| Hydrogen is an important raw material for industrial production and a clean,non-polluting,high-calorie energy source.So the effective separation and storage of hydrogen is vital to human production and life nowadays.In this dissertation,a new gas separation technology,i.e adsorption-absorption hybrid method was adopted to separate gas mixtures.Using ZIF-8/ethylene glycol-water as the slurry system,the adsorption-absorption hybrid method was used to separate CH4/H2 gas mixture.A set of bubbling tower device was built to simulate the separation of CH4/H2 in coke oven gas.Then the effect of different operating conditions on the separation of CH4/H2was investigated.The main research contents of this thesis are as follows:（1）ZIF-8/ethylene glycol-water slurry was synthesized.Then the ab/adsorption of CH4and H2single-component gases by adsorption-absorption hybrid method was studied.The ab/adsorption capacity of two gases in ZIF-8/ethylene glycol-water slurry and the effects of different operating conditions on the ab/adsorption capacity of CH4 and H2were investigated in detail.The results show that the amount of CH4 ab/adsorbed in the slurry is much higher than the amount of H2 ab/adsorbed,so that this method can be used to separate and purify the CH4/H2 gas mixture.（2）The adsorption-absorption hybrid method was adopted to separate CH4/H2 gas mixture.The effects of different solid contents,ethylene glycol contents,pressure,and feed gas on the separation of CH4/H2 were studied.The results show that with the solid content increases,the separation effect of the mixed gas becomes better and better,but the viscosity of the slurry also increases,which seriously affected the operation of the experiment.The solid content of the slurry was determined at 35 wt%then.In addition,it is found that a small amount of ethylene glycol can effectively promote the separation of mixed gas,but too high ethylene glycol content will inhibit the separation of mixed gas.The experiment results show that 20 wt%ethylene glycol has the best separation effect.With the pressure increases,the separation effect of the mixed gas will also increase.Regarding to different feed gases,it is found that with the increase of CH4content in the feed gas,the separation effect of the mixed gas gradually increased.Finally,the performance of ZIF-8 material for repeated use was investigated.Through XRD,SEM measurements and experimental results,it is found that ZIF-8 material has good hydrothermal stability and reproducibility.（3）Finally,a bubble tower device was built.In the bubble tower,column breakthrough tests using CH4/H2 were performed.We explored the effects of different temperatures,solids contents,pressures,and intake air flow rates on the breakthrough time and separation effect of the mixed gas in the slurry.The experimental results show that with the temperature rises,the breakthrough time is shortened and the separation effect becomes worse.In addition,it is found that with the solid content increases,the breakthrough time increases and the separation effect becomes better,but the solid content greater than 30 wt%will affect the experimental operation.So the solid content was determined as 30 wt%.As the pressure increases,the breakthrough time increases and the separation effect increases.Regarding to the intake air flow,the breakthrough time is greatly shortenedand the separation effect becomes worse with increasing the intake air flow. |
PDF Full Text Request