Experimental Study of N2 Impurity Effect on the Steady and Unsteady CO2 Pipeline flow

Abstract

Carbon dioxide capture and storage (CCS) technology is arising as one of the key technology for reducing emission of global warming gas and mitigating climate change. Especially the impurity effect on the CO2 transportation is important, cause with small amount of impurity, specific volume, boiling point and critical temperature of CO2 might possibly change tremendously, and along with that problems such as formation of hydrate and pipe clogging, etc are possible. Moreover the real captured CO2 mixture might contain impurities such as N2, O2, H2O, SOx, H2S. Among them, N2 can affect the CO2 transport process by its low boiling point. In other words, a small amount of nitrogen can make change flow conditions from single phase flow to two-phase flow. And a small amount of water in CO2 stream can trigger the clogging problem due to formation of hydrate. To understand the thermo physical behavior of CO2-N2 mixture, experimental investigations are essential. In this study, we designed and built an experimental apparatus for simulating CO2– N2 mixture pipe-line transportation which consists of 4 parts with high pressure compression module, liquefaction module, mixing module, cooling module and transport test section. The transportation test section consists with 2 parts, one for horizontal pipe-line test section made by a horizontal tube and the other for long-pipe test section which compos, cause with small amount of impurity, specific volume, boiling point and critical temperature of CO2 might possibly change tremendously, and along with that problems such as formation of hydrate and pipe clogging, etc are possible. Moreover the real captured CO2 mixture might contain impurities such as N2, O2, H2O, SOx, H2S. Among them, N2 can affect the CO2 transport process by its low boiling point. In other words, a small amount of nitrogen can make change flow conditions from single phase flow to two-phase flow. And a small amount of wat