A study on municipal solid waste (MSW) combustion in N2/O2 and CO2/O2 atmosphere from the perspective of TGA

In this paper, the combustion behavior of municipal solid waste (MSW) is carried out in a thermogravimetric analyzer under different N2/O2 and CO2/O2 atmospheres with temperature ranging from 100 °C to 1000 °C. TG (thermogravimetric) and DTG (derivative thermogravimetric) curves are analyzed. The nth order reaction fitting model is used to yield the activation energy of reduction process according to the degree of conversion. The results indicate that all samples lose most their weight between 200 °C and 540 °C. As the oxygen concentration increased, conversion rate curves and DTG curves shift to lower temperature without significant change in its shape. At the same oxygen concentration, the peak values in CO2/O2 atmosphere are smaller than those in N2/O2 atmosphere, indicating that CO2 has a higher inhibitory effect than N2 on MSW combustion. After 600 °C, the weight loss peak appears much later in CO2/O2 atmosphere than it does in N2/O2 atmosphere. With the increase of heating rate, the maximum weight loss rates of samples increase obviously. The three-step reaction of nth order reaction model fits the weight loss very well.

Research highlights
► Incineration has become a major development trend of MSW treatment. CO2/O2 combustion technology is considered to be a promising combustion technologies.
► The difference of MSW combustion characteristics in N2/O2 and CO2/O2 atmosphere is not fully understood.
► We investigate the combustion characteristics of MSW in N2/O2 and CO2/O2 atmosphere at different oxygen concentration.
► We concluded that the conversion rate curves and DTG curves shift to lower temperature without significant change in its shape as the oxygen concentration increases.
► We also concluded that at the same oxygen concentration, the peak values in CO2/O2 atmosphere are lower than those in N2/O2 atmosphere.