Study and Experimental Validation of CO2 Blowdown at Cryogenic Conditions

CO₂ solidification is one of the critical issues being identified in cryogenic technology process, particularly during the blowdown process. This poses critical challenge in developing the technology for separation of CO₂ from natural gas as there are limited studies and data to support the design and simulation of the process. Depressurization of high CO₂ fluid at cryogenic temperature would lead to possibility of CO2 solid formation, hence potential blockage of process equipment and venting line.

The new cryogenic technologies are currently being tested for the proof of concept. Hence, a pilot plant, which is a scaled down version of the technology was developed. One of the major challenges faced during the pilot plant testing is the emergency depressurization philosophy as the process involves CO₂ solids handling which is uncommon to the industry standard. Lack of experimental data of CO₂ blowdown at these conditions presented a technical gap which needs to be addressed to properly predict the solidification and mitigations, hence avoiding over-design of the plant and chances of accidents and unscheduled downtimes can be minimized.

Therefore, this paper will focus on the experimental study which have been done on CO₂ blowdown scenarios at a pilot plant. The pressure and temperature profile provide real insight of the solidification of CO2 during several blowdown scenarios. Finally the paper would validate a simulation data conducted using the experimental data as one of the potential prediction tools for CO2 blowdown process.