Fixed Bed Adsorption with Variable Gas Velocity Due to Pressure Drop

Zwiebel, Imre

doi:10.1021/i160032a033

Cited by 12 publications

(4 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We showed that considering a variable velocity through the bed is necessary for correctly describing CO 2 capture in activated carbon, crystalline bulk CuBTC MOF and pelleted CuBTC MOF, unless a very diluted feed is considered (with CO 2 concentration <1%). It should be noted that the effect of a high‐pressure drop was not considered in this study, which can affect the propagation velocity, because the difference in experimentally measured pressure drops in our system was insignificant.…”

Section: Resultsmentioning

confidence: 99%

“…The assumption of constant velocity may result in the incorrect estimation of the propagation velocity and breakthrough curves. Zwiebel showed that considering velocity variations due to pressure drop improves the agreement with experimental data by 5–10%, especially in the tail end of the breakthrough curves. Nevertheless, models assuming constant velocity have been used to describe CO 2 separation from mixtures (15–25% CO 2 in CO 2 /N 2 mixtures), with <2–9.5% differences compared to the experimentally measured breakthrough curves.…”

Section: Introductionmentioning

confidence: 91%

“…Nevertheless, the validity of these assumptions needs to be considered carefully. A common assumption, valid for trace adsorption or systems with negligible pressure drop, is that of constant velocity across the bed, but its validity is questionable for separation processes where the concentration of the adsorbable component is significant or when pressure drop is not negligible. The assumption of constant velocity may result in the incorrect estimation of the propagation velocity and breakthrough curves.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents

et al. 2018

View full text Add to dashboard Cite

This study shows that for a reliable evaluation of porous adsorbents for carbon capture based on the fixed bed adsorption analysis, one must consider the effect of velocity variation due to adsorption to make a fair judgment on predicting the performance of materials under flow conditions. A combined experimental and numerical study of CO 2 /N 2 adsorption in fixed beds using three forms of adsorbents of amorphous powder (bulk activated carbon, AC), crystalline powder (bulk CuBTC metal-organic framework, MOF) and crystalline pellets (pelleted CuBTC) was carried out to show the effect of velocity variation on CO 2 breakthrough curves. Significant deviations are observed in the estimated amount adsorbed calculated from fixed bed experiments when models used for interpretation the measured data consider constant gas velocity because the stoichiometric time is underestimated. We show that the difference in breakthrough times estimated in models that consider constant and variable gas velocity grows exponentially with the feed gas concentration.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents

et al. 2018

View full text Add to dashboard Cite

show abstract

“…There have been many studies on the experiments, simulations, or optimizations of PSA processes, − and several studies have investigated the effect of pressure drops on PSA performance. − This is because pressure variations inside the bed play an important role at every stage of a PSA cycle and are strongly affected by gas-phase velocity, that is, the interstitial gas velocity along the bed. If the pressure drop is very small, it is relatively easy to perform the scale-up design of PSA processes .…”

Section: Introductionmentioning

confidence: 99%

Development of a Simulation Model for the Vacuum Pressure Swing Adsorption Process To Sequester Carbon Dioxide from Coalbed Methane

2016

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Coalbed methane is a worthwhile potential energy source, because methane gas is eco-friendly and a huge amount of coalbed methane has been buried in the United States, China, Australia, etc. This paper introduces a new simulation model of a vacuum pressure swing adsorption process that has been widely used to purify unconventional gases such as coalbed methane and landfill gas. The developed mathematical model includes a novel interstitial gas velocity equation derived by using a mole balance concept and an overall mass balance equation. The model is verified by comparing with three sets of laboratory-scale (about 0.5 Nm3h–1) experimental data and one set of pilot-scale (100 Nm3h–1) design data. Because the differences between the simulation results and the data are reasonably small, one can conclude that the 200 times scale-up design through the new simulation model is successful.

show abstract

Fixed bed desorption behavior of gases with nonlinear equilibria: Part II. Dilute, multicomponent, isothermal systems

1974

View full text Add to dashboard Cite

Generalized depletion curves for desorption (and corresponding breakthrough curves for adsorption) were calculated for systems characterized by the Langmuir-type multicomponent equilibrium equation and controlled by the film type rate model. In contrast with adsorption where the nonkey (or less strongly adsorbed) component curves display overshoots above feed concentration, in desorption the key component depletion curves exhibit the instabilities in the form of inflections and curvatures. As in the one component case, the differences in the depletion and breakthrough curves may be related to the rate phenomena. The undulations in the key component depletion curves may be characterized by derivatives of the rate data. The major significance of these instabilities is to elongate the depletion curves, which in turn requires the expenditure of added effort during regeneration. Process modifications are indicated, which could suppress the instabilities. The predicted trends were c o n k e d by experimental depletion curves. SCOPEMost of the studies dealing with the design of sorption step in the operation of the cyclic processes. Recently it based separation processes have focused on the description was shown that in systems characterized by favorable isoof the adsorption step; and even these have been confined therms (d2W/dC2 < 0) the depletion curves are considermostly to single component systems. From experience, ably elongated in comparison to the corresponding breakhowever, the desorption is known to be the controlling through curves. Mechanistically the elongation may be

show abstract

Fixed Bed Adsorption with Variable Gas Velocity Due to Pressure Drop

Cited by 12 publications

References 7 publications

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents

Development of a Simulation Model for the Vacuum Pressure Swing Adsorption Process To Sequester Carbon Dioxide from Coalbed Methane

Fixed bed desorption behavior of gases with nonlinear equilibria: Part II. Dilute, multicomponent, isothermal systems

Contact Info

Product

Resources

About

Fixed Bed Adsorption with Variable Gas Velocity Due to Pressure Drop

Cited by 12 publications

References 7 publications

Velocity variation effect in fixed bed columns: A case study of CO2 capture using porous solid adsorbents

Velocity variation effect in fixed bed columns: A case study of CO2 capture using porous solid adsorbents

Development of a Simulation Model for the Vacuum Pressure Swing Adsorption Process To Sequester Carbon Dioxide from Coalbed Methane

Fixed bed desorption behavior of gases with nonlinear equilibria: Part II. Dilute, multicomponent, isothermal systems

Contact Info

Product

Resources

About

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents

Velocity variation effect in fixed bed columns: A case study of CO₂ capture using porous solid adsorbents