Studying the Effect of Carbon Dioxide on the Hydrate Formation of Natural Gas Mixtures Using Simulation Packages

Hydrate is a crystalline structure that is composed of water and small gas molecules. In natural gas processing field, the presence of hydrate may cause blockage to natural gas pipeline, which can contribute to huge economic loss. A previous experimental work reported that natural gas with high CO2 content has a higher tendency of hydrate formation (Yu, Huen, and Ji, 2001). Unlike hydrocarbon, CO2 is highly soluble in water. The objective of this project is to look into models that can best predict interaction of CO2 and water to form hydrate. In this project, Aspen HYSYS software and CSMHyd hydrate program are used as simulation tools for hydrate phenomena. Hydrate formation condition is investigated at different composition of CO2-containing gases. As a result, it is found that a higher CO2 content corresponds to a higher tendency of hydrate formation. This is in agreement with the theory and previous experimental results. HYSYS and CSMHyd simulation results in this project can both accurately predict hydrate formation pressure of high CO2 content gases. The presence of N2, glycerol or salts, however, may decrease the accuracy of the prediction.