N,N-二甲基酰胺水溶液吸收气态甲苯实验研究  

Adsorption of Gaseous Toluene by an Aqueous N,NDimethylformamide Solution:An Experimental Study

作　　者：张海杰 寿登 成卓韦 宋万康 ZHANG Haijie;SHOU Deng;CHENG Zhuowei;SONG Wankang(Zhejiang Huanyao Environmental Construction Co.,Ltd.,Hangzhou 310014,China;College of Environment,Zhejiang University of Technology,Huzhou 313200,China)

机构地区：[1]浙江环耀环境建设有限公司,浙江杭州310014 [2]浙江工业大学环境学院,浙江湖州313200

出　　处：《能源环境保护》2025年第2期182-191,共10页Energy Environmental Protection

基　　金：浙江省科技计划资助项目(2022C03073);浙江省生态环境科研和成果推广资助项目(2021HT0009)。

摘　　要：合成革行业排放的有机废气主要成分为N,N-二甲基甲酰胺(DMF),并伴有少量甲苯、丁酮和乙酸乙酯等化合物。传统处理方法通常依赖水吸收工艺,该工艺会产生富含DMF的水性吸收液。系统探讨了DMF水溶液作为吸收剂,利用填料塔对疏水性甲苯的吸收性能。研究表明,添加DMF显著增强了甲苯与吸收剂基质之间的相互作用。基于密度梯度理论(DGT)的分析显示,甲苯与水或甲苯与DMF之间的相互作用较弱,而DMF与水之间存在强氢键。因此,添加DMF可有效增强甲苯与吸收剂分子间的相互作用,从而实现甲苯的高效吸收和资源回收。在动态吸收实验中,40%DMF吸收剂的吸收效率达到32.0%时,去离子水仅为12.7%,40%DMF吸收剂的吸收效率比去离子水提高了2.5倍。停留时间和液气比对DMF水溶液的甲苯吸收效率有显著影响。停留时间从10 s增加到25 s,在30 min的操作时间内,吸收效率从10.0%提升至24.0%。系统在液气比为15 L/m^(3)时达到峰值吸收性能,最大效率为24.3%。此外,30%DMF水溶液对甲苯的饱和吸收量为14 mg/L,其准亨利定律常数远小于水中的对应值,进一步验证了DMF在甲苯吸收中的增强作用。通过加热蒸馏,甲苯可从DMF吸收剂溶液中高效回收,并且吸收剂再生后几乎保持初始的甲苯吸收能力。在50℃的解吸温度下,甲苯的解吸效率达到91.2%。经过8次连续的吸附-解吸循环,DMF溶液对甲苯的吸收饱和容量仍然稳定。这些发现证实了利用DMF水溶液有效吸收低浓度甲苯废气的可行性,并揭示了该技术在处理难水溶性挥发性有机物的实际应用潜力。The synthetic leather industry emits organic waste gases predominantly composed of N,Ndimethylformamide(DMF),with trace amounts of toluene,butanone,and ethyl acetate as secondary components.Conventional treatment methods rely on water absorption processes,which generate aqueous absorbent solutions enriched with DMF.This study systematically investigates the absorption efficiency of hydrophobic toluene in DMF aqueous solutions using a spray-packed column,focusing on the characteristics of exhaust gas components.Through molecular interaction analysis(DMF-toluenewater ternary system)and experimental validation,we demonstrate that DMF addition significantly enhances intermolecular interactions between toluene and the absorbent matrix.Analysis based on density gradient theory(DGT)reveals that only weak interactions exist between toluene and water molecules or between toluene and DMF molecules,whereas strong hydrogen bonding is present between DMF and water molecules.Therefore,the addition of DMF to an aqueous solution enhances the intermolecular interactions between toluene and the absorbent,enabling efficient absorption and resource recovery of toluene.Experimental results indicate that DMF enhances the interaction force between toluene and the absorbent.In dynamic absorption experiments,the absorption efficiencies of 40%DMF absorbent and deionized water were 32.0%and 12.7%,respectively,representing a 2.5-fold increase in absorption efficiency.Residence time and liquid-to-gas ratio significantly influenced the toluene absorption efficiency of the DMF aqueous solution.Increasing the residence time from 10 s to 25 s improved the absorption efficiency from 10.0%to 24.0%over a 30-minute operational period.Additionally,the system achieved peak absorption performance at a liquid-to-gas ratio of 15 L/m^(3),with a maximum efficiency of 24.3%.The saturated absorption capacity of toluene in the 30%DMF aqueous solution was 14 mg/L.The quasi-Henry′s law constant of toluene in the 30%DMF aqueous solution was significantly lower

关 键 词：合成革 有机废气 N N-二甲基甲酰胺(DMF) 水吸收 甲苯吸收剂 挥发性有机化合物(VOCs) 

分 类 号：X701[环境科学与工程—环境工程]