Dioxins In The Waste Incineration Process Low-temperature Formation Mechanism And Control Research

Incineration technology is one of the main municipal solid waste (MSW) disposal measures. Because of emission of toxic organic compounds, such as dioxins, during incineration, formation and control technology of dioxins are widely studied. De novo synthesis is the main route of dioxins formation in incinerators. In the article De novo synthesis and control technology of dioxins were studied.Dioxins formation under low temperature (100-400℃), gas phase and activator were studied in quartz pipe furnace. Results showed formation of dioxins reach maximum in different temperature because of different carbon source; CuCl and CuCl2 have better catalysis activity for dioxin formation. Oxygen in gas phase promote formation of low chlorinated PCDDs and PCDFs.Experiments about co-firing of typical waste with coal were processed on pipe furnace and fluidized bed incinerator. Results indicated that formations of dioxins, especially toxic dioxins, were inhibited with addition of sulfur.The effect of CaO, CaCO3, basic fly ash on the emission of dioxin from precursor (PCP) was studied. TEQ of dioxins and concentration of low chlorinated dioxins could increase with addition of basic compounds. And formation of dioxins was the minimum when CaCO3 was added.The formation capability of active carbon affected by alkalinity, reaction temperature and time was analyzed. Formation of dioxins from active carbon treated by NaOH decreased. Moreover, removal efficiency of dioxins was higher when the height of activate carbon fixed bed increased and its temperature decreased.Dioxins emissions under different conditions of 150t/d MSW fluidized bed incinerator were studied. Result indicated that dioxins were formatted in low temperature zone which were mainly in fly ash. Dioxins removal efficiency was high in wet scrubber, but was affected by addition of desulfurizing agent.