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Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tight sandstone reservoirs are significant sources of natural gas reserves. As traditional reserves become increasingly scarce and costly, optimizing the development of these reservoirs becomes crucial. This study introduces a novel two-phase gas–water flow model for single wells, incorporating both Darcy and non-Darcy flow equations. These equations are derived from mass conservation and momentum principles for both gas and water phases. Using data from a real tight gas well, our model, which includes stress-sensitive phases for gas and water, outperforms traditional Darcy flow models. Specifically, the average relative deviations in daily production rates were 0.1815% for gas and − 0.2677% for water, which are significantly smaller compared to traditional Darcy flow models. Further application of the non-Darcy flow model reveals strategies to enhance well performance. For example, mitigating liquid lock damage within a 2 m radius near the well could restore the permeability from 0.045 to 0.143 mD, thereby tripling the daily gas production. This non-Darcy flow model is easy to implement and shows significant potential in forecasting production yields in tight sandstone reservoirs, highlighting its importance in the petroleum and natural gas industry. [ABSTRACT FROM AUTHOR]

Using the staggered adoption of natural gas in China, we examine how energy substitution policy affects firm innovation. We find that firm innovation significantly increases following the passage of energy substitution policy. Moreover, the positive effect of energy substitution policy on firm innovation is more pronounced when firms are private, small-sized, located in low economic development regions. The channel test shows that firms adopting energy substitution policy can improve financial condition. Finally, we find that energy substitution policy has positive and significant effect on innovation productivity. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The deep-processing utility of pure hydrogen sulfide (H2S) is a significant direction in natural gas chemical industry. Herein, a brand-new strategy of H2S conversion by a,b-unsaturated carboxylate esters into thiols or thioethers using task-specific carboxylate ionic liquids (ILs) as catalyst has been developed, firstly accomplishing the phase separation of product and catalyst without introducing the third component. It can be considered as a cascade reaction in which the product selectivity can be controlled by adjusting the molar ratio of H2S to a,b-unsaturated carboxylate esters. Also, the effects of ILs with different anions and cations, intermittent feeding operations, as well as pressure time kinetic behaviors on cascade reaction were investigated. Furthermore, the proposed interaction mechanism of H2S conversion using butyl acrylate catalyzed by [Emim][Ac] was revealed by DFT-based theoretical calculation. The approach enables the selfhase separation promotion of catalyst and product and achieves 99% quantitative conversion under mild conditions in the absence of solvent, making the entire process ecologically benign. High-efficiency reaction activity can still be maintained after ten cycles of the catalyst. Therefore, the good results, combined with its simplicity of operation and the high recyclability of the catalyst, make this green method environmentally friendly and costeffective. It is anticipated that this self-separation method mediated by task-specific ILs will provide a feasible strategy for H2S utilization, which will guide its application on an industrial scale. [ABSTRACT FROM AUTHOR]

The electricity system and the industrial sector interrelate on the path to decarbonization. The study addresses the drivers and environmental pressure within the industrial sector on the National Electricity System (NES). This article aims to characterize the metabolic pattern of the NES and the industrial sector using the Multiscale Integrated Analysis of Social and Ecological Metabolism (MuSIASEM) from a bioeconomic perspective to identify fields of opportunity in the regulatory policy instruments. A set of extensive and intensive variables (2019) on energy, production factors, and emissions was used at different hierarchical levels based on both subsectors. Our results show that the NES used primary energy sources (PES) and secondary energy carriers to fulfill its functions, of which 72% were domestic sources and 28% were imported. México imported 79.5% of the natural gas (NG) for electricity generation. However, there are favorable conditions for renewable PES to increase the installed capacity of solar plants between 3 and 4 orders of magnitude and 2–3 in wind power from the current capacity. NES's energy consumption per hour of human time is 17,388 MJ/h, with 65% being the heat equivalent to a total energy input consumed of 2139 PJ/y. Public plants contributed 43.7% to the generation, and the independent and self-supply producers the rest. End uses needed the supply of 69.3% of electricity from baseload plants. Sixty-three percent of the metabolic pattern of the industrial sector is based on heat and fuel processes, which depend on NG imports. The NES is reorganizing and recovering its energy autonomy. [ABSTRACT FROM AUTHOR]

AbstractThe creation, dissemination, and application of knowledge are crucial for achieving sustainable development and have been at the heart of international development efforts since World War II. In conventional international development cooperation, the Global North is portrayed as the provider of knowledge and material assistance, with the South often perceived as a more passive receiver. This approach perpetuates hierarchical knowledge-power relations, as what is considered the ‘best practices’ are usually based on experiences, ideologies, and ideals from the North. This paper critically examines the current role of Western development actors as providers of knowledge and policy, specifically in the formulation of good governance for natural gas resources in Tanzania. Following significant offshore natural gas discoveries between 2010–2015, Tanzania has garnered the attention of international energy companies, foreign donors, technical advisors, and consultants, all offering guidance and capacity-building expertise to ready the country for production. Drawing on interviews with key actors supported by secondary sources, this analysis depicts how hierarchical knowledge relations persist, but also highlights the contested and evolving nature of what constitutes good governance of natural gas resources. The paper underscores how context matters in petroleum resource governance and, more broadly, the necessity for contextualising knowledge in international development cooperation. [ABSTRACT FROM AUTHOR]

The utilization of hydrogen (H 2) instead of natural gas (NG) in high-temperature industries has the potential to significantly reduce global greenhouse gas emissions. To obtain detailed information on the combustion characteristics in a semi-industrial air–fuel setup, comprehensive experiments and 3D CFD simulations are performed on a low-swirl burner inside a combustion chamber. The H 2 enrichment in NG of 0–100 vol % is analyzed at burner powers of 75–120 kW and temperatures of 900–1400 ° C. The process efficiency increases by up to 10 percentage points due to higher temperatures and enhanced heat transfer. Furthermore, up to 20% lower NO x emissions are observed, which is attributed to a significant change in the flow and flame characteristics. For the first time, OH* chemiluminescence imaging is successfully applied to validate RANS simulations of an industrial turbulent flame. Further research should be directed toward evaluating OH* reaction kinetics in both laminar and turbulent NG/H 2 combustion setups. • H 2 enrichment of up to 100 vol% at powers of 75–120 kW and temperatures of 900–1400 °C. • Effect on furnace temperatures, heat transfer characteristics and NO x emissions. • Accurate and efficient 3D RANS simulation model for a detailed flame evaluation. • Novel validation method for industrial-type flame simulation using OH* imaging. • Correspondence of NG/H 2 induced OH*-chemiluminescence with 3D numerical OH*-results. [ABSTRACT FROM AUTHOR]

We investigate the challenges and options for repurposing existing natural gas pipelines for hydrogen transportation. Challenges of re-purposing are mainly related to safety and due to the risk of hydrogen embrittlement of pipeline steels and the smaller molecular size of the gas. From an economic perspective, the lower volumetric energy density of hydrogen compared to natural gas is a challenge. We investigate three pipeline repurposing options in depth: a) no modification to the pipeline but enhanced maintenance, b) use of gaseous inhibitors, and c) the pipe-in-pipe approach. The levelized costs of transportation of these options are compared for the case of the German Norddeutsche Erdgasleitung (NEL) pipeline. We find a similar cost range for all three options. This indicates that other criteria such as the sunk costs, public acceptance, and consumer requirements are likely to shape the decision making for gas pipeline repurposing. • Three options for repurposing a natural gas pipeline to use with hydrogen are considered. • The levelized costs of hydrogen transport of each option are calculated. • The calculations are for the case study of the NEL pipeline in Germany. • Levelized costs of hydrogen transport are similar between the three options. [ABSTRACT FROM AUTHOR]

Hydrogen has enormous potential for sustainable future mobility. However, current challenges include high production costs and storage issues, necessitating further engineering advancements. Compressed Natural Gas is also a viable alternative, as it is easily produced and stored but suffers from slow flame speed-related issues. Improving its combustion characteristics by enrichment using a small fraction of hydrogen holds significant promise. Inducting hydrogen directly into the combustion chamber improves the engine's volumetric efficiency, eliminating the backfire issues. However, it is crucial to understand the test fuel's jet and mixing characteristics before engine investigations. This study aims to analyse the macroscopic jet characteristics of hydrogen, compressed natural gas and hydrogen-enriched compressed natural gas in realistic engine-like conditions in a constant volume spray chamber at various fuel injection pressures and varying ambient pressures and temperatures. Fuel injection pressures for hydrogen and CNG were varied at 16, 32, and 48 bar, and ambient pressures in the constant volume spray chamber were set at 4- and 8-bar and ambient temperatures at 25 and 100 °C. The results showed hydrogen exhibited ∼2% shorter jet penetration length than compressed natural gas. Depending on the test conditions, hydrogen showed a ∼1–3% higher jet area than CNG due to its higher diffusivity and faster mixing. This higher jet area improved fuel-air mixing of hydrogen with air compared to CNG. The effect of hydrogen enrichment with CNG on their jet characteristics was also analysed for 8 bar FIP. 10% (v/v), 20%, and 40% hydrogen-enriched compressed natural gas did not significantly alter the macroscopic jet characteristics from baseline compressed natural gas. [Display omitted] • Macroscopic spray characterization of hydrogen and CNG in CVSC using Schlieren. • FIP for hydrogen and CNG was varied at varying ambient pressures/temperatures. • Hydrogen exhibited a ∼2% shorter spray jet penetration length than CNG. • Hydrogen showed a larger spray area than CNG. • Hydrogen enrichment of CNG didn't alter macroscopic spray characteristics. [ABSTRACT FROM AUTHOR]

A well-connected network formed by multi-scale fractures is a key factor in the formation of high-quality reservoirs and the achievement of high and stable oil and gas production in tight sandstones. Taking the Upper Paleozoic of the Qingshimao gas field in the Ordos Basin, China, as an example, based on data from image logs, cores, and thin sections, fine quantitative characterization of multi-scale natural fractures in tight sandstone reservoirs was carried out. We also established a method for dividing network patterns of multi-scale fractures and discussed the effect of each fracture network pattern on the gas enrichment and production capacity. Results indicate regular changes in the length, density, aperture, porosity, permeability, and connectivity of natural fractures at different scales. Based on the spatial combination patterns and connectivity of fractures of different scales, four types of fracture network patterns were established: multi-scale fracture network with high density and multi-orientations, multi-scale fracture network with moderate-high density and dual orientations, small-scale fracture network with moderate density and dual orientations, small-scale fracture network with low density and single orientation. The first fracture network pattern can destroy the integrity of the cap layer, causing natural gas leakage. The second fracture network pattern is a favorable area for natural gas enrichment. The third fracture network pattern requires the use of hydraulic fracturing to obtain commercial airflow. The fourth fracture network pattern has little effect on reservoir control and storage. The study of natural fractures in tight sandstone reservoirs is usually based on a single-scale perspective. Understanding the development characteristics of multi-scale fractures and their controlling effects on the reservoir helps to comprehensively understand the spatial configuration relationship of multiscale fracture network structure patterns and promotes the development of multi-scale fractures in tight reservoir research. [ABSTRACT FROM AUTHOR]

Enriching methane from sources such as natural gas, biogas, and coalbed methane is a valuable gas separation endeavor, given methane as a cleaner and more sustainable fuel resource. Pressure swing adsorption (PSA) is widely regarded as a mature technology for this purpose. The essence of the mathematical model is to capture the fundamental aspects of the problem, enabling an accurate description of the system. This review summarizes recent trends in the mathematical modelling of PSA for methane enrichment. It provides a comprehensive compilation of numerical modelling and simulation studies, with a critical emphasis on methane enrichment applications. A rigorous mathematical model describing the adsorption phenomenology in a packed bed column is presented, incorporating mass, momentum, and energy balances, which serve as the fundamental framework for the cyclic adsorption process. Key analyses and performance metrics of PSA systems are detailed through examples from the literature. A case study based on a single column is presented to exemplify the mathematical modelling pathway and serve as a basis for model validation. The paper concludes by highlighting instructive avenues for future research directions and development in this area. [ABSTRACT FROM AUTHOR]

Highlights This work investigates the comprehensive exploration of transport properties in natural rubber/graphene oxide‐silica hybrid core‐shell (NR/GSC) nanocomposites, focusing on diffusion, sorption behavior, swelling parameters, and gas permeability. The study evaluates the performance of the composite membranes concerning oxygen and nitrogen gas permeability (71.3% and 68.48% reduction, respectively). The experimental results reveal the sorption behavior, swelling parameters, and transport coefficients of NR/GSC composites, providing valuable insights into the material's behavior in different environments. Among various compositions, GSC10 stands out as the optimal composition, exhibiting superior diffusion and gas permeability behavior compared to other compositions. How the filler geometry and concentration are interconnected on the transport properties is carefully dissected, offering a deeper comprehension of the correlation between filler characteristics and composite performance. The study predicts that the Peppas‐Sahlin model and Affine model for mole percentage solvent uptake and molecular mass between successive crosslinks, respectively, best fit experimental values. This work contributes to the growing knowledge in the field of nanocomposites, providing a meticulous perspective on the transport properties of NR/GSC membranes and emphasizing the superior performance of the GSC10 composition. NR/GSC hybrid nanocomposites showed reduced solvent uptake. A 71.3% reduction in oxygen and 68.48% reduction in nitrogen permeation. Theoretically modeled using Peppas‐Sahlin, Korsmeyer‐Peppas, Nielsen and s GSC nanoparticles shows excellent dispersion in NR matrix Enhanced fuel efficiency and reduced environmental footprint in tire manufacturing technology. [ABSTRACT FROM AUTHOR]

It is of great significance for deep oil and gas exploration to understand the origin and evolution behind overpressure. Overpressure occurs in the deep Shahezi Formation of Xujiaweizi fault depression. However, due to limited degree of exploration, there are some problems in the study area, such as unclear understanding of the origin of overpressure and the vague investigation of overpressure evolution. To clarify the impact of overpressure on oil and gas migration and accumulation in the study area, this study focuses on the research of the origin and evolution of overpressure in the Shahezi Formation of the study area, utilizing single well logging parameters and combining methods such as microthermometry of fluid inclusions, laser Raman spectrum, and basin simulation. The results show that the overpressure of the Shahezi Formation in Xujiaweizi fault depression is primarily generated by hydrocarbon generation pressurization, and the evolution of overpressure is closely related to hydrocarbon generation. The development of overpressure can be divided into two evolutionary stages: early hydrocarbon generation pressurization and late uplift release, with slight variations in different regions. Tight glutenite gas reservoirs in the Shahezi Formation are characterized by continuous charging. The overall charging period ranges from the late Denglouku to the early Mingshui (110‐67 Ma ago). There is an obvious paleo‐overpressure during the gas reservoir formation period. The gas generation period of source rocks occurred approximately 125‐60 Ma ago, and the main gas generation period (112‐67 Ma ago) highly coincides with the period of natural gas charging. The anomalously high pressure during the accumulation period is considered the significant driving force for natural gas charging. In addition, the sustained effect of overpressure provides better conditions for the preservation of tight gas reservoirs within the source. The results of the study are of guiding significance for the in‐depth exploration and development of deep tight sandstone gas in the Shahezi Formation of Xujiaweizi fault depression. [ABSTRACT FROM AUTHOR]

The addition of hydrogen in a dual-fuel mode based on natural gas and diesel offers great potential for improving engine efficiency and reducing emissions. Therefore, detailed numerical simulations have been used to explore the effects of soot formation characteristics of natural gas-diesel dual-fuel engines doped by hydrogen at elevated pressure. Numerical simulations are compared with available experimental data, the effects of H 2 addition on soot formation in laminar CH 4 + n-heptane, H 2 + CH 4 + n-heptane, FH 2 + CH 4 + n-heptane diffusion flames at 2, 4, 6 and 8 atm are simulated, FH 2 is added to separate the H 2 chemical effects. The results show that the dilution and thermal effects of H 2 inhibit soot formation, while the chemical effects of H 2 promote soot formation under different pressures. The addition of H 2 increases the concentration of H and OH radicals, which promotes the formation of C 2 H 2 and benzene (A1). By simplifying the reaction path and analyzing the production rate of A1, the mechanism of H 2 addition to promote A1 formation is illustrated. The concentrations of polycyclic aromatic hydrocarbon (PAH) pyrene (A4), benzo(ghi)fluoranthene (BGHIF) and benzo(a)pyrene (BAPYR) are inhibited at higher pressures that result in lower inception and condensation rates. Therefore, the increase of hydrogen abstraction acetylene addition (HACA) rate is the main reason for the increase of soot formation under chemical effects. While the O 2 oxidation rate decreases and the OH oxidation rate increases, that is due to the decrease of O 2 concentration and the increase of OH concentration in the soot formation area under chemical effects. • The dilution, thermal and chemical effects of H 2 addition on soot formation in methane/n-heptane flame were investigated at high pressures. • Key specie A1 formation pathways and related reactions were confirmed when H 2 addition. • The changes of soot formation and oxidation mechanisms with H 2 addition in different pressure were explained. [ABSTRACT FROM AUTHOR]

In this study, three premixed swirl gas turbine nozzles with different fuel injection hole sizes were designed to optimize combustion characteristics influenced by changes in the hydrogen mixing ratio. Experiments involved increasing the hydrogen volume fraction of the fuel from 0 to 60%. The amount of fuel supplied through the pilot flow was increased to suppress combustion instability. The OH* chemiluminescence technique was introduced to analyze flame structure. To understand combustion instability, time delay and time-delay distribution were derived from flame structure analysis and applied to the 1D thermoacoustic model. The results indicated that the amount of fuel required for pilot injection with increasing hydrogen ratio varied with fuel hole size. It was also observed that changes in fuel hole size significantly affected flame characteristic length. Findings from the 1D thermoacoustic analysis confirmed that fuel hole size variation altered combustion instability characteristics by influencing time delay and time-delay distribution variation. [Display omitted] • This study investigated the impact of fuel hole size for H 2 co-firing. • Increase in H 2 fraction reduced flame length and heat release distribution. • Fuel hole size variation affected time delay and its distribution. • Changing the time delay and its distribution influenced combustion instability. [ABSTRACT FROM AUTHOR]

One of the current trends in the complex processing of fine dust from copper smelters is their direct leaching with sulfuric acid. As practical results show, high reliable technological parameters are not achieved due to the high content of arsenic in dust. During sulfuric acid leaching of dust, arsenic is distributed between the lead cake and the solution at a ratio of 40 and 60%, respectively. The redistribution of arsenic between leaching products significantly reduces the technological performance and leads to the accumulation of arsenic in the technological scheme. The paper presents the results of comprehensive studies of the elemental and phase composition of fine dust from one of the copper smelters in Kazakhstan. In the initial dust, along with the main phases presented in the form of lead and zinc sulfate, the following typical components were found: oxides of copper, lead, zinc and copper and zinc ferrites. Arsenic is found in two forms—As(III) and As(V). The laboratory installation and technique for conducting reduction roasting of dust with natural gas are presented. The influence of roasting duration, temperature and natural gas consumption on the extraction of arsenic from dust was studied. It has been established that almost complete, up to 99%, extraction of arsenic from dust is achieved with optimal technological roasting parameters: duration τ = 40 min.; natural gas consumption is 1.5 times higher than the stoichiometrically required amount for the reduction of As2O5, and temperature 500 °C. [ABSTRACT FROM AUTHOR]

Hydrogen, as an energy carrier, is attractive to many stakeholders based on the assumption that the extensive global network of natural gas infrastructure can be repurposed to transport hydrogen as part of a zero‐carbon energy future. Therefore, utility companies and governments are rapidly advancing efforts to pilot blending low‐carbon hydrogen into existing natural gas systems, many with the goal of eventually shifting to pure hydrogen. However, hydrogen has fundamentally different physical and chemical properties to natural gas, with major consequences for safety, energy supply, climate, and cost. We evaluate the suitability of using existing natural gas infrastructure for distribution of hydrogen. We summarize differences between hydrogen and natural gas, assess the latest science and engineering of each component of the natural gas value chain for hydrogen distribution, and discuss proposed solutions for building an effective hydrogen value chain. We find that every value chain component is challenged by reuse. Hydrogen blending can circumvent many challenges but offers only a small reduction in greenhouse gas emissions due to hydrogen's low volumetric energy density. Furthermore, a transition to pure hydrogen is not possible without significant retrofits and replacements. Even if technical and economic barriers are overcome, serious safety and environmental risks remain. [ABSTRACT FROM AUTHOR]

Accurately determining if the sample parameters from a natural gas pipeline's sampling system reflect the fluid characteristics of the main pipe has been a significant industry concern for many years. In this paper, samples of natural gas in a horizontal pipeline are investigated. CFD is used in this work and the turbulence is considered in the simulation. Firstly, the critical diameter for particles affected by gravity within such pipeline is determined. And then, the effects of the operation pressure and velocity of sampling branches on sample parameters, and the influence of particle density on these sample parameters, are analyzed. Finally, four different structures of sample branches for natural gas in a horizontal pipeline are compared. It is found that 100 μm is the critical diameter at which particles are affected by gravity; the operating pressure of the sampling branch has a significant impact on the particle mass concentration. The particle density has little impact on the sampling system. Overall, the design of the sampling branches does not cause significant sampling errors. This study provides guidance for optimal sampling in existing natural gas pipelines and enables effective monitoring of particle impurity content and properties in natural gas. [ABSTRACT FROM AUTHOR]

This study explores the potential role of hydrogen in decarbonizing the transport sector in Uzbekistan by examining different aspects of the country's energy system and transport final use. In road transport, Uzbekistan has already gained experience with the use of alternative fuels through the "Compressed Natural Gas—Mobility" initiatives and has achieved a fleet coverage of 59%. These existing frameworks and knowledge can ease the integration of hydrogen into road transport. The rail sector also has the potential for hydrogen uptake, considering that 47% of rail lines are not electrified. The results of this study indicate that powering all CNG vehicles with a 10% hydrogen blend (HCNG) could reduce road transport emissions by 0.62 MtCO2eq per year, while replacing diesel trucks with hydrogen-based vehicles could contribute to an additional reduction of up to 0.32 MtCO2eq per year. In rail transport, hydrogen-powered trains could reduce emissions in non-electrified lines by up to 0.1 kgCO2eq/km of journey. In assessing the potential infrastructure for hydrogen logistics, this study also identifies opportunities for hydrogen export by repurposing the existing natural gas infrastructure. Focusing on Uzbekistan, this study provides a regional perspective on the potential for the integration of hydrogen into the transport sector in Central Asia. [ABSTRACT FROM AUTHOR]

Following the required adjustments made by the European Union (EU) to adequately absorb the negative social and economic impacts of the COVID-19 pandemic, the EU is once again confronting a crisis. The extended fiscal instability and environmental imbalance resulting from the energy crisis, primarily caused by rising energy prices owing to geopolitical upheavals (the Russian invasion in Ukraine), have been compounded by rising inflation. The main research objective of this paper is the analysis and evaluation of the effects of the current energy crisis on the Greek economy through the perspective of energy poverty, energy dependence, and climate change. Greece has been negatively impacted by the significant rise in energy costs. In 2022, the percentage of the general population that faced difficulties in paying energy bills exceeded the European average, reaching the level of 34.1%, while almost 19% of the population could not keep their homes sufficiently warm. Additionally, in 2022, Greece was one of the countries most energy-dependent on Russia. Greece achieved most of its targets regarding climate change, with the most representative example being the reduction of GHG emissions by 42% from 2000 to 2022. However, this reduction did not come from the successful green transformation of the Greek economy, but instead was due to the reduction in overall energy consumption that came from the prolonged economic crisis, combined with the restrictions of the COVID-19 pandemic. Nevertheless, the majority of Greek buildings are still not considered to be energy efficient, while the transportation industry continues to rely heavily on oil, coal, and natural gas. [ABSTRACT FROM AUTHOR]

CO2 is not only the main gas that causes the greenhouse effect but also a resource with abundant reserves, low price, and low toxicity. It is expected to become an important "carbon source" to replace oil and natural gas in the future. The efficient and clean resource utilization of CO2 has shown important scientific and economic value. Making full use of abundant CO2 resources is in line with the development direction of green chemistry and has attracted the attention of scientists. Environmentally friendly ionic liquids show unique advantages in the capture and conversion of CO2 due to their non-volatilization, designable structure, and good solubility, and show broad application prospects. The purpose of this paper is to discuss the research on the use of an ionic liquid as a catalyst to promote the synthesis of various value-added chemicals in CO2, hoping to make full use of CO2 resources while avoiding the defects of the traditional synthesis route, such as the use of highly toxic raw materials, complicated operation, or harsh reaction conditions. The purpose of this paper is to provide reference for the application and development of ionic liquids in CO2 capture and conversion. [ABSTRACT FROM AUTHOR]

Blending a specific proportion of hydrogen into a natural gas (NG) pipeline network is an effective strategy for achieving long-distance, large-scale, and cost-effective hydrogen transport. Static mixers played a crucial role in this process. In this study, a coaxial shear static mixer with ring-shaped structures instead of turbulence elements is proposed. The mixer exhibited favorable mixing performance and low pressure loss. The flow characteristics of NG and hydrogen within the mixer were investigated with computational fluid dynamics (CFD) methods. The effects of the number of cavities, hydrogen pipe diameter, hydrogen blending ratio and pressure on the mixer performances were investigated, taking into account both mixing uniformity and pressure loss. When the number of cavities in the coaxial shear mixer increases to 48, the mixing uniformity reaches 95.43% (SMX is 95%), and the pressure loss is 67.02 Pa (SMX is 500 Pa). • High mixing uniformity and low pressure loss in the new coaxial shear mixer. • Effects of structural and operating parameters on mixer performance analyzed. • Coaxial shear mixer performs better than SMX mixer. [ABSTRACT FROM AUTHOR]

Although low emission hydrogen has the prospect of huge growth in the future, the cost challenge hinders the deployment and makes it weak in the global market share. Green hydrogen has the advantage of zero carbon emission and has achieved rapid development with the support of renewable energy. Limited by investment, electricity and technology, the large-scale application of green hydrogen faces challenges in the short term. Blue hydrogen comes from natural gas reforming, and its output is guaranteed. However, its production reaction requires high energy consumption and additional carbon emission treatment, resulting in insufficient sustainability. To solve the problem of high-efficiency and large-scale production of low emission hydrogen, a hydrogen co-production scheme combining photovoltaic electrolysis and natural gas reforming with CCS was proposed in this study. Electrolytic hydrogen production, natural gas autothermal reforming, CO 2 sequestration and saline purification in the cogeneration hydrogen production system are coupled by energy and materials such as electricity, O 2 , CO 2 and water. The scheme is applied in Sichuan-Chongqing region to verify the feasibility and effectiveness. The results show that the proposed hydrogen co-production scheme can achieve cost reduction of up to 16.4%, and has long-term development prospects. [Display omitted] • Identifies the development status and bottlenecks of low-emission hydrogen. • Proposes a zero carbon emission co-production scheme of green and blue hydrogen. • Verifies the feasibility and benefit of the scheme in Sichuan-Chongqing region. [ABSTRACT FROM AUTHOR]

Chemical looping dry reforming of methane (CLDRM) using perovskites as a catalyst is considered a promising option for producing hydrogen from biogas. In this work, the life-cycle performance of a system compiling a CLDRM unit paired with a water gas shift unit, a pressure swing adsorption unit, and a combined cycle scheme to provide steam and electricity was assessed. The main data needed to reflect the behavior of the reforming reaction was obtained experimentally and implemented in an Aspen Plus® simulation. Inventory data was obtained through process simulation and used to assess the environmental performance of the process in terms of carbon footprint, acidification, freshwater eutrophication, ozone depletion, photochemical ozone formation, and depletion of minerals and metals. Overall, the environmental viability of the production of green hydrogen from biogas was found to be heavily dependent on the biogas leakage in anaerobic digestion plants. The CLDRM system was benchmarked against a conventional DRM implementation for the same feedstock. While the conventional DRM plant environmentally outperformed the perovskite-based CLDRM, the latter might present advantages from an implementation point of view. [Display omitted] • Scaled-up chemical looping dry reforming of biogas for hydrogen production was simulated. • The life-cycle performance of the configuration with a perovskite catalyst was assessed. • Environmental hotspots refer to biogas leakage, natural gas processes, and catalyst metals. • Environmental advantages of conventional dry reforming were linked to heat integration. • Green hydrogen qualification requires avoiding leakages from anaerobic digestion plants. [ABSTRACT FROM AUTHOR]

In this work, we investigate the electrochemical separation of hydrogen from a 10% H 2 /methane natural gas blend using a single cell experimental setup for electrochemical hydrogen pumping (EHP). Results show that the overall efficiency for hydrogen separation is high, ranging from about 87% at 0.2 A/cm2 to 75% at 0.6 A/cm2. In addition, we develop a zero-dimensional model for the hydrogen separation process including the membrane permeation of H 2 as well as CH 4 , N 2 , and CO 2 as the main components in natural gas. We derive analytical expressions for the permeability of these gases as a function of temperature and membrane humidity using available permeability data. Although the presence of dilutive inert gases poses a challenge, the modelled data indicate that it should be possible to produce fuel cell quality hydrogen using a single hydrogen separation stage. Importantly, this indicates technological feasibility of distributing hydrogen for use in fuel cells through existing natural gas infrastructure. Extension of this research to combined hydrogen separation and compression within the same EHP unit is recommended as future work. • An analytical electrochemical hydrogen pump (EHP) model is developed and validated. • Single cell EHP experiments show high overall hydrogen separation efficiency. • Expressions are developed for the permeability of H 2 , N 2 , CH 4 , and CO 2 in Nafion. • The effects of EHP membrane and operating parameters on H 2 purity are examined. • Fuel cell grade hydrogen extraction is shown to be feasible through system tuning. [ABSTRACT FROM AUTHOR]

Prevention of hydrate plugs during oil and natural gas transportation in the pipeline network is challenging and may require significant operating expenditure. Synthetic inhibitors are deployed in large volumes to inhibit hydrate formation, and these inhibitors are highly expensive and toxic to the environment. Consequently, this study investigates the effectiveness of cassava (Manihot esculenta) leaf extract as an environmentally friendly, biodegradable, and cost-efficient novel green inhibitor of gas hydrate. Cassava is a tropical plant cultivated majorly in Nigeria, and its leaf is, in almost all cases, discarded as waste. In this study, an extract is made from cassava leaf and used in varying weight percentages as hydrate inhibitors using a locally fabricated mini flow. Results show cassava leaf extract (CLE) performed significantly better than conventional inhibitor methanol (MeOH) at a higher weight percentage. The presented results show that at varying weights of 0.02 wt%, 0.04 wt%, and 0.06 wt% of the CLE, the final pressures were found to be the pressures were found to be 29 psi, 27 psi, and 24 psi, respectively. These pressures indicates that more gas was converted to hydrate with the lower pressure value in the system. These results were compared with 2 wt%, 4 wt%, and 6 wt% of MeOH, with a differential pressure of 28 psi, 46 psi, and 50 psi, respectively. CLE's gas hydrate inhibition capacity was found at pressure conditions of 51.7 psi, 55 psi, and 60 psi for 0.02 wt%, 0.04 wt%, and 0.06 wt%, respectively. These results demonstrate that CLE performed significantly better than methanol as a gas hydrate inhibitor, despite being used in a much lower dosage than methanol, which had inhibition pressures conditions of 53.3 psi, 23.3 psi, and 16.7 psi for 2 wt%, 4 wt%, and 6 wt%, respectively. [ABSTRACT FROM AUTHOR]

If dihydrogen (H2) becomes a major part of the energy mix, massive storage in underground gas storage (UGS), such as in deep aquifers, will be needed. The development of H2 requires a growing share of H2 in natural gas (and its current infrastructure), which is expected to reach approximately 2% in Europe. The impact of H2 in aquifers is uncertain, mainly because its behavior is site dependent. The main concern is the consequences of its consumption by autochthonous microorganisms, which, in addition to energy loss, could lead to reservoir souring and alter the petrological properties of the aquifer. In this work, the coinjection of 2% H2 in a natural gas blend in a low-salinity deep aquifer was simulated in a three-phase (aquifer rock, formation water, and natural gas/H2 mix) high-pressure reactor for 3 months with autochthonous microorganisms using a protocol described in a previous study. This protocol was improved by the addition of protocol coupling experimental measures and modeling to calculate the pH and redox potential of the reactor. Modeling was performed to better analyze the experimental data. As in previous experiments, sulfate reduction was the first reaction to occur, and sulfate was quickly consumed. Then, formate production, acetogenesis, and methanogenesis occurred. Overall, H2 consumption was mainly caused by methanogenesis. Contrary to previous experiments simulating H2 injection in aquifers of higher salinity using the same protocol, microbial H2 consumption remained limited, probably because of nutrient depletion. Although calcite dissolution and iron sulfide mineral precipitation likely occurred, no notable evolution of the rock phase was observed after the experiment. Overall, our results suggested that H2 can be stable in this aquifer after an initial loss. More generally, aquifers with low salinity and especially low electron acceptor availability should be favored for H2 costorage with natural gas. [ABSTRACT FROM AUTHOR]

Previous research has indicated that hydrogen decreases the fracture toughness of gas‐transmission pipeline steels. This study produced two values of fracture toughness for the X65 steel in the Dampier Bunbury natural gas‐transmission pipeline in air (JQ of 590 and 778 kJ m−2; equivalent to KQ of 369 and 487 MPa√m$\sqrt{} \text{m}$) and two essentially American Society for Testing of Materials–valid values of fracture toughness of KJ1C of 150 and 189 MPa√m$\sqrt{} \text{m}$ for X65 subjected to in situ hydrogen charging thought to be equivalent to a hydrogen gas pressure of 200 bar. The fracture toughness for hydrogen‐charged specimens was lower than in air. The large spread of the fracture toughness in air was attributable to the fact that these JQ values were dependent on testing details. The spread of fracture toughness values in hydrogen was attributed to the variability of fracture toughness in hydrogen under these hydrogen‐charging conditions. There was considerable stable crack growth. The energy for stable crack growth increased with crack length. The fractography in the presence of hydrogen showed significant ductility, consistent with hydrogen‐assisted plastic fracture. The values of fracture toughness in air and with hydrogen were consistent with literature values. [ABSTRACT FROM AUTHOR]

This study investigates how carbon dioxide emissions, natural gas, energy consumption, energy investment, coal and crude oil, and per capita exports affected the economic growth of the United States from 1993 to 2023 using the Vector Error Correction (VEC) model. The findings highlight the importance of exports and energy investment in driving both short- and long-term economic growth, while also highlighting interactions between carbon emissions, coal use and crude oil. It was determined that changes in natural gas and exports affected energy investment in the short term, while coal and exports affected natural gas. These results provide valuable information about the dynamics of the American economy and contribute to our understanding of the complex interactions between various factors and their effects on economic growth, offering implications for further research and policy development to promote sustainable economic development. [ABSTRACT FROM AUTHOR]

The development of nanoporous metal–organic frameworks (MOFs) capable of effectively separating and purifying CH4 is of significant importance. High surface polarity and suitable pore diameter are two key factors that can synergistically enhance separation performance. Herein, we report two hydroxyl-functionalized Al-MOFs (CAU-1-OH and CAU-1-(OH)2) for the separation and purification of natural gas. They both possess two different types of nanocages as well as a densely hydroxyl-functionalized surface. Significantly, CAU-1-(OH)2 demonstrated exceptional selectivity in separating C3H8/CH4 (50:50, v/v) and C2H6/CH4 (50:50, v/v), with selectivity values of 990 and 36, respectively, surpassing those of most reported porous materials. The dynamic breakthrough experiment of the ternary mixture can generate pure CH4 exceeding 3.46 mmol g–1, which adequately demonstrates the actual CH4 purification performance of CAU-1-(OH)2. Finally, molecular simulations and in situ infrared experiments verified that the high surface polarity and suitable pore diameter synergistically enhance the affinity of the frameworks toward C3H8 and C2H6, giving rise to the high loading capacity and selectivity for C3H8 and C2H6. These results support the significant potential of the double hydroxyl-modified nanomaterial CAU-1-(OH)2 for purifying methane from natural gas. [ABSTRACT FROM AUTHOR]

Ethanol is the most abundant chemical widely used in the fuel additive sector. Currently, it is mainly produced by the fermentation process, but it suffers from low carbon balance and poor reaction efficiency issues. In the past few decades, several promising catalytic methods have been proposed for ethanol production, depending on the available energy resources, technology development, and government policy. Herein, the catalytic pathways for ethanol production from petroleum, coal, natural gas, CO2, and biomass in more sustainable ways are introduced. Specifically, the most crucial elementary steps in these catalytic pathways are reviewed and discussed, and key factors determining the feasibility of these catalytic reactions are listed, providing an all-around overview on the development of ethanol production in the near future. In the last section, an outlook was provided to highlight the challenges and opportunities for ethanol production and applications in more green and sustainable catalytic manners. [ABSTRACT FROM AUTHOR]

In this work, three mathematical models were developed to study the laminar jet diffusion flame in mixtures of natural gas, hydrogen, and CO2 by extending and applying Roper's theory. Model M1 consists of derivation of the Roper's original equation described in the two-dimensional steady state without convection, thus showing the theoretical equations for the length of the diffusion flame for burners with circular, square, and rectangular cross sections and for regimes in which the flames are dominated by the momentum effects, the buoyancy effect, and in the transition regime. Models M2 and M3 extend the Roper's original theory by deriving analytical solutions of the two- and three-dimensional diffusion flame equation with convection in steady and transient states, taking into account the spatially variable velocity and diffusion coefficients. The flame lengths obtained with models M1 and M2 were compared with model M3 by Relative Percentage Difference (RPD) considering 5 mixtures of NG-H2-CO2. For t = 0.1, the maximum RPD in the circular cross-section for M1 in Gas20:60%NG-25%H 2 –15%CO 2 was 14.75%, while for M2 in Gas14:70%NG-15%H 2 –15%CO 2 was 6.47% and the minimum RPD in Gas1:100%NG was 9.78% and 4.83% for M1 and M2, respectively. The same analysis was developed for the square and rectangular (Fr ≪ 1) cross-sections and showed good agreement. The model M3 was tested under transient conditions, studying the effects of time and velocity on the distribution of the profile in the radial direction, in order to better understand the flame phenomenon, which cannot be observed with the Roper's original model M1. Finally, the models M2 and M3 were validated with experimental results and other analytical solutions showing a good performance considering the characteristics of each mixture. • Three mathematical models were developed to study the laminar diffusion flame. • The Roper's original equation was derived and named model M1. • Models M2 and M3 extend the original theory to 2 and 3 dimensions. • Models M2 and M3 were derived for steady and transient states, respectively. • The three models were compared and flame behavior in NG-H2 mixtures was explored. [ABSTRACT FROM AUTHOR]

In this study, the combustion and emission characteristics of natural gas/diesel dual-fuel engines under low load in diesel pilot ignition (DPI) and reactivity controlled compression ignition (RCCI) combustion modes were compared and analyzed by parametric study. The results show that compared with DPI mode, RCCI mode has lower NOx, CO and HC emissions and relatively higher thermal efficiency. However, under low load conditions, the in-cylinder mean temperature and combustion efficiency were reduced, and HC and CO emissions were still high in the RCCI combustion mode. The combustion characteristics of the fuel in the cylinder are changed by adding argon, hydrogen and syngas into the cylinder. The ability of additives to expand the low load operation range of natural gas/diesel RCCI engine was discussed and compared from the aspects of macroscopic combustion process and microscopic chemical reaction kinetics. The results show that argon, hydrogen and syngas can change the combustion characteristics of fuel. When argon, hydrogen and syngas are added, the gross indicated efficiency (GIE) can be increased from 38.1% to more than 50% compared to the basic condition. Maximum GIE and low HC emissions can be achieved with the introduction of 10% argon mass fraction, while a 20% hydrogen or syngas mass fraction is required to maintain low HC emissions. Therefore, argon has the greatest potential to improve the performance of natural gas/diesel RCCI engines under low load conditions. [Display omitted] • The effect of using Ar, H 2 and syngas on natural gas/diesel RCCI engine at low load. • The RCCI mode has lower NOx, HC, and CO emissions than the DPI mode. • The use of Ar, H 2 and syngas can improve the combustion of RCCI engine at low load. • Ar has the greatest potential to improve the performance of RCCI engines at low load. [ABSTRACT FROM AUTHOR]

The usage of liquefied hydrogen (LH 2) is growing fast as the EU aims to be climate-neutral by 2050. Therefore, reliable and consistent measurements of LH 2 amounts (as determined by flow meters) will become increasingly important for custody transfers. Reliability and consistency of measurements is established from calibration. Due to the lack of facilities being able to calibrate flow meters directly with LH 2 as calibration fluid, the question arises whether the measurement error of the calibration performed on a different fluid and different process conditions are representative for the errors when measuring LH 2. An on-site calibration of two turbine meters measuring LH 2 flow was performed. A Coriolis mass flow meter calibrated on water was used as a reference in conjunction with a dedicated flow meter model, which was validated by a directly SI-traceable calibration on liquefied natural gas. LH 2 flow rates were within 1000 kg/h and 3000 kg/h, which are relevant to hydrogen transport by LH 2 trailers. The analysis of the measurement data reveal errors on totalized mass ranging from 2.0 % to 2.9 % with a total calibration uncertainty of 1.3 % (k = 2), where the main uncertainty source was identified as the on-site density estimate necessary to convert the volume flow measurements into mass flow measurements. The results indicate the need for reliable and accurate temperature measurements (the latter allowing for an accurate density estimate), so that volume based and mass based amount measurements can be compared with smaller uncertainties. • Reliable measurements of liquefied hydrogen amounts will be crucial for custody transfer. • Direct calibration of flow meters on liquefied hydrogen is currently not possible. • Novel results of liquefied hydrogen flow measurement of an on-site calibration are presented. • The analysis reveals errors between 2.0 % and 2.9 % with an uncertainty of 1.3 % (coverage factor = 2). • The main uncertainty source was identified as the on-site density estimate. [ABSTRACT FROM AUTHOR]

Converting surplus electricity into hydrogen is considered a promising way for accommodating large-scale wind or solar power. However, it is expensive to establish a new-built hydrogen network or storage facilities at the current stage. Hydrogen-enriched compressed natural gas (HCNG), a mixture of natural gas and hydrogen, can be an alternative approach to consuming surplus renewable energy in the short-medium term. This paper investigates the feasibility of establishing an electricity-gas-hydrogen coupled energy system by modeling the HCNG network, power grid, and hydrogen electrolyzer in Ireland with consideration of pipeline characteristics. The economic analysis based on the planning results of the coupled system is presented in detail. When the hydrogen injection ratio reaches 20% at the HCNG stations, the system operating cost and carbon emission can be reduced by 24.2% and 6.4%, and 100% wind can be consumed. • A detailed modeling method for HCNG pipeline pressure drop and line pack is proposed. • An EGH-IES planning model encompassing entire HCNG supply chain is established. • A case study is conducted based on the real energy system in Ireland. [ABSTRACT FROM AUTHOR]

This study investigated the flame combustion of gas-containing pipe cutting operations by combining experimental and numerical simulation techniques. Based on the empirical flame length formula and experimental and numerical simulation flame length data, a flame length formula for gas outlet with large aspect ratio was proposed. In the experimental phase, cutting experiments were conducted with cutting slit lengths of 1–11 cm for pipe pressures of 10–550 Pa and hydrogen doping ratios of 0%, 10%, and 20%. The flame lengths were then measured. A hydrogen-doped natural gas combustion model based on the vortex dissipation conceptual model and Grimech-3.0 mechanism was established to simulate the experimental conditions. The flame lengths derived from the numerical simulation were in good agreement with the experimentally measured flame lengths, with an average error of 7.02%. This indicates that the reliability of the numerical model can be verified. The effects of hydrogen doping ratio, tube pressure, and cutting slit length on flame length and thermal radiation range were investigated using the control variable method. The results demonstrated that hydrogen doping reduced flame length and flame length away from the flame. Furthermore, an increase in pipe pressure and single cut length also resulted in an increase in flame length. It was observed that under normal operating conditions, a safe intensity of thermal radiation could be maintained within the operating distance when the operator wore protective clothing. • The reveal that hydrogen blending enhances combustion stability and reduces the jet flame height and flame resistance height. [ABSTRACT FROM AUTHOR]

Objective Analyzing the applicability of pipeline simulation technology in energy measurement, and examine the deviation between simulation calculation results and actual pipeline measurement values. Methods Using a closed natural gas pipeline network with multiple gas sources will be as an example, a simulation model with functions for natural gas heat generation, pressure, and flow calculation was established. This model is based on the theoretical foundation of pipeline network simulation for energy measurement. Results The deviation between the simulation results of heat generation and the calculated values of the on-site chromatographic analyzer is within 0.3%, which meets the requirements of the maximum allowable error of assigned heat generation in GB/T 18603—2023 Technical requirement of measuring systems for natural gas. The deviation between the pressure simulation calculation result and the recorded value of the on-site pressure transmitter is within 1.0%, and the deviation between the flow simulation calculation result and the measured value of the on-site flow meter is within 2.0%. Conclusions The energy measurement technology based on pipeline simulation is a feasible method for assigning heat generation values to complex multi-gas source pipelines. This method can also be used for real-time tracking or verification of pipeline pressure, flow rate, and natural gas pipeline inventory. [ABSTRACT FROM AUTHOR]

Natural gas is transported from production areas using high-pressure pipelines to pass through pressure reducing stations and then to the consumer. When temperatures drop, the problem of freezing of natural gas and ice appears. To protect against this phenomenon, we use a water bath to improve the temperature of the gas before reducing its pressure. One of the essential elements in the design of a low thermal efficiency water bath heater is the gas coil that runs inside the heater. In this study, the analysis of heat transfers and gas flow velocity inside the corrugated coil was performed with varying wave amplitude (10 mm, 15 mm, and 20 mm). The three-dimensional unsteady Reynolds-Navier-Stokes equations are solved using both the realizable k-ε turbulent model and the finite volume method to obtain the flow field. The results of this study showed that using corrugated coils with a larger capacity leads to an increase in the Nusselt number and friction factor, respectively, by about 6.57% and 114%. In general, the heat exchange inside the corrugated twisted gas coil can be enhanced by increasing the wave amplitude. [ABSTRACT FROM AUTHOR]

Understanding subsurface geological risks is crucial for the success of the oil and gas industry. This study investigates the accuracy of geological, geophysical, and exploration technology data used for technical evaluation and decision-making in subsurface risk assessment (Pg) and its impact on predicting the success of oil and gas exploration projects at PHE Exploration. Using a case study from PHE Exploration SHU during the period of 2020-2022, portfolio analysis was conducted to evaluate the extent to which project success predictions reflect the accuracy of available data. Effective integration of geological and geophysical data in exploration analysis can improve the accuracy of project success predictions, enabling a more holistic interpretation and better understanding of subsurface structures. Leveraging advanced exploration technologies, such as advanced seismic data processing and reservoir modeling, can enhance prediction accuracy by providing more precise information about reservoir conditions. Standardization of subsurface risk assessments ensures consistency in data interpretation and minimizes ambiguity in risk assessment. This provides certainty in understanding subsurface conditions, which is fundamental in risk assessment and investment decision-making. Portfolio analysis using Pg and validated resource calculation data can predict drilling success rates. Analysis from 2018 to 2022 shows a significant improvement in predicting average success ratios, with accuracy between predicted and actual results reaching 80%, demonstrating the importance of standardization in risk assessment. The findings of this research have important implications for the oil and gas industry. Improving the accuracy ofgeological, geophysical, and exploration technology data will be crucial in optimizing the success of exploration projects in the future. Standardization of subsurface risk assessment is essential for improving prediction accuracy, thus assisting in making informed investment decisions. [ABSTRACT FROM AUTHOR]

The processing of fine dust from copper smelters in Kazakhstan is an urgent task. The currently used technology of hydrometallurgical dust processing, which involves leaching with sulfuric acid to produce lead cake and a solution containing copper and zinc, fails meet modern requirements. The significant content of arsenic in the dust (up to 15%) hinders the production of high-quality products. In this study, fine dust from a copper smelter in Kazakhstan, obtained following conversion of copper mattes from autogenous smelting in Vanyukov furnaces, was used. Comprehensive analytical studies of the elemental and phase composition of dust were carried out using a Bruker D 8 ADVANCE X‑ray diffractometer and a scanning electron microscope with a JED-2300 energy dispersive X‑ray spectrometer (JEOL). This ensured the reliability of the data on the elemental composition of the initial dust, which were subsequently used to examine the behavior of arsenic and other non-ferrous metals under conditions of reduction roasting with natural gas. In order to gain a deeper understanding of the mechanism of the reduction roasting, a detailed thermodynamic analysis was carried out to examine the interactions between dust components and natural gas within the temperature range of 500–1000 K. Thermodynamic calculations were carried out using Outotec HSC Chemistry 8.1.5 software. It was established that favorable conditions are created for the reduction of zinc and copper ferrites, as well as arsenic oxide (As5+) when roasting dust with natural gas. It was demonstrated that the preliminary roasting of dust with natural gas ensures the most effective reduction of arsenic oxide (As5+) and the production of arsenic-free calcine with the subsequent high selective separation of Pb, Cu, and Zn from it into commercial products. The use of this method will significantly improve the technological performance of leaching fine dust with sulfuric acid due to the preliminary maximum removal of arsenic from the general technological scheme and the destruction of copper and zinc ferrites, which are relatively insoluble in acid, to their readily soluble oxides, with their subsequent dissolution. [ABSTRACT FROM AUTHOR]

The study of mixed natural gas can clarify the specific sources of natural gas accumulation and provide the basis for the exploitation of natural gas resources. Analysis of gas compositions and carbon isotopic ratios of different components of mixed natural gas shows that the carbon isotopic fractionation of methane and ethane from different sources has a small difference after mixing. This conclusion is derived from the experimental data in Table 1, 0.88 is the average of all Ro values. Well DN8 and DN9 produced light oil with a density between 0.75 and 0.82 g/cm3 and viscosity between 1.63 and 3.3 MPa. Generally, in the high maturity stage of organic matter, the carbon isotopic fractionation values of methane and ethane of natural gas from a single source should display a difference of at least 4.0% to 5.0%. The δ13C value of methane and ethane in well DN8 are only 1.6%. It is considered that the mixing of natural gas from different sources causes this phenomenon. [ABSTRACT FROM AUTHOR]

Natural gas (NG) is favored for transportation due to its availability and lower CO2 emissions than fossil fuels, despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies, using hydrogen (H2) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions, making it a promising option for diesel engines. Due to the importance and novelty of this, the continuation of ongoing research, and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers, this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design, operating conditions, fuel mixing ratios and supplying techniques on the CO, CO2, NOx and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NOx and CO2 compared to pure diesel. However, using hydrogen with diesel reduces CO, CO2, and HC emissions but increases NOx. On the other hand, HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately, resulting in decreased emissions of CO, CO2, HC, and NOx. The inclusion of hydrogen improves combustion efficiency, reduces ignition delay, and enhances heat release and in-cylinder pressure. Additionally, operational parameters such as engine power, speed, load, air–fuel ratio, compression ratio, and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall, the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels. [ABSTRACT FROM AUTHOR]

This study aims to provide an overview of the growing need for renewable energy conversion and aligns with the broader context of environmentally friendly energy, specifically through producing syngas from biomass. Unlike natural gas, which is mainly composed of methane, syngas contains a mixture of combustible CO, H2, and CnHm. Therefore, optimizing its production requires a thorough examination of various operational parameters such as the gasifying agent, the equivalence ratio, the biofuel type, and the state, particularly in densified forms like pellets or briquettes. As new biomass sources are continually discovered and tested, operational parameters are also constantly evaluated, and new techniques are continuously developed. Indeed, these techniques include different gasifier types and the use or non-use of catalysts during biofuel conversion. The present study focuses on these critical aspects to examine their effect on the efficiency of syngas production. It is worth mentioning that syngas is the primary gaseous product from gasification. Moreover, it is essential to note that the pyrolysis process (prior to gasification) can produce, in addition to tar and char, a mixture of gases. The common feature among these gases is their versatility in energy generation, heat production, and chemical synthesis. The analysis encompasses the resulting gas features, including the yield and composition, mainly through the hydrogen-to-carbon monoxide ratio and the carbon monoxide-to-carbon dioxide ratio, as well as the lower heating value and considerations of the tar yield. [ABSTRACT FROM AUTHOR]

Hydrogen produced from renewable energy sources is a valuable energy carrier for linking growing renewable electricity generation with the hard-to-abate sectors, such as cement, steel, glass, chemical, and ceramics industries. In this context, this paper presents a new model of hydrogen production based on solar photovoltaics and wind energy with application to a real-world ceramics factory. For this task, a novel multipurpose profit-maximizing model is implemented using GAMS. The developed model explores hydrogen production with multiple value streams that enable technical and economical informed decisions under specific scenarios. Our results show that it is profitable to sell the hydrogen produced to the gas grid rather than using it for self-consumption for low-gas-price scenarios. On the other hand, when the price of gas is significantly high, it is more profitable to use as much hydrogen as possible for self-consumption to supply the factory and reduce the internal use of natural gas. The role of electricity self-consumption has proven to be key for the project's profitability as, without this revenue stream, the project would not be profitable in any analysed scenario. [ABSTRACT FROM AUTHOR]

Understanding of thermophysical and transport properties of H2-NG blends are needed for the gradual introduction of hydrogen into the national gas grid. A capillary tube viscometer was used to measure the viscosity of hydrogen + methane blends (with hydrogen mole fraction = 0, 0.1000, 0.1997, 0.5019, and 1) at temperatures from 213 to 324 K and pressures up to 31 MPa. A total 147 experimental viscosity measurements were made for the three H2 + CH4 blends and compared against the predictions of five different viscosity models: a one-reference corresponding states (Pedersen) model, a two-reference corresponding states (CS2) model, an extended corresponding states (ECS) model, a corresponding states model derived from molecular dynamic simulations of Lennard Jones (LJ) fluids, and a residual entropy scaling (SRES) method. All the model predictions showed a relatively low deviation compared to the measured viscosities. The density required for viscosity model predictions were computed using Multi-Fluid Helmholtz Energy Approximation (MFHEA) equations of state (EoS). To check the experimental procedure and applicability of the viscometer equipment, viscosity validation measurements were carried out for propane, hydrogen, and methane. The measured viscosities of the pure components were in good agreement with the respective viscosity models with AARD of 0.24%, 0.25%, and 0.58% for propane, hydrogen, and methane, respectively. [ABSTRACT FROM AUTHOR]

This paper proposes an automated deep learning (AutoDL) framework for dynamic prediction and multi-objective optimization (MOO) on the driving position of the tunnel boring machine (TBM) to enhance tunneling reliability and efficiency. More specifically, AutoDL contains a standard process of data preprocessing, optimal hyperparameter tuning, algorithm selection, and model performance evaluation, which can intelligently learn the time-varying monitoring data collected by the smart sensors installed on TBM. It can return a prediction interval to well consider uncertainty, which is stable enough to raise the reliability of the prediction results. Later, the model from AutoDL serves as a meta-model for MOO-based decision-making to evidently control the four TBM position objectives, including shield head horizontal deviation, shield head vertical deviation, shield tail horizontal deviation, and shield tail vertical deviation. To validate the effectiveness of the proposed approach, it is applied in a TBM project for a natural gas backbone network between Changxing Island and Chongming Island in Shanghai. It is found that the proposed AutoDL can greatly reduce the requirements of professional knowledge of developers on model training. The deviation of the TBM driving position in each segment ring can be dynamically and accurately estimated in the form of both a single point and interval, reaching the average MAE of 1.051. Based on the intelligent model built by AutoDL, Nondominated Sorting Genetic Algorithm II (NSGA-II) is conducted to feasibly adjust TBM operational parameters. The average deviation of the four optimization objectives of the 66-ring data is decreased by 16.05%, contributing to reducing the occurrence of shield tunneling misalignment (STM). [ABSTRACT FROM AUTHOR]

In this study, online ambient volatile organic compounds (VOCs) were collected at an urban site of Zhengzhou in Central China during February 2018. The VOCs characteristics, source contributions and the Chinese New Year (CNY) effects have been investigated. During the sampling period, three haze periods have been identified, with the corresponding VOCs concentrations of (92 ± 45) ppbv, (62 ± 18) ppbv and (83 ± 34) ppbv; in contrast, the concentration during non-haze days was found to be (57 ± 27) ppbv. In addition, the festival effects of the CNY were investigated, and the concentration of particulate matter precursor decreased significantly. Meanwhile, firework-displaying events were identified, as the emission intensity had been greatly changed. Both potential source contribution function (PSCF) and the concentration weighted trajectory (CWT) models results indicated that short-distance transportation was the main influencing factor of the local VOCs pollution, especially by transport from the northeast. Source contribution results by the positive matrix factorization (PMF) model showed that vehicle exhaust (24%), liquid petroleum gas and natural gas (LPG/NG, 23%), coal combustion (21%), industrial processes (16%) and solvent usages (16%) were the major sources of ambient VOCs. Although industry and solvents have low contribution to the total VOCs, their secondary organic aerosol (SOA) contribution were found to be relatively high, especially in haze-1 and haze-3 periods. The haze-2 period had the lowest secondary organic aerosol potential (SOAp) during the sampling period; this is mainly caused by the reduction of industrial and solvent emissions due to CNY. [ABSTRACT FROM AUTHOR]

Usually, deep oil and gas accumulation is often controlled by strike–slip faults. However, in the Tarim Basin, deep Ordovician oil and gas accumulations are also found in areas far from the fault zone. The process of oil and gas accumulation in deep reservoirs far from strike–slip fault zones is still unclear at present. The source and evolution of Ordovician fluids were analyzed using inclusion geochemical methods and the U–Pb dating technique. The analysis of rare earth elements and carbon–oxygen–strontium isotopes in the reservoirs showed that the reservoirs were weakly modified by diagenetic fluid. The fluid was derived from the fluid formation during the same period as the seawater, and no oxidizing fluid invaded the reservoir. The late oil and gas reservoirs had good sealing properties. The U–Pb dating results combined with homogenization temperature data revealed that the first-stage oil was charged during the Late Caledonian Period, and the second-stage natural gas was charged during the Middle Yanshanian Period. The evolution of the paleo-pressure showed that the charging of natural gas in the Middle Yanshanian was the main reason for the formation of reservoir overpressure. The strike–slip fault zone was basically inactive in the Middle Yanshanian. During this period, the charged natural gas mainly migrated to the reservoir along the unconformity surface and the open strike–slip fault zone in the upper part of the Ordovician reservoir. The source of the fluid shows that the reservoir in the late stage had good sealing properties, and there was no intrusion of exogenous fluid. The overpressure in the reservoir is well preserved at present. [ABSTRACT FROM AUTHOR]

Due to limited data on the geochemical properties of natural gas, estimations are needed for the effective gas source rock in evaluating gas potential. However, the pronounced heterogeneity of mudstones in lacustrine successions complicates the prediction of the presence and geochemical characteristics of gas source rocks. In this paper, the Liaohe Subbasin of Northeast China is used as an example to construct a practical methodology for locating effective gas source rocks in typical lacustrine basins. Three types of gas source rocks, microbial, oil-type, and coal-type, were distinguished according to the different genetic types of their natural gas. A practical three-dimensional geological model was developed, refined, and applied to determine the spatial distribution of the mudstones in the Western Depression of the Liaohe Subbasin and to describe the geochemical characteristics (the abundance, type, and maturation levels of the organic matter). Application of the model in the subbasin indicates that the sedimentary facies have led to heterogeneity in the mudstones, particularly with respect to organic matter types. The effective gas source rock model constructed for the Western Depression shows that the upper sequence (SQ2) of the Fourth member (Mbr 4) of the Eocene Shahejie Formation (Fm) and the lower and middle sequences (SQ3 and SQ4) of the Third member (Mbr 3) form the principal gas-generating interval. The total volume of effective gas source rocks is estimated to be 586 km³. The effective microbial, oil-type, and coal-type gas source rocks are primarily found in the shallow western slope, the central sags, and the eastern slope of the Western Depression, respectively. This study provides a practical approach for more accurately identifying the occurrence and geochemical characteristics of effective natural gas source rocks, enabling a precise quantitative estimation of natural gas reserves. [ABSTRACT FROM AUTHOR]