碱处理多级孔钛硅分子筛疏水吸附VOCs研究  

Study on hydrophobic adsorption of VOCs by alkali-treatedhierarchical titanium silicalite zeolites

作　　者：张媛媛 于庆君 易红宏 赵顺征 高凤雨 武文静 孟逢时 唐晓龙 ZHANG Yuanyuan;YU Qingjun;YI Honghong;ZHAO Shunzheng;GAO Fengyu;WU Wenjing;MENG Fengshi;TANG Xiaolong(School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants,Beijing 100083,China)

机构地区：[1]北京科技大学能源与环境工程学院,北京100083 [2]工业典型污染物资源化处理北京市重点实验室,北京100083

出　　处：《能源环境保护》2024年第4期166-178,共13页Energy Environmental Protection

基　　金：国家重点研发计划资助项目(2023YFB3810800);国家自然科学基金联合基金项目重点支持资助项目(U20A20130)。

摘　　要：在一段时间内我国能源结构仍将以燃煤为主,针对燃煤烟气中VOCs的治理,采用具有MFI拓扑结构的钛硅分子筛TS-1进行吸附减排。通过使用不同强度和性质的碱溶液(NaOH、NH_(4)OH、TPAOH)对其进行处理,构建了具有差异化多级孔结构的材料,并调控了分子筛中硅烷醇基团Si—OH(包括外表面孤立硅烷醇基团和内部缺陷位点羟基巢)的相对含量,以提高分子筛疏水吸附VOCs能力。通过XRD、BET、UV-vis、IR、SEM与TEM等手段考察了分子筛骨架结构、内部缺陷和其他性质的变化。研究结果显示,NaOH溶液会严重刻蚀分子筛骨架,导致有序孔道数量减少、缺陷含量增加,从而使吸附能力大幅下降;NH_(4)OH处理可以疏通分子筛孔道,去除无定形硅物种,提高吸附VOCs的性能,但疏水能力略微下降;而TPAOH处理过程中的“溶解-再结晶”效应导致大量有序骨架生成,微孔发达程度显著提高,分子筛内部缺陷得到修复,吸附VOCs的性能与疏水性能都明显提升,VOCs的吸附容量提高了50%,而静态水吸附容量降低了18%。China′s energy structure will likely remain dominated by coal combustion for a period of time.Titanium silicalite zeolites(TS-1)with MFI topology were adopted for adsorption and reduction of VOCs in coal-fired flue gas treatment in this work.We treated the zeolites with alkali solutions(NaOH,NH_(4)OH,TPAOH)of different strength and properties to construct a differentiated hierarchical pore structure.The relative content of Si—OH groups(including isolated Si—OH groups on the outer surface and hydroxyl nests at internal defect sites)was also regulated in order to improve VOCs hydrophobic adsorption capacity.The changes of zeolitic framework structure,internal defects and other relevant properties were investigated using XRD,BET,UV-vis,IR,SEM and TEM.The results showed that the NaOH solution treatment significantly etched the framework,leading to a decrease in ordered pores and increase in defects,which resulted in a sharp decrease in adsorption capacity.NH_(4)OH solution could dredge the pores and remove amorphous silicon species,improving the adsorption performance of VOCs,but the hydrophobic ability decreases slightly.The dissolution-recrystallization effect in TPAOH treatment process led to the formation of numerous ordered zeolitic frameworks.The development of micropores was significantly improved,and the internal defects were repaired,resulting in a significant improvement of hydrophobic adsorption performance of VOCs.The adsorption capacity of VOCs was increased by 50%,and the static water adsorption capacity was reduced by 18%.

关 键 词：燃煤烟气 VOCS 疏水吸附 钛硅分子筛 碱处理 

分 类 号：X701[环境科学与工程—环境工程]