Heat recovery from corrosive gasses

During calcination of bricks in kilns corrosive chemical compounds are released. The exhaust gas is released at 150 - 250° C without any heat recovery. The water vapor in the exhaust gas will form highly corrosive hydrofluoric and sulfuric acids. Investment cost for traditional wet scrubbing systems are 12-15 mill. DKK not including operating and maintenance cost. The project aim to develop a compact two step wet scrubbing system in light materials where solids and water are separated outside the scrubber. As heat from the exhaust gases are transferred to the neutralized scrubbing liquids, heat recovery through traditional plate heat exchangers is now possible. As the material used for the main equipment is light materials and as traditional heat exchangers can be utilized, a price ranges of 1 – 2 mill. DKK is expected. Thus making the investment compared to cost savings on the energy bill lucrative. The recovered heat can be utilized in the district heating system or for process heating, and is mainly aim at the Danish and German brickworks. Participants aim to install a full scale wet scrubbing system based on a small test facility with heat recovery and equipment for separating and handling byproducts.