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Natural gas is a worldwide commodity traded among regions. Regulated or unregulated natural gas markets are in a new process phase leading to a critical change in the market structure and organization while demand grows. Moreover, international trade of high gas volumes and complexity of transportation alternatives create new difficulties in market modeling and price forecasting. Hence, there is a need to define and analyze the future of recently developing gas markets. Turkey has an important geopolitical position with short distances to the regions of the largest natural gas reserves. While largely dependent on the gas import from Russia, Iran and Azerbaijan through pipelines, it is also very close to high demanding countries. That is why Turkey may have the opportunity to play an important role in pricing gas between international market players and becoming a market maker. This paper aims to underline the importance of hub pricing through structuring a virtual gas trade hub in Turkey. [ABSTRACT FROM AUTHOR]

A reduction in greenhouse gases has become an inescapable requirement. An effective scenario for achieving carbon neutrality is to develop a hydrogen economy. Its success, however, requires strict control of the different processes involved in planned hydrogen chains. The energy chain considered in this paper is a stationary application which involves the production of hydrogen by electrolysis (a power-to gas process) and its combustion in gas turbine combined cycles to generate electricity (a gas-to-power process). In such applications, the need is twofold: (i) to control the risk of explosive atmospheres by performing safe gas detection in the presence of hydrogen and (ii) to secure the reliability of all chain processes using hydrogen-rich gases by achieving reliable analyses of these gases. This paper is dedicated to the development of hydrogen energy to decarbonize the thermal production of electricity. We will first describe the hydrogen chain that would best suit the power generation sector. Then, we will highlight the properties of hydrogen that are critical for its reliable operation. Finally, we will review the sensing technologies suitable for hydrogen-containing fuels. This review paper was published as part of a Joint Industrial Project (JIP) aimed at enabling the safe and reliable deployment of hydrogen energy. [ABSTRACT FROM AUTHOR]

Abstract This work introduces and discusses the impacts of the water bridge on gas adsorption and diffusion behaviors in a shale gas-bearing formation. The density distribution of the water bridge has been analyzed in micropores and meso-slit by molecular dynamics. Na+ and Cl− have been introduced into the system to mimic a practical encroachment environment and compared with pure water to probe the deviation in water bridge distribution. Additionally, practical subsurface scenarios, including pressure and temperature, are examined to reveal the effects on gas adsorption and diffusion properties, determining the shale gas transportation in realistic shale formation. The outcomes suggest carbon dioxide (CO2) usually has higher adsorption than methane (CH4) with a water bridge. Increasing temperature hinders gas adsorption, density distribution decreases in all directions. Increasing pressure facilitates gas adsorption, particularly as a bulk phase in the meso-slit, whereas it restricts gas diffusion by enhancing the interaction strength between gas and shale. Furthermore, ions make the water bridge distributes more unity and shifts to the slit center, impeding gas adsorption onto shale while encouraging gas diffusion. This study provides updated guidelines for gas adsorption and transportation characteristics and supports the fundamental understanding of industrial shale gas exploration and transportation.

The growing demand for natural gas as a vital energy source underscores the need to optimize gas transportation networks. This optimization involves reconciling conflicting goals, such as maximizing delivery flow rate, minimizing power and fuel consumption, and optimizing line pack. To address this complexity, and introducing a novel multi-objective optimization method that builds upon the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The study outlines the fundamental research design, which entails applying the TOPSIS-based multi-objective optimization approach to gas transportation networks. This method generates a range of Pareto optimal solutions, equipping decision-makers with multiple viable options. Key outcomes underscore the efficacy of the proposed strategy. The investigation of three case studies reveals that the TOPSIS-based multiobjective optimization technique yields more economical networks than alternative methods. This showcases its potential in augmenting the efficiency and cost-effectiveness of natural gas transmission networks. In conclusion, this study advances gas transportation network optimization by introducing an innovative multi-objective optimization technique grounded in TOPSIS. The approach offers decision-makers an array of Pareto optimal solutions, aiding their selection of the most favorable one. The results emphasize the technique's capacity to develop economical networks and its versatility across various gas transportation scenarios. Moreover, incorporating this approach into existing optimization frameworks holds the promise of overall enhancements in gas transportation network performance. [ABSTRACT FROM AUTHOR]

The optimization of gas pipeline networks plays a pivotal role in ensuring the efficient and economically viable transportation of natural gas. In this research, we have developed a comprehensive mathematical model capable of analyzing diverse network configurations, encompassing both linear and branched topologies. Our scientific investigation aims to explore the optimization potential of gas pipeline networks, employing a sophisticated and systematic approach to enhance network design and operation. The overarching objective is to achieve maximum efficiency and reliability in gas delivery to customers. The optimization process focuses on minimizing power requirements, maximizing gas flow rate, minimizing the fuel consumption, and maximizing line pack to ensure the optimal utilization of the pipeline infrastructure. To accomplish these objectives, our study employs advanced mathematical models that accurately depict network behavior, cutting-edge simulation tools to explore various operational scenarios, and state-of-the-art optimization algorithms to identify the most favorable network configuration and operating conditions. To facilitate this optimization process, we have incorporated the VIekriterijumsko KOmpromisno Rangiranje (VIKOR) method, a potent multi-criteria decision-making technique. Through the application of this approach to two case studies, we have demonstrated its effectiveness in identifying optimal network configurations. Furthermore, we have conducted an analysis to determine the total cost and fuel consumption associated with different network configurations, offering valuable insights for decision-making purposes. The results of our study underscore the superiority of our approach in identifying more economical networks compared to existing methods. By embracing the proposed approach, gas transportation networks can be optimized to achieve superior cost-efficiency and reduced fuel consumption. [ABSTRACT FROM AUTHOR]

Ultralow-temperature fluids (such as liquid nitrogen, liquid CO2) are novel waterless fracturing technologies designed for dry, water-sensitive reservoirs. Due to their ultralow temperatures, high compression ratios, strong frost heaving forces, and low viscosities, they offer a solution for enhancing the fracturing and permeability of low-permeability reservoirs. In this study, we focus on the combined effects of high-pressure fluid rock breaking, low-temperature freeze-thaw fracturing, and liquid-gas phase transformation expansion on coal-rock in low-permeability reservoirs during liquid nitrogen fracturing (LNF). We systematically analyze the factors that limit the LNF effectiveness, and we discuss the pore fracture process induced by low-temperature fracturing in coal-rock and its impact on the permeability. Based on this analysis, we propose a model and flow for fracturing low-permeability reservoirs with low-temperature fluids. The analysis suggests that the Leidenfrost effect and phase change after ultralow-temperature fluids enter the coal support the theoretical feasibility of high-pressure fluid rock breaking. The thermal impact and temperature exchange rate between the fluid and coal determine the temperature difference gradient, which directly affects the mismatch deformation and fracture development scale of different coal-rock structures. The low-temperature phase change coupling fracturing of ultralow-temperature fluids is the key to the formation of reservoir fracture networks. The coal-rock components, natural fissures, temperature difference gradients, and number of cycles are the key factors in low-temperature fracturing. In contrast to those in conventional hydraulic fracturing, the propagation and interaction of fractures under low-temperature conditions involve multifield coupling and synergistic temperature, fluid flow, fracture development, and stress distribution processes. The key factors determining the feasibility of the large-scale application of ultralow-temperature fluid fracturing in the future are the reconstruction of fracture networks and the enhancement of the permeability response in low-permeability reservoirs. Based on these considerations, we propose a model and process for LNF in low-permeability reservoirs. The research findings presented herein provide theoretical insights and practical guidance for understanding waterless fracturing mechanisms in deep reservoirs. [ABSTRACT FROM AUTHOR]

The increase in wind penetration and the stochastic nature of wind can cause some wind power to be curtailed, leading to a loss of revenue. Wind farm owners can invest in power to gas (P2G)--compressed natural gas (CNG) truck systems to utilize the curtailed wind power that would otherwise have been wasted. This paper proposes a coordinated operation and optimal sizing strategy of P2G and CNG trucks. P2G derives its power from curtailed wind power and also purchases electricity at low prices to facilitate methane (natural gas) production. The methane is directly stored in CNG trucks, which are used as temporary storage and as a means of transporting the gas, thereby reducing costs by eliminating storage tank. Firstly, a coordinated operation strategy for P2G and CNG trucks considering curtailed wind power and electricity purchased from the grid is presented. Secondly, an optimal sizing optimization model to determine the capacity of P2G and the number of CNG trucks using particle swarm optimization is presented, considering the coordinated operation strategy and operation constraints to maximize profit when the proposed system participates in the retail gas market. Finally, case studies were conducted to verify the viability of the proposed strategy using curtailed wind power data, electricity price data, and gas price data. Result show that optimal capacity of the P2G plant is 9.9 MW, and the optimal number of CNG trucks is 2. There is a 19.8% cost reduction with a payback period of 5.728 years compared to the conventional strategy with a payback period of 8.52 years. 89.74% of curtailed wind power is utilized, while only 10.26% of curtailed wind power is unutilized. Higher utilization of curtailed wind power that would otherwise have been wasted is achieved. The system earns a profit by selling the produced natural gas to a retail gas market. [ABSTRACT FROM AUTHOR]

The increase in wind penetration and the stochastic nature of wind can cause some wind power to be curtailed, leading to a loss of revenue. Wind farm owners can invest in power to gas (P2G)—compressed natural gas (CNG) truck systems to utilize the curtailed wind power that would otherwise have been wasted. This paper proposes a coordinated operation and optimal sizing strategy of P2G and CNG trucks. P2G derives its power from curtailed wind power and also purchases electricity at low prices to facilitate methane (natural gas) production. The methane is directly stored in CNG trucks, which are used as temporary storage and as a means of transporting the gas, thereby reducing costs by eliminating storage tank. Firstly, a coordinated operation strategy for P2G and CNG trucks considering curtailed wind power and electricity purchased from the grid is presented. Secondly, an optimal sizing optimization model to determine the capacity of P2G and the number of CNG trucks using particle swarm optimization is presented, considering the coordinated operation strategy and operation constraints to maximize profit when the proposed system participates in the retail gas market. Finally, case studies were conducted to verify the viability of the proposed strategy using curtailed wind power data, electricity price data, and gas price data. Result show that optimal capacity of the P2G plant is 9.9 MW, and the optimal number of CNG trucks is 2. There is a 19.8% cost reduction with a payback period of 5.728 years compared to the conventional strategy with a payback period of 8.52 years. 89.74% of curtailed wind power is utilized, while only 10.26% of curtailed wind power is unutilized. Higher utilization of curtailed wind power that would otherwise have been wasted is achieved. The system earns a profit by selling the produced natural gas to a retail gas market.

The course towards active development of the Arctic zone of the Russian Federation by fuel-and-energy companies involves the development of new methods and approaches to the storage and transportation of natural gas to reduce the negative impact on the ecosystems of cold regions while maintaining the economic feasibility of their use. This work proposes a method for optimizing the technology for transporting and storing natural gas in the form of gas hydrates using soy lecithin as a promoting additive. Experimental methods showed that the addition of soy lecithin to a concentration of 0.5 wt % is on a par with the most efficient promoter of hydrate formation—the surfactant sodium dodecyl sulfate at a concentration of 0.1 wt %. However, a comparison of environmental characteristics demonstrates a clear advantage of soy lecithin. In addition, it was demonstrated that the synthesis of methane hydrate from ground frozen solutions of soy lecithin is at least three times faster than that from liquid solutions. [ABSTRACT FROM AUTHOR]

The need to implement projects for the decarbonization of technological processes is relevant in connection with the international climate agenda. To reduce greenhouse gas emissions, especially in Scope 3, carbon sequestration activities are indispensable, which can be implemented in various ways. Of great interest is the creation and implementation of industrial carbon sequestration technologies that use the existing oil and gas infrastructure, and in addition, allow obtaining additional benefits by increasing oil and gas recovery. The implementation of this technology largely depends on the environmental and economic feasibility of the project, which is influenced by the selected technologies for capturing and cleaning gas from impurities, the length of the pipeline to the field, a reasonable injection technology, an emergency monitoring system, and many other factors. For this reason, scientific and practical research in this direction are of practical importance and are quite relevant. The purpose of our study is aimed at reducing the risks of oil and gas companies in the transportation of carbon dioxide from the place of formation to the place of use when injected into the reservoir to enhance oil or gas recovery. The article presents the results of the analysis of possible emergency situations during the transportation of carbon dioxide to the place of injection. Recommendations are given to prevent them, namely, equipping the route of the pipelines being designed with pressure sensors, justifying the reaction time to stop the compressor equipment, which is no more than 6 minutes and the departure of technical specialists to the emergency facility no earlier than 15 minutes after the incident. It is noted that in order to reduce pipeline corrosion and prevent carbon dioxide leaks, it is recommended to comply with the conditions under which the gas is in a supercritical state, in addition, to purify the gas from impurities in the transported carbon dioxide stream and use a corrosion-resistant material for the manufacture of the pipeline. [ABSTRACT FROM AUTHOR]

This paper presents the results of the study of hydrate formation kinetics at 273.2 K and initial pressure of about 5 MPa in powder hydrogel systems stabilized by hydrophobic nanoparticles. The influence of the aqueous phase used to saturate hydrogel on hydrate formation kinetics was studied. The stability of the systems in hydrate formation–dissociation cycles, i.e., their ability to maintain the hydrate growth rate and water-to-hydrate conversion at a high level in multiple reuses, was assessed. [ABSTRACT FROM AUTHOR]

Here, the concept of "aerofluidics," in which a system uses microchannels to transport and manipulate trace gases at the microscopic scale to build a highly versatile integrated system based on gas‒gas or gas‒liquid microinteractions is proposed. A kind of underwater aerofluidic architecture is designed using superhydrophobic surface microgrooves written by a femtosecond laser. In the aqueous medium, a hollow microchannel is formed between the superhydrophobic microgrooves and the water environment, which allows gas to flow freely underwater for aerofluidic devices. Driven by Laplace pressure, gas can be self‐transported along various complex patterned paths, curved surfaces, and even across different aerofluidic devices, with an ultralong transportation distance of more than 1 m. The width of the superhydrophobic microchannels of the designed aerofluidic devices is only ≈42.1 µm, enabling the aerofluidic system to achieve accurate gas transportation and control. With the advantages of flexible self‐driving gas transportation and ultralong transportation distance, the underwater aerofluidic devices can realize a series of gas control functions, such as gas merging, gas aggregation, gas splitting, gas arrays, gas‒gas microreactions, and gas‒liquid microreactions. It is believed that underwater aerofluidic technology can have significant applications in gas‐involved microanalysis, microdetection, biomedical engineering, sensors, and environmental protection. [ABSTRACT FROM AUTHOR]

Chlorine (Cl2), ammonia (NH3), and sulphur dioxide (SO2) are three typical toxic gases of tank-vehicle transportation. it is necessary to conduct online detection of these gases to ensure transportation safety and exhaust emission monitoring. In this study, tin dioxide (SnO2)n (n = 1–3) modified molybdenum (IV) telluride (MoTe2) monolayer were selected to explore its adsorption characteristics towards Cl2, NH3, and SO2 gases. All calculations are based on density function theory, geometric structure, charge transfer, adsorption energy, the density of states, and molecular orbitals were taken into account to compare and analyze the adsorption performance of the gas-sensing material before and after surface modification. The results show that these three gases are physically adsorbed on the intrinsic material. The modified (SnO2)n (n = 1–3) are all stably bound to the MoTe2 surface. For both Cl2 and NH3, the adsorption energies are in order of SnO2-MoTe2 > (SnO2)2-MoTe2 > (SnO2)3-MoTe2. And the adsorption energies for SO2 can be ranked as (SnO2)3-MoTe2 > SnO2-MoTe2 > (SnO2)2-MoTe2. The significant changes in electrical conductivity indicate the modified MoTe2 system consistently showed excellent sensitivity to the three gases. Therefore, the (SnO2)n-modified MoTe2 system is expected to be a candidate gas-sensing material for Cl2, NH3, and SO2, opening up a new perspective on MoTe2 in the field of gas detection.

In modern geopolitical conditions, the transportation of energy resources and, in particular, liquefied natural gas to the Kaliningrad region has acquired key importance. The existing infrastructure facilities and technical devices, in particular the underground gas storage «Kaliningrad» and the floating Storage Regasification Unit «Marshal Vasilevskiy», make it possible to overcome the current crisis in many ways. At the same time, it should underline that the implemented method of liquified natural gas transportation to the Kaliningrad region and its regasification has different drawbacks, as a result of natural losses and imperfections of technological solutions, part of the liquefied gas may be lost. The article presents the results of a study of the causes and preliminary projected volumes of losses of liquefied natural gas during its transportation by the floating Storage Regasification Unit «Marshal Vasilevskiy» from the port of Ust-Luga to the Romanovo underground gas storage with subsequent regasification and injection into underground reservoirs. The analysis of possible technical and technological solutions allowing to reduce the volume of losses and save the transported liquefied natural gas for subsequent use is carried out.

Natural gas is a fossil fuel-generated deep underground containing small amounts of natural gas liquid and non-hydrocarbon gases. Due to its gaseous phase, the volume of natural gas needs to be considered in the distribution process. The capacity of natural gas reserves' production and distance from the gas field to consumer are both related to the cost of production; the smaller the gas reserves, the greater the production cost and the longer the distance the higher the cost per mmscfd. This study will use the multi-attribute decision-making method to determine the most appropriate natural gas distribution model referring to the market priority listing. Besides that, the sensitivity analysis method will also be used in LCCA calculations to obtain the best economic parameters. The result of this study is the highest natural gas price that can be accepted in Indonesia is US$ 6/MMBTU, and the most beneficial model for low-capacity natural gas is CNG, with the potential market that can be reached from a 300 km distance are city gas and power plant. [ABSTRACT FROM AUTHOR]

High-power proton exchange membrane (PEM) fuel cell vehicles are important for the realization of carbon neutrality in transportation. However, it is difficult to maintain enough fuel supply and quick water removal capacity at a high current density where reactant gas transportation and water concentration are directly affected by flow channel configurations. This study aims to investigate the tapered slope effects of a flow channel on fuel cell performance using a 3-D CFD model. The positive, negative, zero and hybrid tapered slopes are proposed to illustrate the fuel cell voltage, reactant gas and water vapor concentration in the flow channels. Among them, the flow channel with a positive tapered slope performs better, especially at a high current density. Then, the positive tapered slope effects are discussed, including different tapered slopes, inlet depths and widths of flow channels. The results show that the larger the tapered slope, the smaller the depth and width, and the better the fuel cell performs; the corresponding current densities are increased by a maximum of 6.53%, 12.72% and 61.13%. The outcomes stated above provide a key direction for flow channel design that can particularly achieve higher fuel cell power density at high current densities. [ABSTRACT FROM AUTHOR]

Accidents on gas pipelines cause significant damage to the national economy and the economy of the state. Thus, it is necessary to always be prepared for such situations in order to restore the normal operation of the gas pipeline as soon as possible. An important role is played by the execution time of the control actions to localize the accident, pump out the gas, and change the operating modes. It is essential that such control be undertaken, especially if such a situation occurs near a gas-measuring installation for measuring the amount of vented gas. Therefore, the control actions must be error-free in order to quickly stop the non-stationary process, which can lead to undesirable consequences. The paper presents a mathematical model of the operation of the pipeline, developed for the management of the pipeline in an emergency. The analysis of the problem of the occurrence of accidents was carried out, and the effect of liquid on its walls was modeled when the operating mode of the pipeline changed. An example is presented using a numerical model carried out in ANSYS, as well as being analyzed analytically. The results of the calculations are presented, and special attention is paid to the parameters influencing the change in the operating mode of the pipeline. [ABSTRACT FROM AUTHOR]

Dynamic and precise manipulation of the gas flow in a liquid environment through a facile and reliable approach is of great importance for directional gas transportation and multiphase chemical reactions. In this research, elastic superhydrophobic strings were prepared by a one-step, non-fluorinated dip-coating strategy. The surface-treatment string demonstrated a good superaerophilicity underwater. By simply elongating or shortening superaerophilic strings, the gas flux underwater was precisely manipulated in a gas-siphon underwater experiment. The result reveals that a large strain of the treated string induces a low gas flow, and a rope woven with more strings results in a larger range of gas flow regulation. The elastic superhydrophobic/superaerophilic string was utilized to adjust the reaction time of carbon dioxide and sodium hydroxide aqueous solution successfully. Furthermore, in a wet oxidation experiment for treating simulated flue gas composed of nitric oxide (NO), nitrogen and oxygen, superhydrophobic and stretched strings with a strain of 200% demonstrated a 7.9% higher NO removal efficiency than that of untreated strings. Interestingly, NO removal efficiency can be regulated by mechanical stretching of gas-conducting strings. We believe that this facile and low-cost approach provides a valid method of on-demand manipulation of the gas flow for underwater gas transportation. [ABSTRACT FROM AUTHOR]

Transportation of fluid is a very important aspect of process industries, especially for oil and gas industries. Pipelines have been considered as the most effective and safest way of transporting fluids. Transportation of gas through a pipeline is an energy-intensive process; hence, energy optimization in gas transportation networks is an important issue to be considered while framing the environmental policies. In this paper, a novel graphical methodology based on pinch analysis approach for simultaneous minimization of capital investment and compression energy requirement in gas allocation network with the aid of thermodynamic relations is developed. The results of the proposed methodology are expressed as a Pareto optimal front. The ε-constraint method is used to generate Pareto optimal front for the two objectives. Identifying the relationship between capital investment and energy requirement gives the opportunity to the decision-maker for choosing the suitable optimal operating point based on the operating and economic conditions of the process. This result allows the planner to calculate the effects via increasing or decreasing energy requirement or capital investment. The applicability of the proposed methodology is demonstrated through two illustrative examples. [ABSTRACT FROM AUTHOR]

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Recently, research focus has shifted from the prevention of hydrate formation in oil/gas pipelines, to the utilization of gas hydrate in various areas of application, such as cold storage, district cooling, and gas transportation. This study, investigated the pressure drop and flow pattern analysis of CO2 hydrate slurry in the presence of anti-agglomerant in a flow loop. A series of experiments were carried out on CO2 hydrate slurry with (10 to 32) % mass fractions at flow rates of (5 to 7) kg/min in the presence of (0, 0.3, 0.5, 0.7 and 1.0) wt.% concentration of Tween 80 (Polyoxyethylene (20) sorbitan monooleate) in a flow loop. The results show that the CO2 hydrate slurry can be divided into two zones based on the pressure drop and temperature behavior; an active formation region, and a less active formation region. It was found that as the hydrate slurry mean flow rate was increased, the gradient of the pressure drop increased. From the flow visualization, three different flow regimes exist for CO2 hydrate slurries, namely homogeneous, heterogeneous, and bedding flow, and those flow regimes were highly dependent on the hydrate fraction in the slurry mixture. [ABSTRACT FROM AUTHOR]

In gas pipeline networks, the set-points should be carefully tuned to minimize the fuel consumption of compressor stations and meet the network requirements. In practice, the real demand has some variations over the forecasted one and consequently utilizing an appropriate controller to minimize the fuel consumption and manage the network variations is inevitable. The model predictive control is a great choice for systems with long delay such as gas networks. In this paper, an intelligent nonlinear model predictive control of a gas pipeline plant is proposed. It models the plant in fully transient state by a multi-layer perceptron neural network. The prediction power of the neural network is used to predict the plant output over a receding horizon. Initially, the network is trained offline and is then paralyzed with the real plant for online training. The proposed strategy consists of two main stages. In the first stage, the compressor set-points are optimized in the open loop condition considering the forecasted demand over a receding horizon and the resulting output pressures are chosen as the reference trajectories for the closed loop system. In the second stage, the controller is applied to compensate the demand variations. The optimization task is carried out using particle swarm optimization gravitation search algorithm (PSOGSA). Numerical results confirm the accuracy and robustness of the proposed controller in the presence of demand variations, noise and uncertainties. [ABSTRACT FROM AUTHOR]

As known, the EU Commission and the Agency for the Cooperation of Energy Regulators (also ACER) are envisaging the possibility to modify the balance of tasks and powers currently in place between ACER and the European Network of Transmission System Operators for Gas (also ENTSOG). Such an initiative, already foreseen by ACER through the "Energy Regulation: A Bridge to 2025 Conclusions Paper - Recommendation of the Agency on the regulatory response to the future challenges emerging from developments in the internal energy market" (also "Bridge 2025"), could be likely carried out (i) through new legislative acts (namely, amendments of the relevant Basic Regulations) and/or (ii) through implementing acts of the Third Energy Package, such as Regulations adopting Network Codes (also "NC") drafted by ENTSOG according to proceedings provided by Regulation (EC) No 715/2009 (also "Gas Regulation"). [ABSTRACT FROM AUTHOR]

In this article various pipes used for transporting of gas are introduced and pros and cons of each one are elucidated. The pipes are categorized in three different subgroups including metallic, polymeric and metallic-wire reinforced polymeric pipes. Metallic-wire reinforced polymeric pipes are nominated as the best option for usage in high pressure pipelines transporting natural gas. As a result, some information about major manufacturers of this kind of polymeric pipes, raw material, production process and metallic-wire orientation are presented. Finally, from economical point of view, some calculations are done to estimate required amount of polymer and metallic-wire to manufacture such pipes. It is also possible to compare their manufacturing cost with usual metallic and polymeric pipes.

The solid residue and condensate from the pipeline transportation of coke-oven gas are investigated. Approaches to disposal of the residue are considered: pyrolysis in coking batch; furnace incineration at thermal power plants; addition to coal tar; and utilization together with heavy tars from the cleaning of tar storage tanks. The residue contains up to 69.4% naphthalene. A technology is proposed for the utilization of solid residue and condensate from the transportation of coke-oven gas. [ABSTRACT FROM AUTHOR]

[Display omitted] • (SnO 2) n (n = 1–3) modification enhances the adsorption capability of MoTe 2 to Cl 2 , NH 3 , and SO 2. • The sensitivity and selectivity of (SnO 2)n (n = 1–3) modified MoTe 2 were improved compared with the pristine MoTe 2. • This study provides a theoretical basis for preparing a potential resistance-type gas sensor based on monolayered MoTe 2. Chlorine (Cl 2), ammonia (NH 3), and sulphur dioxide (SO 2) are three typical toxic gases of tank-vehicle transportation. it is necessary to conduct online detection of these gases to ensure transportation safety and exhaust emission monitoring. In this study, tin dioxide (SnO 2) n (n = 1–3) modified molybdenum (IV) telluride (MoTe 2) monolayer were selected to explore its adsorption characteristics towards Cl 2 , NH 3 , and SO 2 gases. All calculations are based on density function theory, geometric structure, charge transfer, adsorption energy, the density of states, and molecular orbitals were taken into account to compare and analyze the adsorption performance of the gas-sensing material before and after surface modification. The results show that these three gases are physically adsorbed on the intrinsic material. The modified (SnO 2) n (n = 1–3) are all stably bound to the MoTe 2 surface. For both Cl 2 and NH 3 , the adsorption energies are in order of SnO 2 -MoTe 2 > (SnO 2) 2 -MoTe 2 > (SnO 2) 3 -MoTe 2. And the adsorption energies for SO 2 can be ranked as (SnO 2) 3 -MoTe 2 > SnO 2 -MoTe 2 > (SnO 2) 2 -MoTe 2. The significant changes in electrical conductivity indicate the modified MoTe 2 system consistently showed excellent sensitivity to the three gases. Therefore, the (SnO 2)n-modified MoTe 2 system is expected to be a candidate gas-sensing material for Cl 2 , NH 3 , and SO 2 , opening up a new perspective on MoTe 2 in the field of gas detection. [ABSTRACT FROM AUTHOR]

The article considers the technology absorption natural gas dehydration, systematization of the physical processes occurring in the technological chain of preparation of natural gas. Built fuzzy causal model of the process gas drying based on the combined application of fuzzy inference and neural network approximation. The use of the model enables the structural and parametric optimization of production, aimed at improving the quality of preparation of natural gas. [ABSTRACT FROM AUTHOR]

This study assembles a pipeline mist spraying experiment rig and measures the motion characteristics of water mist in the square pipeline using Particle Image Velocimeter. It explores the settling law of water mist in the pipeline with various spraying pressure and airflow velocity and analyzes their influences. The results indicate that the settling volume increases by 96% in the 1 meter long downstream pipeline, when the spraying pressure increases from 0. 1 MPa to 1. 3 MPa at a set airflow velocity, which is mainly caused by impinging. And the settling volume reduces by 76% in the other parts of the pipeline, which is caused by inertance. But when airflow velocity increases from 1.1 m/s to 10.4 m/s with a set spraying pressure, the settling volume reduces by 24% in the 1 meter long pipeline and reduces by 17% in the other parts. The results will provide a reliable theoretical basis for gas explosion suppression and the parameter setting of water mist in the safe transportation of low concentration gas. [ABSTRACT FROM AUTHOR]

• Different degree of mutual interference among needles is observed in experiments. • The EHD force in the plasma model is used to analyze the mutual interference. • The magnitude of the EHD force is used to quantify the mutual interference. • The EHD force is affected by the space charge and the electric field with different needle arrangements. The ionic wind pump with multi-electrode arrangement is helpful in enlarging its application. However, the arrangement has an inherent mutual interference among the electrodes during discharging process, which have a vital influence on the transportation performance of the ionic wind pump. Meanwhile, the relevance between the mutual interference and the intensity of the ionic wind has not been clearly revealed. In this study, the gas transportation experiments of the multi-needle electrode ionic wind pump are conducted. The intensity variation of the ionic wind with mutual interference is observed in the experiments. A simulation model based on the plasma transportation is proposed to describe the multi-needle discharging process with mutual interference effect. The EHD force is used as the indicator parameter for the intensity of the ionic wind. The experimental results show that the measured mass flow rate of the ionic wind pump is enhanced under dual-row needles and weakened under triple-row needles. Based on the simulation results, the above phenomenon is attributed to variations of the space charge and electric field induced by multi-needle discharging. The added needle electrodes reduce the electric field intensity per needle while increasing the net negative charge in the space. Due to the discharging interference among the needles, the increment of the net negative charge is not proportional to the number of needles. As a result, comparing the three arrangements from the simulations, the electrohydrodynamic (EHD) force of each needle, which is the electric field intensity multiplying by space charge density, increases approximately 45.8% under dual needles and decreases approximately 38.1% under triple needles. The conclusions obtained in this paper can help to guide the design and optimization of the multi-needle ionic wind pump. [ABSTRACT FROM AUTHOR]

Soil radon (Rn) has been monitored since August 2013 at three different soil depths on a campus forest of Fukushima University in Japan, where a large amount of fallout nuclides were released by the accident of Fukushima Daiichi Nuclear Power Plant in March 2011. The primary purpose of this study is to evaluate Rn activity level, variability and factors controlling Rn concentration in soil air using data obtained from August to December 2013. Time series of Rn activity concentration showed depth-dependent variability with an equilibrium value (Rn) during this observation period; 7.5, 14 and 23 kBq m at 0.3, 0.6 and 1.0 m in depth, respectively. Two typhoons passing over the site had a great influence on soil radon level, which was practically used for evaluating effective diffusion coefficient of Rn. Transport mechanism of Rn in soil air was considered to be diffusion-controlled with data sets on changing Rn concentration with time in selected cases that showed decreasing (or increasing) Rn concentration with time at every depth. Important factors affecting soil Rn variability are meteorological parameters, low-pressure front passing over the site, and subsequent precipitation. Time lags of decreasing Rn concentration at different depths after rain indicate a certain relationship of Rn level with moving water (and water vapor) in soil. The findings obtained in this study are important to evaluate the fate of fallout nuclides (radiocesium) in contaminated forest sites using soil radon as a tracer of moving soil air. [ABSTRACT FROM AUTHOR]

A collaborative framework by the synergy of Hazard and Operability (HAZOP) process and the Decision-Matrix Risk Assessment (DMRA) in association with safety-color mapping (SCM) is presented, in order to identify critical points and prioritize risks, and also to visualize the occupational safety and health (OSH) situation, at the workplaces (i) of a sour crude-oil processing industry (SCOPI), and (ii) of a measurement and regulatory station (MRS) in a gas transportation system (GTS), situated in Greece. Firstly, the conventional HAZOP analysis is executed in order to identify the potential fault causes of abnormal conditions (deviations) in the plants. The application of the DMRA-modus is valuable to rank the identified risks (hierarchy of risks). In view of the results, both of the HAZOP pattern (for identifying the hazards) and also the DMRA one (for assessing and ranking the risks), SCMs have been derived for the specific workplaces of the SCOPI and the MRS/GTS station, which could be a precious means for safety managers to appraise the urgency of investing limited budgets in measures preventing particular types of deviations, and also protecting the employees. [ABSTRACT FROM AUTHOR]