Study On Desorption And Mass Transfer Velocity By Activated Carbon Fibres Bed

Coal is the main fuel of the power plant in our country, and the acid rain formed by SO2 and NOX which are emitted by coal combustion to the atmosphere causes severe damage, therefore, SO2 and NOX emission controlling in the flue gas is becoming an urgent requirement.First of all, the present technical development of desulphurization and denitrification and the research status of desorption reproduction performance in coal-fired power plant are introduced, besides, the physical and chemical characteristic of activated carbon fibre (ACF) and its mechanism of desulphurization and denitrification are also given brief presentation.The desorption capability of ACF bed under thermal state are investigate as well as the continuous and intermittent desorption. Regard to continuous desorption, the affect of water content in flue gas to the desorption of ACF is the main concern. The experiment proved that with the increase of water content in flue gas, the adsorption efficiency increased as well as the breakthrough time and adsorption capacity increase accordingly which is avail to the adsorption of SO₂ of ACF. However, when the water content in flue gas exceeds 15%, with the increase of water the adsorption efficiency will decrease and the breakthrough time and adsorption capacity decrease too. Intermittent desorption are carried out using two methods which are water scrubbing desorption and negative pressure hot air suction desorption. While water scrubbing desorption research investigates the affect of the ratio of water to carbon and drying to desorption, desorption capability of multiple circulation is also studied. Besides, negative pressure hot air suction desorption method is used to compare with water scrubbing desorption method.While introducing the technical characteristic of ACF bed, the key parameters affecting ACF bed adsorption are also studied. Designing an ACF desulphurization actor for desulphurization and denitrification device test bench of one coal-fired boiler, CFD software is used to simulate and optimize the flow field of ACF desulphurization actor.Finally, the mass transfer process of ACF bed is studied to deduce mass transfer velocity calculation formula and according to the existent experimental data the mass transfer index and velocity of typical working condition are obtained, and the different affects of mass transfer velocity are investigated,...