Simultaneous SO2 and NO removal by pellets made of carbide slag and coal char in a bubbling fluidized-bed reactor

Abstract

In this work, a simultaneous SO2/NO removal method using pellets made of carbide slag and coal char by extrusion-spheronization process was proposed. The effects of char type, reaction temperature, O2 concentration, initial NO/SO2 concentration and the addition of supporters on the simultaneous SO2/NO removal performance of the pellets made of carbide slag and coal char were investigated in a bubbling fluidized-bed reactor. CaO derived from carbide slag not only acts as an excellent desulfurizer but also catalyzes the reduction of NO by coal char. The results show that the pellets made of carbide slag and coal char possess better simultaneous SO2/NO removal performance than the pellets made of carbide slag and bio-char. The optimal reaction temperature range for SO2/NO removal by the pellets made of carbide slag and coal char is 850−875°C. The addition of the supporters such as Al2O3 and high alumina cement enhances the mechanical strength of the pellets. The pellets made of carbide slag and coal char seems promising for efficient simultaneous SO2/NO removal in the circulating fluidized bed decoupling combustion.