The exploitation of a low-quality gas field with high CO₂ concentration is more viable through liquid CO₂ produced from cryogenic distillation technology. Despite the bright potential of the technology, there are deficiencies in handling high concentration of CO₂ at low temperature and high pressure during the blowdown condition. This study focuses on the CO₂ blowdown at a cryogenic pilot plant designed to manage high concentrations of CO₂ in the feed gas, high pressures, and low temperatures. A comprehensive design review and risk assessment using Inherent Safer Design (ISD) indexes were carried out in this study. The ISD was performed to identify the current risk level, and the critical parameters that may cause solid CO₂ formation in the piping or equipment as well as to identify mitigation measures to avoid the temperature to drop below the CO₂ freezing point during blowdown. The present findings confirmed that the initial pressure and temperature, as well as CO₂ concentration are key parameters towards significant impact on blowdown conditions. Therefore, the reduction of the feed gas pressure from 80 bar to 70 bars has minimized the Joule Thomson (JT) effect during blowdown and avoided the CO₂ solid formation in the system. Moreover, the relocation of the blowdown valve at the downstream heater resulted in a higher final temperature above the CO₂ freezing point. The ISD indexes confirmed that the cryogenic facilities are inherently safer during blowdown with the mitigation measures adopted.

通过低温蒸馏技术产生的液态CO ₂，开发具有高CO ₂浓度的低质量气田更加可行。尽管该技术潜力巨大，但在排污条件下，在低温和高压下处理高浓度的CO _2仍存在不足。这项研究的重点是设计用于控制高浓度CO ₂的低温试验工厂中的CO ₂排放进料气中的压力，高压和低温。在这项研究中，进行了使用固有安全设计（ISD）指标的全面设计审查和风险评估。执行ISD以确定当前的风险水平以及可能导致管道或设备中形成固体CO ₂的关键参数，并确定缓解措施，以避免在排污期间温度降至CO ₂凝固点以下。目前的发现证实了初始压力和温度以及CO ₂浓度是对排污条件产生重大影响的关键参数。因此，进料气压力从80 bar降低到70 bar，已将排污期间的焦耳汤姆森（JT）效应降至最低，并避免了系统中形成CO ₂固体。此外，排污阀在下游加热器处的重新定位导致最终温度高于CO ₂凝固点。ISD指标证实，采取了缓解措施后，低温设施在排污期间本质上更加安全。