Electricity Evaluation and Emission Characteristics of Poultry Litter Co-Combustion Process

• Main Authors: Xuejun Qian, Seong Lee, Raghul Chandrasekaran, Yulai Yang, Marc Caballes, Oludayo Alamu, Guangming Chen
• Format: Article
• Language: English
• Published: MDPI AG 2019-10-01
• Series: Applied Sciences
• Subjects: poultry litter; natural gas; electricity; emissions; particulate matter; fly ash; stirling engine; energy; sustainable
• Online Access: https://www.mdpi.com/2076-3417/9/19/4116

Electricity generation and emission characteristics during the poultry litter and natural gas co-combustion process has rarely been studied. In this study, a Stirling engine was successfully integrated into the existing lab-scale swirling fluidized bed combustion system in order to further investigate the poultry litter and natural gas co-combustion process. Electricity, gaseous emissions, particulate matter (PM), and fly ash composition were analyzed under various operating conditions. Results indicated that the electricity reached 905 W under a water flow rate of 13.1 L/min and an engine head temperature of 584 °C. It was found that excess air (EA) ratios between 0.79 and 1.08 can relatively produce more electricity with lower emissions. At a secondary air (SA) height of 850 mm, secondary air/total air (SA/TA) ratios between 0.22 and 0.44 may significantly reduce NO_x and CO emissions. By increasing the mixing ratio (MR), SO₂ was reduced while NO_x increased at the beginning of co-combustion process but then decreased again. Additionally, PM results were lower than Maryland emissions standards. The fly ash results showed a higher nutrient content (close to 16%). This study shows the possibility of using poultry litter as a sustainable energy source for energy production while emitting lower emissions in the small decentralized combustion system.