Mathematical modeling of mass transfer in multicomponent gas mixture across the synthesized composite polymeric membrane

Abtin Ebadi Amooghin,Toraj Mohammadi,Pardis Moradi Shehni,Ali Ghadimi,Mohtada Sadrzadeh 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.3

This study presents a new mathematical model to investigate the ternary gas mixture permeation across a synthesized composite PDMS/PA membrane. A novel algorithm is introduced for direct determination of diffusion coefficients. It pertains to study gas permeation through concentration dependent systems and comparing with traditional time lag method confirms the precision of this approach. Feature is that this method does not require physical properties of the membrane. Accordingly, it can be used as a general comprehensive model. In addition, molecular pair and molecular trio interactions were taken into account and in order to investigate the deviation of gas mixture from ideality, fugacities were calculated. The results showed that permeabilites of H2 and CH4 increase with increasing feed temperature and fugacity, while that of C3H8 decreases. Moreover, increasing C3H8 concentration improved permeation properties of all components. The results demonstrated that considering the concentration dependent system (CDS) leads to the small deviation of about less than 10%, while the deviation of 50–100% by the concentration independent system (CIS) was acquired. Additionally the results indicated that permeability of the lighter gases is specially affected by diffusivity, while solubility is dominant on permeability of the heavier gases.

Functionalized filler/synthesized 6FDA-Durene high performance mixed matrix membrane for CO2 separation

Samaneh Mashhadikhan,Abtin Ebadi Amooghin,Abdolreza Moghadassi,Hamidreza Sanaeepur 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-

Modifying the polymer-filler interface is an efficient strategy to enhance the gas separation performanceof zeolite-filled mixed matrix membranes (MMMs) by overcoming the interfacial defects. In this study,zeolite 13X particles were modified with 3-aminopropyl(diethoxy)methylsilane (APDEMS) andsubsequently embedded into the synthesized 6FDA-Durene polyimide (PI) to prepare MMMs. Thecharacteristic properties of modified zeolite particles and fabricated MMMs were investigated via FTIR,XRD, BET, DLS and SEM analyses. Moreover, the separation performance of resultant membranes wasstudied for CO2/N2 separation consideringfiller content (0–20 wt.%) at different feed pressure in therange of 0.2 to 1 MPa. The best separation performance was obtained by embedding 15 wt.% ofaminosilanized zeolite 13X (ASZX) into the PI membrane that exhibits the excellent CO2 permeability of887 Barrer and CO2/N2 selectivity of 25.3 at the feed pressure of 0.2 MPa. These values increased by about95% and 81%, respectively compared to those for pure PI membrane. In addition, the thermomechanicalproperties of MMMs were improved after aminosilane modification of zeolite particles. Surfacemodification of the zeolite particles via the aminosilane coupling agents can be considered as a suitablestrategy to improvefiller/polymer interfacial adhesion which consequently increases the CO2 adsorptionthrough the CO2-amine interactions.

Time-dependent mathematical modeling of binary gas mixture in facilitated transport membranes (FTMs): A real condition for single-reaction mechanism

Mohammad Mehdi Moftakhari Sharifzadeh,Abtin Ebadi Amooghin,Mona Zamani Pedram,Mohammad Reza Omidkhah 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.39 No.-

In this study, a comprehensive time-dependent mathematical model for gas separation through thefacilitated transport membranes (FTMs) is presented. The model results have been validated withindependent CO2/N2 binary gas mixture experiments in DEA-impregnated PVA membranes. In theproposed model, non-equal diffusion coefficients of the carrier/complex and equilibrium constant for thechemical reaction kinetics between the carrier/permeant in the FTM have been considered. In addition, amethod to compute the diffusion coefficients, which depend on the concentration of each component inthe FTM, is presented. Moreover, effect of carrier concentration, feed partial pressure, kinetics ofreversible chemical reactions and membrane performances depending on operating condition have beenanalyzed. Owing to accurate calculation of physical–chemical parameter involved, this model is muchmore executive comparing to previous works. In addition, the real condition of the reaction kinetics andinfluencing of diffusion parameters of the components in FTMs, have been investigated. The predictedselectivity and permeability revealed good conformity with experimental data; with standard deviation(SD) 8.57% and 12.87%, respectively. In conclusion, this model with significant validity would bepredictive in cases for the entire range of diffusion-limit to a chemical-limit regime where theexperimental data, geometry condition, physical–chemical property of parameters is not available.

Synthesis and characterization of diethanolamine-impregnated cross-linked polyvinylalcohol/glutaraldehyde membranes for CO2/CH4 separation

Mona Zamani Pedram,Mohammad Reza Omidkhah,Abtin Ebadi Amooghin 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

In this research, the cross-linking of diethanolamine (DEA) impregnated poly(vinyl alcohol) (PVA) onpolytetrafluoroethylene (PTFE) by glutaraldehyde (GA) with different blend compositions (GA/PVA: 0.5,1, 3, 5, 7 ratio%) was performed in the absence of an acid catalyst and organic solvents in order to avoidany interference in CO2 facilitation reaction with DEA. The fabricated membranes were characterized bydifferential scanning calorimetry (DSC), Fourier transform infrared (FTIR) and scanning electronmicroscopy (SEM). Furthermore, the effects of cross-linking agent content, feed pressure andcomposition as well as stability on CO2/CH4 transport properties were investigated in both pure andmixed gas experiments. The cross-linked membranes showed reasonable CO2/CH4 permselectivities incomparison with uncross-linked membranes. The best-yield CO2-selective membranes (DEA-PVA/GA(1 wt%)/PTFE) represented the best CO2/CH4 selectivity of 91.13 and 665 for pure and mixed gasexperiments, respectively.

Preparation and characterization of novel Ionic liquid/Pebax membranes for efficient CO2/light gases separation

Ehsan Ghasemi Estahbanati,Mohammad Reza Omidkhah,Abtin Ebadi Amooghin 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.51 No.-

In this study, the goal is to incorporate superior features of the Pebax 1657 copolymer, such as highmechanical resistance and exceptional gas permeability especially for polar gases, with the affinity of the1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) ionic liquid to CO2 gas, which results inincreasing the permselectivity of the membranes for CO2/light gases separation. Generally, the CO2solubility in ILs increases with pressure increment, and temperature decrement. Therefore, gaspermeation results of prepared membranes were obtained at temperature of 35 C and feed pressurerange 2–10 bar. SEM, ATR and DSC analysis were carried out on different compositions of membranes andthe results showed that adding the IL to the polymer make membranes more amorphous and lesscrystalline which lead to increase permeability for all tested gases. In addition, due to the high affinity ofCO2 in both polymer and IL, both CO2 permeability and selectivity increased simultaneously withincreasing IL content. This is confirmed by gas permeation results, where at 35 C and 10 bar, the CO2permeability increased from 110 Barrer for neat Pebax to 190 Barrer in the blended membrane containing50 wt.% IL (about 73%). The related CO2/CH4 and CO2/N2 selectivities were increased from 20.8 to 24.4(about 17%) and from 78.6 to 105.6 (about 34%), respectively. Thus, these types of membranes arepromising to be utilized in gas separation processes in industries for CO2 separation in order to postponethe global warming, which is nowadays the biggest threat to the universe.

Aminosilane cross-linked poly ether-block-amide PEBAX 2533: Characterization and CO2 separation properties

Hamidreza Sanaeepur,Samaneh Mashhadikhan,Ghassem Mardassi,Abtin Ebadi Amooghin,Bart Van der Bruggen,Abdolreza Moghadassi 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.8

Commercial poly (ether-block-amide) (Pebax®) copolymers are thermoplastic elastomers that have attracted attention as membrane materials due to their high performance in CO2 separation. In this study, a cross-linking reaction is reported as a viable strategy to improve the gas separation performance of a highly permeable but low selective Pebax 2533 membrane. To this end, a new bi-functional aminosilane cross-linker (3-aminopropyl(diethoxy)methylsilane (APDEMS)) was applied. Cross-linked Pebax 2533 membranes were prepared via solution-casting with different amounts of APDEMS ranging from 0.5 to 4 wt%, to investigate the effect of the aminosilane concentration on the membrane performance. Gas separation with prepared membranes was studied for CO2/N2 at the feed pressure ranges of 2-10 bar. Instrumental analyses were applied to investigate the effect of the cross-linking reaction on the structure and properties of the membranes. The results showed that a 2 wt% APDEMS cross-linked Pebax 2533 membrane has the best gas separation performance. The CO2/N2 ideal selectivity of the cross-linked Pebax 2533 increased twice compared to the neat Pebax 2533 membrane at the feed pressure of 2 bar, while the CO2 permeability experienced a slight decrease by cross-linking, but still remains higher than the permeability of other Pebax grades.