Pressure responses and phase transitions during the release of high pressure CO 2 from a large-scale pipeline

Abstract

As part of the Carbon Capture and Storage (CCS) process, pipeline transportation is the safest and most economic option for delivering captured CO 2 to a storage site. However, in the event of pipeline rupture an enormous mass of CO 2 may be released very rapidly, presenting several risks to the pipeline and surrounding population including the significantly increased risk of brittle fracture in the pipe wall. The study of pressure variation and phase change in CO 2 during pipeline blowdown can contribute to the understanding of fracture initiation and propagation, as well as downstream CO 2 diffusion behavior. As part of the CO 2 QUEST project, a reusable, industrial scale pipeline experimental apparatus with a total length of 258 m and the inner diameter of 233 mm was fabricated to study pure CO 2 pipeline blowdown. A dual-disc blasting device was used to remotely control the opening of the pipeline. The instantaneous pressure response following release was measured with high frequency pressure transducers. Variation in fluid temperature at the top and bottom of pipeline was also recorded. Six groups of pure CO 2 pipeline release experiments were conducted with initially gaseous and dense phase inventories with three orifice diameters (15 mm, 50 mm and Full Bore Rupture). The pressure undershoots, rebounds and quasi static pressures were observed during the release as result of the propagation of a series of expansion waves. The process of pressure drop and rebound was accompanied by the occurrence of gas-liquid two-phase flow. The complicated phase transitions were obtained during depressurization of gaseous and dense CO 2 releases.

An experimental investigation on pressure response and phase transition of supercritical carbon dioxide releases from a small‐scale pipeline

“…The synchronous changes of fluid pressures at different locations were similar to those tested in large‐scale experimental pipelines with a length of 258 m and an inner diameter of 233 mm. However, no vapour bubbles and pressure rebound were found in the small‐scale experiments. Also, the propagation of decompression waves recorded in the large‐scale experiments was harder to estimate in this study, probably because the experimental pipeline was too short.…”

“…All sensors were calibrated before use. The data acquisition system was accomplished by the NI acquisition module and LabVIEW software …”

“…Numerous publications have examined the release behaviour of CO 2 based on both experimental studies and numerical research. We have given a detailed introduction in our recently published works and will therefore not repeat it in this article. Despite numerous studies nowadays, there is not yet a clear understanding of the pressure response and phase transition of the supercritical CO 2 depressurization process after accidental release from a pressurized pipeline.…”

“…Despite numerous studies nowadays, there is not yet a clear understanding of the pressure response and phase transition of the supercritical CO 2 depressurization process after accidental release from a pressurized pipeline. We performed an experimental study on the pressure response and phase transition of supercritical CO 2 during sudden release to improve the understanding of this process using a large‐scale pipeline with a length of 258 m and an inner diameter of 233 mm from the CO2QUEST project and found that the complex phenomena of pressure undershoot, rebound, or slowdown occurred near the critical region . Moreover, we discussed the phase transitions of CO 2 in the pipeline at different diameters of relief orifices during the release process .…”

Experimental investigation of the impact of liquid carbon dioxide injection on temperature in pulverized coal

“…[16][17][18][19] Woolley et al 20 conducted the pressurized CO 2 releases experiment and summarized LCO 2 will escape and immediately vaporize and expand in the vicinity of the release port. Guo et al 21 presented the results of pressure, temperature, and gas concentration variation during CO 2 discharge process with an industrial-scale test pipeline from the initial liquid condition; according to the experimental data, the properties of phase change were also analyzed. Drescher et al 22 explored the depressurization behavior of LCO 2 through a pipeline of length of 139 m and an inner diameter of 10 mm.…”