Feasibility Study of Vacuum Pressure Swing Adsorption for CO2 Capture From an SMR Hydrogen Plant: Comparison Between Synthesis Gas Capture and Tail Gas Capture

Abstract

In this paper, a feasibility study was carried out to evaluate cyclic adsorption processes for capturing CO2 from either shifted synthesis gas or H2 PSA tail gas of an industrial-scale SMR-based hydrogen plant. It is expected that hydrogen is to be widely used in place of natural gas in various industrial sectors where electrification would be rather challenging. A SMR-based hydrogen plant is currently dominant in the market, as it can produce hydrogen at scale in the most economical way. Its CO2 emission must be curtailed significantly by its integration with CCUS. Two Vacuum Pressure Swing Adsorption (VPSA) systems including a rinse step were designed to capture CO2 from an industrial-scale SMR-based hydrogen plant: one for the shifted synthesis gas and the other for the H2 PSA tail gas. Given the shapes of adsorption isotherms, zeolite 13X and activated carbon were selected for tail gas and syngas capture options, respectively. A simple Equilibrium Theory model developed for the limiting case of complete regeneration was taken to analyse the VPSA systems in this feasibility study. The process performances were compared to each other with respect to product recovery, bed productivity and power consumption. It was found that CO2 could be captured more cost-effectively from the syngas than the tail gas, unless the desorption pressure was too low. The energy consumption of the VPSA was comparable to those of the conventional MDEA processes.

Optimization Strategy for Enhancing the Product Recovery of a Pressure Swing Adsorption through Pressure Equalization or Co-current Depressurization: A Case Study of Recovering Hydrogen from Methane

“…The results of Figure imply that adding the PE steps does not always guarantee increasing the hydrogen product recovery against the stereotype conceived. In the case of a hydrogen purification PSA working for a reforming-based hydrogen production process, , the hydrogen mole fraction in the feed lies in the range of 0.7–0.9. Under the conditions of the light component fraction being so high, at least three PE steps would be able to enhance the hydrogen product recovery, as shown in Figure b.…”

CO2 Removal in Hydrogen Production Plants

“…Indeed, the potential of CO 2 removal from tail gas is under consideration [43], though only a few studies can be found. Chen and Ahn [44] performed a preliminary feasibility study considering two Vacuum Pressure Swing Adsorption and the process based on the MDEA solution. Then, in 2023, Shahid and Kim [45] also focused on this topic, confirming its relevance in recent times.…”

Characteristics of CO2 adsorption and desorption on activated carbon in comparison with zeolite 13X and carbon molecular sieve and applications in biogas upgrading using vacuum pressure swing adsorption

“…[20][21][22] Even though a few studies have reported the analysis of breakthrough curves for the adsorption of CO 2 and CH 4 on AC, to the best of our knowledge, limited data are available on the performance of the PSA process with AC adsorbent, especially for biogas upgrading. [23][24][25][26] To reduce the number of experiments required for process optimization, process simulation for adsorption-based biogas upgrading has been frequently used to analyze the impact of operating parameters. 10,[27][28][29][30][31] Adsorption simulations have been used to some extent to study how the adsorbent properties affect the process performances.…”

“…Higher CH 4 content will lead to higher thermal efficiency and power output of combustion engines 20‐22 . Even though a few studies have reported the analysis of breakthrough curves for the adsorption of CO 2 and CH 4 on AC, to the best of our knowledge, limited data are available on the performance of the PSA process with AC adsorbent, especially for biogas upgrading 23‐26 …”