Utilization of Hematite Particles for Economical Removal of o -xylene in a High-Temperature Gas-Solid Reactor.

To establish a novel approach for VOCs resource utilization, coupled o -xylene oxidation and hematite reduction was investigated in this study in a high-temperature gas-solid reactor in the temperature range 300-700 °C. As the o -xylene-containing inert gas (N 2 ) stream traveled through the hematite particle bed, its reaction behavior was determined in programmed heating and constant temperature modes. Consequently, the effect of bed temperature, flow rate and o -xylene inlet concentration on both o -xylene removal performance and degree of hematite reduction was studied. The raw hematite and solid products were analyzed by TGA, XRF, XRD and SEM-EDS. The results showed that a temperature above 300 °C was required to completely eliminate o -xylene by hematite, and both o -xylene removal capacity and degree of hematite reduction at 5% breakthrough points enhanced on increasing the temperature and decreasing the flow rate. The increment in temperature from 300 °C to 700 °C led to a gradual reduction of Fe 2 O 3 to Fe 3 O 4 , FeO and metallic iron. Thus, this study provides a novel, economic and promising technology for treating the VOC pollutants.