Combustion of chicken manure and Turkish lignite mixtures in a circulating fluidized bed

Abstract

Burning chicken manure (CM) with lignites may be a promising method to ensure waste management. In this study, a circulating fluidized bed boiler (CFBB) system was designed, manufactured, and tested for the disposal of CM in poultry farming. Combustion and co-combustion tests of CM and Kale Lignite (L) were carried out in the CFBB to determine the effect of excess air ratio and CM share in the fuel mixture on combustion efficiency and flue gas emissions. As the CM share in the mixture increased, the combustion efficiency increased from 86 % to 95 %. It was observed that while CO emissions increased, SO2 and NOx emissions decreased with respect to CM share. CO emissions ranged from 726 to 2241 mg/Nm3 for 100%L and between 838 and 2450 mg/Nm3 for 100%CM. The NOx emissions changed between 177.5 and 240 mg/Nm3 for 100%CM; however, it was 276.3 mg/Nm3 for 100%L. While SO2 emissions (average) for 100%L were around 5200 mg/Nm3, as the CM share in the fuel mixture increased, emissions decreased, and when they became zero for 100%CM. CO emissions decreased as the excess air ratio increased. SO2 and NOx emissions increased as the excess air ratio increased in almost all fuel mixtures. This combustion system was proposed for waste disposal, emission reduction, and usage of domestic sources. Photovoltaic panels can support this system and meet farms' operational energy requirements away from the grid. Combustion efficiency can be increased by operating the system at oxy-firing mode instead of air-firing.