Thermogravimetric Analysis of Textile Dyeing Sludge (TDS) in N₂/CO₂/O₂ Atmospheres and its Combustion Model with Coal

Abstract

The combustion characteristics of textile dyeing sludge (TDS) in N2/O2, CO2/O2, and N2/CO2 atmospheres, and blends of TDS with coal were analyzed using TGA (thermogravimetric analysis). Results showed that the replacement of N2 by CO2 resulted in negative effects on the combustion and pyrolysis of TDS. Comparing N2/O2 and CO2/O2 atmospheres, combustion of TDS was easier in a N2/O2 atmosphere, but the residual mass after TDS pyrolysis in pure CO2 was less than that in N2 by approximately 4.51%. When the proportion of TDS was 30-50% in the blends of coal with TDS, a synergistic interaction clearly occurred, and it significantly promoted combustion. In considering different combustion parameters, the optimal proportion of TDS may be between 20-30%. The activation energy Ea value decreased from 155.6 kJ/mol to 53.35 kJ/mol with an increasing TDS proportion from 0% to 50%, and it rapidly decreased when the TDS proportion was below 20%.