Study of the pyrolysis of municipal sludge in N2/CO2 atmosphere

The present study aims to explore the pyrolysis characteristics and gaseous product of municipal sludge including dry sample (DS) and wet sample (WS). The experiments were performed under atmospheres of different N2/CO2 ratios using TG-FTIR. All of the thermal process could be divided into two stages. With the existence of moisture, the releasing of volatiles was enhanced and a large amount of CO2 and NH3 generated earlier. CO2 was inert in first stage and became reactive in second stage. The char gasification by CO2 resulted in more mass loss and macropores generation. As the CO2 concentration increased, the corresponding peak shifted to lower temperature. The kinetic parameters were calculated by Coast-Redfern method and agreed with the pyrolysis properties observed. The activation energy and pre-exponential factor increased (or decreased) simultaneously, illustrating kinetic compensation effect.