碳捕集固体胺吸附剂载体性能优化策略及分析

碳捕集是“双碳”下推动化石能源低碳应用的有效途径,固体胺吸附剂是实现碳捕集、利用与封存的重要手段。其中,载体改性和胺种类优化是固体胺吸附剂研究热点策略。综述和评论了国内外固体胺吸附剂优化策略的作用机制、技术难点和碳捕集效果等,重点阐述并比较了硅基、多孔碳和有机框架载体优化策略在改善CO2选择性、吸附容量和稳定性等方面的作用,展望了固体胺吸附剂未来在高效稳定捕集、生物质吸附和碳利用与封存等研究方向和应用前景。     

TEPA/MCM-41固体胺吸附剂的制备及其CO_2吸附性能研究

制备了具有高CO_2吸附性能的TEPA/MCM-41固体胺吸附剂,并采用N_2物理吸脱附、XRD、FTIR、EA、TG-DSC等方法对其进行系统表征。采用重量法测试了吸附剂的吸附与循环稳定性能。结果表明,吸附温度为75℃,CO_2/N_2(体积比12%/88%)的气氛条件下,60%TEPA/MCM-41的吸附量最高为123.24 mg/g,经5次循环吸脱附后,CO_2吸附量降低约7.8%。同时借助计算流体动力学(CFD)对吸附过程进行了模拟,研究结果对吸附剂的设计与反应器的开发具有一定的指导意义。     

TEPA/MCM-41固体胺吸附剂的制备及其CO_2吸附性能研究

制备了具有高CO_2吸附性能的TEPA/MCM-41固体胺吸附剂,并采用N_2物理吸脱附、XRD、FTIR、EA、TG-DSC等方法对其进行系统表征。采用重量法测试了吸附剂的吸附与循环稳定性能。结果表明,吸附温度为75℃,CO_2/N_2(体积比12%/88%)的气氛条件下,60%TEPA/MCM-41的吸附量最高为123.24 mg/g,经5次循环吸脱附后,CO_2吸附量降低约7.8%。同时借助计算流体动力学(CFD)对吸附过程进行了模拟,研究结果对吸附剂的设计与反应器的开发具有一定的指导意义。     

低浓度CO2的捕集技术及吸附法在碳捕集中的应用

碳捕集是碳封存与利用的先要环节,但迄今针对混合气体中低浓度CO₂的捕集问题仍需深入研究。对比研究了吸收法、膜分离法、深冷分离法和吸附法在用于碳捕集时的可行性与优缺点,在综合考量工艺可实现性、工艺成熟度、能耗投资及设备成本等因素后,确定了吸附法在捕集低浓度CO₂方面存在的显著优势。在此基础上,对沸石分子筛、金属有机框架化合物、碳纳米管、石墨烯与氧化石墨烯、活性炭及活性炭纤维作为碳捕集吸附剂时的特点与优缺点进行深入剖析。论文研究成果为低浓度CO₂的捕集问题提供解决思路。     

碳捕集技术研究进展

碳捕集技术对于减少大气中的CO_2浓度显得至关重要,尤其是对于排放大量温室气体的火力发电厂和工业源的CO_2捕集。本文主要概述了CO_2的燃烧前捕集、富氧燃烧捕集、燃烧后捕集这3种主要的碳捕集技术的研究现状,并结合当前正在研究的碳捕集技术,提出了碳捕集技术未来可能的发展方向。     

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。     

二氧化碳捕集技术研究进展

随着全球工业的快速发展,二氧化碳的大量排放被认为是造成气候变暖最主要原因,二氧化碳的捕集和封存已经成为研究的热点,本文综述了近年来CO2捕集技术的研究进展,主要有燃烧后捕集、燃烧前捕集和富氧燃烧三条技术路线,最后提出了可以提高二氧化碳捕集能力的策略与展望。     

二氧化碳固体碱吸附剂改性研究进展

结合近年来二氧化碳吸附剂主要研究状况,以CO₂固体吸附剂改性后的常用吸附压力为依据,从加压和常压角度重点对碱金属类、多孔炭类、沸石、多孔膜、有机金属框架5种较为普遍的固体吸附剂的改性进行了详细阐述,并对其应用前景进行了展望。     

直接空气捕碳固体多孔材料的研究进展

直接空气捕碳(DAC)技术属于一种负碳技术,作为碳捕集、存储和利用(CCUS)技术的有效补充,是助力实现“双碳”目标的重要技术之一。由于吸附能力强、再生能耗低、应用场景灵活以及结构可调性强,固体多孔材料在降低DAC经济成本和运行能耗方面具有不可替代的优势。本文从固体多孔材料的DAC原理出发,重点综述了包括沸石吸附剂、硅基吸附剂、炭基吸附剂、纳米氧化铝吸附剂、金属有机框架(MOF)材料吸附剂和多孔树脂材料吸附剂等DAC的研究现状,系统介绍和比较了固体多孔吸附材料的吸附容量、吸附选择性、水热稳定性、再生能耗以及循环稳定性方面的优缺点。本文着重分析了胺功能化改性和载体孔隙结构等因素对吸附CO₂性能的影响规律,对各类固体多孔材料在DAC应用中面临的挑战提出了具体的优化方向,并指出未来固体多孔吸附材料的设计开发应兼顾经济性和高效性,加快开展中试规模的DAC试验研究。     

The latest development on amine functionalized solid adsorbents for post-combustion CO2 capture:Analysis review

Global warming and associated global climate change have led to serious efforts towards reducing CO2 emissions through the CO2 capture from the major emission sources.CO2 capture using the amine func-tionalized adsorbents is regard as a direct and effective way to reducing CO2 emissions due to their large CO2 adsorption amount,excellent CO2 adsorption selectivity and lower energy requirements for adsor-bent regeneration.Moreover,large number of achievements on the amine functionalized solid adsorbent have been recorded for the enhanced CO2 capture in the past few years.In view of this,we review and analyze the recent advances in amine functionalized solid adsorbents prepared with different supporting materials including mesoporous silica,zeolite,porous carbon materials,metal organic frameworks(MOF)and other composite porous materials.In addition,amine functionalized solid adsorbents derived from waste resources are also reviewed because of the large number demand for cost-effective carbon dioxide adsorbents and the processing needs of waste resources.Considering the importance of the stability of the adsorbent in practical applications,advanced research in the capture cycle stability has also been summarized and analyzed.Finally,we summarize the review and offer the recommendations for the development of amine-based solid adsorbents for carbon dioxide capture.     

固体吸附剂吸附二氧化碳的研究进展

综述了近年来介孔硅分子筛负载型吸附剂、聚合物负载型吸附剂、沸石负载型吸附剂、活性炭等不同载体CO2固体吸附剂的制备及其对CO2的吸附性能研究情况,同时指出了该研究领域中仍存在的一些问题。     

密闭空间低浓度CO2固态胺吸附剂长寿命评价

在密闭空间实际工况下,通过两组平行对照试验,考察了长时间吸脱附循环对固态胺材料CO₂吸附性能的影响,对材料进行长寿命试验,并验证一年内固态胺材料性能的稳定性。结果表明,两组试验分别经过2128轮和2267轮吸脱附循环后,固态胺材料仍表现出良好的吸脱附稳定性。在长寿命试验条件下,两组吸附剂的CO₂的吸附量维持在约28 mg·g^-1,有机胺含量未见流失,活性胺含量比初始材料有所提高并不再降低,材料机械强度未受到影响。结果证明,高分子树脂基固态胺材料不仅能在室温条件下高效吸附CO₂,且能在温和条件下实现CO₂的解吸,在减少能耗的同时还有利于材料使用寿命的延长,适宜作为太空密闭空间中去除低浓度CO₂的吸附材料,为航天员的生命保障提供技术支撑。     

胺基CO2固体吸附剂脱碳特性及SO2的影响

燃煤电厂烟气中存在的微量SO₂对胺基CO₂固体吸附剂的碳酸化反应及循环特性有不利影响。利用固定床反应器,针对采用溶胶凝胶法制备的胺基CO₂固体吸附剂的碳酸化特性及其在含SO₂气氛下的失效规律进行了实验研究,并结合红外光谱、有机元素分析、BET等测试手段,研究其失效机理。结果表明,所制备的胺基CO₂固体吸附剂在反应温度50℃时具有较好的碳酸化反应特性和循环特性。当反应气氛中存在SO₂时,由于生成了不可再生的亚硫酸/硫酸盐类物质而导致胺基活性位损失,孔隙结构发生变化,影响了吸附剂的脱碳性能,但适当提高反应温度可提高吸附剂的碳酸化反应竞争性。     

烟气胺法CO2捕集技术进展与未来发展趋势

全球气候变化是目前世界面临的严峻问题之一,CO₂等温室气体的过量排放是导致全球气候变暖的主要原因。碳捕集、利用和封存(CCUS)是现阶段解决全球气候变暖的必要手段,基于有机胺的化学吸收法因捕集效率高、烟气适应性好,成为目前燃煤燃气电厂捕集CO₂的关键技术路径。本文详细介绍了胺法CO₂捕集技术的基本原理及胺法CO₂捕集技术工艺流程,分析了新型吸收剂的开发、节能技术的优化等降低胺法CO₂捕集技术再生能耗和成本的关键手段。结合研究现状以及烟气胺法CO₂捕集需求,对其未来的发展趋势进行展望。     

State of the art of ionic liquid-modified adsorbents for CO2 capture and separation

The enormous emission of carbon dioxide (CO₂) from industries has triggered a series of environmental issues. In recent years, ionic liquids (ILs) as novel absorbents are widely used for CO₂ capture owing to their low vapor pressure and tunable structures. IL-modified adsorbents have the advantages of both ILs and porous supports, such as high CO₂ selectivity and high specific surface area, which are novel agents to capture CO₂ with broad application prospects. In this review, more than 140 IL-modified adsorbents for CO₂ capture in recent years were systematically summarized. The types of ILs including conventional ILs and functionalized ILs on CO₂ separation performance of different IL hybrid adsorbents, and their adsorption mechanisms were also discussed. Finally, future perspectives on IL-modified adsorbents for CO₂ separation were further posed.     

Antioxidative degradation mechanism of 2-mercaptobenzimidazole modified TEPA-MCM-41 adsorbents for carbon capture from flue gas

Solid amine adsorbents can efficiently adsorb CO₂, but a significant problem is that amine groups are oxidized. In this research, tetraethylenepentamine-impregnated MCM-41 adsorbents (TEPA-MCM-41) were functionally modified with sulphur-containing antioxidant 2-mercaptobenzimidazole (described as antioxidant MB) and tns-(2.4-di-tert-butyl)-phosphite (defined as antioxidant 168), respectively. The antioxidative degradation mechanism of 8% MB–50% TEPA-MCM-41 was analyzed by in situ diffuse reflectance infrared Fourier transform (in situ DRIFT) spectrum and high-performance liquid chromatography/mass spectrometry (HPLC/mass). The CO₂ adsorption capacity of 50% TEPA-MCM-41 was 4.30 mmol/g under 15% CO₂/85% N₂, but decreased to 1.38 mmol/g after oxidation at 100°C for 42 h under 95% N₂/5% O₂ certain condition. The CO₂ capacity of 8% MB–50% TEPA-MCM-41 reduced from 3.90 to 2.86 mmol/g. After 30 adsorption cycles under 5% O₂/15% CO₂/80% N₂, the capacity of 8% MB–50% TEPA-MCM-41 also only decreased by 16.8%, while 50% TEPA-MCM-41 decreased by 63.2%. The reason for the excellent antioxidant stability of 8% MB–50% TEPA-MCM-41 is that MB scavenged free radicals from amine oxidation and decomposed the hydroperoxides produced by free radical reactions. The hydroperoxides were decomposed into alcohols (non-radical products), which were eventually oxidized to sulphonic compounds. The MB modification inhibited the oxidative degradation of solid amine adsorbents guided for the production of antioxidant-efficient adsorbents.     

Adsorption microcalorimetry applied to the characterisation of adsorbents for CO2 capture

The present work presents the design, assembly and experimental validation of a microcalorimetric device coupled to a volumetric adsorption setup applied to the characterisation of adsorbents for carbon dioxide (CO₂) capture. Three adsorbents were evaluated for CO₂ adsorption at 273 K in the pressure range of vacuum to 101 kPa. The data for CO₂ on zeolite 13X agreed well with the available data reported in the literature, thus validating the device, which also provided reproducible results with an activated carbon sample. For the amine‐modified zeolite, the differential enthalpy at lower coverage was increased by a factor of 1.7 as compared to the zeolite matrix. This points out to the potential of such technique to characterise heterogeneities introduced by amine impregnation. However, the adsorption uptake was decreased by factor of 2.7 at 101 kPa. This fact suggests that amino groups may be blocking some physisorption sites, leading to restricted chemisorption on the outer surface. Thus, the main novelty of this study is the simultaneous measurement of adsorption isotherms and respective differential enthalpy curves for amine‐impregnated adsorbents, which may be considered a fingerprint of the modified surface chemistry. This work has been carried out in the framework of a cooperation project between three South American universities and is part of the effort to develop and fully characterise adsorbent materials intended for CO₂ capture. © 2012 Canadian Society for Chemical Engineering