煤焦孔隙特征对挥发性有机物吸附特性影响的分子模拟研究  

Molecular Simulation Study on Effects of Char Pore Characteristics on VOC Adsorption Behaviors

作　　者：张津铭 王长安[1] 胡广涛 赵鹏勃[1] 车得福 ZHANG Jinming;WANG Chang’an;HU Guangtao;ZHAO Pengbo;CHE Defu(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;School of Energy Engineering,Yulin University,Yulin,Shaanxi 719000,China)

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049 [2]榆林学院能源工程学院,陕西榆林719000

出　　处：《西安交通大学学报》2023年第7期179-190,共12页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52176129);榆林学院-中国科学院洁净能源创新研究院联合基金资助项目(2021004)。

摘　　要：为了减轻挥发性有机物(VOCs)对生态环境和人体健康的危害,针对煤焦吸附VOCs过程进行了分子模拟,研究煤焦微观理化结构特性尤其是孔隙结构对VOCs吸附特性的影响规律。基于煤焦分子建模与分子反应动力学模拟,构建了具有不同孔隙特征的煤焦分子模型,通过蒙特卡罗方法模拟VOCs在两种孔结构煤焦中的吸附特性与反应过程。所构建的煤焦微孔模型中仅有微孔,而中微孔模型在微孔基础上耦合了中孔结构。模拟结果表明:微孔是影响小分子VOCs吸附稳定性和吸附量的主要因素,中孔的加入不会显著增加吸附量,有时反而会使VOCs吸附性能略微降低。不同吸附质间影响吸附的主要因素为分子量与极性,分子量越大,极性越小,在煤焦中的吸附效果越好。研究结果对重构优化煤焦微观孔隙结构,提高VOCs吸附性能具有参考价值。For the purpose of mitigating the harm of volatile organic compounds(VOCs)to ecological environment and human health,this paper carried out molecular simulation on the process of char absorbing VOCs to study the effect of coal char’s microstructures,especially the pore structures,on VOC adsorption.In this paper,char molecular models with different pore characteristics were constructed based on char molecular modeling and molecular dynamics simulation.Monte Carlo method was used to simulate the VOC adsorption characteristics and reaction processes in char models of two different pore structures.The low porosity model of coal char constructed in this paper contains only micropores,while the high porosity model is coupled with mesoporous structure besides the micropores.The simulation results show that micropores are the main factor affecting the adsorption stability and adsorption capacity.The addition of mesoporous structure does not significantly increase the adsorption capacity,but possibly slightly downgrades the adsorption performance under certain circumstances.The main factors affecting the adsorption of different adsorbents are molecular weight and polarity.A larger molecular weight and a smaller polarity will result in a better adsorption.The study of this paper can provide a reference for guiding the reconstruction and optimization of char microstructure,and improving the VOC adsorption performance.

关 键 词：挥发性有机物 吸附 煤焦 分子模型 孔隙结构 

分 类 号：TQ424[化学工程]