Gas Source Research Articles

Возможности и проблемы энергогенерации в Республике Тыва

RELEVANCE. The energy sector forms the basis for functioning of other economic sectors and social services. Presentday technologies of energy generation are based on using coal, gas, oil, hydro, nuclear and renewable sources. PURPOSE. Analysis of the current state of energy generation in the Republic of Tyva, identification of drivers for development and optimization of its structure. RESULTS. A review is made of the current global trends in energy generation. Directions for diversifying energy generation sources are proposed, e.g. using both imported and coal seam gas as well as hydro resources along with coal. CONCLUSIONS. Focusing on only one energy source reduces the energy security of the region. Energy shortages and the presence of costly diesel-based power generation hinder the economic development of the Republic of Tyva. In the republic that has extensive coal reserves, coal generation has to introduce modern “clean coal” technologies. A high share of thermal power plants in the structure of the coal-fired generation capacity will allow the development of cogeneration using innovative, environmentally friendly Russian technologies. Options for solving the challenge of energy shortage in Tuva in the future until 2035 are proposed.

Impact of non‐thermal plasma generated using air and nitrogen on functional properties of milk protein dispersions

AbstractThis study focuses on improving the functionalities of milk protein concentrate (MPC) using a nonthermal plasma jet and plasma‐activated water (PAW) with atmospheric air and nitrogen as source gases. The 5% and 10% MPC dispersions were directly treated with a plasma jet, and PAW was used to make the MPC dispersions. The dispersions were analyzed for changes in protein structure and functional properties. The treatment altered the secondary structure of MPC protein structure by increasing β‐components and changing the order of random coils. The solubility of the PAW‐treated 5% protein dispersions doubled due to plasma‐induced modification of hydrophilic and covalent bonds of the protein, but this increase was not significant for the 10% dispersions due to less hydration. Emulsifying capacity increases by around 7% for plasma jet and PAW with air, owing to hydrophobicity on the particle surface. The gelation capacity and heat coagulation time rise by almost twice; however, foaming capacity decreases, indicating protein structural modifications and aggregations caused by plasma exposure. The viscosity of the 5% dispersions decreased due to high solubility, while that of the 10% dispersions increased due to less hydration. Principle component analysis was used to correlate the change in functionality with different operating parameters. In conclusion, this study illustrates that the functional properties of MPC can be significantly modified through plasma treatment. The observed changes depend on several factors, including the mode of plasma exposure, the source gas used to generate the plasma, and the concentration of the protein solution.Practical applicationsMilk protein concentrate (MPC) is a promising ingredient in food products such as cheese, cultured dairy items, nutritional goods, infant milk formulas, ice cream, dairy‐based drinks, sports beverages, and a variety of health‐focused products. However, the application is profoundly hindered due to its poor solubility and solubility‐related functional properties. MPC powders lose functionalities during manufacturing and gradually lose them again during processing and storage. This study explores the potential of non‐thermal plasma to improve the functional properties of proteins. This study explores the potential of two different discharges: plasma jet and plasma‐activated water (PAW), using atmospheric air and nitrogen as source gases. The findings of this study would also help to understand the types of plasma discharge (jet vs PAW) and types of sources of gases that can be used in industrial applications. Some optimization parameters of this study can be used for scaling up the plasma processing of milk or dairy products. In addition, PAW is being very well studied to improve food safety, and this study would provide information on the physicochemical properties of MPC. Therefore, it would also help to understand how to apply non‐thermal plasma to achieve both microbial and physical effects.

Characteristics of malignant urban gas accidents in China from 2013 to 2022

Malignant urban gas accidents, accounting for only approximately 1 % of the total gas accidents in China, are responsible for over 50 % of fatalities, thus becoming a major cause of public concern regarding gas safety. A comprehensive understanding of the characteristics of historical accidents is an effective way to prevent and reduce future accidents. In this regard, the study meticulously collects and analyzes all malignant gas accidents that occurred in China from 2013 to 2022. This approach can effectively clarify the focus of gas accident prevention, and also facilitate the implementation of more targeted preventive measures. The study provides diverse perspectives and comprehensive statistics on accidents using 10 variables in 6 dimensions: time (year, month, day, hour), location (province, place), gas source, type, cause, and level. In addition to common quantitative statistics, proportional analyses and visual displays, methods such as contingency tables, t-tests, chi-square tests, and cluster analyses were also used to provide more in-depth analyses and identify more potential patterns. The findings elucidate that: (1) Over the past decade, the yearly distribution of malignant gas accidents in China has been relatively stable; but, individual, particularly major accidents, have significantly influenced the overall severity; (2) June and July are the peak months for such accidents; (3) The most severe accidents occur during 6:00–6:59 a.m., 11:00–11:59 a.m., and 11:00–11:59 p.m.; (4) Central and eastern provinces are the epicenters of malignant gas accidents; (5) Residential accommodations, and restaurants and shops are frequently affected; (6) Liquefied petroleum gas, despite comprising merely 8.7 % of the aggregate supply, is implicated in over half of the malignant occurrences and associated fatalities; (7) Explosions account for approximately 78.49 % of these accidents; (8) Among the accident causes, violations of rules by workers stands as the foremost contributor; (9) Malignant gas accidents are generally larger accident. Moreover, this manuscript delves into the underlying reasons behind each noteworthy statistical trend and analyzes the critical issues facing the gas industry. This investigation not only bridges the gap in the statistical profiling of malignant gas accidents within China but also furnishes invaluable insights that may guide preventive measures against urban gas-related disasters. Furthermore, the methodological approaches and variable selections explored in this study lay a robust foundation for future endeavors in the realm of malignant gas accident management research and practice.

Analysing type of plants for reducing noise pollution in climate change adaptation

Abstract The noisier a region or city is, the faster the rate of global warming. Noise is not a substance. However, most sources of carbon dioxide and other greenhouse gases are also sources of noise; for example, busy highways in cities can occasionally see as many as 100 cars per hour. Planting trees to mitigate noise pollution has been identified as one of the most sustainable methods to employ, since plants may function as a buffer and absorb sounds. Several plant species were chosen to assess noise absorption based on parameters such as leaf thickness, breadth, surface area, and length. The initial goal of this study is to estimate the noise absorption on the selected flora native to the Malaysian environment, where the noise was measured using an in-house developed impedance tube to discover the effective acoustic characteristics of leaves. The investigation was then carried on by assessing the data on the correlation coefficient parameter in order to determine the link between noise absorption and leaf features. Because of the freshness and perishability of the materials, measurements were repeated twice. Only 100% and 50% vegetation quantity size were measured for 10 sample species during the initial data collection. According to the findings, half of the leaves’ features were connected with noise absorption. This might be owing to the freshness state, which cannot be maintained for an extended period of time. To acquire a better value, the experiment was repeated within the permissible freshness time. The findings are as predicted, with the maximum noise absorption and features correlation at 100% plant density including twigs. When the vegetation amount is lowered to 50%, this will progressively diminish. The notion is confirmed by the fact that a tube packed with thicker samples absorbs more noise. The correlation study identifies that each leaf has its unique capacity for noise absorption dependent on its properties and freshness level.

Physics-Informed Machine Learning Applied to Complex Compositional Model in a Giant Field

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 23730,“Physics-Informed Machine-Learning Application to Complex Compositional Model in a Giant Field,” by Guido Bascialla, SPE, ADNOC, and Coriolan Rat and Soham Sheth, SLB, et al. The paper has not been peer reviewed. Copyright 2024 International Petroleum Technology Conference. _ Compositional reservoir simulation is a time-intensive activity demanding complex physics. In the complete paper, the authors review the advantages of machine learning (ML) in complex compositional reservoir simulations to determine fluid properties such as critical temperature and saturation pressure. An ML approach to predict critical temperatures during simulation based on the Heidemann-Khalil method is implemented, resulting in more-accurate results with lower computational cost, outperforming the standard method and improving performance on a giant field model with compositional gradient and miscible gas injection. Field Description The case study refers to a giant offshore carbonate field composed of multiple reservoirs. Production is currently in a rampup phase; crestal miscible hydrocarbon gas injection was implemented soon after startup. The availability of high-potential gas producers as a source of makeup gas and the placement of peripheral water injectors maintains the reservoir pressure above minimum miscibility pressure. All reservoirs show complex variable slope compositional gradients along thick oil columns of hundreds of feet (Fig. 1). To match the fluid behavior and the variation of fluid properties with depth, the equation of state needs at least nine components. The rock quality mainly is controlled by diagenesis. Thirteen rock types were modeled. The permeability can change up to four log cycles for the same porosity. Most of the reservoirs are highly heterogeneous, with features such as high-permeability streaks and baffle zones. A wide range of capillary pressure curves is present; these mainly depend on permeability and lithology. Most development wells were completed with inflow control devices (ICDs) to control gas and water breakthroughs and optimize oil production. The combination of numerous ICDs and long slanted production intervals (i.e., thousands of feet) make wellbore-reservoir coupling critical for proper history matching and forecasting. The model grid size in the horizontal direction is 328 ft, which is considered optimal according to simulated sensitivities. The vertical layering is very fine in order to capture the reservoir heterogeneity; the cell thickness ranges from 1 to 1.5 ft. This results in a model with 3.5 million active cells, which makes the simulation performance and run time very challenging when coupled with compositional gradient and ICDs. Phase Labeling In this section of the complete paper, the authors review why accurate phase labeling is important in compositional simulation and how it can lead to convergence problems, particularly for cases with gas injection. A traditional method is compared with an ML method on a simple model using a complex dummy fluid model to highlight issues that may arise in more-complex simulation models.

Source and characteristics of inorganic acidic gases and aerosols emission in a semiconductor plant

Inorganic acids, widely used in semiconductor manufacturing processes, have become a concern as improper handling of these acids can have severe environmental impacts. This study investigates the major contamination source of inorganic acids (hydrofluoric acid, hydrochloric acid, nitric acid, phosphoric acid, and sulfuric acid), the different ratios of solid and gaseous inorganic acids, and the particle size distribution of solid particles emitted after local scrubber (LSC) treatment. An assessment of pollutant status revealed that hydrofluoric acid emissions dominate in the chemical vapor deposition (CVD) process at 65%, hydrochloric acid in the diffusion (DIFF) process at 69%, phosphoric acid in the epitaxy (EPI) process at 100%, and sulfuric acid in wet etching at 85%. In contrast, particulate matter constitutes the primary component, ranging from 82% to 99% of the LSC emission. The LSC configuration is then adjusted based on the overview of inorganic acid emissions from different processes to match their characteristics. After related improvement activities, the results presented a significant reduction of 56% to 87% in inorganic acid emissions at the outlet of the LSC, and 18-68% reduction in the stack emissions.

Research on the gas generation characteristics of power cables when heated

Abstract Power cable fires evolve through several stages. Initially, the fire’s early phase is characterized by an anomalous temperature in the outer sheath without considerable smoke generation. It progresses to a smoldering stage with significant smoke production, leading eventually to open flames, which persist until extinguished. Fault-induced high temperatures initiate the breakdown of chemical bonds in the polymer materials composing the cable’s outer sheath, resulting in specific pyrolysis gases that bear the cable’s temperature information. Investigating the heating and gas production properties of the cable can enhance our understanding of the gas phase characteristics at the onset of fires. This paper presents an experimental platform comprising a power cable overheating fault simulation device and chemical analysis instruments. It examines the gas production traits and sources in power cables under fault-induced, high-temperature conditions based on gas chromatography and infrared spectrum data.

Geochemical Characteristics and Gas Source Comparison Analysis of Fault Adjusted Tight Gas Reservoirs

Geochemical Characteristics and Gas Source Comparison Analysis of Fault Adjusted Tight Gas Reservoirs

Manipulating a beam of barium fluoride molecules using an electrostatic hexapole

An electrostatic hexapole lens is used to manipulate the transverse properties of a beam of barium fluoride molecules from a cryogenic buffer gas source. The spatial distribution of the beam is measured by recording state-selective laser-induced fluorescence on an emccd camera, providing insight into the intensity and transverse position spread of the molecular beam. Although the high mass and unfavorable Stark shift of barium fluoride pose a considerable challenge, the number of molecules in the low-field seeking component of the N = 1 state that pass a 4 mm diameter aperture 712 mm behind the source is increased by a factor of 12. Furthermore, it is demonstrated that the molecular beam can be displaced by up to ±5 mm by moving the hexapole lens. Our measurements agree well with numerical trajectory simulations. We discuss how electrostatic lenses may be used to increase the sensitivity of beam experiments such as the search for the electric dipole moment of the electron.

Analysis of methods of natural gas technical loss determination and technical loss norms in gas supply network

In modern times, the role of energy resources is very large. One of the important energy resources is natural gas. The biggest advantage of using natural gas as a fuel is its high heat capacity and complete combustion without the formation of harmful substances. The process of natural gas distribution in the gas supply network is observed with gas loss. This is an objective, natural situation and creates a number of difficulties for natural gas enterprises. The article focuses on gas consumption in technological processes in the gas supply network, gas purges from pipelines during pipeline repair works, gas flushing out from the pipeline and determination of gas technological losses during the removal of air from the pipeline. Determination of gas losses caused by non-hermeticity of external gas pipelines and equipment, gas pressure regulation station (GPRS), cabinet-type gas control points (GCP), universal pressure regulator (UPR) and gas losses occurring during repairing of other technological equipment are discussed. Also, the determination of technical losses of natural gas at meters, sampling nodes, safety valves, gas distribution stations (GDS) (from gas losses during the management of shut-off valves, during purge of process instrumentation and automatics, when taking gas samples, during purges proses of safety valves, apparatus and pulse lines) is discussed. The article describes the principle of formation of technical losses in the gas supply network. Technical loss sources of natural gas in the process of gas supply, methods of calculating loss norms, the amount of small loss of which is determined separately for each specified loss source, are mentioned. Keywords: gas supply; natural gas; technical losses; pipeline; GPRS; GCP; UPR; gas meters; safety valves; gas distribution station.

Geoecological monitoring during mining operations

In recent decades environmental quality assessment has become a fundamentally important task in the operation of mining enterprises. This assessment becomes an integral part of the strategy for determining maximum permissible loads for mining regions and is aimed at reducing geoecological risk in them. Technological processes of mining and processing plants generate emissions of various pollutants into the atmospheric air, lead to violation of adjacent territories. Monitoring, primarily of atmospheric air and soils, is necessary to ensure the ecological balance of such territories. Lebedinsky Mining and Processing Plant is one of the most significant sources of gas and dust emissions from massive explosions in quarries during ore extraction, which form a large dust and gas cloud, creating a risk of deterioration of the life of the population in the surrounding area. The article examines the main pollutants in soils and in the atmospheric air during mass explosions, and determines the areole of their distribution from the work site. The forecast of an increase in the concentrations of detected harmful substances for the next 50 years is given. A methodology for conducting geoecological monitoring during mining operations is proposed. The research results may be useful in assessing geoecological risks and developing measures to reduce them.

Energy and environmental impacts of air-to-air heat pumps in a mid-latitude city

Heat pumps (HPs) have emerged as a key technology for reducing energy use and greenhouse gas emissions. This study evaluates the potential switch to air-to-air HPs (AAHPs) in Toulouse, France, where conventional space heating is split between electric and gas sources. In this context, we find that AAHPs reduce heating energy consumption by 57% to 76%, with electric heating energy consumption decreasing by 6% to 47%, resulting in virtually no local heating-related CO2 emissions. We observe a slight reduction in near-surface air temperature of up to 0.5 °C during cold spells, attributable to a reduction in sensible heat flux, which is unlikely to compromise AAHPs operational efficiency. While Toulouse’s heating energy mix facilitates large energy savings, electric energy consumption may increase in cities where gas or other fossil fuel sources prevail. Furthermore, as AAHPs efficiency varies with internal and external conditions, their impact on the electrical grid is more complex than conventional heating systems. The results underscore the importance of matching heating system transitions with sustainable electricity generation to maximize environmental benefits. The study highlights the intricate balance between technological advancements in heating and their broader environmental and policy implications, offering key insights for urban energy policy and sustainability efforts.

Comprehensive assessment of refined greenhouse gas emissions from China's livestock sector

Livestock and poultry products are an essential human food source. However, the rapid development of the livestock sector (LS) has caused it to become a significant source of greenhouse gas (GHG) emissions. Consequently, investigating the spatio-temporal characteristics and evolution of GHG emissions is crucial to facilitate the green development of the LS and achieve “peak carbon and carbon neutrality”. This study combined life cycle assessment (LCA) with the IPCC Tier II method to construct a novel GHG emissions inventory. The GHG emissions of 31 provinces in China from 2000 to 2021 were calculated, and their spatio-temporal characteristics were revealed. Then, the stochastic impacts by regression on population, affluence, and technology (STIRPAT) model was used to identify the main driving factors of GHG emissions in six regions of China and explore the emission reduction potential. The results showed that GHG emissions increased and then decreased from 2000 to 2021, following a gradual and steady trend. The peak of 628.55 Mt CO2-eq was reached in 2006. The main GHG-producing segments were enteric fermentation, slaughtering and processing, and manure management, accounting for 45.39 %, 26.34 %, and 23.08 % of total GHG emissions, respectively. Overall, the center of gravity of GHG emissions in China migrated northward, with spatial aggregation observed since 2016. The high emission intensity regions were mainly located west of the “Hu Huanyong line”. Economic efficiency and emissions intensity were the main drivers of GHG emissions. Under the baseline scenario, GHG emissions are not projected to peak until 2050. Therefore, urgent action is needed to promote the low-carbon green development of the LS in China. The results can serve as scientific references for the macro-prevention and control of GHG emissions, aiding strategic decision-making. Additionally, they can provide new ideas for GHG accounting in China and other countries around the world.

Integrated membrane process of tubular ultrafiltration-nanofiltration-electrodialysis-reverse osmosis for treating fracturing flowback fluid

As an underground source of natural gas, shale gas is important for ensuring national energy security and promoting the “dual carbon” target. However, shale gas extraction produces flowback fluid that requires efficient treatment to avoid negative impacts on the environment and human health. In this study, a pilot plant was constructed to implement a novel membrane-integrated process to treat fracturing flowback fluid. This process employs an aeration reaction sedimentation (ARS) tank and a tubular ultrafiltration (TUF) membrane for pretreatment, followed by three separate membranes for nanofiltration (NF), electrodialysis (ED), and reverse osmosis (RO). The pretreatment removed 99.3% of total hardness, 99.4% of total suspended solids (TSS), and 88.1% of total organic carbon (TOC). Four different types of TUF membranes were tested and compared. It was also found that physico-chemical cleaning of the TUF membrane using the ceramic particle technology resulted in a flux recovery rate of up to 98%. In addition, the NF and ED membranes can remove 99.4% of Na2SO4 and 90% of NaCl, respectively, resulting in an 85.6% decrease in TSS. Water recovery rate of the total system can reach 90%. Based on concept of sustainable green development, carbon footprint of integrated membrane process for treating fracturing flowback fluid was approximately 86.7 kgCO2 eq lower than that of traditional process. Low carbon emissions and no generation of secondary pollutants have become the keys to treat fracturing wastewater. In summary, the integrated TUF-NF-ED-RO process based on membranes is very promising for treating fracturing flowback fluid.

Utilization of Livestock Manure as Biogas and Liquid Organic Fertilizer (LOF) in Sumbermulyo Village, Pesanggaran, Banyuwangi

Biogas is a natural gas produced through anaerobic bacteria breakdown of organic materials. Organic materials can include livestock manure, domestic waste, and other organic waste that bacteria can decomposeunder anaerobic conditions. Sumbermulyo is one of the villages in the Pesanggaran sub-district of Banyuwangi Regency, where the majority of the population works as dragon fruit farmers and goat herders. The current phenomena in the area include the scarcity of subsidized urea fertilizer and Liquified Petroleum Gas (LPG). An alternative approach is to utilize goat manure as a source of methane gas, which can be used as a substitute for LPG. The objective of this community service project is to establish a biogas processing pilot project in the Sumbermulyo Village, Pesanggaran sub-district, which the community can implement. Additionally, it aims to analyze the total N, P, K content in the wet sludge from the digester as liquid organic fertilizer. The method used involves constructing a biogas digester on the land owned by one of the farmer groups and evaluating the gas production. The digester is built using a concrete model (fixed dome) in the shape of an airtight dome. The construction of the digester takes 14 days until it is ready for use. Up to the 10th day of use, thehighest pressure is obtained on day -10, with a pressure of 107,486.76 N/m2 or 1.06 atm. Chemical analysis of the liquid organic fertilizer shows that the total N, P, K content is as follows: 0.032%, 0.009%, 0.144% for the sample from the test digester, and 0.044%, 0.005%, and 0.195% for the sample from the reference digester

Modular vehicles can reduce greenhouse gas emissions for departure flight baggage transportation

Rapid and on-time baggage transportation plays a crucial role in ensuring customer satisfaction and is an important source of greenhouse gas (GHG) emissions in the aviation sector. Modular Vehicle (MV) is an emerging transportation technology that allows vehicles to adjust their capacity flexibly by assembling or disassembling identical detachable units. This innovative technology offers a new perspective to decarbonize the aviation sector, as it holds promise for reducing GHG emissions in flight baggage transportation. To investigate this possibility, this study proposes an MV operation paradigm and a corresponding “greenest” MV scheduling problem that aims to minimize MV-relevant GHG emissions while transporting baggage from the terminal to the aircraft without delay. To solve the problem efficiently, a fast construction-merging heuristic is proposed based on the theoretical properties of the problem. A series of case studies at the Tampa International Airport were conducted to evaluate the performance of the proposed MV operation and the construction-merging heuristic. The results indicate that the proposed MV operation effectively reduces GHG emissions, and the heuristic solves near-optimal solutions to the investigated problem much faster than Gurobi, a state-of-the-art commercial solver for integer programs, without much loss of the optimality of the solutions. Results from this study provide important managerial and operational insights into decarbonizing baggage transportation for airport operators.

Penerapan Keselamatan dan Kesehatan Kerja pada Pegawai di Rumah Sakit

With increasing activity and the development of new methods and increasingly sophisticated equipment in hospitals, the problems of Occupational Health and Safety in hospitals (K3-RS) are becoming increasingly complex. Potential dangers in hospitals, apart from infectious diseases, there are also potential other dangers that affect the situation and conditions in hospitals, namely work accidents, explosions, fires, accidents related to electrical installations, and other sources of injury, radiation, dangerous chemicals, anesthetic gases, psychosocial and ergonomic disorders. All the potential dangers mentioned above clearly threaten the life and life of employees, patients and visitors in the hospital environment. Therefore, the implementation of K3 in hospitals absolutely must be implemented.

Hybrid kitchen safety guarding with stove fire recognition based on the Internet of Things

In this paper, we design a hybrid kitchen safety guarding framework using embedded devices and onboard sensors to detect abnormal events and block gas sources in time through the Internet of Things (IoT). According to the relevant literature we studied, this is the first framework for kitchen safety guarding that provides the following features: (1) the deep learning based model integrating densely connected convolutional networks with neural architecture search networks is developed to accurately recognize abnormal stove fire, (2) the acceleration correction method is designed to correct the sensed accelerometer values for estimating the actual earthquake level, and (3) the proper gas leakage threshold is defined to precisely detect the gas leakage for automatic gas blocking, and remote surveillance and control are provided to monitor the kitchen environment and control the gas source anytime and anywhere. In particular, an Android-based prototype consisting of the IoT device, diverse sensors, dedicated server, and smartphones is implemented to verify the feasibility and superiority of our framework. Experimental results show that our framework outperforms existing methods and can precisely recognize stove fire intensity and detect earthquake levels for kitchen safety guarding.

Gas-phase reaction of CH4 and H2S – Evidence from pyrolysis experiments and case study from the Sichuan Basin

The application of routine geochemical analyses for identification of dry natural gas sources and post generation processes poses a challenge as its hydrocarbon composition is typically dominated by CH4 (∼≥99 %) while the presence of non-hydrocarbons may be limited. In particular, the possibility of dry gas interaction with H2S at reservoir conditions (low temperatures, high pressures, millions of years residence time) is not established as previous studies of this reaction focused on conditions typical for industrial reactors (high temperature, ambient pressure, residence time of seconds). To address these issues, we studied the molecular and isotopic (δ34S) composition of volatile organic sulfur compounds (VOSC) formed during pyrolysis experiments between CH4 and H2S at 360 °C (4–96 h), reaching %Ro equivalent of 0.80–1.25 which represents thermally mature oil and gas reservoirs. The results demonstrated that methanethiol (MeSH) is the main product of the reaction, while its δ34S value suggest equilibrium isotopic effect with its parent H2S. Subsequent analysis of the molecular and isotopic (δ13C, δ2H, δ34S) composition of thermogenic, H2S containing, dry natural gases from the Jiannan gas field in China revealed the presence of short thiols and sulfides dominated by MeSH. The δ34S of the VOSC identified suggests they all formed by gas-phase reaction of alkanes (mainly CH4) with the associated H2S.This study demonstrates the applicability of VOSC as a proxy for identification of interaction between H2S and dry gas and identification of H2S sources within a gas reservoir or a basin.

Gas Composition Tracking in a Transient Pipeline Using the Method of Characteristics

For a gas pipeline with multiple gas sources, the significance of tracking the composition of natural gas is increasing with the implementation of X+1+X system for the natural gas industry in China. Mathematically, the tracking problem is usually described by a system of partial differential equations (PDEs). The continuity equation on gas composition has been developed to track natural gas composition according to the law of mass conservation. The algorithm resulting from the method of characteristics (MOC) is proposed to solve the system of PDEs. Compared to the original MOC, numerical solutions of the continuity equation on gas composition are obtained after the hydraulic calculation and thermal calculation. Moreover, different combinations of boundary conditions for the MOC are derived, which could expand the range of application of the MOC and be applicable to various operating conditions. The heating values of diverse gas sources have been determined following the methods documented in ISO 6976:2016. The case study of a gas pipeline in China verified the validity of the algorithm via the commercial simulation software Pipeline Studio for Gas (TGNET). The heating value and gas composition obtained by the algorithm can be used in the custody transfer metering of natural gas pipelines for Class B and C metering stations described in GB/T 18603−2014.