scholarly journals Modeling the separation performance of depth filter considering tomographic data

2020 ◽  
Vol 39 (5) ◽  
Author(s):  
Kevin Hoppe ◽  
Michail Maricanov ◽  
Gerhard Schaldach ◽  
Reiner Zielke ◽  
Dirk Renschen ◽  
...  
Keyword(s):  
Separation Performance ◽  
Tomographic Data

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

scholarly journals High-efficiency CO2 separation using hybrid LDH-polymer membranes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaozhi Xu ◽  
Jiajie Wang ◽  
Awu Zhou ◽  
Siyuan Dong ◽  
Kaiqiang Shi ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Efficiency ◽  
Transmission Rate ◽  
Spray Coating ◽  
Separation Performance ◽  
Pdms Layer ◽  
Operational Testing ◽  
Enhanced Solubility ◽  
Double Hydroxide

AbstractMembrane-based gas separation exhibits many advantages over other conventional techniques; however, the construction of membranes with simultaneous high selectivity and permeability remains a major challenge. Herein, (LDH/FAS)n-PDMS hybrid membranes, containing two-dimensional sub-nanometre channels were fabricated via self-assembly of unilamellar layered double hydroxide (LDH) nanosheets and formamidine sulfinic acid (FAS), followed by spray-coating with a poly(dimethylsiloxane) (PDMS) layer. A CO2 transmission rate for (LDH/FAS)25-PDMS of 7748 GPU together with CO2 selectivity factors (SF) for SF(CO2/H2), SF(CO2/N2) and SF(CO2/CH4) mixtures as high as 43, 86 and 62 respectively are observed. The CO2 permselectivity outperforms most reported systems and is higher than the Robeson or Freeman upper bound limits. These (LDH/FAS)n-PDMS membranes are both thermally and mechanically robust maintaining their highly selective CO2 separation performance during long-term operational testing. We believe this highly-efficient CO2 separation performance is based on the synergy of enhanced solubility, diffusivity and chemical affinity for CO2 in the sub-nanometre channels.

scholarly journals 3D Metal–Organic Frameworks Based on Co(II) and Bithiophendicarboxylate: Synthesis, Crystal Structures, Gas Adsorption, and Magnetic Properties

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1269
Author(s):  
Vadim A. Dubskikh ◽  
Anna A. Lysova ◽  
Denis G. Samsonenko ◽  
Alexander N. Lavrov ◽  
Konstantin A. Kovalenko ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
Magnetic Moments ◽  
Bet Surface Area ◽  
Separation Performance ◽  
Bridging Ligands ◽  
Magnetization Data ◽  
Metal Organic ◽  
Ch4 Adsorption ◽  
Gas Separation Performance

Three new 3D metal-organic porous frameworks based on Co(II) and 2,2′-bithiophen-5,5′-dicarboxylate (btdc2−) [Co3(btdc)3(bpy)2]·4DMF, 1; [Co3(btdc)3(pz)(dmf)2]·4DMF·1.5H2O, 2; [Co3(btdc)3(dmf)4]∙2DMF∙2H2O, 3 (bpy = 2,2′-bipyridyl, pz = pyrazine, dmf = N,N-dimethylformamide) were synthesized and structurally characterized. All compounds share the same trinuclear carboxylate building units {Co3(RCOO)6}, connected either by btdc2– ligands (1, 3) or by both btdc2– and pz bridging ligands (2). The permanent porosity of 1 was confirmed by N2, O2, CO, CO2, CH4 adsorption measurements at various temperatures (77 K, 273 K, 298 K), resulted in BET surface area 667 m2⋅g−1 and promising gas separation performance with selectivity factors up to 35.7 for CO2/N2, 45.4 for CO2/O2, 20.8 for CO2/CO, and 4.8 for CO2/CH4. The molar magnetic susceptibilities χp(T) were measured for 1 and 2 in the temperature range 1.77–330 K at magnetic fields up to 10 kOe. The room-temperature values of the effective magnetic moments for compounds 1 and 2 are μeff (300 K) ≈ 4.93 μB. The obtained results confirm the mainly paramagnetic nature of both compounds with some antiferromagnetic interactions at low-temperatures T < 20 K in 2 between the Co(II) cations separated by short pz linkers. Similar conclusions were also derived from the field-depending magnetization data of 1 and 2.

scholarly journals Adsorption for efficient low carbon hydrogen production: part 2—Cyclic experiments and model predictions

Adsorption ◽  
2021 ◽  
Author(s):  
Anne Streb ◽  
Marco Mazzotti
Keyword(s):  
Hydrogen Production ◽  
Carbon Capture And Storage ◽  
Clean Energy ◽  
Separation Performance ◽  
Low Carbon ◽  
Solution Theory ◽  
Feed Composition ◽  
Ideal Adsorbed Solution Theory ◽  
Adsorbed Solution ◽  
Adsorbed Solution Theory

Abstract Hydrogen as clean energy carrier is expected to play a key role in future low-carbon energy systems. In this paper, we demonstrate a new technology for coupling fossil-fuel based hydrogen production with carbon capture and storage (CCS): the integration of CO2 capture and H2 purification in a single vacuum pressure swing adsorption (VPSA) cycle. An eight step VPSA cycle is tested in a two-column lab-pilot for a ternary CO2–H2–CH4 stream representative of shifted steam methane reformer (SMR) syngas, while using commercial zeolite 13X as adsorbent. The cycle can co-purify CO2 and H2, thus reaching H2 purities up to 99.96%, CO2 purities up to 98.9%, CO2 recoveries up to 94.3% and H2 recoveries up to 81%. The key decision variables for adjusting the separation performance to reach the required targets are the heavy purge (HP) duration, the feed duration, the evacuation pressure and the flow rate of the light purge (LP). In contrast to that, the separation performance is rather insensitive towards small changes in feed composition and in HP inlet composition. Comparing the experimental results with simulation results shows that the model for describing multi-component adsorption is critical in determining the predictive capabilities of the column model. Here, the real adsorbed solution theory (RAST) is necessary to describe all experiments well, whereas neither extended isotherms nor the ideal adsorbed solution theory (IAST) can reproduce all effects observed experimentally.

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