Low-pressure CO2 Research Articles

Catalyst- and Additive-Free Electrochemical CO2 Fixation into Morita–Baylis–Hillman Acetates

AbstractThe electrochemical carboxylation of Morita–Baylis–Hillman (MBH) acetates with CO2 is presented. The process proceeds in the absence of transition-metal catalysts and relies on the cathodic reduction of MBH acetates to generate nucleophilic anions that are able to trap low-pressure CO2. Valuable succinate derivatives are obtained (20 examples) in high yields (up to 90%) and with excellent functional group tolerance. A remarkable substrate-controlled (electronic nature) regioselectivity of the transformation is documented along with a mechanistic rationale based on control experiments.

The characterization and mechanism of carbonated steel slag and its products under low CO2 pressure

Steel slag can be applied as a promising carbon fixing material. This paper mainly explored the characterization and carbonation mechanism of steel slag and its products at relatively low CO2 pressure. The experimental conditions were pure CO2 gas, 0.02 MPa CO2 pressure and 24 h carbonation time. The carbonation reaction degree of samples was evaluated by numerical carbonation rate. The phase composition and microstructure of samples were analyzed by XRD, FTIR, TG and SEM. The mechanical properties of carbonated steel slag bricks were evaluated by flexural strength. The results show that the average flexural strength of carbonated steel slag bricks (CSSB) reaches 15.9 MPa, and the carbonation rate reaches 33.9 %, which has a good carbonation degree. Low pressure and short time operation methods were adopted in this research, which provides ideas for reducing cost and simplifying carbon dioxide storage process in steel slag carbonation industry.

Cobalt-catalyzed carbonylative acetylation of phenols

A new procedure on cobalt-catalyzed carbonylative acetylation of phenols has been developed. In this methodology, DTBP acts as the methyl source and react with various phenols under low CO pressure (5 bar) to give the desired esters in moderate to good yields.

Production of high-purity H2 through sorption-enhanced water gas shift over a combination of two intermediate-temperature CO2 sorbents

Sorption-enhanced water gas shift (SEWGS) that integrates the WGS reaction and in situ CO2 removal in one reactor is a promising technology for producing high-purity hydrogen. In this study, a series of Mg–Al hydrotalcite-based CO2 sorbents were prepared, characterized, and evaluated at low CO2 pressure (0.01 bar). It shows that the layered double oxide prepared at pH = 10 (abbr. LDO_10) has a higher CO2 adsorption uptake at 30–400 °C than other LDO_x, owing to its large surface area. After doping with M2CO3 (M = Li, Na, K, or Cs), the resulting M-LDO_10 sorbents exhibit different CO2 uptake, with Li-LDO_10 the lowest and K-LDO_10 the highest. It is considered that the high total basicity contributed to the high CO2 uptake of K-LDO_10. A single-layered reactor (physically mixed Cu/Ce0·6Zr0·4O2 (catalyst) and K-LDO_10) can realize a stable production of high-purity H2 in 10 SEWGS cycles, but the duration time is rather short (≤1 min). By combining our previously developed MgO-based sorbent (AMS-Mg95Ca5) with K-LDO_10 in a four-layered configuration, i.e., three (Cu/Ce0·6Zr0·4O2|AMS-Mg95Ca5) layers followed by one (Cu/Ce0·6Zr0·4O2 + K-LDO_10) layer, high-purity H2 (>99.9%) without CO contamination is stably produced with extended duration time (22–31 min) in 10 SEWGS cycles (300 °C, 12 bar, and H2O/CO molar ratio of 1.5).

Shallow burial shale gas accumulation pattern of the Wufeng–Longmaxi Formations in the northern Guizhou area, western Yangtze platform

Although continuous breakthroughs of economic shale gas exploitation have been made globally within the middle–deep buried depth (∼1500–3500 m), the shallow–buried (less than 1500 m) shales are also widely distributed, showing excellent exploration prospects. However, the shale gas accumulation (SGA) pattern of the shallow burial shale remains unknown, limiting future shale gas exploration. To investigate the SGA pattern and the exploration potential of shale gas in shallow–buried shales, experiments such as X–Ray Diffractometer, N2 and CO2 adsorption, Focused Ion Beam Scanning Electron Microscopy (FIB-SEM), total organic carbon (TOC) content, gas chromatography–mass spectrometry, and field gas content test were carried out based on three wells penetrated the Wufeng–Longmaxi Formation with the buried depths of less than 700 m in the Northern Guizhou area, western Yangtze Platform. The geochemical and mineral records indicate that the organic matter is enriched as a result of global climate and regional tectonic activity, indicating the sufficient gas generation potential. The results of low pressure N2 and CO2 adsorption, as well as images of the FIB–SEM show that the mesopores are controlled by the organic matter, and the micropores, which are associated with minerals (primarily clays), can provide much more specific surface area and pore space in shallow–buried shales. Furthermore, carbonates with low porosity and permeability from the Songkan, Jiancaogou and Baota Formations, and the shale interval with low TOC values, weak brittleness, and low porosity, can serve as good roofs and floors for the SGA. Despite the fact that multi–stage tectonic movements resulted in the formation of faults and fractures, the good preservation, adequate gas storage space, and sufficient hydrocarbon generation potential contribute to the SGA in the shallow–buried shale.

Gut microbiota facilitates adaptation of the plateau zokor (Myospalax baileyi) to the plateau living environment.

Gut microbiota not only helps the hosts to perform many key physiological functions such as food digestion, energy harvesting and immune regulation, but also influences host ecology and facilitates adaptation of the host to extreme environments. Plateau zokors epitomize successful physiological adaptation to their living environment in the face of the harsh environment characterized by low temperature, low pressure and hypoxia in the Tibetan plateau region and high concentrations of CO2 in their burrows. Therefore, here we used a metagenomic sequencing approach to explore how gut microbiota contributed to the adaptive evolution of the plateau zokor on the Qinghai-Tibet Plateau. Our metagenomic results show that the gut microbiota of plateau zokors on the Tibetan plateau is not only enriched in a large number of species related to energy metabolism and production of short-chain fatty acids (SCFAs), but also significantly enriched the KO terms that involve carbohydrate uptake pathways, which well address energy uptake in plateau zokors while also reducing inflammatory responses due to low pressure, hypoxia and high CO2 concentrations. There was also a significant enrichment of tripeptidyl-peptidase II (TPPII) associated with antigen processing, apoptosis, DNA damage repair and cell division, which may facilitate the immune response and tissue damage repair in plateau zokors under extreme conditions. These results suggest that these gut microbiota and their metabolites together contribute to the physiological adaptation of plateau zokors, providing new insights into the contribution of the microbiome to the evolution of mammalian adaptation.

Pore-Microfracture Structure Alteration of Coal Induced by High-Pressure CO2 Gas Fracturing

High-pressure CO2 gas fracturing (CO2-Frac) is a novel technology to stimulate coal for improving coal-seam permeability and increase gas extraction efficiency. However, the multiscale pore-microfracture evolution characteristics induced by CO2-Frac and its damage mechanism are still in their nascency. Herein, a high-pressure CO2-Frac system of 120–150 MPa was newly developed and carried out on anthracite coal to reveal the damage mechanism. The results of mercury intrusion porosimetry and field emission scanning electron microscopy (FESEM) tests on coal before and after the impact showed that the micropores (<10 nm) and transition pores (10–100 nm) were significantly reduced after CO2-Frac; the volume and specific surface area of seepage pores (large pores, 1000–10,000 nm) increased significantly. The FESEM images show four damage structures including (1) damage marks, (2) tri-wing fractures, (3) pore-microfracture linkage structures, and (4) zigzag fractures. Based on these new findings, a two-stage damage mechanism was proposed as a high-pressure CO2 damage mechanism and a low-pressure quasi-static CO2 damage mechanism.

Nanopore Characteristics of the Cambrian Niutitang Formation Organic-Rich Shales in the Middle Yangtze Region and Its Formation Controlling Factors

The shale of Cambrian Niutitang Formation is one of the most important shale gas reservoirs in the Middle Yangtze region, South China. Nanopores are important reservoir spaces for shale gas. The study of pore characteristics and its formation controlling factors is of great significance for the exploration and development of shale gas in the Niutitang Formation. In this study, two drilling core samples and two profile samples were investigated. The laser Raman, X-ray diffraction analysis, FE-SEM, and low-pressure N2 and CO2 adsorption methods are used to study the geochemical and mineral compositions of the shales, and the nanopore characteristics and its formation controlling factors of the shales are discussed. Results show that the shales have the following features: (1) rich in organic matter (OM) and the total organic carbon (TOC) contents ranging from 2.65 to 11.33%, with an average value of 6.81%. (2) The main mineral components of these shales are quartz, feldspar, clay minerals, calcite, and a small amount of pyrite. (3) The samples from the center of the Middle Yangtze region (EY1 well and BGP profile) have a higher maturity value ( Rmc R 0 % = 4.0 %) relatively to the samples from the south of the Middle Yangtze region (XD1 well and JF profile), where the Rmc R 0 % is 2.8%. (4) The maximum N2 adsorption capacity of the four groups of shale samples ranges from 5.090 to 27.333 cm3/g, with an average value of 15.571 cm3/g, while the maximum CO2 adsorption capacity ranges from 2.686 to 5.567 cm3/g, with an average value of 3.776 cm3/g. The higher maturity leads to the EY1 well having the lowest average maximum N2 adsorption capacity, while most of the OM pores in the EY1 well and BGP profile samples are smaller than 10 nm in diameter. The tectonic uplift leads to the profile samples having more meso-macropores than the core samples. The dissolution pores and granular mineral support are the key factors for the better pore structure of the high-evolution stage Niutitang Formation shale.

The Characteristic Development of Micropores in Deep Coal and Its Relationship with Adsorption Capacity on the Eastern Margin of the Ordos Basin, China

The accurate description of micro-/nanopores in deep coal reservoirs plays an important role in evaluating the reservoir properties and gas production capacity of coalbed methane (CBM). This work studies nine continuous samples of high–rank coal from the Daning–Jixian area of the Ordos Basin. Maceral analysis, proximate analysis, field emission scanning electron microscopy (FE-SEM), low-pressure CO2 adsorption (LPA), low-temperature N2 adsorption (LTA) and high-pressure methane adsorption (HPMA) experiments were conducted for each sample. The fractal dimension (D) of the LPA data was calculated by using the micropore fractal model. The characteristics of the deep coal reservoir pore structure, proximate analysis, relationship between maceral and fractal dimensions, and gas adsorption capacity of the micropores are discussed. The results showed that the combination of LPA with nonlocalized density functional theory (NLDFT) models and LTA with NLDFT models can more accurately determine the pore size distribution of the micropores. The pore volume (PV) and specific surface area (SSA) of the coals were distributed in the ranges of 0.059~0.086 cm3/g and 204.38~282.42 m2/g, respectively. Although the degree of micropore development varies greatly among different coal samples, the pore distribution characteristics are basically the same, and the PV and SSA are the most developed in the pore size range of 0.4–0.7 nm. Ash content (Ad) and mineral composition are two major factors affecting micropore structure, but they have different impacts on the fractal dimension. The higher the vitrinite content, moisture content (Mad) and Ad are, the larger the micropore fractal dimension (D) and the stronger the heterogeneity of the pore structure. Micropores account for 99% of the total SSA in coal, and most methane can be adsorbed in micropores. The fractal dimension of micropores can be used to evaluate the pore structure characteristics. The larger the fractal dimension, the smaller the micro-SSA and micro-PV of the coal sample. Fractal analysis is helpful to better understand the pore structure and adsorption capacity of CBM reservoirs.

Trace level of atomic copper in N-doped graphene quantum dots switching the selectivity from C1 to C2 products in CO electroreduction

To unravel the relationship between trace Cu on the metal-free catalysts toward CO/CO2 reduction reaction (CO/CO2RR), we investigated the effect of trace Cu loading in N-doped graphene quantum dots (NGQDs) on CO/CO2RR. A general trend is that increasing the Cu loading in NGQDs switches the selectivity from C1 (CH4) to C2 products in CORR. When 2.5 μg/cm2 Cu with the atomic size is loaded on NGQDs, the selectivity shifts from 62% Faradaic efficiency (FE) of CH4 to 52% FE of C2 products in CORR. Further increasing the atomic Cu loading to 3.8 μg/cm2 promotes the FE of C2 products to 78%. CO2RR requires one order of magnitude higher Cu loading than CORR to switch the selectivity from C1 to C2 products due to the low partial pressure of CO. This study clarifies the distinct impact of trace (ppm level) Cu on the activity/selectivity between CORR and CO2RR.

Spectral reflectance properties of nontronite exposed to Mars-like surface conditions and low-temperature heating (

Spectral reflectance properties of nontronite [a phyllosilicate with an ideal formula of Na0.3Fe23+(Si,Al)4O10(OH)2·nH2O] were investigated under simulated Mars surface conditions of atmospheric pressure and composition, and after heating to 110°, 180°, and 300 °C. The data can be used to determine the conditions to which nontronites on the martian surface may have been subjected. Nontronite's spectral features include Fe3+ associated absorption features below 1000 nm, H2O/OH features near 1400 nm, H2O features near 1900 nm, a characteristic metal-OH (Fe3+) feature in the 2280–2290 nm region, and an additional Fe-OH absorption feature near 2400 nm. Heating in a low-pressure CO2 environment leads to the loss of Fe-OH-associated features below 1000 nm at temperatures as low as 110 °C. Both OH and H2O are progressively lost upon heating to 300 °C, but small, spectrally-detectable amounts remain at 300 °C. The longer wavelength Fe-OH absorption bands in the 2280 and 2400 nm region persist up to these temperatures. Comparison to other smectites and Fe-rich phyllosilicates show that a strong 2280–2290 nm absorption feature and weak or absent ∼2320 nm feature are unique to nontronite. A broader absorption feature in the 2300 nm region suggests the presence of nontronite and one or more Mg-bearing phyllosilicate(s). A Mg+Fe3+ phyllosilicate is implausible because of the difficulty in incorporating Mg2+ into the dioctahedral structure of nontronite. With increasing grain size, nontronite spectra become darker and progressively more blue-sloped beyond ∼1500 nm with absorption bands showing increasing depth until saturation is reached for some of them beyond a few hundred-micron grain size. The spectral changes documented in this study, as well as a comparison to previous studies, suggest that the absorption features associated with nontronite can be used to place constraints on conditions that nontronite may have been exposed to in the past. This study demonstrates that dehydration as well as dehydroxylation can occur at temperatures <300 °C.

Performance evaluation of phosphonium based deep eutectic solvents coated cerium oxide nanoparticles for CO2 capture

The critical challenge being faced by our current modern society on a global scale is to reduce the surging effects of climate change and global warming, being caused by anthropogenic emissions of CO2 in the environment. Present study reports the surface driven adsorption potential of deep eutectic solvents (DESs) surface functionalized cerium oxide nanoparticles (CeNPs) for low pressure CO2 separation. The phosphonium based DESs were prepared using tetra butyl phosphoniumbromide as hydrogen bond acceptor (HBA) and 6 acids as hydrogen bond donors (HBDs). The as-developed DESs were characterized and employed for the surface functionalization of CeNPs with their subsequent utilization in adsorption-based CO2 adsorption. The synthesis of as-prepared DESs was confirmed through FTIR measurements and absence of precipitates, revealed through visual observations. It was found that DES6 surface functionalized CeNPs demonstrated 27% higher adsorption performance for CO2 capturing. On the contrary, DES3 coated CeNPs exhibited the least adsorption progress for CO2 separation. The higher adsorption performance associated with DES6 coated CeNPs was due to enhanced surface affinity with CO2 molecules that must have facilitated the mass transport characteristics and resulted an enhancement in CO2 adsorption performance. Carboxylic groups could have generated an electric field inside the pores to attract more polarizable adsorbates including CO2, are responsible for the relatively high values of CO2 adsorption. The quadruple movement of the CO2 molecules with the electron-deficient and pluralizable nature led to the enhancement of the interactive forces between the CO2 molecules and the CeNPs decorated with the carboxylic group hydrogen bond donor rich DES. The current findings may disclose the new research horizons and theoretical guidance for reduction in the environmental effects associated with uncontrolled CO2 emission via employing DES surface coated potential CeNPs.

Thermodynamic evaluation on a new CO2 energy storage system assisted by adsorption bed

The share of renewable energy in energy systems is increasing under the background of the accelerated transformation on the current energy structure. Energy storage technologies enjoy excellent functions in dealing with the problems arising from the extensive applications of renewable energies. A compressed CO2 energy storage system configured with adsorption bed is proposed with the merits of high efficiency and large energy density in this paper. The gaseous working fluid at the turbine outlet is directly absorbed and stored by the adsorbent material in the adsorption bed, which solves the low-pressure CO2 storage problem. The thermodynamic performance and parametric analysis are investigated by establishing mathematical models of the proposed system. Results demonstrate that the maximum efficiency can be identified and the optimized HPC exit pressure is shifted to the right when the HPT inlet pressure is lower than 14 MPa, and then it is located at 15 MPa. The curve of system efficiency declines almost in a layered manner with the increase in HPT inlet pressure. The maximum efficiency is ensured by locating HPC exit pressure at 13 MPa and HPT inlet pressure at 12 MPa. Under this condition, the efficiency and energy density can reach 68.79 % and 17.44 kWh/m3, which reveals that the system efficiency is competitive and its energy density is more superior with about 5–6 times of that of the adiabatic compressed air energy storage technique.

Low Subcritical CO2 Adsorption-Desorption Behavior of Intact Bituminous Coal Cores Extracted from a Shallow Coal Seam.

This study focuses on improving fundamental understanding of low, subcritical CO2 adsorption-desorption behavior of bituminous coals with the aim to evaluate the utility of shallow-depth coal seams for safe and effective CO2 storage. Comprehensive data and a detailed description of coal-CO2 interactions, e.g., adsorption, desorption, and hysteresis behavior of intact bituminous coals at CO2 pressures <0.5 MPa, are limited. Manometric sorption experiments were performed on coal cores (50 mm dia. and 30- or 60-mm length) obtained from a 30 m deep coal seam located at the Upper Silesian Basin in Poland. Experimental results revealed that the adsorption capacities were correlated to void volume and equilibrium time under low-pressure injection (0.5 MPa). The positive deviation, observed in the hysteresis of adsorption-desorption isotherm patterns, and the increased sample mass at the end of the tests suggested CO2 pore diffusion and condensation. This behavior is vital for assessing low-pressure CO2 injection and storage capabilities of shallow coal seams where confining pressure is much lower than that of the deeper seams. Overall, CO2 adsorption depicts a type II adsorption isotherm and a type H3 hysteresis pattern of the IUPAC classification. Experimental results fitted better to the Brunauer-Emmett-Teller model than the Langmuir isotherm model. CO2 adsorption behavior of intact cores was also evaluated by characteristic curves. It was found that Curve I favored physical forces, i.e., the presence of van der Waals/London dispersion forces to describe the coal-CO2 interactions. However, analysis of Curve II indicated that the changing pressure-volume behavior of CO2 in the adsorbed phase, under low equilibrium pressures, cannot be ignored.

A comprehensive insight into the effects of acidification on varied-sized pores in different rank coals

Elucidating the evolution law of coal pore structure under acidification is crucial for guiding the practical application of acidizing technology and improving the production of coalbed methane. To comprehensively investigate the influence of acidification on varied-sized pores in different rank coals, in this study, fat coal, meagre coal and anthracite coal were collected and acidified with a mixed solution composed of hydrochloric acid (9 wt%) and hydrofluoric acid (3 wt%). An approach integrating low-pressure CO2 adsorption (LPGA-CO2), low-temperature N2 adsorption (LTGA-N2) and Mercury intrusion porosimetry (MIP) was adopted to fully characterize the varied-sized pore structure before and after acidification to eliminate the limitations of single method. The results demonstrated that acid treatment improved the pore opening degree and connectivity in coal, but had essentially no effect on the pore shape. After acidification, all the coal samples showed significant increases in the porosity and total pore volume, which was mainly contributed by the numerous newly formed large mesopores and macropores, especially the macropores (with an average contribution rate of 74.59%). Taken as a whole, acid treatment had the largest impact on macropores, followed by mesopores, and the smallest impact on micropores. In addition, the variation trend of total specific surface area (SSA) under acidification was primarily determined by micropores. For the three different rank coals selected in this study, the total SSA of fat coal (PM) was more easily affected by acidification and had the largest percentage increase after acid treatment, followed by anthracite coal (YM), while that of meagre coal (LA) decreased slightly. This difference was driven primarily by the different variation trend of micropore SSA in different rank coals. After acidification, the SSA of ultra-micropores and super-micropores all increased in fat coal (PM) and anthracite coal (YM), whereas for meagre coal (LA), although ultra-micropores SSA increased, super-micropores SSA decreased, which ultimately led to the slight decrease of its micropore SSA. Moreover, the total pore volume increment of coal was closely related to the macropore volume increment under acidification, but not significantly related to the coal maturity,which might indicate that, compared with coal rank, the mineral content in coal might be a more important consideration when measuring the applicability of acidification technology.

Dual-templating-derived porous carbons for low-pressure CO2 capture

Dual-templating-derived porous carbons for low-pressure CO2 capture

Pore structure and fractal characteristics of Wufeng–Longmaxi formation shale in northern Yunnan–Guizhou, China

In this study, the microscopic pore characteristics of shale in marine strata are evaluated. Based on field emission scanning electron microscopy (FE-SEM), low-temperature N2 adsorption (LT-N2GA), low-pressure CO2 adsorption (LP-CO2GA) and high-pressure methane adsorption (HPMA) experiments, the pore characteristics of 12 shales from the Wufeng–Longmaxi Formations in northern Yunnan and Guizhou are characterized qualitatively and quantitatively. Fractal Frenkel–Halsey–Hill (FHH) theory is used to analyse the fractal characteristics, and the adsorption pore characteristics of shale are discussed. The correlation between the fractal dimension and pore structure and adsorption performance is determined. The results show that the total organic carbon (TOC) contents of the 12 shales are in the middle–low level, ranging from 0.43% to 5.42%, and the shales are generally in the highly mature to overmaturity stage (vitrinite reflectance (Ro) values between 1.80% and 2.51%). The mineral composition is mainly quartz and clay minerals. The average clay mineral content is 40.98% (ranging from 24.7% to 63.3%), and the average quartz content is 29.03% (ranging from 16.8% to 39.6%), which are consistent with those of marine shale in the Sichuan Basin. FE-SEM and LT-N2GA isotherms reveal a complex shale pore structure and open pore style, mainly ink bottle-shaped and parallel plate-like pores. The total pore volumes (PVs) range from 0.012–0.052 cm3/g, and the specific surface area (SSA) values range from 18.112–38.466 m2/g. All shale samples have abundant micropores and mesopores, accounting for &amp;gt;90% of the total SSA. The fractal dimensions, D1 and D2, were obtained from N2 adsorption data, with different adsorption characteristics at 0–0.5 and 0.5–1.0 relative pressures. The fractal dimensions increase with increasing BJH PV and BET SSA and decrease with decreasing average pore diameter (APD). The fractal dimensions are positively correlated with the TOC and clay mineral contents and negatively correlated with the quartz content. The fractal dimension can be used to evaluate the methane adsorption capacity; the larger the fractal dimension is, the larger the methane adsorption capacity is. Fractal analysis is helpful to better understand the pore structure and adsorption capacity of shale gas reservoirs.

Nanopore structure characteristics and evolution of type III kerogen in marine-continental transitional shales from the Qinshui basin, northern China

Marine-continental transitional (MCT) shale gas, owing to its great potentials in China, has become a new field of exploration and development following marine shale gas. However, the formation and enrichment mechanism of MCT shale gas is still unclear, especially there is a lack of understanding on the nanopore evolution of organic matter in this type of shale reservoirs. Based on a set of MCT natural shale samples with variable maturities from the Qinshui Basin, northern China, and their isolated kerogen, the characteristics and evolution of organic matter (OM) nanopore in this type of shales were investigated. The results from organic petrological and elemental analysis show that the shales have a Ro range of 1.25–3.90%, and their OM is composed of amorphinite, inertinite and vitrinite, belonging to type III kerogen. Scanning electron microscope observations indicate that interparticle pores related to minerals, especially clay minerals develop well, while organic-hosted pores are underdevelopment. There is no obvious secondary pore in inertinite, and secondary pores occur in vitrinite, but with a low abundance. Low-pressure N2 and CO2 adsorption experiments further reveal that OM in the shales (represented by their kerogen samples) develops micropores, and the contribution of their micropores to their total surface areas and pore volumes can reach averagely 92% and 39%, respectively. Micropores have a main control on the nanopore structure evolution of OM in the shales, and the specific surface areas and pore volumes of micropores and total pores continue to increase with increasing maturity from 1.25% Ro up to 3.90% Ro, without a decline when Ro > 3.0–3.5% as revealed in marine shales The results indicate that the exploration of MCT shale gas in the Qinshui and other basins could be extended to a higher maturity (possibly up to a Ro of 3.9–4.5%).

Pore engineering of metal–organic frameworks for boosting low-pressure CO2 capture

This review summarizes recent advances in the pore engineering of metal–organic framework-based materials for boosting carbon dioxide capture by highlighting the structure–performance relationships.

Low-pressure CO2 discharges: 1D modeling

A 1D model of glow low-pressure CO2 discharges is developed. In the framework of this model, simulation of stationary and repetitively pulsed discharges at pressure ranging from 0.5 to 5 Torr and current from 10 to 50 mA is performed. The obtained plasma characteristics are compared with the available experimental results and with the data evaluated based on the approximate 0D approach. The results of 0D and 1D calculations agree for most of plasma parameters, except for the molar fraction of CO molecules produced at CO2 dissociation by electron impact. Agreement between the measured and calculated, in the framework of the 1D model, values of the CO molar fraction is provided by modifying the expression of the dissociation rate constant vs the reduced electric field.