Coal-fired boilers, because of the use of energy is directly burning traditional coal, pollution emissions are mainly two types of cinder and flue gas. Cinders need a special site in the pile or landfill, and the cinder is alkaline, will seriously pollute the surrounding land, so that the land can not grow plants, and even insects and microorganisms are difficult to survive. Flue gas contains a lot of soot, carbon dioxide, carbon monoxide, sulfur dioxide and nitrogen oxides. Among them, soot will lead to PM2.5 exceeding the standard, seriously affecting the air quality; carbon monoxide is easy to cause gas poisoning, fire and other accidents; and the most dangerous nitrogen oxides, can cause acute focus in the short term, and long-term can cause a variety of diseases.