scholarly journals Composition and Physical Properties of the Natural Gas Supplied for Domestic Use through the Distribution Network

2018 ◽  
pp. 1-15
Author(s):  
M. C. Fernández-Feal ◽  
B. Sánchez-Fernández ◽  
L. R. Sánchez-Fernández ◽  
J. R. Pérez-Prado
Keyword(s):  
Natural Gas ◽  
Physical Properties ◽  
Relative Density ◽  
Distribution Network ◽  
Calorific Value ◽  
Entry Points ◽  
Domestic Use ◽  
Wobbe Index ◽  
Superior Calorific Value

Aims: To assess the composition of the Natural Gas (NG) supplied for domestic consumption through the distribution network to correlate the physical properties linked to it were to be determined in order to investigate their fluctuations. Study Design:  The samples were analyzed in accordance with the method described in the ISO 6974‑4 standard, “Natural Gas. Determination of Composition with Defined Uncertainty by Gas Chromatography”. Place and Duration of Study: Center of Technology Research, Fuels Laboratory, between January and December 2016. Methodology: Over the course of the year, a total of eighty-four samples of natural gas for domestic use were analyzed.  These were collected at a rate of one per month in seven cities in the geographical zone under study (Galicia_Spain), in which the number of users is significant. Results and Conclusion: The protocols for technical management of the Gas System have a section on quality specifications for Natural Gas at entry points to the system.  This sets limits for only three of the physical properties of natural gas: Wobbe index, superior calorific value and relative density. The figures obtained for Wobbe index, superior calorific value and relative density from the eighty-four samples studied showed that the quality of the Natural Gas distributed remained steadily within the acceptable limits throughout the whole year. The values for standard deviations bore witness to the fact that any variations did not significantly alter the quality of the Natural Gas supplied. The concentrations of the odorant, THT, were always above the recommended value of 18.0 mg/Nm3, the fluctuations noted over the course of the year were such as to make it possible to see them as excessive. In some instances, a high concentration of odorant may lead users to erroneous impressions, so that they come to think that there are leaks from the gas-pipes or even that the gas is not burning properly.

scholarly journals ANALYSIS OF METHODS AND MEASURES OF MEASUREMENT OF HEAT OF COMBUSTION OF NATURAL GAS IN UKRAINE AND ABROAD

2019 ◽  
pp. 78-87
Author(s):  
K. M. Shynkaruk
Keyword(s):  
Natural Gas ◽  
Calorific Value ◽  
Energy Performance ◽  
Heat Of Combustion ◽  
Indirect Methods ◽  
Global Trends ◽  
The Relationship ◽  
Direct And Indirect Methods ◽  
Qualitative Characteristics

In connection with the increase in prices for natural gas, the urgent issue is to calculate not only the amount of gas consumed, but also its quality precisely with the consumer. The quality of gas is the compliance of its physicochemical parameters with established regulatory documents. With the current gas accounting and payment system in Ukraine, consumers using the same number of cubic meters receive different heat of combustion. The paper analyzes the regulatory framework for assessing the energy performance of natural gas. The necessity of the transition to accounting for natural gas in energy units is substantiated. Existing methods and means for determining the calorific value of natural gas that are used in Ukraine and abroad are considered. Currently, direct and indirect methods are used to determine the calorific value of natural value of natural gas. The most common is the calculation method based on chromatographic analysis, the implementation of which requires expensive equipment. Other methods for determining the calorific value of natural gas is correlation. The essence of which is to establish the relationship between a certain physicochemical property of natural gas and calorific value, which can be established by experimental observations and based on theoretical analysis, which makes it possible to draw a conclusion about the calorific value of natural gas. Based on the analysis, it was found that currently there are no simple in design and not expensive means of controlling the qualitative characteristics of natural gas commercially available. Therefore, it is relevant to solve the problem of operational control of the quality of natural gas, through scientific justification, development and improvement of tools that enable the indirect accounting of the energy value of natural gas in accordance with global trends in energy accounting. A correlation analysis was carried out to establish the relationship between the thermal conductivity and the calorific value of natural gas. The use of the thermocatalytic method for determining the calorific value of gas is proposed, which will allow designing a relatively cheap and easy-to-use device for monitoring the quality of natural gas specifically for the consumer.

Properties of Artificial Gaseous Mixtures for their Safe Use and Support the Natural Gas Supply Networks / Własności Sztucznych Mieszanin Gazowych do Bezpiecznego ich Użytkowania i Wspomagania Zasilania Sieci Gazu Ziemnego

2012 ◽  
Vol 57 (2) ◽  
pp. 351-362 ◽  
Author(s):  
Mariusz Łaciak
Keyword(s):  
Heat Exchange ◽  
Natural Gas ◽  
Landfill Gas ◽  
Gas Mixtures ◽  
Gaseous Mixtures ◽  
Household Appliances ◽  
The World ◽  
Wobbe Index ◽  
Gas Supply

Abstract The increase in natural gas consumption by the general public and industry development, in particular the petrochemical and chemical industries, has made increasing the world interest in using gas replacement for natural gas, both as mixtures of flammable gases and gas mixtures as LPG with air (SNG - Synthetic Natural Gas). Economic analysis in many cases prove that to ensure interchangeability of gas would cost less than the increase in pipeline capacity to deliver the same quantity of natural gas. In addition, SNG systems and installations, could be considered as investments to improve security and flexibility of gas supply. Known existing methods for determining the interchangeability of gases in gas gear based on Wobbe index, which determines the heat input and the burning rate tide, which in turn is related to flame stability. Exceeding the Wobbe index of a value increases the amount of carbon monoxide in the exhaust than the permissible concentration. Methods of determining the interchangeability of gases is characterized by a gas in relation to the above-described phenomena by means of quantitative indicators, or using diagrams interchangeability, where the gas is characterized by the position of a point in a coordinate system. The best known method for determining the interchangeability of gases is Delbourg method, in which the gas is characterized by the revised (expanded) Wobbe Index (Wr), the combustion potential, rate of soot formation (Ich) and the ratio of the formation of yellow ends (Ij). Universal way to determine the interchangeability of gas is also Weaver accounting method. It does not require determination of the reference gas. It is designed for utensils for household gas and gas pressure p = 1.25 kPa. The criteria and definition of gas interchangeability volatility in practice to the combustion in a gas gear. In the case of gas exchange in industrial furnaces, interchangeability criteria are usually not very useful because of other conditions of combustion and heat exchange. In industrial reheating furnace gas is combusted in a sealed combustion chambers. Air supply is regulated. The exhaust gases are discharged into canals and the chimney to the atmosphere. The temperature difference between load (fuel gas) and the flame is much less than in the case of gas household appliances. In the furnace heat exchange takes place mainly by radiation in 85% to 95%. The value of heat flux flowing from the gas to a heated charge is not proportional to the heat load burners. Interchangeability of gas is linked by adding to natural gas, a certain amount of gas that is a substitute for natural gas in meeting the criteria for substitution in order to ensure certainty of supply of natural gas to customers. Gases that can be used in the processes of blending and used as replacement gases are mainly a mixture of propane and propane - butane (LPG - Liquid Petroleum Gas), landfill gas or biogas (LFG - Landfill Gas) and dimethyl ether (DME). One of the more well-known gas mixtures used in many countries around the world to compensate for peak demands is a mixture containing about 75% of natural gas and approximately 25% propane / air (LPG / air). Also in Poland is prepared to amend the provisions in this regard (at this moment - oxygen in the gas network can not exceed 0.2%). In this paper, the calculations of interchangeability of gas mixtures LFG - LPG and LPG - air (SNG) for natural gas was made. It was determined whether the analyzed mixtures have similar stable flame zones regardless of the quality of LFG fuel and whether they may in whole or in part replace CH4, without any modification of equipment suction air for combustion. The obtained results will determine whether the fuel can be used as a replacement for natural gas used in such household appliances and, possibly, industrial burners. In connection with the possibility of changes in the quality of LFG, depending on such factors as storage time, as pre-treatment, will be determined the degree of interchangeability of LFG as a fuel mixed with regard to its quality.

scholarly journals PLOTTING A DIAGRAM OF NATURAL GAS INTERCHANGEABILITY FOR THE ENERGY MARKET OF GEORGIA

World Science ◽  
2020 ◽  
Author(s):  
Dimitri Namgaladze ◽  
Tornike Kiziria ◽  
Lena Shatakishvili ◽  
Tamaz Ghvanidze
Keyword(s):  
Natural Gas ◽  
Calorific Value ◽  
Energy Market ◽  
Gas Industry ◽  
Natural Gases ◽  
Cost Of Energy ◽  
Gas Market ◽  
Wobbe Index ◽  
The Cost ◽  
First Time

The increase in the cost of energy and the appearance of gases of various qualities led to the fact that calculations in the gas industry began to be made by measuring thermal energy.  To this day, in Georgia, the calculation of the amount of natural gas when paying for the used gas is in cubic meters.  As for the study of processes and parameters in the Georgian gas sector, it turned out that these processes are clearly stochastic.  Therefore, the purpose of the work is to develop criteria for the interchangeability of natural gas, in particular, a diagram of the interaction between the Wobbe index in total proportions of propane and nitrogen equivalent for the Georgian gas market, based on stochastic processes.  Thus, for the first time, an original methodology for plotting the Wobbe Index (calorific value) of interchangeable natural gases supplied to Georgia was developed.

scholarly journals Technical aspects of natural gas energy metering implementation

2021 ◽  
pp. 21-25
Author(s):  
Mykola Kuz ◽  
Leonid Zamikhovskyi ◽  
Vitalii Shulha
Keyword(s):  
Natural Gas ◽  
Calorific Value ◽  
Indirect Measurement ◽  
Measuring Instruments ◽  
Regulatory Requirements ◽  
Indirect Methods ◽  
Energy Metering ◽  
Gas Market ◽  
Energy Conversion Devices

In modern conditions, the issue of the quality of natural gas, including the development of gas energy measuring instruments, is becoming increasingly relevant. The Law of Ukraine “On the natural gas market” establishes the need for instrumental metering of natural gas “in order to obtain and register reliable information about the volumes and quality of natural gas during its transportation, distribution, supply, storage and consumption”. In accordance with the “Rules of natural gas supply” in force in Ukraine, settlements with consumers for natural gas should be carried out in cubic meters, reduced to standard conditions and expressed in energy units. However, this contradicts the requirement of the “Technical Regulations on measuring instruments”, which state that settlements with consumers should be based on the results of measuring gas volumes read from the indicating device. However, the indicating devices of gas meters that are operated in Ukraine reflect the measured volumes of gas in cubic meters. Currently, the requirements of the above regulatory documents are partially implemented, in particular, in full-scale industry and partly in the municipal sphere, the readings of measuring the volume of gas by the meters are being adjusted depending on the temperature and pressure of the gas. The purpose of this work is to assess the regulatory requirements and technical possibilities of introducing natural gas metering in energy units in Ukraine. It is proposed to use energy conversion devices to determine the energy of natural gas. A methodology has been developed for measuring natural gas energy by indirect methods based on measurements of the consumed gas volumes, air temperature around the gas meter and the results of measuring the calorific value of gas. The assessment of the metrological characteristics of the indirect measurement of natural gas energy has been carried out.   Keywords: natural gas; energy; volume conversion device.

scholarly journals Studies of the Impact of Hydrogen on the Stability of Gaseous Mixtures of THT

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6441
Author(s):  
Anna Huszal ◽  
Jacek Jaworski
Keyword(s):  
Natural Gas ◽  
Distribution Network ◽  
Experimental Tests ◽  
Gaseous Mixtures ◽  
Odorant Molecule ◽  
Measurement Devices ◽  
The Stability ◽  
The Impact ◽  
Hydrogen Additive

One of the most important requirements concerning the quality of natural gases, guaranteeing their safe use, involves providing the proper level of their odorization. This allows for the detection of uncontrolled leakages of gases from gas networks, installations and devices. The concentration of an odorant should be adjusted in such a manner that the gas odor in a mixture with air would be noticeable by users (gas receivers). A permanent odor of gas is guaranteed by the stability of the odorant molecule and its resistance to changes in the composition of odorized gases. The article presents the results of experimental research on the impact of a hydrogen additive on the stability of tetrahydrothiophene (THT) mixtures in methane and in natural gas with a hydrogen additive. The objective of the work was to determine the readiness of measurement infrastructures routinely used in monitoring the process of odorizing natural gas for potential changes in its composition. One of the elements of this infrastructure includes the reference mixtures of THT, used to verify the correctness of the readings of measurement devices. The performed experimental tests address possible changes in the composition of gases supplied via a distribution network, resulting from the introduction of hydrogen. The lack of interaction between hydrogen and THT has been verified indirectly by assessing the stability of its mixtures with methane and natural gas containing hydrogen. The results of the presented tests permitted the identification of potential hazards for the safe use of gas from a distribution network, resulting from changes in its composition caused by the addition of hydrogen.

scholarly journals EVALUATION OF NATURAL GAS QUALITY BY ITS CALORIFIC VALUE

2021 ◽  
Vol 82 (1) ◽  
pp. 30-36
Author(s):  
Vasil Motalo ◽  
◽  
Bohdan Stadnyk ◽  
Andrij Motalo ◽  
◽  
...  
Keyword(s):  
Energy Source ◽  
Natural Gas ◽  
Comprehensive Evaluation ◽  
Energy Content ◽  
Calorific Value ◽  
Component Composition ◽  
Definition Of ◽  
Own Gas ◽  
Experimental Researches

The article develops and analyzes a method of the comprehensive evaluation of the quality of natural gas as an energy source. The method is based on establishing the calorific value of natural gas as a determinative index of its quality, taking into account all gas properties: both those that positively affect the gas calorific value and its energy content, and those that adversely affect. The generalized definition of natural gas quality as the degree to which the set of the own gas characteristics (component composition and physical properties) meet the requirements concerning energy content, safety, ecology, and other factors is given. The results of experimental researches on natural gas quality according to the developed procedure are also presented.

scholarly journals Impact of Grid Gas Requirements on Hydrogen Blending Levels

2021 ◽  
Vol 25 (1) ◽  
pp. 688-699
Author(s):  
Eduard Latõšov ◽  
Ieva Pakere ◽  
Lina Murauskaite ◽  
Anna Volkova
Keyword(s):  
Natural Gas ◽  
Specific Gravity ◽  
Hydrogen Content ◽  
Calorific Value ◽  
Quality Parameters ◽  
Heat Of Combustion ◽  
Gas Network ◽  
Technical Requirements ◽  
Wobbe Index ◽  
Methane Number

Abstract The aim of the article is to determine what amount of hydrogen in %mol can be transferred/stored in the Estonian, Latvian and Lithuanian grid gas networks, based on the limitations of chemical and physical requirements, technical requirements of the gas network, and quality requirements. The main characteristics for the analysis of mixtures of hydrogen and natural gas are the Wobbe Index, relative density, methane number, and calorific value. The calculation of the effects of hydrogen blending on the above main characteristics of a real grid gas is based on the principles described in ISO 6976:2016 and the distribution of the grid gas mole fraction components from the grid gas quality reports. The Wärtsila methane number calculator was used to illustrate the effects of hydrogen blending on the methane number of the grid gas. The calculation results show that the maximum hydrogen content in the grid gas (hydrogen and natural gas mix), depending on the grid gas quality parameters (methane number, gross heat of combustion, specific gravity, and the Wobbe Index), is in the range of 5–23 %mol H2. The minimum hydrogen content (5 %mol H2) is limited by specific gravity (>0.55). The next limitation is at 12 %mol H2 and is related to the gross heat of combustion (>9.69 kWh/m3). It is advisable to explore the readiness of gas grids and consumers in Estonia, Latvia and Lithuania before switching to higher hydrogen blend levels. If the applicability and safety of hydrogen blends above 5 %mol is approved, then it is necessary to analyse the possible reduction of the minimum requirements for the quality of the grid gas and evaluate the associated risks (primarily related to specific gravity).

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