Issues regarding the recovery of vent gas from the regeneration tower in natural gas CO2 removal
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I would like to ask the teachers: we want to recover and recycle the CO2 emitted from the top of the regeneration tower in order to produce food-grade CO2. But there are several concerns: 1. Besides CO2 and water, does the air released from the top of the tower carry impurities such as hydrocarbons, MDEA, and defoamers? (It seems normal for these to be present, but they have never been detected before.) 2. Can the quality of food-grade CO2 be ensured only if the impurities carried in the released air (hydrocarbons, MDEA, defoamers, etc.) are removed? Or in other words, do these impurities such as XXX not need to be removed? I would appreciate your advice. Thank you.
1. The overhead air from the regeneration tower for natural gas CO2 removal may contain impurities such as hydrocarbons, MDEA (desulfurizing agent), and defoamers. The presence of these impurities is possible, as some substances may dissolve or volatilize during the gas treatment process. Although they may not be detected during operation, the presence of these impurities is possible. 2. If you wish to produce food-grade CO2, it is necessary to ensure that its purity meets the relevant standard requirements. Specifically, you need to determine the impurities that need to be removed in accordance with the relevant standards for food-grade CO2 (such as the standard \"Food Safety – Carbon Dioxide as an Additive in Drinking Water\" in GB1886.44-2016). Regarding hydrocarbon impurities, they can usually be removed using adsorbents such as activated carbon or molecular sieves. For other chemicals such as MDEA and defoamers, you can refer to relevant methods or techniques, such as using appropriate adsorbents or membrane separation to remove them. It should be noted that the specific methods and processes for removing impurities need to be determined based on your specific conditions and equipment setup; experimental research and process optimization may be required. In summary, it is possible to recover CO2 from the off-gas at the top of the regeneration tower to produce food-grade CO2, but impurities in the gas and purity requirements must be taken into account, along with appropriate treatment methods. It is recommended that you conduct detailed discussions and research with relevant professionals to find the best solution. .
Now, the use of carbon dioxide is not limited to food-grade applications; it is also used in industrial contexts. Removing impurities is necessary; could we consider using the properties of various elements to achieve low-temperature liquefaction purification, for reference only.