用于二氧化碳捕集的固体吸附材料研究进展

过量的二氧化碳气体排放造成了全球变暖,二氧化碳的捕集与封存(CCS)势在必行。与传统的液体胺吸附技术相比,固体吸附材料有吸附量高、再生能耗小、循环稳定性好等优点。本文主要介绍了一些典型的二氧化碳多孔吸附材料,如碳基材料、沸石、介孔二氧化硅、MOFs、胺基负载材料等的结构特点及研究进展。     

有机胺改性多孔材料制备固体胺二氧化碳吸附剂的研究进展

人类社会排放的温室气体逐年增多,全球变暖问题日益严重,二氧化碳减排已迫在眉睫。有机胺改性多孔材料制备的固体胺吸附剂,二氧化碳吸附性能十分优越,具有良好的工业应用前景。本文综述了介孔分子筛、硅胶、多孔炭材料等多种多孔材料载体负载有机胺制备固体胺吸附剂的方法,分析了其二氧化碳吸附性能,讨论了多孔材料的孔结构对吸附剂吸附性能的影响。     

部分脱除模板剂对MCM-41修饰负载有机胺吸附CO_2的影响

介孔分子筛MCM-41具有单一的孔道结构和较大的比表面积。通过负载有机胺形成的介孔有机胺二氧化碳固体吸附剂比常见的固体吸附剂具有高选择性、高吸附量等特点。利用化学方法部分脱除模板剂,负载PEI制备固体吸附剂,研究了模板剂脱除率PEI负载和对二氧化碳吸附性能的影响。用XRD、FT-IR、TEM、BET等方法对吸附剂结构进行表征,利用TG/DTA方法测定了CO2吸附量。研究结果表明,使用MCM-41原粉负载50%PEI吸附量达到131.0 mg/g(即262.0 mg/gPEI),比相同负载量除去模板剂的分子筛提高了12.6%;比单一的PEI分子吸附量(80.3 mg/g)提高了3.26倍,这说明在MCM-41原粉孔道内部由于存在丝状胶束而形成的亚纳米空间结构提高了有机胺的分散和利用率,增加了对CO2的吸附量。     

新型无机固体吸附剂在天然气脱水领域研究进展

天然气在进入管网输送之前必须经过脱水处理,目前常用的天然气脱水方法主要有冷干法、液体吸收法和固体吸附法。用于天然气脱水的固体吸附剂主要包括分子筛、氧化铝、介孔二氧化硅和金属有机框架材料（MOFs）等。随着更多海上气田的勘探开发,分子筛和氧化铝等传统吸附剂已无法满足对大量天然气的净化需求,需要使用具有更高负载能力的吸附剂。介孔二氧化硅和MOFs具有高化学稳定性、低密度、高孔隙度的优点,且使用寿命长,避免了频繁更换,作为天然气脱水吸附剂具有潜在优势。围绕高比表面积、孔体积、亲水性和再生能力等综述了介孔二氧化硅和金属有机框架材料（MOFs）在天然气脱水方面的研究进展。介孔二氧化硅具有良好的亲水性和机械稳定性,可在高压力范围内使用,提升处理装置的效率。然而介孔二氧化硅主要是通过溶胶-凝胶法合成,老化时间较长,且传统的蒸发干燥法无法保持完全凝胶的结构。未来有望通过超临界流体干燥法获得具有更好物化性质和孔结构的介孔二氧化硅,进一步提高介孔二氧化硅的吸附能力。MOFs作为无机物和有机物结合形成的多孔材料,具有高度规则的孔结构和可调的性质,且金属离子与配体官能团的自由电子对之间的化学或物理相互作用,使其具有较高的天然气吸附脱水效率和优异的再生循环性能。最后指出,需要进一步研究复杂工况下的MOFs吸附脱水能力、长周期运行稳定性以及高压工况、造粒及不同分离过程（变压吸附和变温吸附）对MOFs的影响,并开发MOFs低成本规模化制备技术实现工业化应用。     

基于氨基功能化介孔硅的pb2＋选择性吸附剂

采用后接枝法将氨丙基三乙氧基硅烷接枝到二氧化硅网络中,合成了氨丙基功能化的MCM-41介孔硅.FTIR结果显示,氨基被共价键键合到了介孔硅基体上.实验结果表明,所制备的功能化材料可以选择性吸附水溶液中的Pb2+,最大吸附量为193 mg·g-1.     

基于氨基功能化介孔硅的Pb^2+选择性吸附剂

采用后接枝法将氨丙基三乙氧基硅烷接枝到二氧化硅网络中，合成了氨丙基功能化的MCM-41介孔硅。FTIR结果显示，氨基被共价键键合到了介孔硅基体上。实验结果表明，所制备的功能化材料可以选择性吸附水溶液中的pb2＋，最大吸附量为193mg·g1。     

功能化介孔材料吸附性能与机理的研究进展

综述了功能化介孔材料的孔径结构、改性基团和吸附条件对废水中的有机污染物、染料分子和重金属离子以及生物大分子、药物分子、CO2和挥发性有机气体污染物的吸附脱除效果的影响,还介绍了功能化介孔材料对液晶材料中的微量无机离子和大极性有机杂质的吸附脱除效果,指出了新型功能化介孔材料的开发和吸附环境的研究是未来的研究热点和发展趋势。     

无机固体吸附剂在二氧化碳捕集应用中的研究进展

随着全球气候变暖,二氧化碳的捕集、利用和封存（CCUS）逐渐成为科学界和工业界的研究热点。CCUS的关键是选择性地从气体混合物中捕集二氧化碳。目前二氧化碳捕集技术包括化学吸收、膜分离、吸附和低温分离等。吸附法是利用吸附剂对不同气体的吸附能力差异来进行二氧化碳捕集。综述了分子筛、介孔二氧化硅、黏土及多孔碳等无机固体吸附剂在二氧化碳捕集应用中的研究进展。对比了不同改性方法对吸附剂吸附二氧化碳性能的影响。从应用角度来看,分子筛、介孔二氧化硅、黏土具有潜在的成本效益,但仍需在工程设计开发方面得以进一步发展,以适用于不同应用需求的二氧化碳捕集。     

介孔氧化硅负载贵金属催化剂研究进展

有序介孔氧化硅材料具有独特的结构和性质,如高的比表面积、大的孔容、均一的孔径分布、丰富的结构和形貌等,在多相催化领域受到广泛的关注和研究。本文回顾了近年来介孔氧化硅在负载贵金属催化剂方面的研究现状,介绍了直接浸渍法、官能团修饰法、原子层沉积法、一锅合成法等不同的负载方法,归纳比较了各种方法之间的优缺点。同时也指出了介孔有序SiO2材料在催化负载方面存在的一些局限,并对其发展前景做了展望,认为降低介孔氧化硅的成本、提高载体的水热稳定性、开发新结构和性能的介孔氧化硅以及探索新的催化剂负载工艺,将是未来介孔氧化硅在多相催化领域应用研究的重要方向。     

纤维介孔硅纳米材料研究进展

CTAB为模板剂加入TEOS和尿素在环己烷和异丙醇为溶剂条件下合成出纤维结构介孔硅材料,材料在许多领域具有很高应用价值。本文综述了纤维介孔硅材料的合成,以及功能化纤维介孔硅材料的制备。材料在工业催化、环境污水、重金属的吸附分离、二氧化碳吸附、药物控制和DNA吸附等领域的应用。     

氨基修饰微孔/介孔复合材料AM-5A-MCM-41对CO2吸附分离的分子模拟

构建了氨基修饰微孔/介孔复合材料AM-5A-MCM-41的全原子模型,采用巨正则Monte Carlo（GCMC）方法研究了它的CO₂吸附分离性能,采用加权混合规则来描述氨基和CO₂分子的弱化学作用。模拟结果表明,CO₂分子优先吸附在复合材料介孔表面的氨基附近,CO₂纯气体的吸附量和吸附热有了显著提高,而N₂的吸附量和吸附热则基本不受影响。对于CO₂和N₂的混合气分离,由于复合材料对CO₂的弱化学吸附作用,显著提高了CO₂吸附量和吸附选择性,在573 K和100 kPa时CO₂/N₂的选择性达到了87.0。通过分子模拟研究可以从微观角度了解CO₂在氨基修饰的微孔/介孔复合材料中的吸附分离的细节和机理,为实验设计和合成高效CO₂吸附剂提供指导。     

氨改性的介孔二氧化硅的直接合成和CO2吸附

Amine-functionalized mesoporous silica was prepared by using lauric acid and N-stearoyl-l-glutamic acid as structure directing agents via the SN+-I mechanism and applied to CO2 adsorption at room temperature. With γ-aminopropyltriethoxysilane as co-structure directing agent and due to the direct electrostatic interaction with anionic surfactant, most of the amino groups were uniformly distributed at the inner surface of pores and the performance was stable. The amine-functionalized mesoporous silica was characterized by Fourier transform infrared spectrometer, X-ray diffraction, nitrogen physisorption and thermogravimetric analysis. The CO2 adsorption capacity was measured by digital recording balance. At the room temperature and under the atmospheric pres-sure, the adsorption capacity of LAA-AMS-0.2 for CO2 and N2 is 1.40 mmol•g1 and 0.03 mmol•g1, respectively, indicating high separation coefficient of CO2/N2.     

Light-responsive adsorbents with tunable adsorbent-adsorbate interactions for selective CO2 capture

Amines in porous materials have been employed as active species for the selective CO₂ adsorption from natural gas because of their target-specific interactions. Nevertheless, it is difficult to modulate such strong interactions to reach a high efficiency in the adsorption processes. Herein, we fabricated light-responsive adsorbents with tunable adsorbent-adsorbate interactions for CO₂ capture. The adsorbents were synthesized by introducing primary and secondary amines into a mesoporous silica that had been grafted with azobenzene groups on the surfaces. The target-specific amine sites render the adsorbents significantly selective in the uptake of CO₂ over CH₄, and the azobenzene groups were used as light-responsive switches to influence the adsorbent-adsorbate interactions. The adsorbents can freely adsorb CO₂ when the azobenzene groups are in the trans state. Ultraviolet-light irradiation makes the azobenzene groups transform to the cis configuration, which greatly hinders amines in the uptake of CO₂. The caused difference of adsorption capacity can reach 34.9%. The alternative irradiation by ultraviolet- and visible-light can lead to a recyclable regulation on adsorption performance. The changes of the electrostatic potentials of amines are responsible for the light-induced regulation on adsorption.     

有机胺功能化介孔固体吸附剂吸附分离CO2性能研究

针对当前固体胺CO₂吸附剂存在吸附容量小、循环稳定性差等问题,采用高比表面积、易嫁接胺的介孔SBA-15作为载体,研究分子筛模板剂脱除方法和有机胺改性方法对制备的固体吸附剂吸附性能的影响,并采用N₂物理吸附、X射线衍射、红外光谱、热失重分析等表征技术并对样品进行表征。实验结果表明,通过嫁接和浸渍能够合成出不同有机胺负载量的胺功能化吸附剂,其中混合胺嫁接法改性的APTES-SBA（U）-T60吸附剂其吸附容量最大,在75℃下的纯CO₂气氛中吸附量达到192.05 mg/g,优于溶剂萃取和煅烧法去除模板剂。此外,混合胺嫁接法制备的样品在多次的吸/脱附操作下,CO₂吸附稳定性良好,表明混合胺修饰的吸附剂具有很好的稳定性和再生性。     

吸附法碳捕集固体胺吸附剂成型技术研究进展

吸附法碳捕集技术是实现工业过程或大气中CO₂分离与脱除的重要途径之一,高性能吸附剂的开发是该技术的关键。固体胺吸附剂由于其优异的CO₂吸附量、选择性以及较低的再生能耗,近年来受到了广泛的关注,但用于工业的成型吸附剂仍面临机械强度低、稳定性差和胺流失严重等关键难题,难以在工业中大范围的推广应用。本文分析了固体胺成型吸附剂制备面临的主要难题,重点总结了近年来国内外吸附剂成型技术的研发进展,并对固体胺工业吸附剂的发展方向进行了展望。未来固体胺吸附法碳捕集技术的研发重点在于立足吸附反应机理和工业烟气的特性,创新成型固体胺吸附剂制备技术,提升吸附剂的CO₂吸附量、胺效率、机械与循环稳定性,研发低能耗的配套吸附工艺和核心装置。     

Amine-immobilized HY zeolite for CO2 capture from hot flue gas

Solid amine-based adsorbents were widely studied as an alternative to liquid amine for post-combustion CO₂ capture (PCC). However, most of the amine adsorbents suffer from low thermal stability and poor cyclic regenerability at the temperature of hot flue gases. Here we present an amine loaded proton type Y zeolite (HY) where the amines namely monoethanolamine (MEA) and ethylenediamine (ED) are chemical immobilized via ionic bond to the zeolite framework to overcome the amine degradation problem. The MEA and ED of 5%, 10% and 20% (mass) concentration – immobilized zeolites were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and N₂ -196 ℃ adsorption to confirm the structure integrity, amine functionalization, and surface area, respectively. The determination of the amine loading was given by C, H, N elemental analysis showing that ED has successfully grafted almost twice as many amino groups as MEA within the same solvent concentration. CO₂ adsorption capacity and thermal stability of these samples were measured using thermogravimetric analyser. The adsorption performance was tested at the adsorption temperature of 30, 60 and 90 ℃, respectively using pure CO₂ while the desorption was carried out with pure N₂ purge at the same temperature and then followed by elevated temperature at 150 ℃. It was found that all the amine@HY have a substantial high selectivity of CO₂ over N₂. The sample 20% ED@HY has the highest CO₂ adsorption capacity of 1.76 mmol·g^-1 at 90 ℃ higher than the capacity on parent NaY zeolite (1.45 mmol·g^-1 only). The amine@HY samples presented superior performance in cyclic thermal stability in the condition of the adsorption temperature of 90 ℃ and the desorption temperature of 150 ℃. These findings will foster the design of better adsorbents for CO₂ capture from flue gas in post-combustion power plants.     

Characterization of acidic property of sulfo-group functionalized microporous and mesoporous silica by adsorption microcalorimetry

Sulfo-group functionalized microporous and mesoporous silica based-on a MCM-41 framework which showed solid acid property were synthesized and characterized by adsorption microcalorimetry. Both the sulfo-functionalized microporous and mesoporous silica (Micro-SO₃H and Meso-SO₃H) were prepared by the oxidation of thiol group (–SH) included mesoporous silica which was obtained through the hydrolysis and co-condensation of tetramethoxysilane (TMOS) and mercaptopropyl trimethoxysilane (MPTMS). The samples have an ordered two-dimensional hexagonal pore array similar to that of MCM-41 as depicted from the XRD patterns. Nitrogen adsorption also shows that both microporous and mesoporous silica have pore characteristics similar to MCM-41, i.e. high surface area and high pore volume. However, pore regularity, surface area and pore volume decreased as the MPTMS loading increased. Solid-state ²⁹Si NMR indicated that the sulfo groups were successfully incorporated into both microporous and mesoporous silica frameworks. This sulfo-functionalized porous silica have high NH₃ uptakes and high differential heats of NH₃ adsorption, suggesting the presence of strong acidic sulfo groups on the silica surface. Acid catalyses of the samples were characterized by the isomerization reaction of but-1-ene to cis, trans-but-2-ene.     

Theoretical and experimental study on the fluidity performance of hard-to-fluidize carbon nanotubes-based CO2 capture sorbents

Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO₂ capture in fluidized beds, suffering from insufficient contact with CO₂ for the high-level CO₂ capture capacity. This study focuses on promoting the fluidizability of hard-to-fluidize pure and synthesized silica-coated amine-functionalized carbon nanotubes. The novel synthesized sorbent presents a superior sorption capacity of about 25 times higher than pure carbon nanotubes during 5 consecutive adsorption/regeneration cycles. The low-cost fluidizable-SiO₂ nanoparticles are used as assistant material to improve the fluidity of carbon nanotubes-based sorbents. Results reveal that a minimum amount of 7.5 and 5 wt% SiO₂ nanoparticles are required to achieve an agglomerate particulate fluidization behavior for pure and synthesized carbon nanotubes, respectively. Pure carbon nanotubes + 7.5 wt% SiO₂ and synthesized carbon nanotubes + 5 wt% SiO₂ indicates an agglomerate particulate fluidization characteristic, including the high-level bed expansion ratio, low minimum fluidization velocity (1.5 and 1.6 cm·s^–1), high Richardson−Zakin index (5.2 and 5.3 > 5), and low Π value (83.2 and 84.8 < 100, respectively). Chemical modification of carbon nanotubes causes not only enhanced CO ₂ uptake capacity but also decreases the required amount of silica additive to reach a homogeneous fluidization behavior for synthesized carbon nanotubes sorbent.     

五乙烯六胺改性制备CO2吸附剂及其对模拟烟气中CO2捕集性能的研究（英文）

A novel solid support adsorbent for CO2 capture was developed by loading pentaethylenehexamine (PEHA) on commercial y available mesoporous molecular sieve MCM-41 using wet impregnation method. MCM-41 sam-ples before and after PEHA loading were characterized by X-ray powder diffraction, N2 adsorption/desorption, thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties. CO2 adsorption performance was evaluated in a fixed bed adsorption system. Results indicated that the structure of MCM-41 was preserved after loading PEHA. Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading. The working adsorption capacity of CO2 could be significantly improved at 60%of PEHA loading and 75 °C. The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)?1 at 75 °C. Adsorption/desorption circle showed that the CO2 working adsorption capacity of MCM-41-PEHA kept stable. ? 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.     

四乙烯五胺改性多孔二氧化硅制备及CO2吸附性能

以十六烷基三甲基溴化铵（CTAB）为模板剂，原硅酸乙酯（TEOS）为硅源，1,3,5-三异丙基苯（TPB）为扩孔剂，制备不同孔道结构的多孔二氧化硅纳米微球（PSNs），将四乙烯五胺（TEPA）通过物理浸渍法负载到PSNs上，合成TEPA-PSNs吸附剂。利用扫描电镜、透射电镜、红外光谱、N₂吸附-脱附循环实验和热重分析对材料的结构性能和热稳定性能进行表征，成功制备了具有不同孔道结构的胺基化多孔二氧化硅。对吸附剂材料进行CO₂吸脱附实验和动力学研究，结果表明：当TPB含量增多时，吸附剂材料吸附的CO₂量也随之增大，并且TEPA-PSNs-0.5在75℃时吸附量最大，达4.70mmol/g；一阶动力学模型能较好地预测该吸附剂的CO₂吸附过程；经过5次循环，其再生性能仍然高达94.34%。因此，合成的胺基化多孔二氧化硅具有高吸附量和良好稳定性，是用于二氧化碳捕集的潜在材料。