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In this study, a Reheat Organic Rankine Cycle (ORC) utilizing the cold energy of liquefied hydrogen (LH2) and liquefied natural gas (LNG) was proposed, and its performance was evaluated by comparing it with the base model, which represented a conventional ORC. The process was simulated using ethane and propane, which were considered as potential refrigerants for the target system. A case study was conducted on the inlet pressure and temperature of the turbine included in the process to determine the optimal operating point. The calculation results indicated that ethane exhibited a higher energy efficiency, and a maximum net power of 34.65 kW was obtained when the inlet pressure and temperature of the turbine were 40 bar and 75 °C, respectively. Additionally, an exergy analysis was conducted to quantitatively analyze the high energy efficiency of the Reheat ORC model. We confirmed that exergy efficiency was up to 2.4% higher than that of the base model. [ABSTRACT FROM AUTHOR]

The production of ethylene (C2H4) is typically accompanied by the formation of impurities like ethane (C2H6), making the separation of C2H4 and C2H6 crucial in industrial processes. Here, we investigated the S-shaped adsorption phenomenon of C2H6 on the metal–organic framework HKUST−1. The virial equation is used to fit the C2H6 and C2H4 adsorption isotherms under low coverage. The results showed that the repulsion energy between neighboring C2H6 molecules was significantly higher than that between neighboring C2H4 molecules, which was an important reason for the lower adsorption of C2H6 by HKUST−1 at low coverage. As more molecules are adsorbed, gas molecules aggregate within pores, leading to more hydrogen bonds formed between HKUST−1 and larger-sized C2H6 under high coverage conditions. This phenomenon plays a crucial role in the S-shaped adsorption behavior of HKUST−1 on C2H6. Additionally, this unique adsorption behavior allows for the efficient separation of C2H4/C2H6 mixtures at low pressures. The ideal adsorbed solution theory (IAST) selectivity of HKUST−1 for C2H4/C2H6 mixtures was 3.78 at 283 K and 1 bar, but increased significantly to 7.53 under low pressure. This unique mechanism provides a theoretical basis for the low-pressure separation of C2H4/C2H6 by HKUST−1 and establishes a solid foundation for future practical research applications. [ABSTRACT FROM AUTHOR]

To address the need for efficient separation of ethylene and ethane in the industry, this research employed molecular dynamics simulations using the LAMMPS Software. To explore the effect of pore size on separation, circular holes of varying diameters were created in the BC3 membrane (graphene modified with boron) by removing specific numbers of atoms. Triangular arrangements of atoms were also removed, distinct from the circular ones, to further delve into the separation mechanisms mediated by different pore shapes. Among the studied pores, the circular hole P2 with a diameter of 4.23 Å and area of 14 Å2 emerged as the most effective pore for separation. P2 boasts an infinite selectivity coefficient for ethylene over ethane, meaning it allows only ethylene to pass through, and an impressive ethylene flow rate of 463 mol/m2s. Trailing P2 in performance, the triangular P9 (13.36 Å2) exhibits notable separation efficiency. It allows ethylene to pass through four times easier than ethane (selectivity coefficient 4), impressing with an ethylene flow rate of 195 mol/m2s while strictly limiting ethane to 48.7 mol/m2s. This superior performance can be attributed to the shape and size of the sheet and the specific arrangement of boron and carbon atoms at its edges. These factors influence the electron charge density around the cavity, ultimately affecting the overlap with gas molecules. The optimized cavity diameter effectively restricts the passage of larger ethane molecules while allowing ethylene to permeate freely, achieving complete separation. [ABSTRACT FROM AUTHOR]

Triazine-based covalent organic framework CTF-1 was synthesized via polymerization of 1,4-dicyanobenzene in the presence of zinc chloride. Two different methods of the post-synthesis treatment of the obtained material were compared. It was demonstrated that ultrasonication effectively removes impurities from CTF-1. Adsorption of hydrocarbon gases (methane and ethane) and carbon dioxide was measured at 298 K in a wide pressure range for the first time. Ideal selectivity and IAST values for methane/ethane and methane/CO2 pairs were calculated from the obtained isotherms. [ABSTRACT FROM AUTHOR]

Ethane, hydrazine, and hydrogen peroxide are three structurally similar substances composed of the elements from the same period with hydrogen, respectively. However, their stability significantly decreases in a sequential manner, and their stable conformations are also dissimilar. These differences have not been explained adequately in the current textbooks. This article provides a possible explanation for the variation in stability among these substances by analyzing their n–σ* hyperconjugation. Additionally, it elucidates the absence of anti-conformation in hydrazine and hydrogen peroxide. The hyperconjugation theory is extended to illustrate and to discuss stability and stable conformation of inorganic compounds. [ABSTRACT FROM AUTHOR]

This study is focused on examining the incorporation of oxidative dehydrogenation into the aromatization of ethane, utilizing thermodynamic analysis and catalytic experiments. The catalysts were characterized by inverse temperature programmed reduction, X‐ray photoelectron spectroscopy (XPS) and X‐ray diffraction (XRD). The results indicated that a blend of the M1 catalyst, containing oxides of vanadium, niobium, and tellurium, with H‐ZSM‐5, serves as an effective catalyst system for the oxidative aromatization of ethane at T = 380 °C. The M1's role in the oxidative dehydrogenation of ethane contributes to de‐bottlenecking the essential step of the reaction. On the zeolitic catalyst aromatic compounds are formed from a surface hydrocarbon pool. In parallel, the oxidation of these intermediates was observed. Also, the formation of paraffins through H‐transfer was evident from the catalytic results. Although the zeolite underwent significant deactivation due to coking, the M1 catalyst demonstrated highly stable activity. Interestingly, the system did not show any synergistic effects. Based on the structure‐activity relation of the catalytic system a reaction mechanism is proposed. [ABSTRACT FROM AUTHOR]

In the global energy mix by 2040, the growth in demand for oil and gas will be predominantly driven by the petrochemical sector across all regions of the world. The strong performance of this industry is anticipated to necessitate additional volumes of key feedstocks. Therefore, understanding the demand dynamics within the petrochemical sector is crucial for policy makers and industry stakeholders to make informed decisions regarding economic diversification, economic planning, and environmental sustainability. However, there is a notable lack of existing literature that explicitly addresses comprehensive regional and product-level demand modeling for petrochemical feedstocks. In this context, this study aims to estimate the demand for four main petrochemical feedstocks (Naphtha, Ethane, Liquefied Petroleum Gas (LPG), and other petrochemical feedstocks) across eight regions of the world. By estimating a total of 30 equations for price and income elasticities of demand in both the short and long term, the study provides detailed insights into the factors driving demand across different regions. The results demonstrate the robustness of the model, with good econometric properties and significant coefficients. In-sample regional simulations revealed small percentage errors across all regional equations, highlighting the model's accuracy in tracking historical data. For each of the four feedstocks, an aggregate world equation—in other words, one single econometric world equation for each of the four petrochemical feedstocks' categories mentioned earlier—was also estimated and compared against the aggregation of the regional simulations, with the latter found to track the history of global petrochemical feedstock demand better in-sample than a single econometric world equation. Overall, the study offers valuable contributions to the existing literature by filling a gap in comprehensive demand modeling for petrochemical feedstocks. It underscores the importance of regional and product-level analyses in understanding global demand patterns and informing strategic decisions in the industry. [ABSTRACT FROM AUTHOR]

Acetic acid (AA), a vital compound in chemical production and materials manufacturing, is conventionally synthesized by starting with coal or methane through multiple steps including high‐temperature transformations. Here we present a new synthesis of AA from ethane through photocatalytic selective oxidation of ethane by H2O2 at 0–25 °C. The catalyst designed for this process comprises g‐C3N4 with anchored Pd1 single‐atom sites. In situ studies and computational simulation suggest the immobilized Pd1 atom becomes positively charged under photocatalytic condition. Under photoirradiation, the holes on the Pd1 single‐atom of OH−Pd1⊕ ${{}^{\oplus }}$ /g‐C3N4 serves as a catalytic site for activating a C−H instead of C−C of C2H6 with a low activation barrier of 0.14 eV, through a concerted mechanism. Remarkably, the selectivity for synthesizing AA reaches 98.7 %, achieved under atmospheric pressure of ethane at 0 °C. By integrating photocatalysis with thermal catalysis, we introduce a highly selective, environmentally friendly, energy‐efficient synthetic route for AA, starting from ethane, presenting a promising alternative for AA synthesis. This integration of photocatalysis in low‐temperature oxidation demonstrates a new route of selective oxidation of light alkanes. [ABSTRACT FROM AUTHOR]

The aim of this study is to unravel the influence of single, double and triple bonds in hydrocarbons on the mechanisms of adsorption on zeolites. Therefore, the adsorption of the C2 hydrocarbons ethane, ethene and ethyne on different adsorbents is studied by adsorption calorimetry. As adsorbents pure sodium LTA (NaA) and FAU (NaX) zeolites and calcium exchanged CaNaA and CaNaX zeolites are used. Based on experimental loadings and heat of adsorption, the influence of the number and distribution of cations on different cation positions are discussed in detail. With increasing degree of exchange the increasing number of Ca2+-cations introduce energetically more valuable adsorption sites into the zeolites. On the other hand, the decreasing total number of cations has a negative effect on saturation loading. The impact of these opposing effects and the different occupation of cation positions on the interactions and mechanisms occurring are discussed. The loading increases from ethane to ethene to ethyne and shows higher values on FAU compared to LTA. In terms of interactions, due to the single bond, in ethane only dispersion and induction interactions are formed. In ethene and ethyne due to the double and triple bonds, respectively, additional quadrupole cation and π-interactions occur. In this study, for the first time the formation of a π-complex with Ca2+-cations at position I in LTA and at positions II, III, and III' in FAU is demonstrated. For ethyne, additional π-complex formation with Na+-cations on the identical positions is also detected, which was previously unknown in literature. [ABSTRACT FROM AUTHOR]

This work focused on the solubility of ethane in three promising ionic liquids {1-Hexyl-3-methylimidazolium bis(trifluormethylsulfonyl) imide [HMIM][Tf2N], 1-Butyl-3-methyl-imidazolium dimethyl-phosphate [BMIM][DMP], and 1-Propyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)-imide [PMIM][Tf2N]}. The solubilities were measured at 303.15 K to 343.15 K and pressures up to 1.4 MPa using a gravimetric microbalance. The overall ranking of ethane solubility in the ionic liquids from highest to lowest is the following: [HMIM][Tf2N] > [PMIM][Tf2N] > [BMIM][DMP]. The Peng–Robinson equation of state was used to model the experimental data using three different mixing rules: van der Waals one, van der Waals two, and Wong–Sandler mixing rules combined with the Non-Random Two-Liquid model. The average absolute deviations for the three mixing rules for the ionic liquids at the three temperatures were 4.39, 2.45, and 2.45%, respectively. Henry's Law constants for ethane in [BMIM] [DMP] were the highest (lowest solubility) amongst other ionic liquids studied in this work. The solubility ranking for the 3 ILs was confirmed by calculating their overall polarity parameter (N) using COSMO-RS. The selectivity of CO2 over C2H6 was estimated at three temperatures, and the overall ranking of the selectivity was in the following order: [PMIM][Tf2N] > [BMIM][DMP] > [HMIM][Tf2N] > Selexol. Selexol is an efficient and widely used physical solvent in gas sweetening. It has lower selectivity than the three ionic liquids studied. [PMIM][Tf2N], a promising solvent, has the highest selectivity among the three ILs studied and would, therefore, be the best choice if, in addition to carbon dioxide capture, ethane co-absorption was to be avoided. The enthalpy and entropy of solvation at infinite dilution were also estimated. [ABSTRACT FROM AUTHOR]

The cost-effective separation of ethylene (C2H4), ethyne (C2H2), and ethane (C2H6) poses a significant challenge in the contemporary chemical industry. In contrast to the energy-intensive high-pressure cryogenic distillation process, zeolite-based adsorptive separation offers a low-energy alternative. This review provides a concise overview of recent advancements in the adsorptive separation of C2H4, C2H2, and C2H6 using zeolites or zeolite-based adsorbents. It commences with an examination of the industrial significance of these compounds and the associated separation challenges. Subsequently, it systematically examines the utilization of various types of zeolites with diverse cationic species in such separation processes. And then it explores how different zeolitic structures impact adsorption and separation capabilities, considering principles such as cation-π interaction, π-complexation, and steric separation concerning C2H4, C2H2, and C2H6 molecules. Furthermore, it discusses methods to enhance the separation performance of zeolites and zeolite-based adsorbents, encompassing structural design, modifications, and ion exchange processes. Finally, it summarizes current research trends and future directions, highlighting the potential application value of zeolitic materials in the field of C2H4, C2H2, and C2H6 separation and offering recommendations for further investigation. [ABSTRACT FROM AUTHOR]

The author considers the main patterns characteristic of the processes of hydrogen chloride oxidation (the Deacon reaction) and oxidative methane and ethane chlorination. It is shown that the most widely recognized and best studied catalysts of these processes are copper chloride systems that are based on different supports and contain alkali and rare-earth metal chlorides, which reduce the entrainment of an active phase from the surface of a catalyst with a simultaneous increase in its activity. The prospects for using ruthenium catalysts are also noted. The main kinetic and technological patterns of oxychlorination are considered. Conditions are described that allow the yield of target products (lower methane chlorides) to be increased in the oxychlorination of methane and vinyl chloride during the oxychlorination of ethane. Variants of reactor units for oxychlorination are proposed. [ABSTRACT FROM AUTHOR]

The shale gas revolution bolsters ethane supply, thereby enhancing the economic viability of ethylene production from ethane. Presently, catalytic ethane dehydrogenation technology exhibits immense potential in the realm of ethylene production. This study achieves the electrochemical oxidative dehydrogenation conversion of ethane to ethylene via a solid oxide electrolysis cell (SOEC), effectively circumventing the issue of excessive oxidation during the ethane oxidative dehydrogenation process. An active electrode with an in situ grown metal-oxide interface significantly promotes the activation of the ethane C–H bond, leading to efficient ethylene production. Under the co-electrolysis mode of ethane with CO 2 , the Co@CeO 2 electrode demonstrates exceptional performance, achieving an ethane conversion rate of 33.1% and an ethylene selectivity of 88.9% at an applied voltage of 1.0 V. Moreover, the metal-oxide interface constructed via an in situ exsolved method effectively prevents the agglomeration of nanoparticles at high temperatures, thus enhancing the catalyst's resistance to coking and stability. Notably, the electrode's performance does not exhibit significant degradation even after 100 h of electrochemical reaction. • The electrochemical oxidative dehydrogenation of ethane effectively inhibited excessive oxidation. • The in situ grown metal-oxide interface has stability and promotes the activation of the ethane C–H bond. [ABSTRACT FROM AUTHOR]

The self-diffusion coefficients of carbonaceous fuels in a supercritical CO2 environment provide transport information that can help us understand the Allam Cycle mechanism at a high pressure of 300 atm. The diffusion coefficients of pure CO2 and binary CO2/CH4 and CO2/C2H6 at high temperatures (500 K~2000 K) and high pressures (100 atm~1000 atm) are determined by molecular dynamics simulations in this study. Increasing the temperature leads to an increase in the diffusion coefficient, and increasing the pressure leads to a decrease in the diffusion coefficients for both methane and ethane. The diffusion coefficient of methane at 300 atm is approximately 0.012 cm2/s at 1000 K and 0.032 cm2/s at 1500 K. The diffusion coefficient of ethane at 300 atm is approximately 0.016 cm2/s at 1000 K and 0.045 cm2/s at 1500 K. The understanding of diffusion coefficients potentially leads to the reduction in fuel consumption and minimization of greenhouse gas emissions in the Allam Cycle. [ABSTRACT FROM AUTHOR]

In studying the effects of oxygen concentration and molecular structure on the morphologies of the soot particles produced by hydrocarbon fuels, ethylene and ethane were chosen as experimental fuels. With a Gülde laminar coaxial diffusion flame device, a soot particle device was used to sample soot particles at different oxygen concentrations (21%, 24%, 26%, 28%, and 31%) and at different heights above a burner (HABs = 10 mm, 20 mm, 30 mm, 40 mm, and 50 mm). High-resolution transmission electron microscopy (HRTEM) was used to scrutinize and analyze the soot particles at varying oxygen concentrations. The findings suggest that at the same oxygen concentration, ethylene produces brighter and taller flames. With an increase in the oxygen concentration, ethylene flames and ethane flames gradually decrease in height and become brighter. With an increase in the HAB, the average primary soot particle diameter (Dp) increases initially and then decreases, the fractal dimension (Df) increases, and the aggregates transition from strips and chains to clusters. At the same flame height (HAB = 30 mm), the Dp decreases, the Df increases, the carbon layer torsion resistance (Tf) and the carbon layer spacing (Ds) increase, and the carbon layer changes from a parallel arrangement to a curved arrangement to form denser network aggregations. [ABSTRACT FROM AUTHOR]

The thermodynamic characteristics of adsorption (TCAs) of methane and ethane on the basal face of a semi-infinite graphite crystal were calculated by the Monte Carlo method in the Gibbs ensemble. The results obtained using the described calculation algorithm are in good agreement with the literature data. The calculations were performed in the approximation of additivity of atom-atom potentials (AAPs), taken in the Lennard-Jones form (6, 12). When varying the AAP parameters, a quasi-rigid methane molecule was used as a reference. The same AAP parameters make it possible to calculate the adsorption of ethane on graphite under the assumption that the height of the internal rotation barrier does not change during adsorption, but the potential energy of the adsorbed molecule depends on the internal rotation angle. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks based on 2-methylimidazolate linkers with different particle size (200–1000 nm) and controlled content of Zn2+ and Co2+ ions have been synthesized by microwave (MW) assisted technique according to original procedures and room-temperature method. The produced materials including monometallic ZIF-8 and ZIF-67 samples, bimetallic ZIF-Zn/Co (or ZIF-8/ZIF-67) system, and "core-shell" ZIF-8@ZIF-67 and ZIF-67@ZIF-8 composites have been studied in the practically relevant process of selective adsorption of ethane and methane (25 °C). The adsorption isotherms for both gases on the obtained ZIF materials were measured in a wide pressure range (1–20 atm) for the first time. For ZIF-67, the isosteric heats of adsorption for both gases were obtained also for the first time. It was found that the nature of the coordination centers in the ZIF frameworks influences their adsorption characteristics. Thus, the obtained materials with Co2+ ions show an increased adsorption capacity towards ethane, which exceEDX the capacity measured for the Zn2+-based samples, while the highest methane adsorption value is achieved on a "core-shell" ZIF-67@ZIF-8 composite. [ABSTRACT FROM AUTHOR]

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This study compares the CO2-assisted oxidative dehydrogenation of ethane (CO2-ODHE) performance of Mg-Al spinel catalysts doped with various metals (Cr, Fe, Co, Ga) that possess dehydrogenation activity. Both experimental and theoretical analyses were conducted to explore the reaction mechanism of CO2-ODHE on the spinel catalyst. The findings indicate that the MgFeAlO4 spinel catalyst exhibited CO2-ODHE activity at 600 °C, achieving a CO2 conversion rate of 20.3 %, an ethane conversion rate of 27.9 %, and an ethylene selectivity of 87.9 %. Mechanistic studies revealed that CO2 activation primarily occurs through the reverse water-gas shift reaction, and density functional theory calculations identified the doped metal ions as the principal active sites for ethane activation. These results suggest that CO2-ODHE on the spinel surface follows a mechanism of catalytic dehydrogenation coupled with the reverse water-gas shift reaction. Additionally, the effects of Fe doping contents and reaction temperature were investigated. When the ratio of Fe3+ to Al3+ was 1, corresponding to the MgFeAlO4 spinel catalyst, the CO2-ODHE performance was optimal, yielding 23.3 % ethylene. Increasing the reaction temperature enhanced ethane conversion but reduced ethylene selectivity, with both ethane conversion and ethylene selectivity reaching approximately 49 % at 700 °C.

Oxygen vacancies (OV) in nonmetallic plasmonic photocatalysts can decrease the energy barrier for CO2 reduction, boosting C1 intermediate production for potential C2 formation. However, their susceptibility to oxidation weakens C1 intermediate adsorption. Herein we proposed a "photoelectron injection" strategy to safeguard OV in W18O49 by creating a W18O49/ZIS (W/Z) plasmonic photocatalyst. Moreover, photoelectrons contribute to the local multi‐electron environment of W18O49, enhancing the intrinsic excitation of its hot electrons with extended lifetimes, as confirmed by in situ XPS and femtosecond transient absorption analysis. Density functional theory calculations revealed that W/Z with OV enhances CO2 adsorption, activating *CO production, while reducing the energy barrier for *COH production (0.054 eV) and subsequent *CO−*COH coupling (0.574 eV). Successive hydrogenation revealed that the free energy for *CH2CH2 hydrogenation (0.108 eV) was lower than that for *CH2CH2 desorption for C2H4 production (0.277 eV), favouring C2H6 production. Consequently, W/Z achieves an efficient C2H6 activity of 653.6 μmol g−1 h−1 under visible light, with an exceptionally high selectivity of 90.6 %. This work offers a new strategy for the rational design of plasmonic photocatalysts with high selectivity for C2+ products. [ABSTRACT FROM AUTHOR]

The urgency to mitigate environmental impacts from anthropogenic CO2 emissions has propelled extensive research efforts on CO2 reduction. The current work reports a novel approach involving transforming CO2 and ethane into carbon nanotubes (CNTs) using earth‐abundant metals (Fe, Co, Ni) at 750 °C. This route facilitates long‐term carbon storage via generating high‐value CNTs and produces valuable syngas with adjustable H2/CO ratios as byproducts. Without CO2, direct pyrolysis of ethane undergoes rapid deactivation. The participation of CO2 not only enhances the durability of the catalyst, but also contributes about 30 % of the CNTs production, presenting a viable solution to CO2 challenges. The CNT morphology depends on the catalyst used. Co‐ and Ni‐based catalysts produce CNT with a 20 nm diameter and micrometer length, whereas Fe‐based catalysts yield bamboo‐like structures. This work represents a pioneering effort in utilizing CO2 and ethane for CNT production with potential environmental and economic benefits. [ABSTRACT FROM AUTHOR]

Chromium and molybdenum incorporated MgO and MgO–C catalysts were synthesized for hydrogen production from a non-oxidative ethane dehydration reaction. Hydrogen production studies were carried out using a microwave-heated reactor system. The study investigated the effects of reaction temperature, type of active metal, and catalyst preparation method (physical mixture or core–shell structure) on hydrogen selectivity and ethane conversion during dehydrogenation reactions. The results showed that the optimal reaction temperature for the non-oxidative ethane dehydration reaction was 450 °C. Above this temperature, the selectivity of undesired byproducts increased. Catalysts containing molybdenum exhibited higher ethane conversion. Moreover, a comparison of MgO–C-supported catalysts with MgO-supported catalysts revealed that the core–shell catalysts exhibited superior ethane conversion. Notably, the 5Mo@MgO–C catalyst demonstrated exceptional catalytic activity, achieving a high ethane conversion rate of 72% along with excellent stability. [ABSTRACT FROM AUTHOR]

Biodegradation of 1,4-Dioxane at environmentally relevant concentrations usually requires the addition of a primary electron-donor substrate to sustain biomass growth. Ethane is a promising substrate, since it is available as a degradation product of 1,4-Dioxane's common co-contaminants. This study reports kinetic parameters for ethane biodegradation and co-oxidations of ethane and 1,4-Dioxane. Based on experiments combined with mathematical modeling, we found that ethane promoted 1,4-Dioxane biodegradation when the initial mass ratio of ethane:1,4-Dioxane was < 9:1 mg COD/mg COD, while it inhibited 1,4-Dioxane degradation when the ratio was > 9:1. A model-independent estimator was used for kinetic-parameter estimation, and all parameter values for 1,4-Dioxane were consistent with literature-reported ranges. Estimated parameters support competitive inhibition between ethane as the primary substrate and 1,4-Dioxane as the secondary substrate. The results also support that bacteria that co-oxidize ethane and 1,4-Dioxane had a competitive advantage over bacteria that can use only one of the two substrates. The minimum concentration of ethane to sustain ethane-oxidizing bacteria and ethane and 1,4-Dioxane-co-oxidizing bacteria was 0.09 mg COD/L, which is approximately 20-fold lower than the minimum concentration reported for propane, another common substrate used to promote 1,4-Dioxane biodegradation. The minimum 1,4-Dioxane concentration required to sustain steady-state biomass with 1,4-Dioxane as the sole primary substrate was 1.3 mg COD/L. As 1,4-Dioxane concentrations at most groundwater sites are less than 0.18 mg COD/L, providing ethane as a primary substrate is vital to support biomass growth and consequently enable 1,4-Dioxane bioremediation. [ABSTRACT FROM AUTHOR]

The Well Mitan-1 has achieved a major breakthrough in the exploration of Ordovician subsalt natural gas in the mid-eastern Ordos Basin, demonstrating a high-yield industrial gas flow in fourth member of the Majiagou Formation of Ordovician (O1m4). Despite this success, there are ongoing disputes regarding the origin of the natural gas found in Well Mitan-1. Measured results show that the natural gas in Well Mitan-1 is mainly composed of alkane gas (95.18 %). The gas drying coefficient (C1/C1-5) is measured at 0.947, and the H2S content is 3.49 %, with a small amount of N2 and CO2 in the non-hydrocarbon gas. The carbon isotopic compositions of methane, ethane, and propane in the natural gas are −45.5 ‰, −26.4 ‰, and −24.3 ‰, respectively. Based on the regional geological background, the characteristics of potential source rocks and the geochemical characteristics of natural gas, it is considered that the natural gas in Well Mitan-1 is self-generated and self-accumulated oil-associated gas in Ordovician subsalt carbonate rocks. However, certain geochemical anomalies, such as the lighter methane carbon isotope value (δ13C1) and coal-type gas characteristics in ethane carbon isotope (δ13C2), raise questions. Further insights from thermal simulation experiments on hydrocarbon generation and the analysis of residual gas in rocks suggest a close relationship between the special geochemical characteristics of Well Mitan-1 and the presence of gypsum rocks. The ubiquitous gypsum rock serves a dual purpose: acting as an effective caprock, facilitating the retention of early-generated natural gas, and promoting the generation of heavy hydrocarbon gases (C2+) and H2S. The relatively low H2S content (less than 5 %) and higher C2+ content indicate that thermochemical sulfate reduction (TSR), if present, is not strong enough to significantly impact methane. The δ13C2 is identified as a potentially sensitive parameter for identifying TSR.

Triazine-based covalent organic framework CTF-1 was synthesized via polymerization of 1,4-dicyanobenzene in the presence of zinc chloride. Two different methods of the post-synthesis treatment of the obtained material were compared. It was demonstrated that ultrasonication effectively removes impurities from CTF-1. Adsorption of hydrocarbon gases (methane and ethane) and carbon dioxide was measured at 298 K in a wide pressure range for the first time. Ideal selectivity and IAST values for methane/ethane and methane/CO2 pairs were calculated from the obtained isotherms.

Combining multiple secondary oil recovery (SOR)/enhanced oil recovery (EOR) methods can be an effective way to maximize oil recovery from heavy oil reservoirs; however, previous studies typically focus on single methods. In order to optimize the combined process of ethane-based cyclic solvent injection (CSI) and water/nanoparticle-solution flooding, a comprehensive understanding of the impact of injection pressure, water, and nanoparticles on CSI performance is crucial. This study aims to provide such understanding through experimental evaluation, advancing the knowledge of EOR methods for heavy oil recovery. Three approaches (an ethane-based CSI process, water flooding, and nanoparticle-solution flooding) were applied through a cylindrical sandpack model with a length of 95.0 cm and a diameter of 3.8 cm. Test 1 conducted an ethane-based CSI process only. Test 2 conducted a combination approach of CSI–water flooding–CSI–nanoparticle-solution flooding–CSI. Specifically, the injection pressure of the first CSI phase in Test 2 was gradually increased from 3500 to 5500 kPa. The second and the third CSI phases had the same injection pressure as Test 1 at 5500 kPa. The CSI process ceased once the oil recovery was less than 0.5% of the original oil in place (OOIP) in a single cycle. Results show that the ethane-based CSI process is sensitive to injection pressure. A high injection pressure is crucial for optimal oil recovery. The first CSI phase in Test 2, where the injection pressure was increased gradually, resulted in a 2.9% lower oil recovery and five times as much ethane consumption compared to Test 1, which applied a high injection pressure. It was also found that water flooding improved the oil recovery in the CSI process. In Test 2, the oil recovery factor of the second CSI phase increased by 57% after the water flooding process, which is likely due to the formation of water channels and a dispersed oil phase that increased the contact area between ethane and oil. Although the nanoparticle-solution flooding only had 0.3% oil recovery, after that the third CSI phase stimulated another 10.8% of OOIP even when the water saturation achieved more than 65%. This demonstrated that the addition of nanoparticles can maintain the stability of the foam and enhance the transfer of ethane to the heavy oil. Finally, Test 2 reached a total oil recovery factor of 76.1% on a lab scale, an increase of 45% compared to the single EOR method, which proved the combination process is an efficient method to develop a heavy oil field. [ABSTRACT FROM AUTHOR]

Thanks to investments in diversifying the supply of natural gas, Poland did not encounter any gas supply issues in 2022 when gas imports from Russia were ceased due to the Russian Federation's armed intervention in Ukraine. Over the past few years, the supply of gas from routes other than the eastern route has substantially grown, particularly the supplies of liquefied natural gas (LNG) via the LNG terminal in Świnoujście. The growing proportion of LNG in Poland's gas supply leads to a rise in ethane levels in natural gas, as verified by the review of data taken at a specific location within the gas system over the years 2015, 2020, and 2022. Using measurements of natural gas composition, the effectiveness of the steam hydrocarbon reforming process was simulated in the Gibbs reactor via Aspen HYSYS. The simulations confirmed that as the concentration of ethane in the natural gas increased, the amount of hydrogen produced, and the heat required for reactions in the reformer also increased. This article aims to analyze the influence of the changes in natural gas quality in the Polish transmission network caused by changes in supply structures on the mass and heat balance of the theoretical steam reforming reactor. Nowadays, the chemical composition of natural gas may be significantly different from that assumed years ago at the plant's design stage. The consequence of such a situation may be difficulties in operating, especially when controlling the quantity of incoming natural gas to the reactor based on volumetric flow without considering changes in chemical composition. [ABSTRACT FROM AUTHOR]

Photocatalytic CH4 coupling into high-valued C2H6 is highly attractive, whereas the photosynthetic rate, especially under oxygen-free system, is still unsatisfying. Here, we designed the negatively charged metal supported on metal oxide nanosheets to activate the inert C–H bond in CH4 and hence accelerate CH4 coupling performance. As an example, the synthetic Au/ZnO porous nanosheets exhibit the C2H6 photosynthetic rate of 1,121.6 µmol gcat−1 h−1 and the CH4 conversion rate of 2,374.6 µmol gcat−1 h−1 under oxygen-free system, 2 orders of magnitude higher than those of previously reported photocatalysts. By virtue of several in situ spectroscopic techniques, it is established that the generated Auδ− and O− species together polarized the C–H bond, while the Auδ− and O− species jointly stabilized the CH3 intermediates, which favored the coupling of CH3 intermediate to photosynthesize C2H6 instead of overoxidation into COx. Thus, the design of dual active species is beneficial for achieving high-efficient CH4-to-C2H6 photoconversion. [ABSTRACT FROM AUTHOR]

The efficient conversion of ethane has attracted more and more attention because of the shale gas revolution. The coupling of ethane dehydrogenation (EDH) and benzene alkylation over the 1.5Pt/HZSM-5 realize high activity close to the thermodynamic equilibrium of EDH at 500 ℃ and 0.9 bar ethane partial pressure. Meanwhile, the coupled reaction shows long-term stability during 22 h with a slightly decreased ethane conversion of 0.03% per hour and as high as 42% selectivity of ethylbenzene. Based on various characterization, including XRD, HR-TEM, NH3-TPD, Py-IR, TGA, it is confirmed that the coupling reaction could convert ethylene, formed by EDH over Pt sites, to ethylbenzene via benzene alkylation over Brönsted acidic sites (BAS) subsequently, and suppressing the sintering of Pt species and coke deposition induced by aromatization and deep dehydrogenation, resulting in high activity and long-time steady state. [ABSTRACT FROM AUTHOR]

This study explores the tuning of a Pd/Al2O3 hydrogenation catalyst for the selective removal of trace acetylene from ethylene-rich feeds by coating the catalyst with non-functionalized and functionalized ionic liquids (denoted as SCILL and Advanced SCILL materials, respectively). These materials were tested in an automated continuous hydrogenation rig converting 3300 ppm of acetylene in excess ethylene, a gas mixture mimicking a technical front-end steam cracker feed composition. While the sulfonic-acid-functionalized IL coating resulted in a highly active but very unselective catalyst converting mainly ethylene to ethane, an Advanced SCILL catalyst prepared from a nitrile-functionalized IL reduced the acetylene concentration down to less than 1 ppm, while leaving over 99% of the ethylene untouched. We also examined the potential transformations of the IL layer under reaction conditions by means of 1H NMR. Except for a ketone-functionalized IL, which was inherently labile, all tested ILs primarily underwent C2-ethylation or remained unaltered. Our findings highlight the great potential of functionalized ILs in modifying heterogeneous hydrogenation catalysts.

We use global airborne observations of propane (C3H8) and ethane (C2H6) from the Atmospheric Tomography (ATom) and HIAPER Pole-to-Pole Observations (HIPPO), as well as U.S.-based aircraft and tower observations by NOAA and from the NCAR FRAPPE campaign as tracers for emissions from oil and gas operations. To simulate global mole fraction fields for these gases, we update the default emissions' configuration of C3H8 used by the global chemical transport model, GEOS-Chem v13.0.0, using a scaled C2H6 spatial proxy. With the updated emissions, simulations of both C3H8 and C2H6 using GEOS-Chem are in reasonable agreement with ATom and HIPPO observations, though the updated emission fields underestimate C3H8 accumulation in the arctic wintertime, pointing to additional sources of this gas in the high latitudes (e.g., Europe). Using a Bayesian hierarchical model, we estimate global emissions of C2H6 and C3H8 from fossil fuel production in 2016-2018 to be 13.3 ± 0.7 (95% CI) and 14.7 ± 0.8 (95% CI) Tg/year, respectively. We calculate bottom-up hydrocarbon emission ratios using basin composition measurements weighted by gas production and find their magnitude is higher than expected and is similar to ratios informed by our revised alkane emissions. This suggests that emissions are dominated by pre-processing activities in oil-producing basins.

A pair of simulated left and right circularly polarized ultra‐fast laser pulses of duration 20 femtoseconds that induce a mixture of excited states are applied to ethane. The response of the electron dynamics is investigated within the next generation quantum theory of atoms in molecules (NG‐QTAIM) using third‐generation eigenvector‐trajectories which are introduced in this work. This enables an analysis of the mechanical and chiral properties of the electron dynamics of ethane without needing to subject the C‐C bond to external torsions as was the case for second‐generation eigenvector‐trajectories. The mechanical properties, in particular, the bond‐flexing and bond‐torsion were found to increase depending on the plane of the applied laser pulses. The bond‐flexing and bond‐torsion, depending on the plane of polarization, increases or decreases after the laser pulses are switched off. This is explainable in terms of directionally‐dependent effects of the long‐lasting superpositions of excited states. The chiral properties correspond to the ethane molecule being classified as formally achiral consistent with previous NG‐QTAIM investigations. Future planned investigations using ultra‐fast circularly polarized lasers are briefly discussed. [ABSTRACT FROM AUTHOR]

Converting hydrocarbons and greenhouse gases (i.e., carbon dioxide, CO2) directly into electricity through fuel cells at intermediate temperatures (450 to 550 °C) remains a significant challenge, primarily due to the sluggish activation of C–H and C=O bonds. Here, we demonstrated a unique strategy to address this issue, in which light illumination was introduced into the thermal catalytic CO2 reforming of ethane in the anode as a unique thermo-photo anode process for carbonate-superstructured solid fuel cells. The light-enhanced fuel activation led to excellent cell performance with a record-high peak power density of 168 mW cm−2 at an intermediate temperature of 550 °C. Furthermore, no degradation was observed during ~50 h operation. Such a successful integration of photo energy into the fuel cell system provides a new direction for the development of efficient fuel cells. [ABSTRACT FROM AUTHOR]

New polymeric pipes have been used to overcome difficulties created by metal pipes in gas transmission lines such as corrosion and leakage. In this work, diffusion and solubility cells are designed to determine the diffusivity and possible leakage of methane and ethane gases in the glass-reinforced epoxy (GRE) composite. A composite sample with a diameter of 5.95 mm and thickness of 1.40 mm to determine the diffusivity and a composite powder to estimate the gas solubility are used. The experiments are done under temperatures varied from 25 to 40 ℃ and a pressure of 20 bar. The results show that the diffusivity of both gases increases with increasing temperature; while gas solubility decreases. The highest diffusion coefficient of methane and ethane are observed at 8.23 × 10−11 and 7.94 × 10−11 m2/s at 40 ℃, respectively. Moreover, novel correlations for estimating gas diffusion coefficient and mass flow rate in terms of temperature are developed based on the experimental data with the correlation coefficients (R2) of 0.98 and 1 and the average relative error percent (AREP) less than 4.5% and 0.5%, respectively. Interestingly, CFD (Computational fluid dynamics) results show a good consistency with experimental data for gas concentration profiles through the composite with AREP ranges of 1.95–15.78%. [Display omitted] [ABSTRACT FROM AUTHOR]

The efficacy of gaseous solvents in enhancing oil recovery (EOR) in unconventional reservoirs and the influence of operational and design parameters are still debated among the oil recovery research community. This work investigated the recovery-enhancing capabilities of two potent gaseous solvents, CO² and ethane, in tight core samples. Laboratory huff-n-puff (H-n-P) experiments were conducted under three miscibility conditions to investigate the influence of the key operating parameters and the dependency of their impact on the miscibility conditions and gas composition. The results show that oil recovery increased with increasing pressure from below (BM) to above (AM) miscibility pressure in a non-linear trend, irrespective of the gas composition. Furthermore, the influence of the soak period was noticeably dependent on the miscibility condition, specifically more remarkable under AM conditions and less apparent under BM conditions. Likewise, the effect of the production period was more pronounced at AM conditions for both gases. Finally, the impact of rock surface area-to-volume (SA/V) was only observed at BM, where both gases recovered more oil in the core samples with high SA/V. In general, ethane showed a higher efficacy for oil recovery than CO2; CO2 recovered 21%e70% of oil in small core samples, while ethane could recover 32%e88%. The highest recovery was achieved with ethane injected under AM conditions, with a prolonged soak time, a short production period and into a core sample with a high SA/V. We believe the findings from this work will help better understand and design H-n-P EOR projects. [ABSTRACT FROM AUTHOR]

Selective adsorption using nanoporous materials is an efficient strategy for separating gas mixtures. In a nanoporous material, pores can exist in different shapes and can have different degrees of inter-connectivity. In recent studies, both pore connectivity and tortuosity have been found to affect the adsorption and dynamical properties of ethane and CO2 in silicalite differently. Here, using Monte Carlo simulations, we investigate if these two attributes can affect the selective adsorption of one component from a mixture of ethane and CO2 in silicalite. For this, the adsorption of an equimolar mixture of ethane and CO2 is simulated in 12 models of silicalite—SnZm (n, m = 0, 1, 2, 3 or 4; with n and m denoting, respectively, the fraction (out of 4) of straight and zigzag channels of silicalite that are available for adsorption)—differing in degrees of pore connectivity and tortuosity. The adsorption selectivity in this system is found to exhibit a reversal with the adsorption dominated by ethane at low pressures (below ~1 atm) and by CO2 at higher pressures (above ~10 atm). Pore connectivity is found to suppress the selective adsorption of CO2 at higher pressures and also shifts the selectivity reversal to higher pressures. The selectivity reversal results from a competition between the polarizability-affected adsorption at lower pressures and efficient packing at higher pressures. The efficient packing of CO2 is a compounded effect resulting from the larger effective pore volume available for CO2 due to its stronger interaction with the pore surface and smaller molecular volume. CO2 molecules show a preference to adsorb in non-tortuous pores, and this preference is found to be stronger in the presence of ethane. The effects of pore connectivity and tortuosity elucidated here should be applicable to a wide range of natural and engineered nanoporous materials, and this knowledge could be used to identify materials with better capability for separating and storing CO2 based on their pore attributes. [ABSTRACT FROM AUTHOR]