A new solution for destruction of PCDD/Fs by a catalytic filter system at waste incinerators

Zhengtian Xu,Eiji Motoda,Hong Sun,Xueqing Li,C.-H Weng,R Weerasinghe,J Wu

doi:10.1051/e3sconf/201911804046

Abstract

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are emitted from high temperature combustion processes such as municipal waste incinerators, hazardous waste incinerators, medical waste incinerators, and secondary metal processing plants. Due to their extreme toxicity, stringent regulations on PCDD/Fs emissions have been in effect around the world since the early 1990s. W. L. Gore & Associates, Inc. developed a catalytic filter system in 1997 that can effectively remove and destroy PCDD/Fs in the industrial flue gases. The REMEDIATM Catalytic Filter System has been installed in various industrial facilities around the world. The dioxin emission measurements in these plants achieve more than 98% PCDD/Fs removal efficiencies and reach the European standard. In this paper, three case studies will be presented on the performance of the REMEDIA Catalytic Filter System at municipal, medical, and hazardous waste incinerators. Three cases in the paper demonstrate the efficiency and results.

Highlights

There are three sources of PCDD/Fs from incineration processes
The third source of PCDD/Fs is through “de novo Synthesis” from materials not directly related to these compounds, the result of heterogeneous catalytic reaction on fly ashes, during the gas cooling process
This paper demonstrates the performance of the REMEDIATM Catalytic Filter System at a medical waste incinerator, a municipal waste incinerator, and a hazardous waste incinerator

Summary

Introduction

There are three sources of PCDD/Fs from incineration processes. The first source of PCDD/Fs occurs as trace constituents in the waste itself, and a portion survives the incineration process and is carried through in the flue gas. The second source for PCDD/Fs formation is through pyrolysis processes from precursors in the wastes such as PCBs, chlorinated phenols, chlorinated benzenes, etc. The third source of PCDD/Fs is through “de novo Synthesis” from materials not directly related to these compounds, the result of heterogeneous catalytic reaction on fly ashes, during the gas cooling process. A common solution to remove PCDD/F from the flue gas is injection of powder activated carbon into the flue gas upstream of the baghouse. Activated carbon can adsorb PCDD/Fs in the gas phase and remove them by fabric filter bags in a baghouse. Carbon injection creates problems, the plant needs to purchase additional equipment, obtains adequate storage, and disposes the large quantity of contaminated ashes

Methods

Results

Conclusion