Study On Characteristics Of Gas-liquid Two-phase Reaction And Mass Transfer Within The Microreactor

This article mainly introduced various important parameters and characteristics of the micro channel of circle horizontal section,also carried out the corresponding research,including the pressure between gas and liquid two channel drop,absorption properties and mass transfer.First of all,the nitrogen water two-phase flow pressure drop experiments were carried out in the micro channel of 0.9mm and 0.5mm diameter pipeline respectively,and the main purpose was to test the frictional pressure drop between gas and liquid in the micro channel which is related to the diameter of the pipeline and the gas and liquid superficial velocity in the tube,and understood that both have a certain impact on the frictional pressure drop.Analysis of the experimental results,it can be seen that there is a certain relationship between the former and the latter two,specifically,frictional pressure drop was proportional to the velocity of gas and liquid in the tube,and inversely proportional to the size of the pipe diameter;in addition to doing specific experiments,through the actual value to understand the correlation between these data,we can also used the mathematical model to predict the experimental results.Generally,we used uniform mixture model and the two phase flow model to predict the result.By comparison,we can knew that,the phase model was closer to the experimental data due to the Lockhart-Martinelli relation in the model can better predict the frictional pressure drop.In addition,we can used the sodium hydroxide absorbing CO₂-N₂ gas mixture,determined the volumetric mass transfer coefficient K_Gα in the pipeline with a 0.5mm diameter,and combined with the obtained K_Gα to predict the two-phase segregation area,then compared the experimental data and the corresponding values in the macroscopic mass transfer system.According to the experimental data and the comparison,we can knew that,there was a certain correlation between the K_Gαvalue and the gas and liquid apparent speed in the pipe,which showed a positive correlation.The difference was that,when the gas velocity increased,while the K_Gαalso increased,but the increasing rate decreases;when the liquid velocity increased,different from the former decreased gradually,the rate of K_Gα is no change and slowing trend;when the interfacial area between gas and liquid in the experiment reached the maximum value 3879m²/m³,compared with the traditional macroscopic mass transfer system,the mass transfer effect and quality is much better at this time.And the area is even higher than traditional equipment 1-2 orders.Finally,this article studied the specific experiments by using the MDEA solution to absorb the hydrogen sulfide gas mixture in the micro channel diameter of 0.9mm.According to the experimental data the analysis of the experimental results,we can knew that,the removal of hydrogen sulfide on this issue can reach a better level,especially with a 200:1 ratio of gas and liquid,the removal efficiency can reached 99.2%.In addition to the absorption solution,we had verified that,different experimental methods,steps,experimental conditions and other external environmental factors also had a certain influence and acceleration to the hydrogen sulfide removal rate.Through corresponding experiments,we can knew that,operating pressure,temperature,solution concentration and the initial concentration of raw materials in the experimental process have great effect on this value.Among them,hydrogen sulfide removal rate was proportional to the pressure and solution concentration,and inversely proportional to the temperature and initial concentration.Moreover,the system operating pressure and entrance concentration of the raw gas had a small influence on the mass transfer coefficient.