(286g) Chemical Conversion Processes at Ultra-High Temperatures in Thermal Plasma Reactors

Chemical conversion processes are often operated at the temperatures below 1000°C. However, challenges have been encountered when the feedstock can be hardly converted using conventional means. This presentation will overview our recent efforts to convert coal, coal tar, asphaltenes, solid wastes, SiCl₄ and MgCl₂ to valuable chemicals or materials at ultra-high temperatures in thermal plasmas. The interest in the investigations and applications of the thermal plasma in chemical engineering field is caused by its unique thermodynamic and transport properties, for example:

• high efficiency of the transformation of electrical energy into thermal energy;

• the possibility of stationary heating of the gas to the mean mass temperature of the order of 10³-10⁴ K;

• high rate of the chemical reactions, leading to high-productivity reactors;

• high concentration of energy in the small volume of plasma;

• the possibility of heating almost any gases: reduction, oxidation, inert gases and mixtures.

To deeply understand the thermal conversion processes at extreme conditions, fundamental researches have been carried out in my group in the past ten years. Representative processes involve (1) pyrolysis of coal, coal tar and asphaltenes to acetylene and other light gases; (2) conversion and re-utilization of electronic wastes (e.g., waste printed circuit board, WPCB); (3) high-purity materials fabrication of nc-Si, nc-SiC, MgO. In the special session to memorize the distinguished researcher of Prof. Mooson Kwauk, I would like to share our experience in the specific topic of chemical conversion processes at ultra-high temperatures in thermal plasma reactors. It should be mentioned that some of the processes have been shown the great potential at industrial demonstration.