A regenerative thermal oxidizer (RTO) is a piece of industrial equipment used for the treatment of exhaust air. The system is a type of thermal oxidizer that uses a bed of ceramic material to absorb heat from the exhaust gas. It then uses this captured heat to preheat the incoming process gas stream and destroy air pollutants emitted from process exhaust streams at temperatures ranging from 815 °C (1,500 F) to 980 °C (1,800 F)[1].

The cells of the ceramic blocks are square and hexagon, triangle, rotundity and the channels of cells are straight and parallel to each other. This structure reduces the resistance of passing through and enhances the heat exchange effects of every cell.