Jin Yuqi

Study on the comprehensive combustion kinetics of MSW

The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000°C at a heating rate of 10°C/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results.

Combustion of electronic wastes using a drop tube furnace

High temperature combustion is a key during the pyrometallurgical recycling for electronic wastes. Former researches relating to thermal treatment concentrated on thermal decomposition during electronic wastes pyrolysis and oxidation, using e.g. thermogravimetric analysis (TGA) or lab-scale batch-feeding furnace. In the present research, a bench-scale incineration system was developed to study the combustion of electronic wastes and the emission characteristics. The system features a continuously-fed drop tube furnace. By using it, the combustion proceeds under comparable conditions and the emitted flue gas is steady & uniform, the thermodynamic equilibrium approach for conversions of inorganic halogen could be investigated. It also equips with a cooling & sampling unit for investigating the emission of post-combustion area. The effects of operating conditions on the completeness of combustion and the emission of inorganic Br for waste printed circuit boards were investigated systematically by using this furnace. Under the proposed conditions, the combustion is quiet complete and more than 99.89% organobrominated compounds contained in raw materials are destroyed and convert to HBr & Br2 in flue gas. The two forms of inorganic bromine seem reach thermodynamic equilibrium within 0.25 s. Further experiments could provide the datum for analyzing the combustion performance, the emission characteristics of organic pollutants and the mechanism of chlorinated dioxins (PCDD/Fs) & brominated dioxins (PBDD/Fs) formation by fly ash catalyzed de novo synthesis.