空气中CO_(2)直接捕捉逆流式吸收塔特性研究  

Study on the characteristics of countercurrent absorption tower for direct capture of CO_2 in air

作　　者：黄文慧 宋小军[1] 王明宇 孔艳强 HUANG Wenhui;SONG Xiaojun;WANG Mingyu;KONG Yanqiang(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Inner Mongolia Helin Power Generation Co.,Ltd.,Hohhot 011508,Inner Mongolia China;Key Laboratory of Power Station Energy Transfer Conversion and System,Ministry of Education,School of Energy Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]中国水利水电科学研究院,北京100038 [2]内蒙古和林发电有限责任公司,内蒙呼和浩特011508 [3]教育部电站能量转换与系统重点试验室(华北电力大学能源动力与机械工程学院),北京102206

出　　处：《电力科技与环保》2024年第6期657-668,共12页Electric Power Technology and Environmental Protection

基　　金：国家自然科学基金项目(52276062)。

摘　　要：为了降低空气中CO_(2)浓度,缓解温室效应和气候变暖,直接空气捕捉(direct air capture,DAC)技术成为研究的热点,但其捕集成本较高。因此对DAC技术进行研究,得到影响CO_(2)吸收效率的因素及其变化规律并加以优化,有利于降低CO_(2)捕捉成本,对DAC技术的推广和实际工程应用具有重大意义。针对可用于直接空气捕捉的吸收塔,采用模拟试验的方法,搭建了逆流式机械通风吸收塔小试试验平台,通风截面积为0.6 m×0.6 m,以碱液为吸收剂,研究了碱液类型、碱液浓度、淋水密度、填料断面风速、淋水填料类型、淋水填料高度、淋水高度等对CO_(2)吸收效率的影响。研究结果表明,在相同淋水密度下,填料高度每增加1 m,CO_(2)吸收效率大约提高8.5%;氢氧根浓度每升高0.1 mol/L,CO_(2)吸收效率提高约2%;CO_(2)吸收效率随气水比的增加而减小,当气水比从500升高到2 200时,CO_(2)吸收效率从60.33%下降到41.47%,在相同的气水比下,最大淋水密度较小时吸收效率较高;淋水高度每增加1 m,CO_(2)吸收效率提高约1%;相同条件下,氢氧化钠碱液作为吸收液时CO_(2)吸收效率稍高于氢氧化钾碱液。在以上研究的基础上,可对逆流式吸收塔进行设计优化,为后续CO_(2)的捕捉和利用提供技术支持。In order to reduce the concentration of CO_(2) in the air, alleviate the greenhouse effect and climate warming,direct air capture(DAC) technology has become a research hotspot. But its capture cost is relatively high. Therefore,conducting research on DAC technology and obtaining factors and their changing patterns that affect CO_(2) absorption efficiency is beneficial for reducing CO_(2) capture costs, and has significant significance for the promotion and practical engineering application of DAC technology. For absorption towers that can be used for DAC, a small-scale test platform for counter-flow mechanical ventilation absorption tower was established using simulation experiments, with a ventilation cross-sectional area of 0.6 m × 0.6 m by using alkaline solution as the absorbent. The effects of alkaline solution type,alkaline solution concentration, mass water flow per unit plan area of packing, packing section wind speed, packing type,packing height, and water spraying depth on CO_(2) absorption efficiency were studied. The research results indicate that under the same mass water flow per unit plan area of packing, for every 1 m increase in packing height, the CO_(2) absorption efficiency increases by approximately 8.5%. For every 0.1 mol/L increase in hydroxide concentration, the carbon dioxide absorption efficiency increases by about 2%. The CO_(2) absorption efficiency decreases with the increase of the gas-water ratio. When the gas-water ratio increases from 500 to 2 200, the CO_(2) absorption efficiency decreased from 60.33% to 41.47%. Under the same gas-water ratio, the absorption efficiency is higher when the maximum mass water flow per unit plan area of packing is smaller;For every 1 m increase in water spraying depth, the CO_(2) absorption efficiency increases by about 1%. Under the same conditions, the CO_(2) absorption efficiency of NaOH alkaline solution as the absorption solution is slightly higher than that of KOH alkaline solution. On the basis of the research, the design optimization of the

关 键 词：直接空气捕捉 逆流式吸收塔 填料高度 气水比 吸收效率 

分 类 号：TK09[动力工程及工程热物理] X701[环境科学与工程—环境工程]