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.

Research of pressure influence in the gas supply system on the energy consuption level of gas devices

2019 ◽  
Vol 6 (2) ◽  
pp. 56-63
Author(s):  
L. D. Pylypiv ◽  
І. І. Maslanych
Keyword(s):  
Natural Gas ◽  
Residential Buildings ◽  
Supply System ◽  
Normal Operation ◽  
Gas Combustion ◽  
Efficient Operation ◽  
Gas Consumption ◽  
Natural Gas Combustion ◽  
Gas Supply

There are investigated the influence of operating pressures in the gas supply system on the level of such energy indicators as efficiency, gas flow and gas overrun by gas equipment in residential buildings. There is established a relationship between the values of operating pressures in the gas supply system and the gas consumption level of household appliances. The causes of insufficient pressure in the gas networks of settlements are analyzed in the article. There is also developed an algorithm for calculating the change in the efficiency of gas appliances depending on the operational parameters of the gas network. It has been found that the most efficient operation of gas appliances is observed at an overpressure at the inlet of gas appliances of about 1200 Pa.To ensure the required quality of natural gas combustion among consumers and minimize gas consumption there are justified the following measures in the article: coordinating a domestic regulatory framework for assessing the quality of natural gas with international norms and standards; improving the preparation of gas coming from local wells before supplying it to gas distribution networks; auditing low pressure gas pipelines and reconstructing areas affected by corrosion; ensuring standard gas pressure in the network for the normal operation of domestic gas appliances; stating quality indicators of natural gas combustion by gas sales organizations.

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 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.

Small-scale technology solutions to eliminate flaring

2016 ◽  
Vol 56 (2) ◽  
pp. 612 ◽  
Author(s):  
James Brown ◽  
Chiew Yen Law ◽  
Katherine Fielden ◽  
Ceri-Sian Dee ◽  
Neil Pollock
Keyword(s):  
Natural Gas ◽  
Economic Value ◽  
Cost Effective ◽  
Oil Fields ◽  
Small Scale ◽  
Well Testing ◽  
Associated Gas ◽  
Future Technologies ◽  
Gas Supply

Five percent of the world’s gas supply is wasted by being flared or vented into the atmosphere, leading to a huge loss of potential revenue, not to mention a significant impact on the environment. This is equivalent to 150 billion cubic metres of natural gas per year and the release of 400 million metric tons of CO2 equivalent. The industry does this for a variety of valid reasons, including well testing, emergencies, commissioning, maintenance, or simply because an economic solution for capturing and using the gas has not been discovered. Capture of flared gas, therefore, presents an economic and environmentally beneficial opportunity to create new value chains that can benefit not only the industry but also people’s quality of life. This extended abstract draws on a recent DNV GL project to assess existing and future technologies and concepts for capturing small volumes of associated gas that are normally flared from oil fields, both onshore and offshore. The following four technology options that can be used to capture associated gas, convert it, and either utilise the product onsite or transport it to market for consumption are considered. Using more cost-effective ways of transporting natural gas where there is no existing pipeline. Converting gas into products with a higher economic value through chemical processes. Novel concepts—bringing the solution closer to the source of gas flaring. Other solutions. The extended abstract then focuses on cost-effective ways of transporting gas, in particular the use of micro-LNG solutions

scholarly journals REGULATORY PROVISION OF SAFETY OF GAS TRANSPORT. CONSTRUKTIONAL DESIGN OF MOBILE COMPRESSOR STATIONS

2021 ◽  
pp. 13-19
Author(s):  
V. BIELIKOV ◽  
Z. MATSUK
Keyword(s):  
Natural Gas ◽  
Gas Pressure ◽  
Gas Pipeline ◽  
Industrial Safety ◽  
Technical Requirements ◽  
The World ◽  
Transportation Process ◽  
Mobile Compressor ◽  
Main Gas Pipeline ◽  
Gas Supply

Problem statement. The basis for the safety and efficiency of the main gas transportation in the world is the tightness of the gas transportation system. A component of the level of industrial safety and efficiency of gas transmission enterprises is the emissions of natural gas into the working area, the environment and the associated costs. Numerous methods of repairing pipeline gas transportation facilities, such as enhancing the bearing capacity of pipelines, repairing defects under gas pressure without interrupting the transportation process, etc., are either not devoid of risks from the point of view of industrial safety, or are energy and resource inefficient. The main type of repair that restores the operable state of the gas transmission system is the replacement of defective equipment, but it is still associated with the release of large volumes of natural gas into the environment. In the second decade of the 2000s, thanks to the rapid development of compressor technology and the invention of a sufficient number of ways to connect compressor units (stations) to main gas pipelines, without stopping the gas transportation process, gas transmission enterprises of the world had a real opportunity to evacuate gas from pipeline sections subject to repair (maintenance ) or accumulate it (control gas pressure in local areas), but the analysis of world experience in the development of gas pressure control technology in localized sections of gas pipelines allows us to assert that there are certain disparities between them in terms of operational safety and the complete absence of regulatory support for the transportation process in Ukraine gas using mobile compressor stations. With this approach to the production process, it is difficult to improve the safety and efficiency of the gas transportation process. The potential for reducing natural gas emissions from the world's gas industry reaches billions of cubic meters of natural gas per year. Purpose of the article. Development of technical requirements for mobile compressor units (stations), which will make it possible to design domestic gas compressor units (stations) capable of safely performing work on pumping natural gas from a localized section of the main gas pipeline to an existing main gas pipeline, within no more than 96 hours, without restrictions on gas supply to consumers. Conclusion. The technical requirements developed by us for mobile compressor units (stations) allow us to design domestic compressor units (stations) capable of safely performing work on pumping natural gas from a localized section of the main gas pipeline to the existing main gas pipeline, within no more than 96 hours, without restrictions on gas supply to consumers.

scholarly journals Design and Experiment of Low-Pressure Gas Supply System for Dual Fuel Engine

2020 ◽  
Vol 27 (2) ◽  
pp. 76-84
Author(s):  
Xiaoyong Gu ◽  
Guohe Jiang ◽  
Zhenghua Guo ◽  
Shangzhi Ding
Keyword(s):  
Heat Exchange ◽  
Natural Gas ◽  
Low Pressure ◽  
Supply System ◽  
Dual Fuel ◽  
Exchange Area ◽  
Dual Fuel Engines ◽  
Buffer Tank ◽  
Glycol Solution ◽  
Gas Supply

AbstractA low-pressure gas supply system for dual fuel engines was designed to transport liquid natural gas from a storage tank to a dual fuel engine and gasify it during transportation. The heat exchange area and pressure drop in the spiral- wound heat exchanger, the volume of the buffer tank and the pressure drop in the pipeline of the gas supply system were calculated by programming using Python. Experiments were carried out during the process of starting and running the dual fuel engine using this gas supply system. Experimental data show that the gas supply system can supply gas stably during the process and ensure the stable operation of the dual fuel engine. The effects of the parameters of natural gas and ethylene glycol solution on the heat exchange area of the spiral-wound heat exchanger and the volume of the buffer tank in the gas supply system were studied. The results show that the heat exchange area calculated according to pure methane can adapt to the case of non-pure methane. The temperature difference between natural gas and ethylene glycol solution should be increased in order to reduce the heat exchange area. The heat exchange area selected according to the high pressure of natural gas can adapt to the low pressure of natural gas. The volume of the buffer tank should be selected according to the situation of the minimum methane content to adapt to the situation of high methane content. The main influencing factor in selecting the volume of the buffer tank is the natural gas flow. The results can provide guidance for the design of the gas supply system for dual fuel engines.

scholarly journals Development status and suggestions of Natural Gas Power Generation Industry in China

2019 ◽  
Vol 136 ◽  
pp. 02005
Author(s):  
Sun Li ◽  
Li Hongmei ◽  
Xing Jinyan ◽  
Pan Yun
Keyword(s):  
Power Generation ◽  
Sustainable Development ◽  
Power Plant ◽  
Natural Gas ◽  
World Average ◽  
Development Status ◽  
Existing Problems ◽  
The World ◽  
Gas Price ◽  
Gas Supply

At present, the development speed of natural gas power generation in China lags far behind the world average level, and there are many problems in the gas electricity industry, including the high gas price of natural gas is difficult to dredge the electricity price, the online electricity quantity is difficult to guarantee, the natural gas supply has the bottleneck, the power plant lacks the bargaining right and so on, which seriously restricts the healthy and sustainable development of the natural power generation industry. On the basis of combing and investigating the existing problems of natural gas power generation in China, this paper expounds the orientation and goal of the development of China's natural gas power generation industry, and puts forward some concrete suggestions for promoting the development of China's natural gas power generation industry.

Intelligent Operation of Siemens (SGT-300) DLE Gas Turbine Combustion System Over an Extended Fuel Range With Low Emissions

2011 ◽  
Author(s):  
Ghenadie Bulat ◽  
Kexin Liu ◽  
Gavin Brickwood ◽  
Victoria Sanderson ◽  
Brian Igoe
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Intelligent Control ◽  
Control Algorithm ◽  
Landfill Gas ◽  
Stable Operation ◽  
Nox Emissions ◽  
Single Digit ◽  
Engine Operation ◽  
Wobbe Index

The use of an innovative, intelligent control algorithm applied to the Siemens SGT-300 DLE engine is described. The algorithm ensures stable operation and minimises emissions over a wide variation in fuel composition. The Siemens 8MW class SGT-300 gas turbine has been in operation at the University of New Hampshire (USA) since 2006. As well as operating on natural gas or diesel, the engine also operates on a gas processed from a landfill. These gases have a variable Wobbe Index (WI) covering the range 29.7 to 49 MJ/m3. No modifications have been required to the standard DLE combustion hardware. Introduction of the intelligent control algorithm has been instrumental in achieving this tri-fuel capability. Accumulation of more than 10 000 hours running on non-standard fuel has been achieved. The intelligent control algorithm exploits knowledge of the stable operating window through continual modification of the fuel schedule to avoid both lean blow out and high metal temperatures. Operationally, this results in a reduction in the NOx emissions, through controlling the unmixedness, and higher engine reliability, through the response of the algorithm to flame stability. Combining these advantages the control algorithm can deliver reliable engine operation on variable composition fuels when using standard combustion hardware achieving single digit NOx emissions not only on natural gas but also on processed landfill gas. This paper describes the control algorithm and presents results of the development from high pressure combustion rig and engine development test to field operation with both natural gas and processed landfill gas.

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