Abstract:

During the process of storage and transportation of light oil such as crude oil and gasoline in oil tank, some light components evaporate to produce many kinds of volatile organic compounds (VOCs) that are toxic and harmful to the atmosphere. In the terminal of oil vapor recovery, activated carbon is usually used to further absorb volatile organic compound (VOCs) with low concentration to meet the strict VOCs emission standard and high-quality environment requirement. Regeneration of VOCs-saturated activated carbon can not only prolong the life of activated carbon, but also reduce the solid waste treatment charge. Supercritical CO₂ regeneration is considered to be a promising method to regenerate the activated carbon because it overcomes the inherent defects of traditional thermal regeneration methods. In this paper, the regeneration mechanism of activated carbon under supercritical CO₂ is described in detail, and the key points and existing problems of the mechanism research are summarized. It is pointed out that the micro mechanism of VOCs desorption under the supercritical CO₂ and the calculation model of mass transfer coefficient of VOCs in activated carbon after desorption are the key breakthrough of the mechanism research in the future, and it is also the referenced research direction for further improvement of the regeneration theory of activated carbon under supercritical CO₂.

Key words: oil vapor recovery, supercritical CO₂, activated carbon, regeneration mechanism

摘要：

储油罐中的原油及汽油等轻质油品在储存或运输过程中，部分轻组分蒸发产生多种对大气有毒、有害的挥发性有机物（VOCs）。在油气回收的终端环节，常采用活性炭对VOCs进行充分吸附达标后排放至大气。对吸附VOCs饱和的活性炭进行脱附再生，既可延长活性炭使用寿命，又可减少固体废弃物处理量。超临界CO₂再生活性炭方法较好地克服了传统的热再生法固有的缺陷，被认为是目前有前途的再生活性炭方法。本文详细阐述了超临界CO₂再生活性炭的机理研究现状，总结了机理研究的关键点及存在的问题，指出了VOCs在超临界CO₂作用下脱附的微观机理及脱附后的VOCs在活性炭中相关传质系数的计算模型为今后机理研究的关键突破口，为超临界CO₂再生活性炭基础理论的进一步完善指明了研究方向。

关键词: 油气回收, 超临界二氧化碳, 活性炭, 再生机理