Effect of furnace temperature and oxygen concentration on combustion and CO/NO emission characteristics of sewage sludge

Addressing the growing energy crisis, the development and utilization of solid waste have become a critical research areas. Sewage sludge, rich in organic matter, can serve as an alternative fuel to coal. This study employs a thermogravimetric analyzer to investigate the combustion characteristics of sewage sludge at heating rates of 10, 20, and 40 degrees C/min. Additionally, a horizontal tube furnace is utilized to analyze the CO and NO emission characteristics during sewage sludge combustion at varying oxygen concentrations and temperatures. Results indicate that at a constant gas velocity, the primary factor influencing combustion characteristics and CO/NO emissions is the composition difference. Higher furnace temperatures lead to lower CO generation and increased combustion efficiency. The conversion of coke-N to NO rises with increasing temperature. Moreover, higher furnace temperatures decrease the conversion of fuel-N to NO. Increasing oxygen concentration reduces the ignition concentration limit of sewage sludge. The lowest NOx emissions were recorded at an oxygen concentration of 21 vol%. This study provides essential data for reducing coal consumption and enhancing the safe and efficient treatment of sewage sludge.