Chemical looping gasification of automotive paint sludge with red mud oxygen carrier for flammable gas production
Ruihao Yang, Zixuan Wang, Mingqian Cheng, Yanyu Yang, Zechun Huang, Qihong Cen, Youcai Zhao, Tao Zhou, Zewei Liu, Bin Li
Abstract
Automotive paint sludge (APS) is a hazardous waste with many harmful substances, which should be properly disposed and managed. Red mud (RM) is a solid waste generated during the production of alumina industry, of which the components are highly similar to the components of synthetic iron-based oxygen carriers. In this study, RM was used as an oxygen carrier (OC) for chemical looping gasification(CLG) of APS to produce flammable gas (H 2 , CH 4 and CO). The effects of different reaction conditions on the production of flammable gas were explored. Among them, the red mud oxygen carrier addition ratio plays a decisive role in the production of CH 4 , CO and H 2 . The reaction temperature determines the percentage of CH 4 in the flammable gas. Meanwhile, the experimental reaction mechanism was further elaborated. The lattice oxygen in the Fe 2 O 3 of RM-OC can migrate to form reactive oxygen (ROS). In the presence of ROS, the hydrocarbons react to produce large amounts of CH 4 , while CH 4 is cracked to produce large amounts of H 2 and CO. This study can provide theoretical basis for the comprehensive utilization of APS and RM, which is of great practical significance for protecting the ecological environment.