Thermodynamic Properties of Synthetic Natural Gases. 5. Dew Point Curves of Synthetic Natural Gases and Their Mixtures with Water and with Water and Methanol: Measurement and Correlation

Abstract

Dew points for two synthetic natural gas (SNG) mixtures between 1.2 × 105 and 81.8 × 105 Pa in the temperature range from 213.6 to 261.4 K, four SNG + water mixtures between 1.1 × 105 and 41.0 × 105 Pa and temperatures from 244.7 to 288.1 K, and four SNG + water + methanol mixtures between 1.1 × 105 and 20.7 × 105 Pa and temperatures from 247.6 to 288.6 K were experimentally determined. The experimental results obtained on the multicomponent systems were analyzed in terms of a predictive excess function−equation of state (EF−EOS) method, which reproduced experimental dew point temperature data with absolute average deviation (AAD) between 0.9 and 3.1 K for the dry systems, from 0.0 to 1.6 K for the systems with water, and from 0.0 to 3.0 K for the systems with water and methanol. The experimental results obtained for synthetic natural gas (SNG) + water mixtures at pressure values higher than 5 × 105 Pa were also compared to a predictive equation of state (EOS) model. It reproduced experimental dew point temperature data within AAD between 1.8 and 5.3 K.