Catalytic NO reduction at high temperature by de-ashed chars with catalysts

To study the effect of single metal oxides contained in coal ashes on NO reduction at high temperature, experiments and predictions for NO reduction were conducted in a drop-tube furnace at 1223 to 1523 K. The de-ashed chars used in experiments were prepared from Chinese Shenfu bituminous coal, and then a single catalyst (KOH or NaOH) was added into the de-ashed chars. Experimental and predicted results show that NO is more easily reduced on chars from Shenfu bituminous char than on its de-ashed char, indicating that minerals in char have some catalytic effect on NO reduction. Experimental and predicted results, using de-ashed char with catalysts KOH or NaOH as fuels to reduce NO, also show that the catalysts have a great positive effect on NO reduction and that catalytic activity of KOH is slightly better than that of NaOH. The influence of temperature and stoichiometric ratio (SR) on catalytic NO reductions is also discussed briefly. (c) 2006 Published by Elsevier Inc. on behalf of The Combustion Institute.