Investigation of co-pyrolysis characteristics and kinetics of municipal solid waste and paper sludge through TG-FTIR and DAEM

Highlights: • Compared to N₂, the pyrolysis of MSW and PS was more complete under CO₂ atmosphere. • The evolution of six typical pyrolysis products were illustrated by TG-FTIR. • MgO could act as a catalyst to promote the pyrolysis reaction of blends. • Through DAEM, the activation energy in two stages were about 170 and 300 kJ/mol. In order to explore a harmless and resource-based way to treat municipal solid waste (MSW) and paper sludge (PS), the co-pyrolysis MSW and PS was studied in this paper. Firstly, MSW and PS had the lower residue mass, and MSW had higher pyrolysis index under CO₂ atmosphere, compared with the one under N₂ atmosphere. Hence, the CO₂ was used as the carrier gas in the following study. Secondly, under CO₂ atmosphere, the co-pyrolysis of MSW and PS with and without MgO were researched. With the increasing of PS ratio, the pyrolysis performance of the blends decreased constantly. MgO act as catalyst could improve the pyrolysis characteristic index of the blends. However, MgO was an inorganic salt and it would affect the synergistic effect of MSW and PS. The curves of online evolutions of all the gas products and the functional groups had an obvious peak at around 500 ℃. The activation energy of the blends in the first step (<600 ℃) were around 170 kJ/mol and reached more than 300 kJ/mol of the second step (600−1000 ℃). In addition, the adding of MgO could decrease the activation energy of MSW, 50M50P and PS. Finally, 50M50P-M was suitable for treating more sludge. And these results could offer some referential information for designing and optimizing the co-pyrolysis technology for MSW and PS.