Mechanism Of Pollutants Adsorbed By Fly Ash In Coal Fired Power Plant

In recent years the government have strongly advocated the development of clean energy, but coal-fired power plants still accounts for the majority of all generating units, which are an important source of heavy metals and particle matter and other pollutants. On the basis of strict enforcement of environmental standards, ensure the transformation of thermal power to the direction of energy saving in an orderly manner. For the large quantities of pollutants produced by thermal power plants, it is necessary to control the pollutant emission in flue gas, the adsorbent method is an effective pretreatment measures of flue gas emissions, which can significantly reduce the pollutants in the flue gas. This paper first introduced the basic mechanism of adsorption, and the relevant situation of research about flue gas contaminants removed by adsorbent, the field of the research is physical adsorption, based on the typical force of particles in the adsorption process, this paper researched the adsorption process of adsorbent, and put forward the relevant theoretical adsorption model.Then the article introduced the van der Waals force, electrostatic force and the liquid bridge force exsisted among the particles, in which details the van der Waals force and its derivation. Van der Waals force is the attraction force in the physical adsorption process, which was the foundation of adsorption model on the follow-up. Adsorption model was divided into two types of models to be introduced, First type study the process that mercury atom(on behalf of heavy metals) adsorbed by spherical fly ash particles, firstly make assumptions and propose model, then according to the situation of one-dimensional and two-dimensional study the kinetics of process about mercury atom adsorbed by particulate and calculate the trajectory of atom, finally establish a MATLAB program which can obtain atom trajectory from anywhere in flat. The second type was put foward to study the influence of the porosity for the particle adsorption. Digging process was performed in spherical particle, which was considered in two cases of tapered hole and cylindrical bore hole, this part researched the atom adsorption force in the different locations inside the hole, compared adsorption forces generated by different aperture, and discovered a conclusion that, large adsorption force was attained when atom was in the location of the hole entrance, and the force was larger than that when aton was in the adjacent locations. At last, the paper analysed forces of charged particle in ESP, derived the conclusion that the dominant force of particle was the electric field force, so the adsorption process could be ignored in the electrostatic precipitator.This paper put forward the adsorption model from the perspective of theoretical analysis, the model facilitated our in-depth understanding of the adsorption process, and also provide theoretical support for the adsorption experiments.