Reduction of NOx and CO emissions through the optimization of incineration parameters in a rotary kiln

Theoretical and experimental results of the investigation illustrate how the rotary kiln operation affects the oxygen demand in the combustion of meat and bone wastes. The main objective of this study was to achieve optimal CO and NOx emissions for the cyclic operation of a rotary kiln, including in stoppage/operation mode. The tests were carried out in a plant in Poland for thermal animal waste management. A rotary kiln with a maximum capacity of 1000 kg/h was used to incinerate bones, carcasses, processed meat and by-products. The results showed that excessive short-term (1 min) CO and NOx emissions could be prevented by using appropriate time settings for the kiln rotation and adjusting the air flow to the afterburner chamber. Despite the strong negative correlation between CO and NOx emissions, we found an operation level that met the strict requirements of the new EU Directive 2010/75/EU of the European Parliament and the November 24, 2010 Council on industrial emissions.