The accurate knowledge of the thermodynamic properties of natural gases and other mixtures of natural gas components is of indispensable importance for the basic engineering and performance of technical processes. The processing, transportation, and storage of natural gas requires property calculations for a wide range of mixture compositions and operating conditions in the homogeneous gas, liquid, and supercritical regions, and also for vapour-liquid equilibrium states. These data can advantageously be calculated from equations of state. 

This monograph thoroughly presents the new equation of state, adopted by GERG in 2004 and called GERG-2004 equation of state or GERG-2004 for short.

The water content of natural gases often poses problems during the production, transmission and distribution of natural gas. 

In order to solve these problems, this project was set up by the GERG WATER taskforce, to conduct experimental investigations and the development of a calculation procedure. 

This monograph presents a sound method for calculating the water dew point and the water content of natural gases that are used in the GERG standard method. 

The European Gas Research Group, GERG (Groupe Européen de Recherches Gazières), has undertaken an R&D project with the aim of increasing the general knowledge about, and advancing the technology on, the concept of multipath ultrasonic transit time flow meters (USM) for fiscal, allocation and sales metering of natural gas. This Technical Monograph is based on the project reports resulting from the project.

This monograph extends and updates the GERG Technical Monograph TM4 (1990) databank of high accuracy-compression factor measurements.  

This Monograph provides a detailed account of the concept, development, performance and use of the Standard (or Simplified) GERG-88 Virial Equation for the accurate calculation of compressibility factors for natural gases. The equation has been developed from the Master (or Molar) GERG-88 Virial Equation and utilises a restricted set of input variables in place of the detailed (13 components) composition analyses required for the Master equation. The simplified input data requirement comprises any three from superior (gross) calorific value, relative density, carbon dioxide content (the usual set) and nitrogen content, together with pressure and temperature.

Please find below the Abstract and Table of Contents, and the complete work. 

This monograph provides a complete listing in a single document of the entire contents of the GERG compressibility factor databank. The databank comprises high-accuracy measurements of compressibility factor within specified ranges of pressure (from 0 to 12MPa), temperature (265 to 335K) and gas composition, and includes all of the data used in the development and testing of the GERG virial equation. 

The European Gas Research Group (GERG, Groupe Européen de Recherches Gazières) has undertaken a round-robin test of six Z-meters manufactured by Desgranges et Huot, with two Burnett apparatus and an interferometric device used to complement the pVT data from the Z-meters.

This monograph provides a detailed account of the concept, development, performance and use of the GERG virial equation. This equation predicts the compressibility factor Z(p, T) for natural gas-type mixtures (specified by a 13-component molar composition) within the respective pressure and temperature ranges of 0 to 12MPa (0 to 120 bar) and 265 to 335K (-8 to 62°C) with an expectation accuracy of 0.1%. 

[…] Evidence is given that performance is better than that of the GRI-SuperZ (AGA8) equation within the stated range of applicability.

Because of the prospect of increasing international trade (custody transfer) of natural gas amongst the G.E.R.G. member countries, as well as for other reasons relating to the mutual interests of the European gas industries, it is important that there be a substantial (preferably complete) measure of agreement about how best to determine the relevant thermophysical properties of pipeline quality gas and other fluids.  

[…] This booklet presents a compilation of [best values for] pure component constants and properties prepared as a collaborative effort by the G.E.R.G. Thermodynamics Research Committee.