Gasification kinetics of char formed from waste polyvinyl chloride for efficient utilization in ironmaking process

In the prevailing incineration processes of municipal solid waste, the presence of polyvinyl chloride (PVC) may cause environmental problems. The energy-intensive ironmaking sector in the iron and steel industry operates at high temperature and under high reduction potential with the function of energy conversion, which can provide a potential path for the collaborative utilization of waste plastics in large quantities and low cost. The gasification of the char formed from PVC when processed in the ironmaking sector is significant for the development of the related technologies. Thus, the gasification experiment of PVC char and traditional carbonaceous materials was performed by thermogravimetric analysis. The results indicated that the gasification ability decreased in the sequence of PVC char > anthracite coal > coke > graphite. Then, kinetics were also analyzed by Coats-Redfern and Doyle approximations. The PVC char showed the best gasification ability with the smallest activation energy, ranging from 87.18 to 117.52 kJ/mol, and the smaller graphitization degree of PVC char compared with other carbonaceous materials should be the main reason for its excellent gasification reactivity.

Automated summary

The presence of PVC in incineration processes of municipal solid waste can cause environmental problems. The energy-intensive ironmaking sector in the iron and steel industry provides a potential path for the collaborative utilization of waste plastics. Gasification experiments and analysis showed that PVC char has the best gasification ability and the smallest activation energy, possibly due to its unique graphitization degree.