Plasma destruction of rubber waste

The production of synthesis gas from scrap rubber at up to 1 000 ℃ by the reverse-Boudouard reaction between carbon and carbon dioxide is explored. Thermodynamic modelling was performed using HSC Chemistry software and experimental data were analyzed using Microsoft Excel. TGA data were collected using a Hitachi STA7300 horizontal-beam TGA-DTA system. Videographic data from tube furnace experiments were collected by DLSR camera and analyzed using VLC Media Player software. Plasma pyrolysis and gasification experiments were conducted in a pilot plant at Necsa. The process yield and energy requirements were estimated by thermodynamic modelling.

An empirical kinetic model was derived from thermogravimetric analysis. This was correlated with results from videographic observations of the behaviour of rubber cubes in a tube furnace. The combined results allowed estimation of the temperature-dependent residence times in a furnace and its size. Plasma arc gasification on the kg per hour scale in a pilot plant revealed the importance of careful reactor design for sufficient processing time. A conceptual process flow diagram and -description for a transportable plasma gasification facility is presented and various suitable types of reactors discussed.