Vadim Fetisov

This study presents a mathematical model to evaluate the performance of gas pipelines during hydrogen injection in a gas pipeline-compressor station. The developed model presents the calculation of methane–hydrogen mixture (CH₄/H₂) transportation through the compressor station, where the compensation of pressure drops in the mass and energy balance takes place. Simultaneously, in the operation of the centrifugal blower system of gas compressor stations, the emissions of CO₂ are considered, considering the mixing of gas media and the compression of CH₄/H₂. This mathematical model is realized for the pipeline transportation of hydrogen, at which the principle of mixture expansion occurs. The aim is to solve the problem of CO₂ emissions at compressor stations. The optimization procedure has been formulated using a system of nonlinear algebraic equalities. The research focuses on the adaptation of existing gas transportation systems to CH₄/H₂ transportation and the impact of environmental risks on the operation of compressor station equipment. In this case, it is possible to determine the quantitative amount of hydrogen that can be added to natural gas. By solving the problem of finding the inner point of sets using the system of nonlinear algebraic equalities, it is possible to obtain the control parameters for safety control of technological modes of CH₄/H₂ mixture transportation. The study findings reveal that the consumption of gas charger and hydrogen was 50.67 and 0.184 kg/s, respectively, and the estimated efficiency resulting from the modified turbine design was 75.1 percent. These results indicate that the equipment operates more efficiently when hydrogen is being transported. The numerical analytical results indicated in this study hold practical significance for design applications. It will assist in identifying and evaluating the restrictions that may develop during the technological, operational, and design stages of decision-making.

A fully dense ZrB2–30 vol% SiC composite containing 5 wt% Si3N4 and 4 wt% phenolic resin (1.6 wt% carbon) was sintered using the hot-pressing route under the external pressure of 10 MPa at 1900 ºC for 2 h. The microstructural evolution and interfacial phenomena were scrutinized using advanced microscopy facilities such as high-resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). The FESEM images showed the ZrB2 and SiC grains without any evidence of Si3N4. The formation of the hexagonal BN (hBN) phase was proven in the sintered composite. The hBN nanosheets had a graphite-like morphology with an average thickness of 20 nm. This phase has a perpendicular orientation to the pressure direction and prevents abnormal ZrB2 grain growth. Two types of ZrB2/SiC interfaces were detected, which exhibited an amorphous phase along with the grain boundary and a clean/smooth interface, resulting from the Si3N4 addition. HRTEM and inverse fast Fourier transform (IFFT) observations disclosed that the d-spacing value in the ZrB2 grain (0.335 nm) is higher than those reported in the literature. Furthermore, it was found that the exerted pressure during the sintering distorted atomic planes. The presence of numerous dislocations within the ZrB2 grains confirmed dislocation creep as the main densification mechanism.

Pipeline transportation is widely regarded as the most cost-effective method for conveying substantial volumes of hydrogen across extensive distances. However, before hydrogen can be widely used, a new pipeline network must be built to reliably supply industrial users. An alternative way to rather expensive investments in new infrastructure could be to use the existing pipeline network to add pure hydrogen to natural gas and further transport the gas mixture in an industrially safe way. The new solution necessities will be examined for compression, transportation, and fire hazard accidents, which have not been scrutinized by other scholars. This study presents the results of a comprehensive analysis of the methane–hydrogen mixture compression process and a mathematical description of the main pipeline operation during gas mixture transportation, considering industrial fire safety issues. By examining a case study involving a main gas pipeline and its associated mathematical model for hydrogen transportation, it becomes feasible to assess the potential hazards associated with various leakage areas and the subsequent occurrence of fires. The findings of this investigation demonstrate that the spontaneous combustion of hydrogen due to leakage from a natural gas pipeline is directly influenced by the proportion of hydrogen present in the gas mixture. If the hydrogen percentage reaches a balanced ratio of 50–50%, it is plausible that the equipment at the compressor station could be subject to detrimental consequences, potentially leading to accidents and fires. Furthermore, the obtained results from modeling in ANSYS Fluent software propose two practical scenarios, which demonstrate that despite the limited research conducted on the safety aspects and the occurrence of fires during the operation of hydrogen gas pipelines, industrial and fire safety necessitate the inclusion of hydrogen transport infrastructure as a pivotal element within the broader framework of hydrogen infrastructure development.

This article presents the results of a numerical experiment and an analysis of temperature fields (coolers for gas) using cooling elements in the case study gas pipeline. An analysis of the temperature fields demonstrated several principles for the formation of a temperature field, which indicates the need to maintain a relative temperature for gas pumping. The essence of the experiment was to install an unlimited number of cooling elements on the gas pipeline. The purpose of this study was to determine at what distance it is possible to install cooling elements for the optimal gas pumping regime, regarding the synthesis of the control law and the determination of the optimal location and assessment of control error depending on the location of the cooling elements. The developed technique allows for the evaluation of the developed control system's regulation error.

The impact of emissions from the fuel and energy sectors adversely affects the environment on the economies of countries. One of these pollutants is volatile organic compounds (VOCs), which contribute to the formation of tropospheric ozone. Emissions of hydrocarbon formation in the form of VOCs occur in four stages of the fuel and energy industry sector: (1) production, (2) processing, (3) transportation, and (4) storage. The oil and gas industry ranks among the top polluting industries in terms of VOC emissions. Research on the negative impact of VOCs, as well as CO₂ emissions from the consequences of the extraction, processing, transport, and storage of oil and gas on the ecosystem of the planet and the population, has begun to be studied by science recently. Typically, these studies were conducted using laboratory and field analyses, as well as using data on anthropogenic emissions in the development of regulatory documents and requirements governing the control of VOC and CO₂ emissions in the oil and gas industry. This paper presents a critical analysis of the literature on research on the negative effects of VOC emissions on the ecosystem and human health because of such factors as production, processing, transportation, and storage of hydrocarbons. This analysis shows the global magnitude of VOC emissions. Data from human‐made emissions from the oil and gas industry and direct emissions from transportation and energy processing were used to figure out how VOCs affect the environment around the world and how far they spread. In conclusion, this study found patterns of VOC emissions that show how important it is to control VOCs during the production, processing, transportation, and storage of oil and gas, as well as how important it is to create a single research base on emissions for each industry sector and on sources of greenhouse gas absorption.

This study determines and presents the capital and operating costs imposed by the use of CO₂ capture technologies in the refining and petrochemical sectors. Depending on the refining process and the CO₂ capture method, CO₂ emissions costs of EUR 30 to 40 per ton of CO₂ can be avoided. Advanced low-temperature CO₂ capture technologies for upgrading oxyfuel reformers may not provide any significant long-term and short-term benefits compared to conventional technologies. For this reason, an analysis was performed to estimate the CO₂ reduction potential for the oil and gas industries using short- and long-term ST/MT technologies, was arriving at a reduction potential of about 0.5–1 Gt/yr. The low cost of CO₂ reduction is a result of the good integration of CO₂ capture into the oil production process. The results show that advanced gasoline fraction recovery with integrated CO₂ capture can reduce the cost of producing petroleum products and reduce CO₂ emissions, while partial CO₂ capture has comparative advantages in some cases.

Nowadays, modern gas supply systems are complex. They consist of gas distribution stations; high-, medium-, and low-pressure gas networks; gas installations; and control points. These systems are designed to provide natural gas to the population, including domestic, industrial, and agricultural consumers. This study is aimed at developing methods for improving the calculation of gas distribution networks. The gas supply system should ensure an uninterrupted and safe gas supply to consumers that is easy to operate and provides the possibility of shutting down its individual elements for preventive, repair, and emergency recovery work. Therefore, this study presents a mathematical calculation method to find the optimal operating conditions for any gas network during the period of seasonal changes in thermal loads. This method demonstrates how the reliability of gas distribution systems and resistance to non-standard critical loads are affected by consumers based on the time of year, month, and day, and external factors such as outdoor temperature. The results in this study show that this method will enable the implementation of tools for testing various management strategies for the gas distribution network.

This work describes the experience in developing and testing software for oil industry automation control systems based on the simulation of technological processes and control systems combined in virtual reality, this approach is called virtual commissioning and is widely used in the world both to create automated process control systems and to simulate interactions between different systems.

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.