Removal of dioxins and related aromatic hydrocarbons from flue gas streams by adsorption and catalytic destruction

The dioxin removing capacity of the shell dedioxin system (SDDS - a Ti/V oxidative type catalyst) has: been tested using the Umea lab-scale incinerator over the temperature range 100-230 degreesC and at space velocities of 8000 and 40,000 h(-1). Other analogous organic compounds, such as PCBs, PAHs, chlorobenzenes and chlorophenols have also been investigated. Results show a high degree of dioxin removal already at 100 degreesC (82%), which occurs mainly by adsorption. When the temperature is raised a transition towards destruction is seen and at 150 degreesC, gas hour space velocity (GHSV) 8000 and at 230 degreesC, GHSV 40,000 virtually all removal is by destruction. High PCDD/F destruction efficiencies are reported (> 99.9%, based on T-TEQ); the other dioxin-related species and PAHs are also removed and destroyed to a significant extent. The SDDS has proved to be an effective means of destroying organic compounds in the gas phase, particularly dioxins, at temperatures as low as 150 degreesC. (C) 2001 Elsevier Science Ltd. All rights reserved.