Modeling and simulation of the efficient separation of methane/nitrogen mixtures with [Ni3(HCOO)6] MOF by PSA

Águeda, V.I.; Dobladez, José Antonio Delgado; Larriba, Marcos; Rodrı́guez, A.

doi:10.1016/j.cej.2018.12.154

Cited by 30 publications

(9 citation statements)

References 35 publications

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“…The emerging MOFs have recently attracted extensive attention for gas separation/purification because of their fascinating tunability for pore size, shape, and surface functionality. 7−21 To date, many MOFs, Ni-MA− BPY, 22 Al-CDC, 23 Co 3 (C 4 O 4 ) 2 (OH) 2 , 24 SBMOF-1, 25 ATC-Cu, 26 Cu(INA) 2 , 27 Ni 3 (HCOO) 6 , 28 Ni-MOF-74, 29 and so forth, 30 have been reported for CH 4 /N 2 separation. It is noteworthy that water vapor is inevitably present in natural gas in the actual separation process of CH 4 /N 2 .…”

Section: ■ Introductionmentioning

confidence: 99%

Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions

Jia

Chen

et al. 2022

ACS Appl. Mater. Interfaces

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Adsorption separation technology using adsorbents is promising as an alternative to the energy-demanding cryogenic distillation of natural gas (CH4/N2) separation. Although a few adsorbents, such as metal–organic frameworks (MOFs), with high performance for CH4/N2 separation, have been reported, it is still challenging to target the desired adsorbents for the actual CH4/N2 separation under humid conditions because the adsorption capacity and selectivity of the adsorbents might be mainly dampened by water vapor. Except for the high CH4 uptake and CH4/N2 selectivity, the adsorption material should simultaneously have excellent stability against moisture and relatively low-water absorption affinity. Here, we tuned the ligands and metal sites of reticular MOFs, Zn-benzene-1,4-dicarboxylic acid–1,4-diazabicyclo[2.2.2]octane (Zn-BDC–DABCO) (DMOF), affording a series of isostructural MOFs (DMOF-N, DMOF-A1, DMOF-A2, and DMOF-A3). Because of the finely engineered pore size and introduced aromatic rings in the functional DMOF, gas sorption results reveal that the materials show improved performance with a benchmark CH4 uptake of 37 cm3/g and a high CH4/N2 adsorption selectivity of 7.2 for DMOF-A2 at 298 K and 1.0 bar. Moisture stability experiments show that DMOF-A2 is a robust MOF with low water vapor capacity even at ∼40% relative humidity (RH) because of the presence of more hydrophobic aromatic rings. Breakthrough experiments verify the excellent CH4/N2 separation performances of DMOF-A2 under high humidity.

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Section: ■ Introductionmentioning

confidence: 99%

Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions

Jia

Chen

et al. 2022

ACS Appl. Mater. Interfaces

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“…Comparison of methane upgrading performance in this work with literature-reported results. ,,,,,− The operations are mostly under ambient temperatures, adsorption is within the range of 1 to 20 bars, and desorption is at 7 to 140 kPa. Original data are available in Appendix II.…”

Section: Resultsmentioning

confidence: 61%

“…As the adsorption pressure in the studied system was only slightly above the atmospheric pressure (1.2 bar), and feed gases were often used as provided in practice, the compression energy consumption was ignored, and only evacuation work ( W ) was considered in the energy analysis. The energy consumption of the vacuum pump per mole of CH 4 produced was calculated using eq , where γ was the ratio of specific heats, R was the gas constant, T was the temperature, P dis was the discharge pressure of the pump (1 bar), P vac was the average vacuum pressure, and η was the pump efficiency and set to be 0.7. ,,, W = γ italicRT η ( γ − 1 ) ( P d i s ( γ − 1 / γ ) P v a c − 1 ) …”

Section: Methodsmentioning

confidence: 99%

Separation of Methane and Nitrogen Using Heavy Reflux Pressure Swing Adsorption: Experiments and Modeling

Guo

Zhao

et al. 2023

Ind. Eng. Chem. Res.

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Pressure swing adsorption (PSA) is commonly used for the challenging task of separating methane (CH 4 ) and nitrogen (N 2 ) gas mixtures. Previously we used pilot-scale tests and process simulations to demonstrate how PSA cycles can be optimized for methane−nitrogen separations by adjusting the feed flow, cycle step time, and desorption pressure for a given column size. However, to produce a high-value product stream, dilute feeds with <25% CH 4 generally require greater enrichment than can be achieved with optimized conventional cycles. In this work, we investigated the effects of including a heavy product reflux/purge step in PSA cycles on the separation of CH 4 /N 2 using ionic liquidic zeolites (ILZs) as adsorbents through both pilot plant tests and process simulations. In the pilot demonstrations, the use of a heavy purge step allowed the enrichment of feed mixtures with 5.6 and 25.1% methane to 27.4 and 85.5% with recoveries of 83 and 96%, respectively, which outperforms most reported studies under similar operational conditions. However, while the refluxes increased from 74 to 80%, the recovery of CH 4 dropped from 79 to 75% as CH 4 was lost into the light product stream. Optimum separation performance in terms of CH 4 purity and recovery occurred at a bed capacity ratio for the purge step of C PU ≅0.87, which could help guide future selections of heavy purge flow rates for a given column size and adsorbent material.

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“…The energy consumption of the vacuum pump ( W ) per mole of methane produced is estimated using Equation (), 16

W goodbreak= \frac{γRT}{normalη ((), γ goodbreak- 1)} ((), {\frac{P_{Dis}}{P_{Vac}}}^{\frac{γ - 1}{γ}} goodbreak- 1),

where γ is the ratio of specific heats, R is the gas constant, T is the temperature, P Dis is the discharge pressure of the pump (1 bar), P Vac is the average vacuum pressure and η , the pump efficiency, is set to 0.7 17,18,35,36 …”

Section: Methodsmentioning

confidence: 99%

Separation of methane and nitrogen using ionic liquidic zeolites by pressure vacuum swing adsorption

Xiao

Guo

et al. 2022

AIChE Journal

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The separation of methane (CH 4 ) and nitrogen (N 2 ) is a significant challenge to the enrichment and utilization of low concentration CH 4 due to the similarity in the physical and chemical properties of the two molecules. In this work, we investigated the separation of CH 4 from N 2 using 100 kg of a new ionic liquidic zeolite (ILZ) material in a 6-bed pilot-scale pressure swing adsorption process. Feed gases with CH 4 concentrations of 5.0% and 16.1% were upgraded to 11.5% and 34.6%, respectively, with CH 4 recoveries higher than 80%. The pilot test results were used to anchor a numerical model that then allowed the efficient investigation of multiple operational parameters including desorption pressure and feed gas flow rates. The numerical model produced CH 4 concentrations for both product streams consistent with those measured in the pilot experiments, with root mean square deviations below 2%. The modeling results revealed that sufficiently low desorption pressures can unexpectedly lead to lower heavy product purities under limited feed gas flow conditions. Furthermore, the optimum feed gas flow rate under which maximum heavy product purity is achieved increases with lower desorption pressure. The maximum CH 4 concentrations increased from 31.8% to 41.5%, as desorption pressures decreased from 22.8 to 12.2 kPa for optimum feed flow rates between 78.2 and 105.5 mol/h. We also demonstrate a method of process optimization based on the bed capacity ratio, C, which provides a scale-independent measure of the degree to which the column is being used effectively. By varying feed flow rate and/or desorption pressure, C values between 0.2 and 0.8 were explored, with maxima in the combined separation performance metric (methane recovery) Â (methane purity) occurring for values of C in the range 0.29-0.36. This separation performance optimization by adjusting C provides an effective strategy for integrating and understanding the impact of multiple operating parameters.

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Modeling and simulation of the efficient separation of methane/nitrogen mixtures with [Ni3(HCOO)6] MOF by PSA

Cited by 30 publications

References 35 publications

Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions

Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions

Separation of Methane and Nitrogen Using Heavy Reflux Pressure Swing Adsorption: Experiments and Modeling

Separation of methane and nitrogen using ionic liquidic zeolites by pressure vacuum swing adsorption

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Modeling and simulation of the efficient separation of methane/nitrogen mixtures with [Ni3(HCOO)6] MOF by PSA

Cited by 30 publications

References 35 publications

Tuning the Pore Environment of MOFs toward Efficient CH4/N2 Separation under Humid Conditions

Tuning the Pore Environment of MOFs toward Efficient CH4/N2 Separation under Humid Conditions

Separation of Methane and Nitrogen Using Heavy Reflux Pressure Swing Adsorption: Experiments and Modeling

Separation of methane and nitrogen using ionic liquidic zeolites by pressure vacuum swing adsorption

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Product

Resources

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Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions

Tuning the Pore Environment of MOFs toward Efficient CH₄/N₂ Separation under Humid Conditions