The differences between oil-fired boilers and gas-fired boilers in pollutant emission are analyzed.

Answer: (1) For oil-fired and gas-fired boilers, due to the low ash content of oil and gas, the atomized oil and gas are fully mixed with air, and the oil and gas burn-out time is short. The main pollutants of oil-fired and gas-fired boilers are carbon black particles, carbon monoxide gas, carbon dioxide gas and low-temperature waste heat.

(2) Coal-fired boiler: layer-fired boiler: the main pollutants are ash and fly ash particles, carbon dioxide gas, sulfur dioxide gas, low-temperature waste heat, etc. Fluidized bed boiler: The main pollutants are ash particles, carbon dioxide gas, sulfur dioxide gas and low-temperature waste heat. Pulverized coal boiler: The main pollutants are fly ash and bottom slag particles, carbon dioxide gas, sulfur dioxide gas and low-temperature waste heat.