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-Membrane separation of carbon dioxide. A partial pressure difference across the membrane drives carbon dioxide permeation, with the membrane providing selectivity. The driving force, membrane area (A) and thickness (l) are used to calculate membrane performance metrics such as flux, permeability and permeance.
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Membranes for selective carbon dioxide permeation are likely to be important devices in future separation processes relevant to the energy industry. Here we review the current state of research into a particular class of carbon dioxide permeable membrane: the supported molten-salt membrane. Such membranes rely upon ionic transport pathways through...
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... -feasibility studies and front end engineering design; Execute -construction and commissioning; Operate -asset management. Number labels indicate the number of projects in each geographical region. Adapted from reference 3. transport typically comes from a partial pressure difference between the feed and permeate sides of the membrane, (pfpp) (Fig. 3). For permeant transfer from feed to permeate stream, it follows that pf > ...
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... 1-5 µm and 10 µm have been reported, using 50 at% Ag -50 at% Al and 50 at% Ag -50 at% Zn alloys, by chemical or electrochemical dealloying. 99, 100 The advantage of this method is the formation of a well-connected porous network with uniform microstructure. The pore size and total porosity can be simply controlled by adjusting the dealloying time (Fig. 13). In the case of 50 at% Ag -50 at% Al, α-Al dissolves faster than Ag2Al, and as the alloy is far richer in α-Al, initially a network with pore sizes in the range of single to tens of µm is formed (Fig. 13c). 100 Subsequently, a sub-micron pore network derived from the Ag2Al regions is formed (Fig. 13d). Sub-micron pores, and a high ...
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... porous network with uniform microstructure. The pore size and total porosity can be simply controlled by adjusting the dealloying time (Fig. 13). In the case of 50 at% Ag -50 at% Al, α-Al dissolves faster than Ag2Al, and as the alloy is far richer in α-Al, initially a network with pore sizes in the range of single to tens of µm is formed (Fig. 13c). 100 Subsequently, a sub-micron pore network derived from the Ag2Al regions is formed (Fig. 13d). Sub-micron pores, and a high density of triple-phase-boundaries, contribute to an enhanced This journal is © The Royal Society of Chemistry ...
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... controlled by adjusting the dealloying time (Fig. 13). In the case of 50 at% Ag -50 at% Al, α-Al dissolves faster than Ag2Al, and as the alloy is far richer in α-Al, initially a network with pore sizes in the range of single to tens of µm is formed (Fig. 13c). 100 Subsequently, a sub-micron pore network derived from the Ag2Al regions is formed (Fig. 13d). Sub-micron pores, and a high density of triple-phase-boundaries, contribute to an enhanced This journal is © The Royal Society of Chemistry ...
Citations
... Recently, Pebax polymer has been widely used for CO 2 removal from air pollutants. The molecular structure of Pebax consists of polyamide (PA) and flexible polyether (PEO) parts, which can offer outstanding gas solubility as well as bulk-free fractional volume for CO 2 permeation [27]. Incorporating inorganic fillers into the polymer structure to create a polymer-inorganic composite membrane has been proven to improve the permeability of the polymer. ...
... Incorporating inorganic fillers into the polymer structure to create a polymer-inorganic composite membrane has been proven to improve the permeability of the polymer. Typical fillers are polyethylene glycol (PEG), titanium dioxide, silica, graphene oxide, carbon nanotubes, polyurethane, polyvinyl alcohol, etc., which improve the separation performance of Pebax polymer membranes [20][21][22][23][24][25][26][27][28]. A natural carbohydrate polymer of chitosan, it is an excellent bio adsorbent because of its biocompatibility, low cost, richness, not harmfulness, and degradability synthesized chitosan nanoparticles and incorporated different dosages of them in the matrix of polyethersulfone (PES) membrane [8, 10.24]. ...
... Many scholars have stated that available membranes to separate CO 2 and methane (CH 4 ) are polymeric because of their higher stage of development [3,24]. Mutch, and Qu [27] have investigated and suggested molten-salt membranes for CO 2 permeation and showed that YSZ, CGO, and alumina as supports for membranes can considerably affect the permeability of CO 2 . Kim et al. [32] stated that membrane gas-liquid contactors are very effective in decreasing the capital cost and energy consumption of traditional CO 2 absorption. ...
Newly, Pebax polymer (pure and composite polyether block amide) has been extensively applied for CO2 elimination from air contaminants. The Pebax involves of polyamide (PA) and stretchy polyether (PEO) portions, which can suggest excellent solubility as well as bulk-free fractional volume for CO2 permeation. In the present work, the polymeric nanocomposite membranes (Pebax/PEG/NCS) were synthesized by adding different amount of nanochitosan particles (NCS) and polyethylene glycol (PEG) to the Pebax with applying Taguchi’s experimental design with Minitab software as well as using thermal phase separation method. The input variables to the software included 4 factors at 4 levels, namely wt% of PEG, wt% of NCS, temperature (°C), and pressure (bar) in the ranges of (0, 20, 30, 40), (0, 10, 20, 30), (30, 35, 40, 45), and (4, 6, 8, 10), respectively. The Taguchi method yielded 16 optimal test arrays, each with different conditions. The morphology and structure of NCS and synthesized membranes, Pebax/PEG/NCS, were studied using infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM) tests. Their thermal properties were analyzed using thermal gravity analysis (TGA) and differential scanning calorimetry (DSC) tests. The effect of NCS amount, polymer concentration, temperature, and pressure on the performance of the Pebax/PEG/NCS was then studied. Lastly, the permeability of the constructed membranes was measured using the constant pressure-variable volume method. The first result of the present work indicated that the permeability of CO2 was higher than N2 gas due to its non-polarity and determinability. The second result obtained is that the increase of NCS increases the permeability and selectivity of N2 and CO2 gases. The third result showed that in the gas permeation test in Pebax/PEG/NCS, the maximum permeability of CO2 was from the B15 test with a value of 281.111 barrer, and the maximum permeability for N2 gas from the B14 has a permeability of 17.477 barrer at a temperature of 35 °C and a pressure of 10 bar. The obtained results are in good agreement with the literature.
... Melting points of carbonates and their mixtures83 produced at 650°C but 31.4 kW h kg −1 at 450°C. 81 CO 2 solubility in chlorides is extremely low, resulting in low mass transfer.82 ...
Carbon capture and storage (CCS) technology is believed to be a promising solution for global CO2 emission control and climate change. However, the application of CCS projects is facing a dilemma due to their negative cash flow. To address the challenge, it is critical to adopt an innovative technology that can capture and convert CO2 simultaneously with satisfying efficiencies and can make a profit for the end users. Recently, molten salt CO2 electrolysis that splits CO2 into carbon and oxygen has been extensively studied. This study reviews the process mechanisms, the salt selection, and the effects of operating conditions, including temperature and voltage. In most reported articles, the CO2 to carbon conversion efficiency reached at least 80%, and the current efficiency is over 90%, proving the promising potential of the molten salt CO2 electrolysis method. Still, some aspects, such as the impurities' influences and electrode corrosion, have not been thoroughly investigated. Therefore, some suggestions are recommended for future work.
Keywords: CO2 capture; CO2 conversion; Molten salt CO2 electrolysis; CO2 reduction; Carbon nanotubes.
... Although the amount of energy required for cooling in the process is relatively high and water must be removed to prevent cooling of the blocks by gas flow, the use of membranes in the gas separation process is promising [29]. Some of the membranes known to decompose CO 2 are palladium membranes, polymeric membranes, and zeolites [30]. ...
Food production heavily depends on ammonia-containing fertilizers to improve crop yield and profitability. However, ammonia production is challenged by huge energy demands and the release of ~2% of global CO2. To mitigate this challenge, many research efforts have been made to develop bioprocessing technologies to make biological ammonia. This review presents three different biological approaches that drive the biochemical mechanisms to convert nitrogen gas, bioresources, or waste to bio-ammonia. The use of advanced technologies—enzyme immobilization and microbial bioengineering—enhanced bio-ammonia production. This review also highlighted some challenges and research gaps that require researchers’ attention for bio-ammonia to be industrially pragmatic.
... Although the amount of energy required for cooling in the process is relatively high and that water must be removed to prevent cooling of the blocks by gas flow, the use of membranes in the gas separation process is promising [20]. Some of the membranes known to decompose CO2 are palladium membranes, polymeric membranes, and zeolites [21]. 5 of 20 Another notable CCUS technology uses an adsorption device rotary concentrator on solid. ...
Food production heavily depends on ammonia-containing fertilizers to improve crop yield and profitability. However, ammonia production is challenged by huge energy demand, the release of ~2% of global CO2, and political instability. To mitigate this challenge, many research efforts have developed bioprocessing technologies to make biological ammonia. This review presents three different biological approaches that drive the biochemical mechanisms to convert nitrogen gas, bioresources, or waste to biological ammonia. The use of advanced technologies— enzyme immobilization and microbial bioengineering – enhanced bio-ammonia production. This review also highlighted some challenges and research gaps that require researchers’ attention for bio-ammonia to be industrially pragmatic.
... The carbonate ion is transported through the molten carbonate (MC) phase to the other side of the membrane, according to the reaction below: On the permeated side of the membrane, with low CO 2 partial pressure, the reverse reaction occurs, releasing CO 2 back into the gas phase. This reaction also releases the oxide anion in the reverse path through the ceramic phase, to the feed side of the membrane with a high CO 2 partial pressure, to restart the reaction [20,21]. For the carbon dioxide to be transported through the membrane, the flow of carbonate ions needs to be balanced by a counter flow of O 2− ions. ...
An experimental setup for the evaluation of permeation of gaseous species with the possibility of simultaneously collecting electrochemical impedance spectroscopy data in disk-shaped ceramic membranes was designed and assembled. It consists of an alumina sample holder with thermocouple tips and platinum electrodes located close to both sides of the sample. Water-cooled inlet and outlet gas connections allowed for the insertion of the sample chamber into a programmable split tubular furnace. Gas permeation through a ceramic membrane can be monitored with mass flow controllers, a mass spectrometer, and an electrochemical impedance analyzer. For testing and data validation, ceramic composite membranes were prepared with the infiltration of molten eutectic compositions of alkali salts (lithium, sodium, and potassium carbonates) into porous gadolinia-doped ceria. Values of the alkali salt melting points and the permeation rates of carbon dioxide, in agreement with reported data, were successfully collected.
... CO2 permeation of the SDC-carbonate membranes with CO2/N2 mixture feed containing various amount of SO2 at 750 oC (The data in brackets are the concentrations of SO2) Figure 10: [17] [ 18] membranes. Ag as a support, however, comes at a hefty cost. ...
Global warming cannot be stopped by reducing CO2 emissions alone; additional measures must be taken to capture CO2 that has already been released into the atmosphere. Negative CO2 emission technology, or technology that removes CO2 from the atmosphere, is therefore regarded as crucial. Due to its great potential capacity for CO2 capture, direct air capture (DAC), also known as direct CO2 capture, has received a lot of attention as one of the most promising technologies. DAC is primarily based on the absorption, adsorption, and membrane separation techniques that are known as representative CO2 capture methods. Specifically, DAC employing absorption and adsorption technologies has already achieved plant scale, but the desorption process of collected CO2 from the absorbent or adsorbent uses a significant quantity of heating energy and water. However, due to the immaturity of the membrane performance for CO2 capture, specifically CO2 permeance, DAC by membrane separation has not even been considered. Membrane separation is generally regarded as the most energy- and cost-efficient process among these capture technologies. Membrane processes, however, may now be thought of as a novel DAC strategy thanks to recent advancements in membrane technology. We review recent advancement in the use of membrane technology for DAC.
... It was believed that the higher CO 2 uptake activity could be attributed to a higher mobility of ions in promoters with lower melting points [75]. Unlike direct solid doping, molten salt promoters have mainly two hypotheses put forward [88,89,91]. Equilibrium partial pressure of CO 2 , pCO 2 ,eq, as a function of temperature for typical oxide systems [57,58] tion. ...
... Besides the dual fluidized-bed reactors, as shown in Fig. 4 section 2, several types of reactors such as membrane reactor [91,105], fixed-bed reactor [106][107][108], and moving-bed reactors [47,109] are reviewed when integrated with calcium-looping beyond CCS. The challenges associated with possible synergistic integrations are also discussed in this section. ...
... Membrane reactors are likely to continue to attract attention. Nevertheless, this concept is still at an early stage with very low methane conversion rates at about ~ 8% mL·min − 1 ·cm − 2 for a nickel /alumina catalyst deposited on the permeate side [91]. Additionally, CaO supported molten salt is still limited to the membrane fabrication process. ...
With the global ambition of moving towards carbon neutrality, this sets to increase significantly with most of the energy sources from renewables. As a result, cost-effective and resource efficient energy conversion and storage will have a great role to play in energy decarbonization. This review focuses on the most recent developments of one of the most promising energy conversion and storage technologies – the calcium-looping. It includes the basics and barriers of calcium-looping beyond CO2 capture and storage (CCS) and technological solutions to address the associated challenges from material to system. Specifically, this paper discusses the flexibility of calcium-looping in the context of CO2 capture, combined with the use of H2-rich fuel gas conversion and thermochemical heat storage. To take advantage of calcium-looping based energy integrated utilization of CCS (EIUCCS) in carbon neutral power generation, multiple-scale process innovations will be required, starting from the material level and extending to the system level.
... In a different manifestation, a new class of high-temperature CO 2 transport membranes is recently developed, which offers several advantages in CO 2 capture over previously-developed molten carbonate electrolyzers. Excellent reviews [123][124][125] have discussed processes, materials, reactors, and performance aspects of these emerging technologies, and are not further described here. ...
Carbon capture and storage (CCS) is essential if global warming mitigation scenarios are to be met. However, today's maturing thermochemical capture technologies have exceedingly high energy requirements and rigid form factors that restrict their versatility and limit scale. Using renewable electricity, rather than heat, as the energy input to drive CO2 separations provides a compelling alternative to surpass these limitations. Although electrochemical technologies have been extensively developed for energy storage and CO2 utilization processes, the potential for more expansive intersection of electrochemistry with CCS is only recently receiving growing attention, with multiple scientific proofs-of-concept and a burgeoning pipeline with numerous concepts at various stages of technology readiness. Here, we describe the emerging science and research progress underlying electrochemical CCS processes and assess their current maturity and trajectory. We also highlight emerging ideas that are ripe for continued research and development, which will allow the impact of electrochemical CCS to be properly assessed in coming years.
... Thermodynamic data taken from references (Barin, 1989;Chinarro et al., 2007;Bale et al., 2016 including the oxygen and CO 2 partial pressure and temperature, mainly due to there are different CO 2 and oxygen transport possibilities in membranes exhibiting a combination of pure ionic and electronic conductivity properties as previously reported Ortega-Lugo et al., 2020). Fig. 7. Total conductivity of the 50 SDC/50 Ag cermet was measured in the temperature range of 450-900°C in an air atmosphere. ...
This work proposes a cermet infiltrated with a mixture of Li2CO3/Na2CO3/K2CO3 as a dense membrane to selectively separate CO2 and O2 at high temperatures. The cermet consisted of a mixture of the Ce0.8Sm0.2O2-δ (SDC) ceramic and silver as the metallic phase. This type of membrane is a novel design of the ceramic/carbonates type and represents an improvement of state-of-art designs by avoiding microstructural changes in the metallic phase and improving chemical inertness and wettability with the carbonate phase. First, an SDC nanostructured powder was chemically synthesized by direct combustion of urea: lanthanide nitrates-based deep eutectic solvent; then, SDC and silver powders were mixed in a 50:50 vol % ratio by using high energy ball milling. The mixture was uniaxially pressed and sintered to form a support. This cermet exhibited excellent wettability properties against the ternary molten carbonate phase; therefore, it readily allowed infiltration of the molten salts to form a dense membrane. Hence, the cermet showed excellent electronic conductivity as well as corrosion resistance in contact with carbonates for 200 h of continuous immersion.
The cermet-carbonate membrane showed permselectivity by separating CO2 and O2 at high temperatures. It reaches simultaneous permeation values of 0.49 and 0.26 ml·min⁻¹·cm⁻², for CO2 and O2, respectively, at 850 °C. Finally, continuous permeation tests at 825 °C for 85 hours proved the excellent chemical stability of the cermet-carbonate membrane. Any chemical reactivity was not observed between the cermet and the carbonates.
... These encompass carbon capture and sequestration (CCS) applications for high temperature CO 2 separation in pre-and post-combustion CO 2 capture processes [4] and oxyfuel combustion, as well as in steam/dry reforming membrane reactors [5][6][7][8]. In addition, the gas selectivity towards CO 2 for the dual-phase membrane is infinite in theory providing the membrane an advantage for use in processes where high selectivity is needed [9]. ...
... Therefore, knowing the absolute pressure tolerance is critical for this membrane type. Depending on the pore size and wettability of carbonates towards the membrane matrix, the pressure tolerance of this type of membrane was calculated in Ref. [9]. Recent work shows by experiment that this type of dual-phase CO 2 separation membrane can tolerate 14 bar absolute pressure difference for a tubular architecture with a small pore size [26]. ...
Dual-phase CO2 separation membrane consisting of molten carbonates confined in a solid matrix can separate CO2 at high temperatures. The contact angle of molten carbonates to different oxides that can potentially serve as membrane supports was screened between 450 and 650 °C. These oxides have different electrical transport properties, including oxide ion, mixed, and electronic conducting. The contact angles vary between 80° to 10° for different materials. Asymmetric membranes were fabricated using wettable oxide ion conductors BTM and CGO (Bi0.8Tm0.2O1.5 and Ce0.8Gd0.2O2-δ) infiltrated with molten carbonates supported by the most "non-wetting" oxide BPR (Bi0.8Pr0.2O1.5) selected in the contact angle screening. The membranes show CO2 flux in the range of 0.035–0.35 ml/min cm² at temperatures from 500 to 650 °C. Compared to a symmetric membrane with similar total membrane thickness, the asymmetric architecture significantly reduces the effective membrane thickness and increases CO2 flux. After the CO2 flux measurements, the membrane was examined with SEM and EDS mapping, showing that the molten carbonates were mainly confined within the top membrane and sealing area without penetrating the support layer.
