The Experimental Research Of Hollow Fiber Membrane Flash Process

Emissions of CO₂ and other greenhouse gas has brought disastrous impact on the global climate. In the present stage it is imminent to find the way how to effectively curb CO₂ emissions of coal-fire power plants. Traditional CCS technology often use amine solutions to capture CO₂ emissions in packed column or tray column. But in traditional carbon capture technology there are many difficult problems, such as, high desorption energy, inefficient mass transfer sections and worth performance of absorbent. In this context our group have developed physical-chemical complex absorbent which add alcohol and amide. The absorbent includes good elements of high efficiency, low consumption and excellent desorption performance. The research is based on hollow fiber membrane flash technology and the feasibility of combining new absorbent with new technology has been systemically studied. Meanwhile we use membrane absorption and membrane flash technology to carry out the stability of absorbent and membrane process in a long term.Hollow fiber membrane flash technology uses principle of membrane dispersion to disperse the absorbent to micro-scale droplets.Through this process transfer area is enlarged and efficiency of mass-transfer has been improved. The influence of desorption temperature, vacuum degree, desorption frequency and other operation conditions on the desorption properties of hollow fiber membrane flash technology has been investigated. The influence of the addition of alcohol and amide on desorption properties has been compared and the possibility of membrane flash technology in desorption of high viscosity absorbent. Besides, the long-term operation status of physical-chemical complex absorbent in membrane process has been investigated to provide valuable reference for industrial applications.The research result shows that under 80 ? and 40kPa desorption rate, cyclic load and flow rate of new absorbent 1 are 68.6%,0.486 molCO₂/mol amine,0.875g·s-1, which are obviously higher than new absorbent 2 and MDEA absorbent. Meanwhile new absorbent 2 is superior to MDEA absorbent in all aspects of performance. The long-term experiment result shows that the concentration of alcohol 5 descends to 0wt.% when new absorbent 1 runs 23h and the concentration of amide 4 remains 32.2wt.% when new absorbent 2 runs 100h.