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Chemical Looping Combustion (CLC) is one of the viable and efficient technology to capture the carbon dioxide from combustion process due to inherent removal of nitrogen. In a typical CLC, combustion of fuel takes place in absence of air, where metal oxides such as ilmenite acts as oxygen carriers therefore, the resultant flue gas contains ∼99% by volume of carbon dioxide. The current work focuses on energy analysis of the chemical looping combustion using Rankine cycles of 662 MWth power plant. The thermal cycle under consideration is conceived with idea of integrating the energy flow between fuel and air reactor and as well as preheating the air and fuel before entering the respective reactors. For the comparative study of thermal performance natural gas and syngas with oxygen carriers nickel oxide with alumina and ilmenite are considered respectively. The composition of syngas under consideration is assumed to be the same as that of generated from gasification of bituminous coal. The energy balance shows that the gross thermal efficiency of the natural gas based CLC thermal cycle and syngas based CLC cycles are 44.99% and 44.80% respectively whereas the net efficiency is found to be 40.13% and 37.6% with carbon capture and compression respectively. The reason for large reduction in net efficiency in the case of syngas-CLC plant is attributed to increase in auxiliary power consumption than natural gas-CLC power plant. The carbon dioxide concentration is higher in case of syngas as it contains higher carbon to hydrogen ratio than that of natural gas. It is also found in the study that carbon capture efficiency is 100% in case of natural gas-CLC power plant whereas for syngas-CLC power plant CO2 capture efficiency is 89.55%. [ABSTRACT FROM AUTHOR]

One factor that potential to reduce of gas production in PT. EMP is low level of reliability pipeline network. Beside that it also affects the distribution of gas to the customer. In the long term run, it makes company loss. The solution to increase reliability of the pipeline is to implement Pipeline Integrity Management System (PIMS). This system consist of modeling or simulation carried out through a continuous assessment process of a system in terms of design, construction, operation, maintenance in accordance with natural gas pipelines. The action taken to implement this modeling is to find and integrate existing information, identify the causes of failure and carry out risk analysis, develop integrity management plans, implement integrity management programs. The data will be analyzed by Probability of Failure (POF) and Consequence of Failure (COF). Base on the data analyze, it can be known that 8 line pipe in PT. EMP in medium level risk failure and 2 pipe line in low level risk failure. [ABSTRACT FROM AUTHOR]

Compressed natural gas (CNG) is alternative fuel for internal combustion engines. In diesel engines, compressed natural gas is used by organizing a dual-fuel operation cycle. Spark ignition engines can work both in a mode with CNG only and in dual-fuel mode with gasoline. This paper presents an experimental study of the impact of the use of compressed natural gas as independent fuel, on the effective indexes of a spark ignition engine. The study has been carried out by comparing the engine indexes when operating separately with gasoline and compressed natural gas. The comparison is made both on the basis of the engine load characteristics and the engine speed characteristics at full load. The load characteristics are taken at a constant mean effective pressure dictated by the engine operation with CNG. The speed characteristics at full load are registered at an air-fuel ratio providing maximum braking power when the engine is running on both fuels. A quantitative assessment has been made of the changes in the power indexes, fuel economy parameters and ecological performances of the engine during its operation with both types of fuel. The indicator diagrams of the engine are registered on the studied modes. Based on the indicator diagrams, the changes in some of the burn parameters are analysed. [ABSTRACT FROM AUTHOR]

The power density and fuel efficiency of a diesel engine can greatly be improved using a compressed natural gas-diesel dual fuel (CNG-DDF). At low loads, however, the effect of DDF causes a number of issues, including decreased engine performance and an increase in pollutant output (i.e., CO and NOx) during operation. As a result, a combined approach using backpropagation neural networks (BPNN), genetic algorithms (GA), and particle swarm optimization has been developed to predict and optimize the maximum CNG-DDF engine parameter outputs (cylinder pressure, maximum thermal efficiency, and minimum carbon monoxide) (PSO). To begin with, the DDF engine parameter input was carried out in order to generate experimental data by varying the values of the pilot injection time (Tpi), CNG injection timing (TiCNG), supercharger voltage (Vsp), and injection timing (Ti). Next, a three-replication orthogonal array L25 was used to generate seventy-five experimental data points. Then, using training, testing, and validation, BPNN created a fitness function using the experimental data. The best DDF engine performance was then determined by GA and PSO using the fitness function developed by BPNN. The optimization findings indicated that PSO outperformed GA, with the best cost of PSO being 25% more expensive than the GA outcome. [ABSTRACT FROM AUTHOR]

The article considers the issue of cleaning natural gas from hydrogen sulfide and organic compounds containing sulfur. In order to select the most effective zeolite adsorbents for the conditions of gas filling stations, a large number of experimental studies were conducted on the value and speed of sorption of moisture, H2S, RSH, CO2, CO2 and other components of natural gas. In order to choose the optimal mode of regeneration, its various options were compared in a modeled industrial process pilot plant. The results of these studies made it possible to choose the optimal option, which consists in the following: the driven gas is injected at 320°C, but first (∼1 hour) it is diluted with cold purified gas (30 vol.%) at the entrance to the adsorber. Regeneration duration is 4-5 hours, fuel gas consumption is 185000-230000 m3 per one adsorber. [ABSTRACT FROM AUTHOR]

The purpose of this work is to study the degree and structure of contamination of spent zeolites and their effect on adsorption-desorption characteristics in natural gas desulfurization processes, to determine the number and structure of zeolite transport pores and their role in the adsorption process, to develop an optimal method for the recovery of zeolite waste for their secondary use in desulfurization processes. In solving the above tasks, the methods of physical chemistry, quantitative and qualitative analysis of pollution products, the theory of redox reactions of the gorenje process, methods of calculating mass-heat exchange processes are used in the work. The study of the composition of spent zeolites showed that during long-term operation of zeolites in adsorption-desorption cycles at industrial natural gas desulfurization plants, they are contaminated with oxidation-reduction reaction products contained in raw gas, which leads to the deposition of these products on the zeolite surface and a sharp narrowing of transport pores. [ABSTRACT FROM AUTHOR]

The aim of this work is to develop an open-source fluid-dynamic modeling tool that allows monitoring, controlling, optimizing the existing gas infrastructures which would be useful for further improvement of gas networks. The modeling can be performed both for the steady state and unsteady state conditions, whereas a transient analysis for large-scale networks loses its meaning. A straightforward approach to model simple gas network is based on a solution of the fluid flow basic governing equations, however a more sophisticated for a complex network has to be developed. The electrical analogy concept is an approach which provides a simpler and more robust model, especially in large networks with different and numerous components. In this study, a new model has been developed to investigate a steady state behavior of a sample gas distribution network. [ABSTRACT FROM AUTHOR]

This article presents research in the field of saving natural gas through the use of waste oils in industrial facilities by the method of their safe combustion to obtain thermal energy. [ABSTRACT FROM AUTHOR]

This article presents the prospects of using natural gas for car engines, which can be expressed through, first of all, environmental cleanliness, the abundance of raw materials in our country, and unique motor performance. Therefore, additional air to engines running on natural gas provides opportunities to improve economic efficiency and environmental performance of modern gas engines without making drastic changes to their designs. Information is provided on the development of a set of tools, methods and theoretical foundations aimed at improving the energy-economical and environmental performance of automobile engines by adding air to gas fuel. Furthermore, the article includes the study of the Ravon nexia 3 car with additional air to natural gas, determination of the conditions of its use and the fuel consumption at a distance of 100 km. [ABSTRACT FROM AUTHOR]

For the import substitution of sodium sulfide, which is necessary for the industries of the republic, a new method and technological scheme, as well as the necessary equipment, have been developed. As a result, the cost of the products obtained has been reduced due to the available local cheap feedstock of sodium hydroxide and hydrogen sulfide, which is an impurity of the produced natural gas, and the simplification of the technological scheme of the equipment used. [ABSTRACT FROM AUTHOR]

Experts and researchers are looking for alternatives to traditional jet fuel that are better for the environment because oil reserves are running out, fuel prices are rising, and the aviation industry needs to grow sustainably. Even though biofuels made from biomass are becoming more appealing, some significant problems still need to be solved with how they are made. Thus, natural gas and hydrogen are desirable options for the aviation sector. This article aims to investigate whether or not it is feasible to use natural gas and hydrogen as major jet fuels. It highlights that their reserves are accessible, that they already know how to create them, and that they could utilize them to power the aviation sector if they decided to do so. The preliminary findings indicate that in spite of the challenges associated with cryogenic fuels, a more significant advancement in the aviation sector might be accomplished via the appropriate implementations of such fuels. This is the case despite the fact that these fuels provide their own unique set of challenges. [ABSTRACT FROM AUTHOR]

The existing problem in the natural gas plant is a large amount of water vapor in the pipeline. The water content in the natural gas component reaches 0.3192 weight fraction from the well. The chemical separation in the separator still has a 0.0019 - mole fraction of water, and water content is up to 19.54 lbs/mmscf. The permissible water vapor content in the gas plant is less than 15 lbs/mmscf, which is under pipe specifications. Therefore, it is necessary to carry out a gas dehydration process to reduce the water vapor content of natural gas by the absorption method using triethylene glycol (TEG) absorbents. The research was conducted to determine the impact of temperature, pressure, and purity of lean TEG in reducing water content in the contactor using a commercial simulator. Based on the data obtained at lean TEG 100 is up to 10.03 lbs/mmscf. The sensitivity simulation shows that the lean TEG 90℉ temperature has the lowest water content of 1.012 lbs/mmscf. Meanwhile, with a pressure of 875 psi, the total water content is 1.170 lbs/mmscf. Finally, 99% TEG, a water content of 0.314 lbs/mmscf, is obtained. [ABSTRACT FROM AUTHOR]

The problem emerging in the natural gas plant is carbon dioxide content in the pipeline. Wellhead natural gas can contain as much as 30% carbon dioxide. Meanwhile, the minimum specification required includes no more than 2%-3% carbon dioxide. The separation of CO2 from biogas is indispensable to improve so that its quality can be improved. One of the separation methods is adsorption. The adsorption process was varied at the pressure of 14, 13.5, 13, 12.5, 12, 11.5, 11, 10.5, and 10 bar, while the temperature varied at 335, 330, 325, 320, 315, 313, 310, 305, and 298°K. This study aims to determine the influence of temperature and pressure on the reduction of CO2 in this adsorption process. This research was conducted by simulating Aspen Adsorption using silica drying as an adsorbent. The total CO2 content of 38 % mol was obtained from the wellhead based on actual data. Nine scenarios have been run to estimate the lowest CO2. After running for combining parameters, the higher Pressure and Temperature, the CO2 content in dry gas is 1.0902×10−3 mole fraction. [ABSTRACT FROM AUTHOR]

Parallel compressor gas operation mode is used when the natural gas pressure is still sufficient with one compression stage to reach high pressure; if the gas feed pressure is below the compressor design pressure, it is necessary to increase the pressure to two stages. The purpose of this study was to analyze the effect of changing the gas turbine compressor operating mode from parallel to series due to a decrease in gas well pressure. The ability of a compressor to compress gases under its design pressure can be simulated with a simulator. Parallel compressor operation can be simulated as two-stage compression by being connected in series using the ASPEN HYSYS. The simulation results of the compressor suction pressure drop from 318 psig to 200 psig at the compressor unit at the natural gas processing station of PT. Z show the compressor performance curve is still stable and far from the surge line when used in series operation mode. Recalculation of the surface facilities of the separator and scrubber units shows that the fluid retention is still under 5 minutes, the velocity and momentum of the fluid in the vessels are still below the maximum capacity of the equipment, and the required cooling load is still below the available duty coolers. In the piping system, when operating under compressor design pressure, the fluid velocity value is still below the pipe erosion velocity (for two-phase flow), while for single-phase flow it is below 60 ft/s for the gas phase and 15 ft/s for the liquid phase. Based on the simulation carried out and recalculation of the feasibility of surface facilities, changing the compressor operating mode from parallel to series is feasible and can be carried out safely. [ABSTRACT FROM AUTHOR]