Carbon Dioxide Permeability Research Articles

The Effect of the Temperature and Moisture to the Permeation Properties of PEO-Based Membranes for Carbon-Dioxide Separation.

An increased demand for energy in recent decades has caused an increase in the emissions of combustion products, among which carbon-dioxide is the most harmful. As carbon-dioxide induces negative environmental effects, like global warming and the greenhouse effect, a decrease of the carbon-dioxide emission has emerged as one of the most urgent tasks in engineering. In this work, the possibility for the application of the polymer-based, dense, mixed matrix membranes for flue gas treatment was tested. The task was to test a potential decrease in the permeability and selectivity of a mixed-matrix membrane in the presence of moisture and at elevated temperature. Membranes are based on two different poly(ethylene oxide)-based polymers filled with two different zeolite powders (ITR and IWS). An additive of detergent type was added to improve the contact properties between the zeolite and polymer matrix. The measurements were performed at three different temperatures (30, 60, and 90 °C) under wet conditions, with partial pressure of the water equal to the vapor pressure of the water at the given temperature. The permeability of carbon-dioxide, hydrogen, nitrogen, and oxygen was measured, and the selectivity of the carbon-dioxide versus other gases was determined. Obtained results have shown that an increase of temperature and partial pressure of the vapor slightly increase both the selectivity and permeability of the synthesized membranes. It was also shown that the addition of the zeolite powder increases the permeability of carbon-dioxide while maintaining the selectivity, compared to hydrogen, oxygen, and nitrogen.

The Effect of Whey Protein-Based Edible Coatings Incorporated with Lemon and Lemongrass Essential Oils on the Quality Attributes of Fresh-Cut Pears during Storage

This study aimed to determine the effect of edible coatings based on whey protein isolate and essential oils (lemon and lemongrass) on the colour, hardness, polyphenols and flavonoids content, structure, and sensory attributes of fresh-cut pears during storage at 4 °C. The optical and barrier properties of the edible films were also determined. Analysed films showed good transparency (Lightness 86.6–95.0) and excellent oxygen and carbon dioxide permeability, which were reduced due to the presence of lemon and lemongrass essential oils. Pears were coated by immersion in a solution containing 8% of whey protein isolate and the addition of lemon oil at 1.0% or lemongrass essential oil at 0.5%. Coating caused a reduction in colour changes, loss in hardness, polyphenols and flavonoids. The study showed that the highest efficiency was demonstrated by the whey protein isolate coatings without the addition of essential oils by preserving the colour and firmness of fresh-cut pears. For these samples, the highest sensory acceptability was also achieved.

Polymer-Grafted Porous Silica Nanoparticles with Enhanced CO2 Permeability and Mechanical Performance.

Three different types of polymer ligands, poly(methyl methacrylate) (PMMA), poly(methyl methacrylate-random-poly(ethylene glycol)methyl ether methacrylate) (PMMA-r-PEGMEMA), and poly(ionic liquid)s (PIL), were grafted onto the surface of 15 nm solid and large hollow porous silica nanoparticles (average particle size ∼60 nm) by surface-initiated atom transfer radical polymerization (SI-ATRP) to demonstrate the enhanced carbon dioxide (CO2) permeability as well as mechanical properties. After characterizing the purified products, free-standing bulk films were fabricated by the solvent-casting method. The poly(ionic liquid) nanocomposite films exhibited a much higher carbon dioxide permeance than PMMA and PMMA-r-PEGMEMA systems with a similar silica content. Also, the hollow silica-mixed matrix membranes showed a significant enhancement in CO2 permeability compared to the 15 nm solid silica films because of the pore structure. Despite the transparency loss due to the scattering of larger particle sizes, the hollow silica particle brush films exhibited the same mechanical properties as the 15 nm solid silica-derived ones.

Physicochemical and antimicrobial properties of chitosan composite films incorporated with glycerol monolaurate and nano-TiO2

Antimicrobial composite films for active food packaging were developed based on chitosan, glycerol monolaurate (GML), and nano-TiO2. The rheological, morphological, physical, and antimicrobial properties of chitosan-based composite films doped with GML and nano-TiO2 were investigated. All film-forming solutions showed typical pseudoplastic properties, and the viscosity of film-forming solutions increased after the addition of GML. The chitosan films incorporated with GML were transparent, and the transparency of films decreased after adding nano-TiO2. The chitosan-TiO2 composite film containing 1.5% GML exhibited the highest UV–vis barrier properties. Scanning electron microscopy images showed that the surface of films containing GML presented a rough structure, and the changes in the microstructure of films were also confirmed by the results obtained using atomic force microscopy. The addition of GML and nano-TiO2 improved the water-resistance and the barrier properties of the chitosan film. Increasing the GML content resulted in increased water contact angle and decreased the permeability of water vapor, oxygen, and carbon dioxide of composite films. Moreover, the incorporation of GML reduced the tensile strength of composite films. Fourier transform infrared spectroscopy and X-ray diffraction indicated that the interaction among chitosan, GML, and nano-TiO2 could be established through non-covalent bonds. Notably, chitosan-based composite films doped with GML and nano-TiO2 exhibited strong antimicrobial activity, and the film containing 1.5% GML was the most effective. The structure of bacterial cells was injured by the composite films. Overall, the developed composite films exhibited excellent functional properties and could be potential targets for bioactive packaging.

Antimicrobial properties of chitosan and galactomannan composite coatings and physical properties of films made thereof

The aim of this study was to produce antimicrobial coatings and films based on the mixture of chitosan and galactomannan from Adenanthera pavonina L., with the incorporation of sodium acetate. The antimicrobial activity of the coatings was evaluated against L. monocytogenes, S. aureus, P. aeruginosa and S. enteritidis. Then the films produced, based on the coating formulations, were characterized in terms of water vapour permeability (WVP), oxygen (O2) and carbon dioxide (CO2) permeability, moisture content (MC), water solubility (S), tensile strength (TS), elongation at break (EB), elastic modulus (EM), opacity and color. The composite coatings with Chi were effective against Gram-negative and Gram-positive bacteria. Films Chi presented the low water solubility and high values of component b*, which indicates the predominance of yellowish coloration and the highest TS values. Films of Chi-Gal-NaA present lower values of S, MC, WVP and EB and is the film presenting the higher value of EM. While for the films of Gal-NaA there was a reduction of the O2 permeability and an increase of CO2 permeability. Chi in combination with NaA can be used in the development of antimicrobial coatings and films for food applications, therefore contributing to food preservation and shelf-life extension.

High-performance 7-channel monolith supported SSZ-13 membranes for high-pressure CO2/CH4 separations

Continuous SSZ-13 zeolite membranes were reproducibly synthesized on the inner surface of 7-channel monolith supports for the first time. Packing density and mechanical strength were much greater than those using normal tubular and disc membranes. The membrane in the central channel of monolith was thinner than these of the side channels. The best monolith supported SSZ-13 membrane (with spacers) showed a CO2/CH4 selectivity of 72 and a CO2 permeance of 163 × 10-8 mol/(m2 s Pa) at pressure drop of 2.0 MPa and feed flow rate of 20 standard L/min for an equimolar CO2/CH4 mixture. Such separation performance was higher than most of zeolite membranes prepared on single-channel tubes or discs. The effects of temperature, pressure drop and fluid state on separation performance of the membranes were investigated. The extent of concentration polarization through monolith supported membrane was modelled by the concentration polarization index (CPI). Increasing feed flow rate and inserting spacers into the channels were effective ways to reduce the negative influence of concentration polarization. The latter way was more effective for our monolith supported membranes than the former because the dead volume was reduced greatly. Carbon dioxide permeance and CO2/CH4 selectivity increased by 24% and 85%, respectively, when the CPI increased from 0.79 (without spacer) to 0.89 (with spacer) at feed flow rate of 20 standard L/min.

Fabrication, characterization and antibacterial mechanism of in‐situ modification nano‐CaCO3/TiO2/CS coatings

SummaryIn order to obtain the chitosan (CS) coatings with excellent physicochemical properties and antibacterial abilities, the CS coatings were modified by in situ modification nano‐CaCO3 and nano‐TiO2. The coatings were characterised, and their physicochemical properties were measured. The antibacterial mechanism of the coatings was investigated with the Shewanella putrefaciens and Pseudomonas aeruginosa. The nano‐CaCO3/TiO2 can improve the tensile strength and elongation at break of the CS coatings. In addition, the carbon dioxide permeability of the CS coatings is increased after modification by nano‐TiO2. The nano‐CaCO3/TiO2/CS coating can effectively disrupt the integrality of bacterial cell membrane and improve their permeability, reduce the cellular enzyme activities, and affect the synthesis and expression of the bacterial protein. Eventually, the growth and reproduction of S. putrefaciens and P. aeruginosa are inhibited. The in situ modified nano‐CaCO3/TiO2/CS coatings have potential to be applied in the field of preservation of aquatic products.

The effect of Cu-BTC metal–organic framework (MOF) in mixed matrix membranes on permeability and separation of carbon dioxide and methane

This research was conducted aimed to investigate the performance of mixed matrix membranes including polysulfone (PSF) and poly (ether sulfone) (PES) as polymers and cooper (II)-benzene-1, 3, 5-tricarboxylate (Cu-BTC) as filler with different blend ratios. The response surface methodology (RSM) was employed to design the experiments. The permeation of CO2 and CH4 gases was measured at a feed pressure of 3–9 bar. Morphology, thermal stability, spectral properties and mechanical properties of the membranes were evaluated by SEM, TGA, FTIR, XRD and tensile tests, respectively. According to the results, an increase in the pressure led to a gradual fall in the permeability of CO2 and CH4. Thermal and mechanical stability of the membranes increased by the addition of nanoparticles and polymers to the pure PSF and PES membranes, molecular interaction between the two polymers and MOF was observed by FTIR analysis. The morphology of the membranes was homogenous and good disperse of MOF in matrix polymer. Gas permeability studies indicated that the permeation and ideal selectivity were improved by 100% and 34% with the addition of the Cu-BTC (20%) and PES (73%) in the PSF matrix. It was concluded that synthesized PSF/PES/CUBTC mixed matrix membranes provided an optimized performance with a good combination of permeability, selectivity.

Effect of Gas Adsorption on the Application of the Pulse-Decay Technique

The permeability of coal is an indispensable parameter for predicting the coalbed methane (CBM) and enhanced CBM (ECBM) production. Considering the low permeability characteristics of coal, the permeability is usually measured by the transient technique in the laboratory. Normally, it is assumed that the calculated permeability will not greatly vary if the pulse pressure applied in the experiment is small (less than 10% of pore pressure) and previous studies have not focused on the effect of the pulse pressure on the measurement permeability. However, for sorptive rock, such as coals and shales, the sorption effect may cause different measurement results under different pulse pressures. In this study, both nonadsorbing gas (helium) and adsorbing gas (carbon dioxide) were used to investigate the adsorption effect on the gas permeability of coal measurement with the pulse-decay technique. A series of experiments under different pore pressures and pulse pressures was performed, and the carbon dioxide permeability was calculated by both Cui et al.’s and Jones’ methods. The results show that the carbon dioxide permeability calculated by Jones’ method was underestimated because the adsorption effect was not considered. In addition, by comparing the helium and carbon dioxide permeabilities under different pulse pressures, we found that the carbon dioxide permeability of coal was more sensitive to the pulse pressure due to the adsorption effect. Thus, to obtain the accurate permeability of coal, the effect of adsorption should be considered when measuring the permeability of adsorptive media with adsorbing gas by the transient technique, and more effort is required to eliminate the effect of the pulse pressure on the measured permeability.

The Effect of Irradiation Sterilization on Poly(Lactic) Acid Films

Ionizing radiation is known to cause the deterioration of polymeric materials. In this study, the goal was to determine the effect of gamma and E-beam radiation on poly(lactic) acid (PLA) film at irradiation dosages of 1 to 30 kGy and on post-irradiated PLA after 9-months storage. The physical, chemical, mechanical, thermal, and permeability properties were investigated. Ionizing radiation of the commercial PLA film resulted in a decrease in molecular weight, crystallization temperature and melting temperature Tc and Tm, which suggested a degradation of PLA by irradiation. Irradiation had no effect on the color of the PLA film. The surface tension of PLA was decreased by gamma irradiation at dose of 1–10 kGy and E-beam irradiation at dose of 1–5 kGy. A decrease in the tensile strength, break elongation and elastic modulus was found for the gamma and E-beam irradiated PLA. Irradiation resulted in a decrease in water vapor and carbon dioxide permeability of PLA while there was no effect on oxygen permeability.

Effect of Zeolite on Mechanical and Barrier Properties of PBAT Films for Life Extension of Agricultural Products

In this research, the biodegradable film of poly (butylene adipate-co-terephthalate) (PBAT) would be used as the polymer matrix. The influence of zeolite (as the filler) type and content were investigated on the mechanical and barrier properties of film packaging. Zeolite was treated with (3-aminopropyl) trimethoxy silane. Films were produced by cast film extruder. Effects of different types of zeolite (5A and 13X) as well as zeolite loading (1-5 wt%) on mechanical properties and permeability of gases (oxygen, carbon dioxide and water vapor) of PBAT composites films have been extensively studied. Tensile properties of PBAT incorporated with zelolite 5A are higher than the one with zeolite 13X. In addition, increasing zeolite content into PBAT film is likely to improve Young’s modulus with the sacrifices of both tensile strength and percentage of elongation at break of PBAT film. For barrier properties, PBAT/zeolite 5A possessed lower permeation both of oxygen and carbon dioxide gases than PBAT/zeolite 13X. The effect of zeolite content plays a major role on oxygen and carbon dioxide permeability of composite films. PBAT/zeolite composite film could certainly extend the ripening period of Homthong bananas for approximately longer than one week.

Controlling molten carbonate distribution in dual-phase molten salt-ceramic membranes to increase carbon dioxide permeation rates

Dual-phase molten salt-ceramic membranes show high permselectivity for CO2 when molten carbonate is supported in a porous oxygen-ion and/or electron conductor. In this arrangement, the support likely contributes to permeation. Thus, if one is to understand and ultimately design membranes, it is also important to perform experiments with an inert support where permeation relies upon the molten carbonate properties alone. Here, a nominally inert material (Al2O3) was used in order to restrict permeation to molten carbonate. Model Al2O3 dual-phase membranes were fabricated using laser drilling to provide an order of magnitude difference in molten salt-gas interfacial area between feed and permeate sides. Molten carbonate thickness in the model membranes was also varied, independent of the molten salt-gas interfacial area. For all thicknesses studied, CO2 permeation rates showed a significant temperature dependence from 500 to 750 °C, suggesting an activated process was rate-limiting, likely a permeate-side molten salt-gas interfacial process, i.e. desorption of CO2. We applied these findings in asymmetric hollow-fibre supports, a geometry with inherent modularity and scalability, by developing a new carbonate infiltration method to control molten carbonate distribution within the hollow fibre. Compared to a conventionally prepared dual-phase hollow-fibre membrane with an uncontrolled distribution of carbonates, permeation rates were increased by up to 4 times when the molten salt was confined to the packed-pore network, i.e. without infiltrating the hollow-fibre micro-channels. X-ray micro-CT investigations supported the idea that the resulting increase in interfacial area for desorption of CO2 was the key structural difference contributing to increased permeation rates. For CO2 separation, where large volumes of gas must be processed, such increases in permeation rates will reduce the demand for membrane materials, although one must note the higher permeation rates achievable with oxygen-ion and/or electron conducting supports.

Effect of graphene oxide content on morphology and topography of polysulfone‐based mixed matrix membrane for permeability and selectivity of carbon dioxide and methane

AbstractIn this work, mixed matrix membranes based on polysulfone containing different contents of graphene oxide were prepared using a phase inversion process. The morphological, and structural properties as well as surface features of the samples were investigated by means of field‐emission scanning electron microscopy, infrared and x‐ray diffraction spectroscopies, as well as atomic force microscopy. The gas permeation/selectivity behavior of graphene oxide‐loaded polysulfone samples was studied using pure carbon dioxide, and methane. Morphological images depicted that the addition of graphene oxide to polysulfone in the presence of isopropyl alcohol as non‐solvent was reduced the numbers of finger‐like macro‐voids, and caused to the formation of teardrop‐like structures. Besides the x‐ray patterns and Fourier transform infrared spectra confirmed the graphene oxide nano‐plates and polysulfone with no chemical interactions, the atomic force microscopic patterns demonstrated a decrease in the average roughness of samples’ surface from 21.85 nm for plain polysulfone membrane to 5.02 nm for ones containing 2 weight percentages of graphene oxide as the optimum sample. Finally, a significant enhancement for the selectivity of carbon dioxide/methane with the value of 38.08 has been observed by the sample which was approximately 22‐fold more than that of plain polysulfone.

Active packaging for table grapes: Evaluation of antimicrobial performances of packaging for shelf life of the grapes under thermal stress

Abstract The paper reports the formulation of an active packaging based on PET coated with a Layered Double Hydroxide (LDH) hosting 2-acetoxybenzoic anion (salicylate) as antimicrobial molecule. The release of the molecule anchored to the LDH, compared to the molecule free dispersed into the coating, appeared much slower. Permeability of carbon dioxide and oxygen through the packaging at different temperatures was evaluated, as well as the capability of the active material to inhibit Pseudomonas, Listeria and Lactobacillus. Table grape was stored in thermal stress conditions (i.e. 10 °C) into the active packaging and the total mesophilic aerobic count and yeasts and moulds population was evaluated up to 14 days of storage. The experimental results were used for a theoretical prediction of shelf life of the packed grapes and compared with the same fruit packed into untreated material. Global and specific migration of salicylic acid from the active packaging demonstrated, in compliance with the migration limits of the EU regulation, the suitability of the considered material for food contact.

Development of a mathematical model to predict the growth of Pseudomonas spp. in, and film permeability requirements of, high oxygen modified atmosphere packaging for red meat

Typically, packaging films used for modified atmosphere packaging are multi-layered structures with high barrier properties, but these are difficult to recycle and therefore unsustainable. Lower barrier properties would allow a reduction in barrier layer thickness and therefore a reduction of raw materials or enable the use of alternative materials like bioplastics. The aim of this paper is to propose a model that determines the minimum permeability requirements to maintain shelf-life of red meat in high oxygen modified atmosphere packaging, therefore, providing the basis for the development of a new film. A mathematical model was developed to predict Pseudomonas spp. (spoilage bacteria particularly sensitive to changes in carbon dioxide) growth and headspace gas dynamics; predictions were validated against 15 published datasets that varied meat product, temperature, permeability of the packaging and initial headspace composition. The bias and accuracy factors comparing the model to the experimental maximum specific growth rate were 0.8426 and 1.2063 respectively, indicating a fail-safe model. Using response surface methodology, an empirical equation was developed for use as a decision support tool. To maintain shelf life, carbon dioxide permeability of 1.7 × 10-6 m3m-2h-1 atm-1 was required, higher than currently recommended permeabilities (approximately 1 × 10-8 m3m-2h-1 atm-1); this implies a clear potential for alternative films or a reduction in barrier layer thickness.

Corrosion protection of steel pipelines with metal-polymer composite barrier liners

Pipelines are efficient in transporting natural gas over large distances. Wet carbon dioxide present in pipelines can create an environment that is corrosive to steel. Polymer liners made from either polyethylene or polyamide (nylon) are presently used to mitigate internal corrosion in natural gas pipelines. Gas diffuses through all polymers over time, and polymer-only liners lower the steel corrosion rate by reducing the reactive gas flux to the internal surface of a pipeline. Composite liners, which incorporate one or more metallic layers that are impermeable to corrosive gases, offer better protection than polymer-only liners. We measured the methane, water vapor, and carbon dioxide permeability of a multi-layer barrier film and found it to be more effective in resisting gas permeation than polyethylene and nylon-11 films. The composite barrier film was more effective in protecting steel coupons immersed in a mixture of gaseous methane and wet carbon dioxide at 1 and 24 atm compared with polyethylene and polyamide films.

Ionic liquid loaded polyether sulfone microspheres for CO2 separation

Carbon dioxide permeation studies were conducted on polyether-sulfone (PES) microspheres fabricated using phase-inversion technique by loading various amine-functionalized imidazolium cation ILs with a common anion bis-trifluoromethylsulfonylamide ([TF2N]−) on PES-polymer matrix. The cations include: Aminopropyl-butyl-imidazolium [APBIM], Diethyl-aminoethyl-imidazolium [DEAEBIM], Diaminopropyl-butyl-imidazolium [DMAPBIM]. Breakthrough adsorption of CO2 and CH4 was studied with a feed composition of 20% CO2, 20% CH4 and 60% N2 by weight (4.835 mmol/L of CO2, 13.296 mmol/L of CH4 and 22.794 mmol/L of N2), at flow rates of 22 and 36 mL/min (superficial gas velocities are 0.29 cm/s and 0.47 cm/s). Among the ILs studied, [APBIM] showed maximum CO2 permeation. Results indicate that pore size and porosity are crucial for better CO2 absorption and need of further modification to microspheres morphology.

Effects of Nanofiller-Induced Crystallization on Gas Barrier Properties in Poly(lactic acid)/Montmorillonite Composite Films

This study performs a novel examination of the gas transport properties in the poly(lactic acid)/montmorillonite (PLA/MMT) interface layer by comparing the permeation parameters of dry gases and those dissolved in water. Furthermore, the relationship between the transport properties of oxygen and carbon dioxide in the gas and water phases and the crystallinity/crystal structure of the PLA/MMT composite films prepared by varying the MMT content in the PLA polymer and cooling conditions was systematically investigated. The results showed that the crystallinity of the PLA/MMT composite film increased with decreasing cooling rates, while the oxygen and carbon dioxide permeabilities increased with increasing MMT content and crystallinity. A small continuous space of size ranging from a few nanometers to a few dozen nanometers wherein the gas molecules easily diffuse around the interface might be formed between the crystalline and amorphous regions, which could not be observed by microscopic analysis. This interfacial space caused an increase in the selective permeation of carbon dioxide, which exhibits higher solubility in water, and the selective elimination of oxygen, which exhibits lower solubility in water.

Optimization analysis of polyurethane based mixed matrix gas separation membranes by incorporation of gamma-cyclodextrin metal organic frame work

In this article, a polyurethane-based mixed matrix membrane employed for the separation of carbon dioxide from methane (CO2/CH4) and permeability as well as selectivities of both the gases were determined. Gamma-cyclodextrin metal–organic framework (γ-CD-MOF) was used as a filler and incorporated (0.2–1 wt%) weight percentage into the polyurethane matrix for the fabrication of dense gas separation membrane through the solution casting method. These membrane samples were undergone following characterization techniques, i.e., FTIR, SEM, XRD and UTS for qualitative analysis. Gamma-CD-MOF equipped with an ideal cavity of 17 A diameter and an abundance of the hydroxyl group in a single molecular structure. This unique characteristic stands out Gamma-CD-MOF as the most preferential filler that can adsorb carbon dioxide from mixture of gases. Membrane samples were tested using single and mixed gases and results reflected the enhancement in carbon dioxide (CO2) permeability. The best CO2/CH4 selectivity of 28.56 is achieved by PU/γ-CD-MOF 0.2 wt%.

Highly selective high-silica SSZ-13 zeolite membranes for H2 production from syngas

A highly CO2-selective high-silica SSZ-13 zeolite membrane was used for H2 production by separating CO2 from syngas (CO2/H2 mixture). High-silica SSZ-13 zeolite membranes were fabricated using outside asymmetric alumina tubes by secondary growth of ball-milled SSZ-13 seeds. The composition of membrane gel and synthesis time were modified. The Si/Al ratio in framework of the membrane was as high as 42 when SiO2/Al2O3 ratio of the gel increased to 140. The effects of test parameters such as pressure drop, temperature, feed flow rate and concentration on membrane performance were investigated. The test pressure drop was up to 2 MPa. The ultra-high CO2/H2 selectivity of 161 with excellent CO2 permeances of ~6.3 × 10−7 mol/(m2 s Pa) (=3760 GPU) were observed for the best membrane at 243 K and pressure drop of 0.2 MPa. Carbon dioxide permeance through high-silica SSZ-13 zeolite membrane was 4.2 × 10−7 mol/(m2 s Pa) (=2500 GPU) at 298 K and pressure drop of 2.0 MPa, and the CO2/H2 selectivity was 17.4. The current high-silica SSZ-13 zeolite membranes exceeded the upper bound of polymeric membranes and other inorganic membranes in CO2/H2 plots and owned great potentials for H2 production from syngas.