Comparison Of Organic Pollutants Generated In Coal Chemical-Looping Combustion Process By Different Cu-Based Oxygen Carriers

In order to improve phenomenon that the carbon deposition of oxygen carriers after repeated cycling, in this paper, based on the study of Polycyclic Aromatic Hydrocarbons (PAHs) generation characteristics to explore the reaction mechanism of chemical-looping combustion of coal and the interaction mechanism of copper-based oxygen carriers and PAHs. At different levels for the experimental study of Cu-based oxygen carrier with titanium and Cu-based oxygen carrier with silicon, after the reaction, the experiments carried out by GC for qualitative and quantitative analysis of PAHs in smoke and cinders. Experimental studies are:production methods oxygen carrier; chemical-looping combustion conditions; PAHs emission characteristics of different copper-based oxygen carriers; look for effective methods to control carbon deposits.The main findings are as follows:(1) Tricyclic aromatic hydrocarbons were produced most during the chemical-looping combustion; the difference is mainly in the production of PAHs in flue gas; coal 1 is more suitable for the CuO/SiO2 oxygen carrier; coal 2 is more suitable for the CuO/TiO2 oxygen carrier; the zone of high temperature (800-1000℃) can control the production of PAHs.(2) CuO having a multi catalytic function, it could catalytic synthesis PAHs and oxidative decomposition PAHs. The temperature less than 800℃, CuO beneficial catalytic synthesis of PAHs; When the temperature is above 800, catalytic synthesis of gradually weakened.(3) TiO2 has larger surface area, better photocatalytic activity, and has high oxidation resistance, can catalyze the decomposition of PAHs, TiO2 as inert carrier showed good reactivity.(4) Preparation of oxygen carriers with different proportions of CuO and inert carrier, the suitable preparation proportion was 7:3 with the mechanical mixing. Impregnation method is more conducive to control carbon deposition than mechanical mixing.(5) Adds a certain amount of dispersant in the preparation process with mechanical mixing method of CuO/TiO2 oxygen carrier, it has better pore structure, and showed good activity in the experiment, the combustion reaction completely, effectively controlled the production of PAHs.