Experimental Investigation On Removal Hg~0 From Simulated Flue Gas By Different Properties Filtration Materials Loaded With Deposit Dust Layer

With the arrival of second industrial revolution era, how to control coal-fired mercury pollution becomes a hot topic in the field of environmental protection. Since 1990's, the Chinese government pay more and more attention on control technology of coal-fired mercury pollution, both national "973" Program and "863" Program take the control coal-fired mercury pollution as an important special research subject.The research content in this paper is an important part of this projects.This paper focuses on describing the characteristics of coal-fired mercury and the control technology and methods of mercury in coal-fired power station domestic and abroad. Assembling and optimized a set-up for dry process to united removing Hg0 depending on these methods.The different performance was investigated by changing elements. Such as different filter fiber, coal fly ash, PPS-carbon fiber co-doped load of fly ash, filter dust layer and so on. The different performance was investigated by changing different adsorption reaction temperature, inlet Hg0 concentration, flue gas residence time and other factors. It will provide useful reference for combined fly ash with different fiber filter removal of particulate matter and mercury by dry process.The results find that PPS fiber could be the best C-loaded fiber which is choosen from seven fibers and the best doped proportion is 1:1. The removal rate of Hg0 is increasing with the higher proportion of activated carbon fiber. However, the removal rate of mercury is not proportional increasing. The adsorption of coal fly ash and PPS-carbon fiber for mercury is the combination of physical adsorption and chemical adsorption. Their own mercury removal efficiency is 27% and 65%, respectively. The joint removal of mercury removal efficiency of PPS carbon fiber load of fly ash is not the simple algebraic superposition of the removal efficiency. It depends on the reaction temperature, inlet concentration and gas residence time of mercury and other factors. The higher the adsorption temperature, the lower unied removal Hg0 efficiency of coal fly ash and mixed with carbon fiber PPS. Increase the mercury concentration at the entrance will not necessarily improve the removal efficiency; the longer flue gas residence time, the more favorable for Hg0 removal.The optimized materials by trial were HBT filter and coal-fired fly ash dust layer, by which removal efficiencies of Hg0 was 35% and 42.5%, respectively. The removal efficiency of the HBT filter with coal-fired fly ash cake was affected by adsorption temperature, initial concentration of mercury vapor and gas retention time, among other factors. The removal efficiency of 64.4% can be achieved at optimized conditions. The higher the adsorption temperature, the lower the removal efficiency; and the longer gas retention time, the higher the removal efficiency. Increment of the initial mercury concentration did not increase necessarily the removal efficiency of mercury by the HBT fibrous filter with fly ash dust cake.We exploit dry process combined removal particulate matter from coal combustion and heavy metals like mercury experimental device to given reliability test. We are taking adsorption reactor and bag filter as the experimental device, studing the removal effiency of Hg0 by fludization of ash. We also studied the Hg0 removal capacity of the fly ash in the bag and on the bag surface under different filtration velocity, pressure and other factors.Fly ash can removal Hg0 in different ways, the convection mode is more benefit for adsorption, the best removal efficiency is up to 37.9%. The removal Hg0 efficiency of fly ash was reduced when the temperature increased. The higher the adsorption temperature, the lower the removal efficiency. Injet Hg0 concerntation has a certain impact of Hg0 removal efficiency.The higher the concentration, the better the removal efficiency. The removal of Hg0 by fly ash is affected greatly by C/Hg. The removal of HgO increases with the increase of C/Hg. The higher the filtration velocity, the lower the bag filter removal efficiency. As the fly ash is injected into the bag filter, the gradual pressure becomes larger. The longer the reaction time, the less the removal efficiency. The best removal efficiency is 42.4%. The removal efficiency slightly increased after reverse blow for dust-clean. The removal efficiency of the device for removing particulate matter and elemental mercury by dry process is up to as high as 63.1%.