Prediction of Hydrate Formation in Supercritical CO2 Containing Impurities Long-Distance Transportation Pipelines with a Capacity of 0.36 Million t/a

Abstract

Abstract Long-distance pipeline transportation is the most economical and feasible way to transport CO2. Hydrates can easily form during the transportation of supercritical CO2 containing impurities, leading to pipeline blockage. Therefore, accurate prediction of the deposition location and amount of hydrates in pipelines is crucial. This paper established a prediction model for hydrate growth in the long-distance CO2 transportation pipeline containing impurities. The phase equilibrium diagram and kinetic growth model were combined to simulate the formation behaviour of CO2 hydrate. The long-distance CO2 transportation pipeline of 0.36 million t/a in Yunlin was taken as an example. The results show that the volume of CO2 hydrate increased whereas the growth rate of CO2 hydrate gradually decreased with time. Hydrates begin to form in pipeline L11 at a distance of 35-44.3 km away from the inlet, whereas at a distance of 8.1 km away from the inlet for pipeline L12. The places with the highest amount of hydrate formation in both of the pipelines were at the end of pipelines. The area for hydrates formation in pipeline L12 was much longer than that in pipeline L11 due to the lower temperature. The cleaning cycle for pipeline L12 should be much shorter than that of pipeline L11. This paper will provide guidance for the operation of CO2 long distance pipelines.