Predicting effect factors of dual bag filter system for PCDD/Fs removal from hazardous waste incineration flue gas

Abstract

The dual  bag filter (DBF) system is a new polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) emission control technology that has more efficient (PCDD/Fs) removal performance,  a higher activated carbon utilization rate and less activated carbon consumption compared with the traditional single bag filter system. Moreover, few studies have been relevant to the mechanism of the PCDD/Fs removal process in the DBF system, and the selection of operating conditions of the DBF system lacks an academic basis. This study established a PCDD/Fs removal efficiency model of activated carbon injection combined bag filter (ACI+DBF) system for hazardous waste incineration flue gas and predicted  the crucial effect factors. New adsorption coefficients k₁=532,145 Nm³/(mol s) and k₂=45 Nm³/(mol s), and the relationship expression between the number of available adsorption positions of recycled AC (A_AC′) and cycle times (n) are proposed in the model. The results verify that the model error was below 5%. In addition, the PCDD/Fs removal efficiency model predicts that in a certain range, the PCDD/Fs removal efficiency increases with increasing activated carbon injection concentration. The best cycle number of activated carbon was less than 3, and the ratio of circulating activated carbon to fresh activated carbon in second bag filter (SBF) should be controlled at 7–8.