Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans in co-combustion of mixed plastics with coal: Exploratory principal component analysis

Principal component analysis was used to study the formation pattern of polychlorinated dibenzo-p-dioxins and dibenzofurans in co-combustion of mixed waste plastics with coal. The experimental tests were performed in a bubbling fluidized bed steam boiler. The purpose of the tests was to examine the effects of sulphur-rich coal on the formation of chlorinated hydrocarbons like PCDD/PCDFs. PCDD/PCDF concentrations were clearly dependent not only on CO concentration but also on the total concentration of PCBs and PAHs in the flue gas. A strong correlation between HCl in flue gas and PCDFs in fly ash samples was found. Also the effect of chlorine and tin content in fly ash on the formation of tetra-, penta- and hexachloro furans was obvious.