Review of water recovering technologies from flue gas in coal fired power plant

In order to reduce the water content in scrubbed gas after FGD discharged from coal-fired power plant,to recover water and waste heat from saturated flue gas,as well as to eliminate the problems of corrosion,stack liquid discharge and plume downwash caused by vapor condensation,this paper analyzed the thermal characteristic and energy distribution in wet flue gas,and made a brief introduction and comparison of three approaches on water recovering from wet flue gas.Such methods,including condensation,liquid desiccant-based dehumidification (LDD) and membrane were feasible for the wet flue gas dehumidification,and their technical features,research status,shortcomings and research progress were reviewed.It is found that the vapor concentration in wet flue is about 80 g,more than 70% of waste heat is in the form of latent heat.Condensation method is a relatively matured technology at the present stage,while LDD method has a higher water recovery capacity and the process of membrane method is relatively simple.These technologies have a promising application prospect and represent the research trend of flue gas dehumidification.The economic way of low grade heat utilization will be one of the important research directions of flue gas dehumidification.