Simulation And Analysis Of Separation And Purification Technology By Pressure Swing Adsorption(PSA) From Blue Coke Gas

Blue coke is a new type of carbon material,named after it produces a blue flame during the combustion process.In the production process,blue charcoal will by-produce tar and blue coke tail gas.With the increasing the demand for clean energy,the production scale of blue charcoal will be further expanded,and more blue coke tail gas will be produced more than before.Therefore,the problem of industrial application of blue charcoal tail gas has become a problem that needs to be solved urgently.The research and development of hydrogen energy and the carbon capture are very important.Therefore,this article used pressure swing adsorption（PSA）to separate H₂and CO₂ from the blue coke tail gas,aiming to recovery hydrogen and capture CO₂ to alleviate energy and environmental pressure.The performance of the adsorption material is the key factor affecting gas separation and purification.In this paper,the adsorption amount of CH₄,CO,CO₂,H₂and N₂ on activated carbon,5A molecular sieve and silica gel was measured by static volume method.Then,the adsorption isotherms were fitted by Extended Langmuir 2model and the heat of adsorption is calculated.Moreover,the adsorption isotherm equation,energy transfer equation,momentum transfer equation and mass transfer equation were established to design a third-order pressure swing adsorption（PSA）process to purify the H₂ in the blue coke tail gas and recover CO₂.The first stage is the preliminary separation of blue charcoal tail gas process with 3 beds and 5 steps.Meanwhile,the influence of the proportion of activated carbon layer and 5A molecular sieve in the bed and the feed rate on the purity and recovery of hydrogen product gas were investigated.Based on the first-stage process,the hydrogen product gas whose composition is CH₄/CO/H₂/N₂=1%/0.6%/64.5%/33.9%,with 5A molecular sieve as the adsorbent,the second stage 4 beds and 9 steps hydrogen purification process were designed to produce hydrogen with purity higher than 99%.The third stage took the first-order heavy product as feed,used silica gel as the adsorbent to design a carbon capture process with 3 beds and 6 steps,more than 90%of CO₂ is recovered.