The HRSG (Heat Recovery Steam Generator) waste heat boiler is designed with a steam pressure of 5.3 MPa, a steam temperature of 410°C, and a steam flow rate of 297 t/h. Its maximum supplementary firing capacity is 82 MW.

This HRSG waste heat boiler is designed to generate high-pressure superheated steam by recovering heat from the total flue gas of the CATOFIN unit reactor system. The total flue gas comprises reactor regeneration air and exhaust gas from the air compressor's gas turbine. It is preheated to a maximum of 650°C (with a design temperature of 800°C) in the HRSG's supplementary combustion device.

The HRSG waste heat boiler consists of four sections. The first section preheats turbine condensate water, which is then sent to the deaerator. The second section preheats boiler feed water for both the high-pressure evaporator and the reactor effluent steam generator. The third section is the high-pressure evaporator, composed of a high-pressure coil and a steam drum. The fourth section superheats the high-pressure steam generated by the high-pressure evaporator and the reactor effluent steam generator. In addition, an SCR (Selective Catalytic Reduction) system is integrated to reduce NOₓ emissions in the total flue gas stream.