Study On Mass Transfer Performance Of Microporous Gas Liquid Contactor

Microporous gas liquid contactor makes use of microporous gas distributor is applied in mass transfer,which divides gas into micro-bubble,it has greatly increased gas liquid contact area and enhanced gas liquid mass transfer.According to the literatures,the developments on gas liquid contactor in formation of bubble,mass transfer mechanism and its application are summarized.At present,aperture of which is larger than 1mm was studied by many boffins. The results showed that dispersed performance of bubble formed from gas liquid contactor is bad,gas liquid transfer is worse.So,inventing a new kind of microporous gas liquid contactor which can achieve higher mass transfer effect with lower energy consumption plays a very important role in our study.In this paper,the experimental study about mass transfer and application of home-made reactor with microporous gas liquid contactor(its average aperture of gas distributor is 1μm) was done.We took Na₂SO₃ and air as a system to study mass transfer specific surface area. The gas-liquid mass transfer specific surface area decreased with increased liquid height and surface tension,increased with increased gas flux.While gas flux gently decreasing at the high point,gas-liquid mass transfer specific surface area began to decrease.A correlation was nonlinearly regressed with experimental data by the way of the dimensional analysis,which showed the influences between mass transfer specific surface area and all kinds of factors indirectly.The liquid volumetric mass transfer coefficient(K_La) was studied by a system contained water and air.K_La increased with increased gas flux(Q),and a linear relationship between mass transfer coefficient and gas flux become obvious with increased liquid height. While mass transfer coefficient decreased with increased liquid height.At last,the empirical model was set up by the way of similarity theory,which provided theory for K_La in different h. The absorption process of CO₂ in mixed gas by microporous gas liquid contactor was studied with sodium hydroxide solution as absorbent.The absorptivity of CO₂ decreased with increased gas flux,but increased with liquid flux and absorbent solution concentration.When pressure drop between two sides of ceramic membrane increased,the absorptivity increased firstly,and decreased later.It is expected that gas-liquid mass transfer specific surface area is several or several tens times higher than conventional tray.And compared with gas liquid contactor with aperture larger than 1mm,the liquid volumetric mass transfer coefficient(K_La) and power efficiency (Ep) are several times higher.The absorptivity of CO₂ can be up to 99%when the microporous gas liquid contactor is used in absorbing CO₂.Microporous gas liquid contactor has excellent mass transfer,micro-mixing,low energy consumption,being easily design and manipulate.The paper has provided the basic data for industrial experimentation.It will have some reference value and guidance.