time longer than 2s, which ensures the complete decomposition and combustion of toxic organic gases such as dioxins at high temperature. In addition, the use of bag filter can avoid the catalytic effect of copper, nickel and iron particles on dioxin formation when electrostatic precipitation is used.