Mass‐transfer models for rapid pressure swing adsorption simulation

Todd, Richard S.; Webley, Paul A.

doi:10.1002/aic.10948

Cited by 24 publications

(13 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The kinetic model contains a discrete pellet version implementing the Dusty Gas Model to describe mass transfer within porous materials. We have described this in detail in previous work (Todd and Webley 2006). Parameters required are dimensionless coefficients for Knudsen flow (C K ), viscous flow (C v ) and molecular flow (C m ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Capture of CO2 from flue gas streams with zeolite 13X by vacuum-pressure swing adsorption

et al. 2008

View full text Add to dashboard Cite

Vacuum swing adsorption (VSA) capture of CO 2 from flue gas streams is a promising technology for greenhouse gas mitigation. In this study we use a detailed, validated numerical model of the CO2VSA process to study the effect of a range of operating and design parameters on the system performance. The adsorbent used is 13X and a feed stream of 12% CO 2 and dry air is used to mimic flue gas. Feed pressures of 1.2 bar are used to minimize flue gas compression. A 9-step cycle with two equalisations and a 12-step cycle including product purge were both used to understand the impact of several cycle changes on performance. The ultimate vacuum level used is one of the most important parameters in dictating CO 2 purity, recovery and power consumption. For vacuum levels of 4 kPa and lower, CO 2 purities of >90% are achievable with a recovery of greater than 70%. Both purity and recovery drop quickly as the vacuum level is raised to 10 kPa. Total power consumption decreases as the vacuum pressure is raised, as expected, but the recovery decreases even quicker leading to a net increase in the specific power. The specific power appears to minimize at a vacuum pressure of approximately 4 kPa for the operating conditions used in our study. In addition to the ultimate vacuum level, vacuum time and feed time are found to impact the results for differing reasons. Longer evacuation times (to the same pressure level) imply lower flow rates and less pressure drop providing improved performance. Longer feed times led to partial breakthrough of the CO 2 front and reduced recovery but improved purity. The starting pressure of evacuation (which is not necessarily equal to the feed pressure) was also found to be important since the gas phase was enriched in CO 2 prior to removal by vacuum leading to improved CO 2 purity. A 12-step cycle including product purge was able to produce high purity CO 2 (>95%) with minimal impact on recovery. Finally, it was found that for 13X, the optimal feed temperature was around 67°C to maximize system purity. This is a consequence of the temperature dependence of the working selectivity and working capacity of 13X. In summary, our numerical model indicates that there is considerable scope for improvement and use of the VSA process for CO 2 capture from flue gas streams.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Pressure drop in the adsorption bed is calculated with Ergun equation. We have used our numerical simulator extensively over the past decade to evaluate air separation systems and help guide experiments (Todd et al 2001(Todd et al , 2006.…”

Section: Introductionmentioning

confidence: 99%

Capture of CO2 from flue gas streams with zeolite 13X by vacuum-pressure swing adsorption

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Using the Ultra-rapid piston driven PSA, the total cycle time was less than 5 seconds (its adsorption/desorption cycles resemble the expansion and compression of an internal combustion engine). Under such conditions, the mathematical models used to simulate normal PSA processes may not work [210,217]: mass and energy transfer description using simplifications like LDF (linear driving force) are not applicable. There are also some particularities related to RPSA that could be overcome with the utilization of specialized devices.…”

Section: Advances In Process Engineeringmentioning

confidence: 99%

“…This alternative was suggested many years ago [197] and has started been implemented in the 80s [198]. When the total cycle time is smaller than 30 seconds, the process is normally called Rapid PSA (RPSA) [145,179,[198][199][200][201][202][203][204][205][206][207][208][209][210][211][212][213][214].…”

Section: Advances In Process Engineeringmentioning

confidence: 99%

Advances in Pressure Swing Adsorption for Gas Separation

Grande

2012

ISRN Chemical Engineering

186

108

View full text Add to dashboard Cite

Pressure swing adsorption (PSA) is a well-established gas separation technique in air separation, gas drying, and hydrogen purification separation. Recently, PSA technology has been applied in other areas like methane purification from natural and biogas and has a tremendous potential to expand its utilization. It is known that the adsorbent material employed in a PSA process is extremely important in defining its properties, but it has also been demonstrated that process engineering can improve the performance of PSA units significantly. This paper aims to provide an overview of the fundamentals of PSA process while focusing specifically on different innovative engineering approaches that contributed to continuous improvement of PSA performance.

show abstract

“…Published correlations for relevant adsorptive properties and transport coefficients were used in the simulation. They included (a) adsorption equilibria for pure N 2 , O 2 , and their mixtures on LiX zeolite, (b) linear driving force adsorbate mass‐transfer coefficients for N 2 and O 2 on pelletized LiX zeolite crystals where the overall mass transfer is controlled by the pellet size due to binder macropore diffusion control, (c) gas‐phase mass axial dispersion coefficient, (d) gas–solid heat‐transfer coefficient in presence of gas thermal axial dispersion, and (e) transient column pressure drop . Specific values of these parameters can be found in Chai et al…”

Section: Mathematical Model For Simulation Of N2 Desorption By Rapid mentioning

confidence: 99%

Efficiency of Nitrogen Desorption from LiX Zeolite by Rapid Oxygen Purge in a Pancake Adsorber

2013

View full text Add to dashboard Cite

show abstract

Mass‐transfer models for rapid pressure swing adsorption simulation

Cited by 24 publications

References 32 publications

Capture of CO2 from flue gas streams with zeolite 13X by vacuum-pressure swing adsorption

Capture of CO2 from flue gas streams with zeolite 13X by vacuum-pressure swing adsorption

Advances in Pressure Swing Adsorption for Gas Separation

Efficiency of Nitrogen Desorption from LiX Zeolite by Rapid Oxygen Purge in a Pancake Adsorber

Contact Info

Product

Resources

About