Changes in the composition and quality of gas during its movement in the gas supply system

Abstract

Gas produced at different deposits has different compositions, namely different amounts of methane, propane, nitrogen and so on. Different gas composition determines different physical and chemical characteristics of the gas, its heat of combustion, dew points on water and hydrocarbons, and Wobbe number. Previously, when using gas, little attention was paid to its characteristics, which are guided by the requirements of GOST 5542-87. With the restoration of Ukraine's independence and the transition to market conditions, attitudes toward gas have changed. Gas is a commodity and has a price. With the integration into the European Union, there was not only the implementation of European legislation but also the widespread use of advanced equipment and technologies in these countries. Gas will be metered in units of energy, not volume as before. This forces us to pay more attention to the quality of gas, set stricter requirements for its component composition, and monitor compliance with regulatory requirements in the process of transporting and supplying gas to the final consumer. GOST 5542-87 defined only a few quality parameters. Currently, the Code of Gas Transmission and Gas Distribution Systems, the Technical Regulation of Natural Gas and other regulations determine the quality of gas by more than 20 parameters that meet European standards. The methane content in the composition of natural gas must be at least 90 %, and other components of the gas are regulated. However, different deposits have different methane compositions. These limits range from 85 % to 99 % of methane. Different composition of natural gas affects not only its properties but also the reliability of the gas transmission and distribution system and affects the work of individual end-users. This problem is especially relevant when using gas appliances with high efficiency. The problem of gas quality is important for its metering in Ukraine and in settlements with other countries. The analysis of gas composition and quality during its transportation from the field to the consumer is carried out. It is determined that in the distribution part of the gas transmission system of Ukraine there are deviations in gas quality from regulatory requirements. This reduces the efficiency of some gas appliances and throttling equipment.