基于二级双回流的变压吸附捕碳工艺研究  

Research on carbon capture by pressure swing adsorption based on two-stage dual reflux

作　　者：姚佳逸 张东辉[1] 唐忠利[1] 李文彬[1] YAO Jiayi;ZHANG Donghui;TANG Zhongli;LI Wenbin(State Key Laboratory of Chemical Engineering,Chemical Engineering Research Center,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学化工学院,化学工程研究所,化学工程联合国家重点实验室,天津300350

出　　处：《化工学报》2025年第2期744-754,共11页CIESC Journal

摘　　要：碳捕获、利用与封存是应对全球气候变化的关键技术,而火电厂烟气是工业碳排放主要来源之一。变压吸附是常用的烟气捕碳工艺之一,已有的研究表明常规真空变压吸附难以获得满足指标的二氧化碳产品,双回流变压吸附可获得两种高纯度和回收率的产品,但生产能力较低。对此,基于文献数据对组成为N_(2)/CO_(2)=85%/15%的烟气进行了二级耦合工艺的模拟,探究了进料位置,吸附时长,空塔气速和轻、重回流量对工艺的影响。结果表明,吸附压力为一级200 kPa,二级105 kPa,解吸压力为一级30 kPa,二级2 kPa,进料位置距塔底与塔高比0.4,吸附时长90 s,空塔气速0.07 m/s,轻回流量5.5×10^(-3)mol/s,重回流量1.1×10^(-2)mol/s时,能得到96.42%的CO_(2)和99.93%的N_(2),回收率96.22%和99.47%。此外,与文献对比,提出的二级工艺具有高生产能力和较低能耗。Carbon capture,utilization,and storage technology is a key technology for addressing global climate change,and flue gas from thermal power plants is one of the main sources of industrial carbon emissions.The pressure swing adsorption process is one of the commonly used flue gas carbon capture processes.Existing studies have shown that conventional vacuum pressure swing adsorption is difficult to obtain carbon dioxide products that meet the indicators.Double reflux pressure swing adsorption can obtain two products with high purity and recovery rate,but the production capacity is low.For this purpose,using silica gel as the adsorbent,a simulation study was conducted on a two-stage process coupling the dual reflux pressure adsorption process and conventional vacuum pressure swing adsorption process for flue gas with a feed composition of N_(2)/CO_(2)=85%/15%based on literature data.The effects of feed position,adsorption time,gas velocity,light component reflux rate,and heavy component reflux rate on performance were explored.The results showed that when the adsorption pressure was 200 kPa for the first stage and 105 kPa for the second stage,the desorption pressure was 30 kPa for the first stage and 2 kPa for the second stage,the feed position was 0.4 times higher than the bottom,the adsorption time was 90 s,the gas velocity was 0.07 m/s,the reflux flow rate of light components is 5.5×10^(-3)mol/s and the reflux flow rate of heavy components is 1.1×10^(-2)mol/s,96.42%CO_(2)and 99.93%N_(2)can be obtained,with recovery rates of 96.22%and 99.47%,respectively.In addition,compared with existing research results in the literature,the proposed two-stage process has high productivity and low energy consumption.

关 键 词：双回流 变压吸附 二氧化碳捕集 硅胶 烟道气 数值模拟 

分 类 号：TQ028.1[化学工程]