Comparative analysis of methods for determination of calorific values of natural gas mixtures

Abstract

Procedures for calorific value determination of natural gas from the molar composition are described in a number of internationally accepted standard methods and in a number of published papers. In principle these suggested methods should be the same but they differ in the following important respects: 1. · formula for calorific value calculation from the molar composition: 2. · number of components used for calorific value calculation. In this study comparative analysis of chosen methods for calorific value determination of natural gas are shown. Obtained differences and standard deviations of differences of any chosen procedure are given with respect to the others. The evaluation of precision of these differences is obtained by using a common statistical test. The tested methods have shown little agreement. Also discussed is the number of components of natural gas necessary for calorific value calculation using simplified existing procedures. It was found that components of the natural gases studied which were present at concentrations less than 0.2 mol.% may be grouped as C5+ or C6+ components. © 1991.