| dc.description.abstract | Pressure swing adsorption process is a technique used to separate gas mixtures according to the different adsorption capacities and selectivity toward adsorbent. Based on the property of adsorption at high pressure and desorption at low pressure, we can choose the appropriate processes to achieve the desired separation. Pressure swing adsorption process is used to concentrate carbon dioxide in order to mitigate the effects of global warming and reduce emissions.
In this study, pressure swing adsorption process is utilized to separate CO2 and N2 from syngas after water gas shift reaction. The compositions of syngas are simulated as 41.4% CO2 / 58.6% N2. To purify 41.4% CO2 with balance N2 as a captured gas mixture, two-bed six-step pressure swing adsorption process using zeolite 13X were experimentally studied.
Breakthrough curve experiments were carried out. These experimental results could be foundation of investigating pressure swing adsorption process. Two-bed pressure swing adsorption process was applied to carry out CO2 capture experiment.
The design of experiment (DOE) of two-bed six-step pressure swing adsorption process. Pressurization / cocurrent depressurization time, adsorption / countercurrent depressurization time, adsorption / purge time, feed pressure, temperature, vacuum pressure are the factors of two-level six-factor fractional factorial design to investigate the change of CO2 concentration and recovery. The analysis shows that the main effects feed pressure and adsorption / countercurrent depressurization time were significant effects for purity. CO2 with 90.39% purity and 79.73% recovery was found at pressurization / cocurrent depressurization time 140 s, adsorption / countercurrent depressurization time 160 s, adsorption / purge time 20 s, temperature 358 K, feed pressure 3.45 atm and a fixed vacuum pressure of 0.05 atm.
Finally, we build a model relating purity to factors and recovery to factors, and use a regression model to present the results of our designed experiment. | en_US |