Water Solubility in CO2 Mixtures: Experimental and Modelling Investigation

Abstract

The capture of CO2 from power plants and other large industrial sources is offering a main solution to reduce CO2 emissions. The captured mixture will contain impurities like nitrogen, argon, oxygen, water and some toxic elements like sulfur and nitrogen oxides, the types and quantities of which depend on the type of fuel and the capture process. The presence of free water formation in the transportation pipeline causes severe corrosion problems, flow assurance failure and might damage valves and instrumentations. In the presence of free water, CO2 dissolves in the aqueous phase and will partly ionize to form a weak acid. Thus, free water formation should be avoided. This work aims to investigate the solubility of water in CO2 mixtures under pipeline operation conditions in the temperature range of (5–35 °C) and the pressure range of (90–150 bar). A test set up was constructed, which consists of a high pressure reactor in which a CO2 mixture containing water at initial soluble conditions was prepared. The purpose of this study is to identify the maximum water content level which could be allowed in CO2 transportation pipelines. The experimental data generated were then compared to the calculations of two mixture models: the GERG-2008 model and the EOS-CG model.