TG analysis and kinetic study of organic constituents in wastewater from coal-gasification process

In the paper, the thermal reactivity of organic constituents from coal-gasification wastewater is performed through physicochemical and thermogravimetric (TG) analysis. The effects of reaction atmosphere, oxygen concentration, heating rate, and final temperature on both solids conversion and degradation rate are experimentally studied. The results indicate that organic constituents mainly consist of aliphatic hydrocarbon, phenols, and ammonium, and so on. The thermal degradation of organic constituents in various atmospheres can be divided into four regions: 100–200, 200–300, 300–410, and 410–900 °C. The TG/DTG curves present considerable differences in the last region compared with that in the first three regions. In addition, the degradation rate shows a considerable increase and moves toward higher temperature region with heating rate. Furthermore, the kinetic parameters of organic constituents are analyzed by one multi-heating rate method. The calculated results show that apparent activation energy of organic constituents varies between 82.8 and 91.3 kJ mol⁻¹ under various reaction atmospheres. This information is potentially useful for the design and retrofitting of the large-scale equipment to recover industrial wastewater.