The Influence of Oxygen Concentration and Equivalence Ratio on Pyrolysis Gas in Oxygen-Enriched Pyrolysis by Theoretical Calculation

Oxygen-enriched pyrolysis for the treatment of municipal solid waste (MSW) was proposed in this paper. Its advantages with respect to air pyrolysis, such as high efficiency, lower heat loss and emissions, have been described based on mechanism analysis and thermodynamic calculations. Effects of oxygen concentration, equivalence ratio (ER) on gas products and their heat values were investigated by theoretical calculation. It was found that with the increase of oxygen concentration the gas yield and heat values decrease, with the increase of ER, the content of CO and CH4 decrease, while the content of H2 varied from increase into decrease with ER=0.27 as the turning point. When ER exceeded 0.3, the pyrolysis controlled reaction became into the combustion controlled reaction. The most suitable ER for oxygen-enriched pyrolysis ranges from 0.2 to 0.3 and water content of MSW should be controlled in the range from 15% to 25%. Therefore, choice of ER was very important in oxygen-enriched pyrolysis process. ER could control the components and heat values of gas products. In addition gas product quality could be improved owing to the increase of oxygen concentration within a certain ER range.