湿法脱硫净烟气中的细颗粒物对膜吸收CO2的影响

在使用膜吸收装置脱除燃煤电厂尾气中二氧化碳的实际应用中,膜吸收二氧化碳系统装配于湿法烟气脱硫系统(WFGD)出口是最适宜的选择。经过湿法脱硫的烟气中含有一定量的细颗粒物,这些颗粒物可能会影响膜的性能,因此有必要揭示细颗粒物对膜吸收二氧化碳的影响。本文采用模拟实验装置,选取飞灰、硫酸钙、硫酸铵3种颗粒物,考察了它们对聚丙烯(PP)中空纤维膜吸收二氧化碳的影响。结果表明:3种颗粒物通过膜组件时,均会在膜表面沉积,导致二氧化碳脱除效率下降;膜吸收二氧化碳的性能与颗粒物沉积程度呈负相关;3种颗粒物对膜吸收二氧化碳的影响程度从大到小依次为硫酸钙、硫酸铵、飞灰;颗粒物在膜表面沉积后很难被气体反吹,这会使膜基本失效。

Effects of fine particulate matters on the wet-process desulfurized flue gas on CO2 adsorption by membrane

The outlet of wet flue gas desulfurization(WFGD) system is the best location in the application of using membrane adsorption equipment in the removal of carbon dioxide from flue gas in coal-fired power plants. Wet-process desulfurized flue gas contains fine particulate matters which may deteriorate the performances of membrane. In order to obtain a better understanding on the influences of particulate matters on CO₂ adsorption, this research investigated the capture process of carbon dioxide using polypropylene(PP) hollow fiber membrane from flue gas containing three kinds of particles(coal-fired fly ash, calcium sulfate, ammonium sulfate). The results showed that fine particulate matters reduced carbon dioxide removal efficiency due to deposition on the membrane surface. The results also demonstrated a negative correlation between the performance of CO₂ adsorption by membrane and the deposit degree of fine particulate matters. Calcium sulfate affected the performances of CO₂ adsorption by membrane the most among the three materials, and coal-fired fly ash had least influences on CO₂ adsorption. It was difficult to back flush the fine particulate matters adsorbed on the surface of membrane, resulting invalid membrane.