Parameter Optimization Design And Experimental Study Of Activated Carbon Adsorption Desulfurization Unit

In recent years,China's environmental problems have become increasingly serious,and the reduction and control of SO₂ emission has become an urgent problem to be solved.At present,the wet flue gas desulfurization technology widely used in China has some disadvantages,such as secondary pollution,high water consumption and unrecoverable sulfur resources.Activated carbon flue gas desulfurization technology is an advanced dry desulfurization technology,the process of desulfurization high efficiency,no water,no waste water pollution,the desulfurization product is high concentration of SO₂,can be used to produce sulfuric acid and other products,in our country has a good prospect for development.In order to promote the application of activated carbon desulfurization technology in coal-fired power plants,this paper mainly studies the process of activated carbon adsorption desulfurization by means of experimental research.Firstly,the development status of activated carbon desulfurization process,adsorption theory,basic theory of activated carbon desulfurization,difference between physical adsorption and chemical adsorption,and related knowledge of adsorption kinetics are introduced,which provide a theoretical basis for the subsequent experimental data processing.Then the pore structure and chemical composition of activated carbon are studied.The desulfurization performance of activated carbon is closely related to the pore structure and surface functional groups of activated carbon.The surface structure of activated carbon was obtained by SEM analysis of the activated carbon samples,and then three forms of existing activated carbon adsorption desulfurization devices are listed.Secondly in order to better determine the dry desulfurization device moving bed structure size parameters,Based on the selected activated carbon and simulated flue gas parameters in the experiment,calculate the Archimedean criterion number Ar and the Reynolds number Re_crifrif at the critical fluidization velocity U_crif,and according to the empirical coefficient of moving bed adsorption reactor empty bed gas velocity of 1.94 m/s,the cross-sectional area of 85.91 m²;In the fixed bed adsorption column experimental device,based on the desulfurization penetration curves under five different working conditions,and using the polynomial equation fitting integral,the adsorption equilibrium curve in good accordance with the monolayer Langmuir isothermal adsorption equation was obtained,where Langmuir constant was 0.88m³/g,and the saturated adsorption capacity of activated carbon was 4.43 x 10^-2 kg/kg.According to the material balance,the adsorption capacity of activated carbon is 1 081.76 kg/h.It is approximately considered that under 5 different test conditions,the adsorption degree of activated carbon at the outlet of the adsorption column at the intermediate moment is close to that at the stable operation state of flue gas desulfurization in the mobile bed.Thus,the effective adsorption bed thickness is calculated to be 12.97m.This can provide a reference for the design of the key structural parameters of the moving bed of the dry desulfurization unit for boiler flue gas tail treatment.Finally,the influence of bed temperature and SO₂ concentration on desulfurization efficiency was studied,and Na₂CO₃ and NaOH solutions of different concentrations were selected to modify the activated carbon by equal volume impregnation,place in the fixed bed desulfurization experiment device desulfurization through experiments,and carries on the thermogravimetric?TG?and SEM,the adsorption and desorption of SO₂ on activated carbon were analyzed qualitatively.