Natural Gas Distribution Research Articles

Economic analysis and investment in fuel industry considering risk management by analytical hierarchy process

Natural Gas production and distribution network plans are one of the most common ways to increase energy consumption efficiency. Due to the uncertainty of the economic parameters, the economic justification of this system is very difficult. In this research, the economic risk of investing in urban gas distribution systems has been done with the analytical hierarchy process (AHP). With the development and condensation of urban gas supply networks, accidents caused by gas leaks and other external factors have also increased. Therefore, in recent years, the issue of safety and risk analysis of urban gas networks has received special attention from responsible companies and other urban and safety experts. Gas distribution lines often pass in the vicinity of crowded areas and buildings, so any accident for these lines will lead to a lot of human and financial losses. In the present study, in order to improve the gas supply situation and reduce the risk of failure in Indonesia, urban gas pipelines have been studied to reduce the costs. In this paper, multi-criteria decision making method analysis is used to identify and evaluate the hazards of urban gas pipelines and the risk of occurrence of each hazard is calculated. There was a meaningful relationship based on economic-financial theories between economic factors and investment risk in the gas industry, which emphasizes the greater and more significant effect of exchange rate, failures and inflation rate variables in comparison with other research variables in the matter of controlling investment risk in the gas industry. The effects of changes in energy prices and the economic environment in explaining the behavior of investment risk in this industry have placed the next level of importance. The results showed that with the increase in energy prices, the economics of gas production and distribution risk management plans have improved and the regular trend of energy price increases can guarantee the profitability of fuel consumption optimization plans.

An Asymmetric Bargaining Model for Natural-Gas Distribution

For the sustainable socio-economic growth, the energy supply is one of the foundations for any country. The gas shortage is one of the most significant impediments to any emerging country’s economic progress, making it a contested and disputed resource. In the middle of a supply–demand mismatch, distributing limited available gas across administrative units/provinces with competing requirements is a key challenge. In this work, an asymmetric gas allocation bargaining model is proposed under gas shortage to resolve natural gas-related disputes among Pakistan’s administrative units/provinces. Each administrative unit/province is characterized by its gas demand. Results show that the Nash bargaining theory, when applied under equal and bargaining weights, can address the supply–demand mismatches of the gas sector in Pakistan. Such an approach could help policymakers to make a fair gas-supply management system during gas shortage periods and would help in resolving the disputes between the provinces.

REORGANIZATION OF THE NATURAL GAS DISTRIBUTION COMPLEX OF JSC “MOLDOVAGAZ”

For the reorganization of the gas distribution companies affiliated to JSC “Moldovagaz”, a bibliographic study of the experience of foreign countries in this field was carried out, analyzing the production, financial and economic conditions of the activity of the mentioned companies. In order to improve the organizational structure of the 12 existing natural gas distribution companies, the analysis of technical and economic indicators and their evaluation were performed as well as the development of three management models of the natural gas distribution system. The comparative analysis of the functions and responsibilities of the management of natural gas distribution companies as well as the organizational structural options was performed, thе tаrgеt struсturе оf thе singlе gаs distributiоn соmраny wаs аnаlyzеd. Thе аdvаntаgеs аnd disаdvаntаgеs оf еасh rеоrgаnizаtiоn mоdеl wеrе аnаlyzеd sо thаt in thе еnd it wаs determined and rесоmmеndеd thе орtimаl model.

Interdependent response of three critical infrastructures in a South American megacity

Abstract Critical infrastructures (CIs) are key for the functionality of urban areas. Their failure due to natural disasters or manmade disruptive events could severely obstruct normal city activities, producing considerable social and economic impacts. Understanding CI performance and interdependence during these events is imperative. This study aims to comprehend the independent and interdependent response of three CIs in a South American megacity: Lima, Peru. Topological indicators were used to study three CIs: potable water distribution, electricity distribution and natural gas distribution; five disruption scenarios were modeled. Results show that, compared to the other CIs, the potable water system has the highest redundancy, while the electricity network has the best capacity to connect among all elements. The structure of the natural gas system makes it fragile and susceptible to failures, generating the lowest values across indicators. Regarding the interdependence analysis, certain elements (e.g., medium- and high-voltage substations, water treatment plant, pressure stations) with a high degree of connectivity influence the entire performance of the systems; the interdependent effect exposes some CIs to damage more than others. Earthquakes have a comparatively more negative impact on the CIs studied than manmade disruptive events. In order to reduce vulnerability factors in the three systems, an important mitigation action would be to reduce the centralization of the systems.

Feasibility study of a combined system of electricity generation and cooling from liquefied natural gas to reduce the electricity cost of data centres

Global data centre power demands would expand from 286 TWh in 2016 to around 321 TWh in 2030. The cooling system represents electricity consumption of approximately 40–50% of the total energy used. The global LNG trade has reached 356.1 MTPA. Cold energy equal to 89025 GW is released into the ocean. Therefore, this study focused on the technical and economic feasibility of an LNG receiving terminal combined with a data centre using a direct expansion cycle (DEC), a Rankine cycle (RC) and a combination of Rankine cycle and direct expansion cycle (RC + DEC) under different natural gas distribution pressures to produce a supply of cooling water and electricity to reduce electricity consumption and greenhouse gas emissions. According to the study, the RC + DEC produces the maximum cold water at 7 °C, with the total cold energy of 44.23 MW which is sufficient for cooling a data centre with a capacity of 5345 racks, to reduce the electricity for conventional cooling system is 13521 kWh and generated electricity form turbine is 9968 kWh. This research has the potential to reduce the operating costs of data centres by more than USD 23.87 million per annum as well as CO2 emissions by 83859 t per annum with exergy efficiency of 78.94%. In an economic study, indicated a payback period of 1.60 years with an IRR of 62%.

Development Design of Risk Study of Natural Gas Pielines Dissemination and Substainment Upgrade of Safety Enactment

Abstract: The study describes the basic features, design, maintenance, and risks of natural gas transportation. The paper begins with a discussion of the natural gas distribution networks, which complete the natural gas transit. Accidents on the distribution gas line might jeopardize urban safety. The primary dangerous implications of a natural gas pipeline breakdown are outlined. Correct design, installation, and maintenance limit the incidence and severity of these accidents: a quick summary of the key technical requirements. Keywords: Release rate, Natural Gas pipeline, Natural gas pipeline design, Risk assessment.

Experimental and numerical investigation on development of a method for measuring the rate of natural gas leakage

Measuring gas leakage flow with conventional flow metric methods is impossible due to the extremely low flow rate, the uncertain flow path of gas emitted into the environment, and the inability to detect the exact location of leakage. However, quantifying the amount of natural gas released into the environment is critical because, in addition to resource depletion, natural gas leakage results in the emission of methane gas, a highly potent greenhouse gas. The purpose of this study is to develop a method for determining the leakage rate of gas from household gas pipes that branch off from natural gas distribution lines and their connections. In this method, through passing a forced airflow over gas leakage pores, a mixture of gas and air is created, and then the gas leakage volumetric flow rate is determined using a relationship between the volumetric flow rate of the gas-air mixture and the gas concentration value in the mixture. The first step involves developing a three-dimensional numerical model of a gas branch based on its actual conditions. Numerical simulations establish the model's overall geometry and various components to accurately predict the leaking gas flow rate from the outlet gas concentration value. A physical model based on the numerical results was constructed to validate the numerical solution's results. A gas leak simulator setup was designed and built to verify the results as well as the device's performance accuracy. Measurements were conducted in four different airflows and nine distinct leakage flows. Volumetric flow rates calculated using the proposed method are extremely close to the actual values. Additionally, the numerical solution produced results within an acceptable range of error compared to the experimental results. The measurement errors of this method were less than ±10% in all cases and less than ±5% in approximately 75% of cases.

Natural gas as a vehicular fuel in Brazil: Barriers and lessons to learn

This study aims to analyze the adoption and growth of light-duty natural gas vehicles in Brazil and observe how state incentives and taxes impacted the development of this market at the state level. Brazil's light-duty natural gas vehicles market has slowed its growth considerably since the states with the largest share in the country, Rio de Janeiro and São Paulo, have diverged in the progress of natural gas vehicles. To clarify what led to this scenario, we selected and explored seven parameters: i) availability of natural gas distribution network; ii) the number of certified conversion garages; iii) historic compressed natural gas fuel prices; iv) state value-added taxes; v) motor vehicle property taxes; vi) vehicle-to-refueling-station index and; vii) payback period. In conclusion, it was found that state market incentives are fundamental for the continuous development of alternative fuels such as natural gas to the already established liquid fuels in the country. In Rio de Janeiro, the advantages obtained through tax incentives to compressed natural gas and motor vehicle property taxes are crucial to decrease payback time and strengthen the price of natural gas. Otherwise, in the state of São Paulo, the lowest state value-added tax levied on hydrated ethanol and, consequently, the smallest price difference between fuels hinders the development of the compressed natural gas market.

Environmental Injustices of Leaks from Urban Natural Gas Distribution Systems: Patterns among and within 13 U.S. Metro Areas.

Natural gas leaks in local distribution systems can develop as underground pipeline infrastructure degrades over time. These leaks lead to safety, economic, and climate change burdens on society. We develop an environmental justice analysis of natural gas leaks discovered using advanced leak detection in 13 U.S. metropolitan areas. We use Bayesian spatial regression models to study the relationship between the density of leak indications and sociodemographic indicators in census tracts. Across all metro areas combined, we found that leak densities increase with increasing percent people of color and with decreasing median household income. These patterns of infrastructure injustice also existed within most metro areas, even after accounting for housing age and the spatial structure of the data. Considering the injustices described here, we identify actions available to utilities, regulators, and advocacy groups that can be taken to improve the equity of local natural gas distribution systems.

A Review of the Impact of Hydrogen Integration in Natural Gas Distribution Networks and Electric Smart Grids

Hydrogen technologies have been rapidly developing in the past few decades, pushed by governments’ road maps for sustainability and supported by a widespread need to decarbonize the global energy sector. Recent scientific progress has led to better performances and higher efficiencies of hydrogen-related technologies, so much so that their future economic viability is now rarely called into question. This article intends to study the integration of hydrogen systems in both gas and electric distribution networks. A preliminary analysis of hydrogen’s physical storage methods is given, considering both the advantages and disadvantages of each one. After examining the preeminent ways of physically storing hydrogen, this paper then contemplates two primary means of using it: integrating it in Power-to-Gas networks and utilizing it in Power-to-Power smart grids. In the former, the primary objective is the total replacement of natural gas with hydrogen through progressive blending procedures, from the transmission pipeline to the domestic burner; in the latter, the set goal is the expansion of the implementation of hydrogen systems—namely storage—in multi-microgrid networks, thus helping to decarbonize the electricity sector and reducing the impact of renewable energy’s intermittence through Demand Side Management strategies. The study concludes that hydrogen is assumed to be an energy vector that is inextricable from the necessary transition to a cleaner, more efficient, and sustainable future.

An experimental investigation on using heat pipe heat exchanger to improve energy performance in gas city gate station

Natural gas pressure drops in city gate stations, in the natural gas distribution network, and bypassing through throttle valves. On the other hand, sudden gas pressure drop causes extreme temperature drop. To prevent natural gas from being hydrated in city gate stations, a water bath heater is used, leading to heating natural gas before the pressure reduction stage.The main consequence of this research is the consideration of the challenge of low thermal efficiency in water bath heaters and the high potential of flue gases, which leads to the preheating of the gas by heat loss recovery and consequently improving the energy performance of the whole system.In this study, a heat pipe heat exchanger was laboratory designed and constructed by using the ε-NTU method. The heat exchanger performs to recover partly the waste energy of flue gas emitted to the environment through heat pipes. This has been investigated in several experiments, based on conducted studies, measured data from a city gate station during a year, and also corresponding the experimental results with real conditions. In addition, to determine energy saving in fuel consumption, the city gate stations process was simulated in HYSYS software and evaluated according to gas temperature in new conditions.As major findings applying heat pipes reduces natural gas consumption by 510,132 SCM a year; it also annually prevents 756 tons of CO2 from being emitted off a city gate station.

On the effectiveness of the use of polyethylene pipes with coextrusion layers in natural gas distribution systems

The article analyzes the efficiency factors of the use of polyethylene pipes with coextrusion layers of PE100-RC on the outer and / or inner surface of the pipe in the natural gas distribution systems. It is noted that efficiency factors are manifested at the construction stage and allow reducing capital investments in the construction of gas distribution networks. The proposals for amendments to the current regulatory documentation specifying the requirements to the design, technical characteristics, application, design and installation of polyethylene pipes in gas distribution networks are formulated, the features of the application of PE100-RC polyethylene pipes are presented. An assessment of the economic efficiency of the use of polyethylene pipes with PE100-RC co-extruded layers on the outer and/or inner surface of the pipe in gas distribution networks was carried out.

Investigation on flow distribution of supercritical natural gas in a printed circuit heat exchanger

Printed circuit heat exchanger is considered as an promising candidate for floating storage and regasification unit of liquefied natural gas due to its high compactness and efficiency. The flow maldistribution is an essential issue in practical applications of the printed circuit heat exchanger, which leads to the performance degradation. In this study, the flow distribution of supercritical natural gas in a printed circuit heat exchanger plate is three-dimensionally simulated, and the thermal-hydraulic performance of the channels is investigated. To save the computational cost, a simplified two-dimensional model is proposed. The comparisons of results between the two- and three-dimensional models show that the effects of backflows, vortex, interaction between properties and flow distribution are the reasons that result in the differences between the two models. The findings suggest that the simplified two-dimensional model is capable for engineering demands with the satisfaction of computational accuracy and efficiency. It helps to overcome numerical difficulties and save computational resources in engineering applications such as the PCHE design.

CO2 Pipeline risk assessment and comparison for the midcontinent United States

A comprehensive quantitative risk assessment for the construction and operation of CO2 transportation networks considered for the Midcontinent United States was conducted. The results showed risks associated with CO2 pipelines were significantly less than those of other pipeline types. The assessment used four conceptual pipelines of different lengths to discuss risks operators may see. The assessment evaluated the risk associated with construction and operation using data from the US Occupational Safety Health Administration to determine the risk of injury or death for pipeline workers and data from the US Pipeline and Hazardous Materials Safety Administration for CO2, natural gas distribution, natural gas transmission/gathering, and non-CO2 hazardous liquid pipelines to develop quantitative likelihood and severity values leading to risk values. The data for the assessment covered incidents from 2010 to 2017 for CO2 pipelines. The average risk for construction and 30 years of operation for four CO2 pipeline configurations ranging between 79 and 1,546 miles in length was found. The construction and operational risk averaged between $1,400,521 (approximately $0.02/tonne of CO2) for the shorter pipeline (79 miles) and $27,481,939 (approximately $0.10/tonne of CO2) for a longer pipeline (1,546 miles). The largest risks of fatality for CO2 pipelines comes from vehicle transport. The largest operational risk to the pipeline was due to leakage. Public pipeline opposition is also a significant risk; it was not quantified but is addressed.

Feasibility Study of Fuel Oil and Coal Replacement with Natural Gas in Thailand Context

Natural gas is a viable option to oil-based fuels and coal as it has advantage on reliability, domestic availability and more environmental friendliness. This paper assesses the feasibility of replacing fuel oil and coal with natural gas in Thailand's industrial sector. The study covers the identification of regulatory limitation, the projection of fuel demand and prices, and the assessment of financial and economic feasibility of the fuel replacement project. The financial feasibility study shows interesting investment opportunities only for fuel oil users located within 50 kilometers from the compressed natural gas distribution center. On the contrary, the economic feasibility study shows that there is an outstanding value for investment, particularly for the coal replacement. Consequently, it needs strong measures from the government to drive the replacement. The results of the study are expected to be beneficial in energy management and planning for industrial enterprises. They are also expected to assist the government in developing policies to support the country's long-term demand for natural gas.

Low‐carbon coordinated scheduling of integrated electricity‐gas distribution system with hybrid AC/DC network

Under the promotion of low-carbon policies, the coordinated operation of integrated electricity-gas distribution system (IEGDS) considering CO2 emission is of great significance to accelerate the process of energy conservation and could improve the economy of IEGDS. The paper proposes a low-carbon coordinated operation of the IEGDS considering hybrid AC/DC distribution network, carbon capture and carbon storage. Firstly, the coordinated scheduling model of the IEGDS is discussed, with coupling constraints of gas turbines and power-to-gas. Secondly, the paper presents the model of hybrid AC/DC power distribution system, where non-linear network constraints are relaxed into second-order-cone programming forms. Regarding carbon emission, the CO2 produced by fossil fuel burning can be partly captured by carbon capture plant, stored in carbon storage tank, and transported by trucks to carbon storage warehouse that trades with the carbon market. With the cooperation of various components, a comprehensive model considering carbon flow and trading in the distribution system is innovatively presented here. Numerical experiments validate the effectiveness of proposed low-carbon coordinated scheduling model for the integrated electricity and natural gas distribution system.

The potential of the natural gas grid to accommodate hydrogen as an energy vector in transition towards a fully renewable energy system

The temporal and geographical availability of renewable energy sources is highly variable, which imposes the importance of correct choices for energy storage and energy transport systems. This paper presents a smart strategy to utilize the natural gas distribution grid to transport and store the hydrogen. The goal is twofold: evaluating the capacity limits of the grid to accommodate “green hydrogen” for preset increasing shares of renewable energy sources (RESs) and determining at the same time the optimal mix of wind, photovoltaic (PV), biomethane and power-to-gas systems that minimizes the investment and operation costs. To this end, the energy supply system of an entire country is modelled and optimized considering the real characteristics and pressure levels of the gas grid, which is assumed to be the only storage mechanism of green hydrogen. The operational concept is to fill up the gas grid with hydrogen during the day and with natural gas during the night while always consuming the natural gas-hydrogen blend. Green hydrogen is generated by electrolysers powered by PVs, wind turbines and biomethane power systems. Results of the optimizations showed that: i) as long as the share of RES does not exceed 20%, there is no need to use the gas grid as RES storage system, ii) from 20 to 50% of RES share the gas grid receives the surplus of electricity in the peaks that would be necessary to “complete” the dispatchability of RES electricity, iii) above 50%, the excess of electricity in the peaks has to be used to generate the thermal energy required by the consumers. The gas grid can be used as unique renewable energy carrier and storage system up to 65% of RES share.

Current Legislative Framework for Green Hydrogen Production by Electrolysis Plants in Germany

(1) The German energy system transformation towards an entirely renewable supply is expected to incorporate the extensive use of green hydrogen. This carbon-free fuel allows the decarbonization of end-use sectors such as industrial high-temperature processes or heavy-duty transport that remain challenging to be covered by green electricity only. However, it remains unclear whether the current legislative framework supports green hydrogen production or is an obstacle to its rollout. (2) This work analyzes the relevant laws and ordinances regarding their implications on potential hydrogen production plant operators. (3) Due to unbundling-related constraints, potential operators from the group of electricity transport system and distribution system operators face lacking permission to operate production plants. Moreover, ownership remains forbidden for them. The same applies to natural gas transport system operators. The case is less clear for natural gas distribution system operators, where explicit regulation is missing. (4) It is finally analyzed if the production of green hydrogen is currently supported in competition with fossil hydrogen production, not only by the legal framework but also by the National Hydrogen Strategy and the Amendment of the Renewable Energies Act. It can be concluded that in recent amendments of German energy legislation, regulatory support for green hydrogen in Germany was found. The latest legislation has clarified crucial points concerning the ownership and operation of electrolyzers and the treatment of green hydrogen as a renewable energy carrier.

Toward a theory of high reliability for natural gas distribution utilities

High-reliability organizations facilitate the reliable accomplishment of high-risk goals while avoiding catastrophe. Our paper evaluates natural gas utilities in the United States against the features of high-reliability organization (HRO) theory. We ask: 1) How is high-reliability organizational theory applicable to natural gas infrastructure? And 2) How might natural gas hazards be reconsidered using HRO models of industrial organization? We conclude that natural gas organizations are not high reliability but might be in a period of transition toward becoming HROs. Our conclusions are cautionary, noting that the expanded use of this energy source poses substantial environmental and societal risks under present organizational circumstances.

Multi-stage stochastic programming for resilient integrated electricity and natural gas distribution systems against typhoon natural disaster attacks

Recent energy systems have witnessed a large number of extreme weather events due to the global climate change, resulting in severe damages and economic losses. To address this problem, this paper proposes a multi-stage stochastic programming model for resilient integrated electricity and natural gas distribution systems under typhoon natural disasters. A three-stage modeling is employed to quantify the system resilience against the dynamic process of a typhoon, where the network reinforcement, network reconfiguration, and network repairing are coordinated. Moreover, the interaction between the power system and natural gas system during a typhoon attack is reflected in this model. To address the uncertainties introduced by the typhoon moving paths, non-anticipativtity constraints are adopted in the proposed multi-stage stochastic programming model. Case studies on a 33-bus-48-node and a 144-bus-85-node integrated electricity and natural gas distribution systems verify the effectiveness of the proposed method. The results of the case studies show that the current IEGDS is still fragile when facing natural disasters, and building a resilient IEGDS to recover from natural disasters rapidly is meaningful in recent vigorous trends of developing integrated energy systems. By applying the proposed model, the proposed model and strategies can enable the IEGDS to reduce the load curtailment by about 52%, and the total economic loss will be reduced by 54%.