Upward and downward two-phase flow of CO2 in a pipe: Comparison between experimental data and model predictions

In order to deploy CO2 capture and storage (CCS) systems to mitigate climate change, it is crucial to develop reliable models for design and operational considerations. A key element of the system is the interface between transportation and storage, namely the injection well, where various transient scenarios involving multiphase flow will occur. In the literature there are very few data relevant for validation of vertical multiphase flow models for CO2. Hence in this work, we present measurements of liquid holdup, pressure drop and flow regime for upward and downward flow of CO2 in a pipe of inner diameter 44mm at a pressure of 6.5MPa, a condition relevant for CO2-injection wells. The experimental results indicate that the flow is close to no-slip. We have compared the experimental data to predictions by well-known models for phase slip and frictional pressure drop, and the results show that overall, the best model is the simplest one - the fully homogeneous approach, in which no slip is assumed and the friction is calculated simply by employing gas-liquid mixture properties in the single-phase friction model. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/ )

Automated summary

This study conducted experimental research on the upward and downward flow of CO2 in a pipe, analyzing the flow regime, liquid holdup, and pressure drop. The experimental results indicated that the fully homogeneous approach, which assumes no slip and calculates friction using gas-liquid mixture properties, was the best model for predicting the behavior of CO2 in multiphase flow scenarios.