PEBA/氮硫共掺杂多孔碳球混合基质膜的制备及CO_(2)分离性能研究  

Preparation of PEBA/N,S co-doped porous carbon sphere mixed matrix membrane for CO_(2) separation

作　　者：周毅 王永洪[1,2] 张新儒 李晋平[1,2] ZHOU Yi;WANG Yonghong;ZHANG Xinru;LI Jinping(College of Chemistry and Chemical Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization,Taiyuan 030024,Shanxi,China)

机构地区：[1]太原理工大学化学化工学院,山西太原030024 [2]气体能源高效清洁利用山西省重点实验室,山西太原030024

出　　处：《化工学报》2021年第10期5237-5246,F0002,共11页CIESC Journal

基　　金：国家自然科学基金面上项目(22078216);山西省回国留学人员科研资助项目(2020-027,2021-056);广东省高性能与功能高分子材料重点实验室开放基金项目(20190002);山西省煤层气联合基金项目(2015012009)。

摘　　要：为了获得高性能的混合基质膜,有效捕集烟道气中的CO_(2),设计了对CO_(2)有优异的扩散选择性和吸附选择性的氮硫共掺杂多孔碳球添加剂,实现了烟道气中CO_(2)/N2的高效分离。选用表面含氧基团丰富的葡萄糖作为碳源,硫脲作为氮源和硫源,通过水热法制备了氮硫共掺杂碳球(NSC),并用KOH活化,获得了具有多孔结构的氮硫共掺杂碳球(NSPC),再加入聚醚嵌段酰胺(PEBA)中制备出PEBA/NSPC混合基质膜。采用FTIR、XRD和BET表征了材料的化学结构和孔结构,借助力学性能表征了膜的两相界面相容性。系统研究了PEBA/NSPC混合基质膜中葡萄糖与硫脲的质量比、NSC和KOH的质量比、NSPC的添加量、操作压力、操作温度,以及模拟烟道气条件对膜CO_(2)渗透性、CO_(2)/N_(2)选择性的影响。结果表明:NSPC材料成功实现了氮、硫元素的共掺杂,而且具有较好的孔结构。在操作温度25℃、操作压力0.2 MPa的条件下,混合基质膜中NSPC添加量为3%(质量)时气体分离性能最优,CO_(2)渗透系数和CO_(2)/N2选择性分别为589 Barrer和64,相比纯PEBA膜分别提高了244%和139%。这是因为多孔碳球的微孔结构显著提高了CO_(2)的扩散选择性,同时氮、硫元素的掺杂因为酸碱相互作用和良好亲和性有效提高了CO_(2)的吸附选择性。稳定性实验表明,PEBA/NSPC混合基质膜在360 h连续运行过程中气体分离性能稳定,具有较好的工业应用前景。In order to obtain high-performance mixed matrix membrane to effectively capture CO_(2) in flue gas,this paper designed a N,S co-doped porous carbon sphere with excellent diffusion and adsorption selectivity for CO_(2) as an additive to achieve the efficient separation of CO_(2)/N2 from flue gas.Glucose with rich oxygen groups as the carbon source and thiourea as nitrogen and sulfur source are selected to prepare the nitrogen and sulfur co-doped carbons(NSC)by hydrothermal method.The porous structure of NSPC is produced by the activation of NSC with KOH.FTIR,XRD and BET tests indicate the successful synthesis of NSPC,which has high specific surface area and microporosity.The optimal ratio of glucose to thiourea,the optimal ratio of NSC to KOH in the synthesis of NSPC,the effect of NSPC content,feed pressure,test temperature on the performance of the membrane are studied.It proves that the nitrogen,sulfur-containing CO_(2) affinity sites and micropores in NSPC have beneficial effects on the gas separation performance of the membrane.The results show that when the NSPC content is 3%(mass),the performance of membrane is the best at 25℃and 0.2 MPa.The CO_(2) permeability is 589 Barrer,and the CO_(2)/N_(2) selectivity is 64.The performance of the membrane in the mixed gas is slightly lower than that in the pure gas,and it can remain stable for 360 h,which has good industrial application prospects.

关 键 词：混合基质膜 活性炭 CO_(2)捕集 烟道气 聚醚嵌段酰胺 

分 类 号：TQ028.8[化学工程]