二氧化碳和甲烷在MFI/MCM-41和JSR/MCM-41中吸附行为的模拟研究

摘要：分子筛具有独特孔结构和较大比表面积，广泛应用于CO2/CH4体系的吸附存储与分离。本文以硅基分子筛MFI和JSR为基础，采用圆柱形孔结构模型构建微孔/介孔复合材料MFI/MCM-41和JSR/MCM-41，对CO2、CH4及其二元混合组分在分子筛MFI、JSR、MFI/MCM-41和JSR/MCM-41中的吸附行为进行GCMC模拟，获得CO2和CH4吸附等温线、相互作用能、吸附热力学性质以及二元混合组分在分子筛中吸附选择性。结果表明：纯组分CO2和CH4吸附量随压力升高而增加，随温度升高而减少。298 K和1000 kPa下MFI/MCM-41对纯组分CO2和CH4最大吸附量分别为3。35和2。73 mmol·g-1，JSR/MCM-41对纯组分CO2和CH4最大吸附量分别为6。05和1。71 mmol·g-1。综合考虑四种分子筛对CO2/CH4体系吸附量和选择性，低压下JSR对CO2/CH4体系具有较高选择性，最大分离系数可达8。68。76065

毕业论文关键词：分子筛，微孔/介孔复合材料， CO2，CH4，分子模拟，吸附

Abstract: Zeolites have been intensively investigated in recent decades because of their large surface areas and molecular sized porous structures。 The nanoporous zeolites are considered as potential sorbents for the adsorption and separation of CO2 and CH4 gas mixtures。 In this work, the model of the micro/mesoporous composite MFI/MCM-41 and JSR/MCM-41 were constructed by carving out cylindrical mesopores in MFI and JSR matrix。 The adsorption properties of CO2 and CH4 in siliceous MFI, JSR and two micro/mesoporous composite were investigated using the GCMC simulation methods。 The adsorption isotherms and adsorption heat for pure components and binary mixtures of CO2 and CH4 were obtained。 The results demonstrate that the adsorbed amount of CO2 and CH4 increases with an increase in pressure。 The adsorption amount of CO2 and CH4 in the four zeolites decreases as the temperature increasing。 The maximum amount of CO2 and CH4 adsorbed in MFI/MCM-41 respectively was 3。35 mmol·g-1 and 2。73 mmol·g-1 at 1000 kPa and that in JSR/MCM-41 was 6。05 mmol·g-1 and 1。71 mmol·g-1, respectively。 By considering the adsorption uptake and selectivity for CO2/CH4, the JSR zeolite is a good candidate for the separation of CO2/CH4 at low pressure。 The maximum selectivity of CO2 and CH4 gas mixtures is 8。86。

Keywords: Zeolite, micro/mesoporous composite, CO2, CH4, Molecular simulation, Adsorption

1 引言 3

1。1 沸石分子筛 3

1。2 介孔硅基分子筛 4

1。3 分子模拟技术 5

1。3。1 模拟软件 5

1。3。2 蒙特卡洛方法 6

2 实验部分 7

2。1 模拟构建 7

2。2 气体吸附模拟过程 8

3 结果与讨论 9

3。1 CO2/CH4在MFI和复合材料MFI/MCM-41中吸附模拟 9

3。1。1 纯气体吸附模拟 9

3。1。2 温度的影响 9

3。1。3 二元混合组分吸附 10

3。2 CO2/CH4在JSR和复合材料JSR/MCM-41中吸附模拟 12

3。2。1 纯气体吸附模拟 12

3。2。2 温度的影响 13

3。2。3 二元混合组分吸附二氧化碳和甲烷在MFI/MCM-41和JSR/MCM-41中吸附行为的模拟研究:http://www.youerw.com/huaxue/lunwen_87164.html