The direct-fired thermal oxidizer system is used to treat process off-gas emitted during the production process of a 300,000-ton/year propylene oxide project. This system can achieve a processing speed of 9418~13316 kg/h for process off-gas.

During normal operation of the direct-fired thermal oxidizer system, the off-gas is pressurized and conveyed to the incinerator's off-gas burner by the buyer. Inside the combustion incinerator, the off-gas undergoes high-temperature oxidation combustion. The design of the combustion incinerator ensures that the flue gas produced by the combustion of off-gas has sufficient residence time in the furnace, with a designed flue gas temperature of 900~1100°C.

Due to the high-temperature oxidization of off-gas, a small amount of thermal and prompt NOx is generated. Therefore, ammonia injection nozzles are designed at appropriate temperature ranges in the incinerator to achieve selective catalytic reduction (SNCR) for flue gas denitrification.

The heat generated by incineration is recovered by a waste heat boiler, producing byproduct 2.5 MPaG, 226°C saturated steam at a rate of 9~12 t/h. The waste heat boiler consists of evaporator tubes, SCR reactor, economizer, induced draft fan, chimney, etc. After recovering heat through the waste heat boiler, the flue gas is sent to the chimney by the induced draft fan for standard discharge into the atmosphere. The facility occupies an area of approximately 40m x 25m.

The project completed equipment installation and oven drying in May 2022, with equipment handover completed in November 2022.