Effect of the oxidation of activated carbon by hydrogen peroxide on its catalytic activity in the regeneration of Co(II)TETA

Cobalt(II) triethylenetetramine (Co(II)TETA) formed by soluble cobalt(II) salt combining with triethylenetetramine will be used as a wet denitration technique since it can interact with nitric oxide to accomplish quick absorption of NO from gas phase. However, the oxygen in the flue gas will oxidize Co(II)TETA to Co(III) TETA, resulting in the reduction of denitrification efficiency. Activated carbon has been used to promote the regeneration of Co(II)TETA due to its unique surface characteristics. Hydrogen peroxide solution is utilized as a modifier in the carbon modification to improve the catalytic performance of activated carbon. The experiments demonstrate that the best regeneration efficiency of Co(II)TETA is gained by the modified carbon impregnated in 0.05 mol L-1 H2O2 solution at 70 degrees C for 12 h with a solid/liquid ratio of 1/50 (g/mL) followed being activated at 400 degrees C for 2 h in N-2. After being treated with hydrogen oxide solution, the surface area and acidity of the carbon is increased. Continuous experiments reveal that the NO removal efficiency gained by modified activated carbon is about 8.36% higher than that gained by the original carbon.