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。     

稀有气体Xe/Kr吸附分离研究进展

稀有气体Xe/Kr的高效捕集分离是气体工业、核环境监测和乏燃料处理等领域的重要分离过程之一。氙与氪结构与极化率相似,传统低温精馏方法借助氙与氪的沸点差异实现二者分离,能耗巨大,吸附分离是较为理想的替代分离技术。以金属有机框架材料为代表的新型多孔材料具有结构多样性与高度可设计性,通过调节材料微孔表面的极化环境与孔道窗口结构,借助氙与氪极化率的微小差异,可实现对二者的精准辨识,有良好的吸附分离性能与应用前景。重点综述了金属有机框架材料在氙氪分离中的研究进展,归纳了材料的极化环境、孔道结构、框架柔性等因素对氙氪吸附分离性能的影响规律,探讨了金属有机框架材料在氙氪吸附分离研究中存在的问题和局限,并对未来发展方向进行了展望。     

石脑油高效资源化研究进展

为了实现石脑油的高效资源化利用,需开发石脑油高效分离技术。简述了石脑油正/异构烷烃吸附分离原理及分离技术现状,介绍了新型吸附剂材料的研发进展,包括金属有机框架材料(MOFs)、沸石咪唑框架材料(ZIFs)、碳分子筛(CMS)、中空沸石分子筛等,阐述了新型吸附材料对正构烷烃的分离效果和分离机理,探讨了新型吸附剂、膜分离技术和吸附-膜分离耦合技术用于分离石脑油中正/异构烷烃的可行性,展望了新型正/异构烷烃分离技术,以期为石脑油高效资源化利用提供新途径。     

改性吸附剂去除废水中磷的应用研究进展

去除废水中过量的磷可以减缓水体富营养化。吸附除磷因具有能耗低、容量大、污染少等优点而备受关注，改性吸附剂则可在此基础上提高除磷的靶向性，拓宽操作条件，增大吸附容量。本文分析了改性硅酸盐类、改性金属氧化物类、改性固体废弃物类和聚合物类4类除磷吸附剂的改性方法和吸附性能。硅酸盐类吸附材料以及固体废弃物类材料除磷效果略差，但因来源丰富、价格低廉而具有极大的吸引力。聚合物类吸附剂具有高吸附容量、高选择性，但价格昂贵。金属（氢）氧化物具有出色的磷酸盐吸附性能，且选择性好、吸附速度快，这些化合物已被掺入到沸石、介孔二氧化硅和生物炭等材料中，进一步增强其吸附性能，并在工程材料应用中取得重大突破，主要包括磁性吸附剂和颗粒吸附剂。4类吸附剂的作用机理可归纳为两种：一种是吸附剂上的金属与磷酸盐离子发生配位反应，形成沉淀；另一种是酸性条件下吸附剂上的羟基质子化，使羟基带正电，质子化的羟基通过静电吸引使磷得以去除。通过对不同类别吸附剂的吸附特性进行对比分析，提出将高分子技术运用到吸附剂制备过程中，开发同时具有较强解吸能力的改性吸附剂将成为除磷吸附剂研究的新热点。     

低浓度煤层气吸附浓缩技术研究与发展

我国是一个多煤少气贫油的国家,煤层气储量约30万亿立方米,由于缺乏先进实用的低浓度煤层气甲烷分离浓缩技术,当前抽采煤层气利用率仅为50%左右。因此,对低浓度煤层气甲烷富集浓缩过程开展研究,可在开发能源的同时减少温室气体的排放,具有重大的应用价值和战略意义。简要介绍了我国煤层气资源开发利用情况,综述了近年来低浓度煤层气吸附浓缩技术研究进展,包括新型吸附材料及先进吸附工艺。对于低浓度煤层气中CH₄/N₂分离,目前文献报道吸附材料的吸附容量及分离系数仍然处于较低水平;受吸附材料的分离性能较差影响,传统变压吸附工艺对低浓度煤层气中CH₄浓缩效果并不理想。最后指出,高吸附容量、高选择性吸附材料及多种方法结合的新型吸附工艺是未来低浓度煤层气吸附浓缩技术的发展方向。     

海藻酸钠-氢氧化镧改性Y型分子筛颗粒除氟研究

为解决除氟吸附剂分离困难、有效成分流失等问题,以海藻酸钠（SA）与氢氧化镧改性Y型分子筛（LHMS）为原料,采用滴球法制备了SA@LHMS颗粒吸附剂,并采用模拟废水对其进行了除氟研究。通过正交实验确定了吸附剂最佳制备条件,并通过间歇吸附实验测试了吸附剂投加量、pH、共存离子等因素对吸附的影响,探究了吸附速率、吸附等温线等吸附性能。结果表明,SA@LHMS吸附速率曲线符合拟二级反应速率方程;吸附等温线符合Ⅱ型等温线,为多分子层吸附;初始pH（3~12）对吸附效果没有显著影响;高浓度共存阴离子（50 mg/L）对吸附过程有一定抑制;1 mol/L和2 mol/L氢氧化钠溶液对SA@LHMS再生效果较好,经3次再生仍然保留较高的吸附能力。SA@LHMS颗粒表面和截面形态以及吸附前后颗粒的表面形态差异明显;吸附前后颗粒表面能谱（EDS）分析以及红外光谱（FT-IR）分析结果显示,吸附过程中溶液中的氟离子（F^-）与颗粒表面及内部的羟基（—OH）发生配体交换。     

离子强度对吸附有机污染物影响的研究进展

吸附由于其高效、低成本、易操作等特点,是目前国内外应用最广泛、最有效的废水处理方法之一。废水成分复杂,尤其是存在的背景离子会通过改变吸附剂和吸附质的相互作用影响有机物的吸附效果,造成主要吸附机制难以确认、吸附条件难以优化等问题。因此,研究离子强度对废水中有机物吸附性能的影响是提高吸附处理废水效果的重要途径。本文以吸附剂种类进行分类,阐述了在最常见氯化钠盐存在条件下钠离子和氯离子对于各类吸附剂吸附分离废水中有机物的影响,总结了各个研究者对此所做的研究,并以此展望了在离子存在条件下吸附剂在废水处理中的应用发展,指出开发新型、高效、经济、绿色、环保的吸附剂必将成为未来的发展趋势。     

选择吸附脱硫研究进展

燃油中的含硫化合物在高温燃烧时生成的硫氧化物是大气中主要的污染物之一,对环境和人类健康有极大的危害。本文介绍了目前所发展的燃油脱硫的常用方法,重点阐述了吸附脱硫技术的研究进展。首先对吸附脱硫剂的开发现状进行了介绍,对目前发展的多种吸附脱硫剂包括活性炭、金属有机物框架、表面分子印迹聚合物、无机吸附剂的吸附脱硫量、选择吸附性、吸附影响因素进行了深入分析,总结了不同吸附剂的脱硫机理,并对不同吸附剂的再生方法、再生后的吸附效果进行了概述和评价。随后对比总结了这几类吸附剂的优缺点。最后介绍了目前吸附脱硫技术所存在的问题,指出开发在非硫化合物存在的情况下对含硫有机物具有高选择性、再生性能好的吸附脱硫剂是未来的发展趋势。     

The use of low rank coal-based adsorbents for the removal of nitrophenol from aqueous solution

A range of Victorian brown coal based materials (Yallourn brown coal, grus, briquette char, power station char and an activated carbon) have been assessed as potential adsorbents for the removal of organics from aqueous wastes. The compound 4-nitrophenol has been used as the adsorbate. The influence of adsorbent dosage levels, particle size, and the presence of buffer solution components, other electrolytes, and pH on the kinetics of adsorption of nitrophenol have been investigated. For some adsorbents, pH changes in the acidic region appear to have little influence on adsorption rates of nitrophenol, but for chars, reduced pH conditions appear to reduce adsorption rates. In the alkaline pH range, leaching from some of the adsorbents occurs, with the extent of leaching reducing as the carbon content of the adsorbent increases. Adsorption capacities for Yallourn coal, grus, briquette char and power station char using nitrophenol in phosphate buffer have been measured. The technique of differential pulse polarography has been shown to be useful as a means of measuring nitrophenol adsorption in situ for concentrations up to 30 mg l⁻¹.     

Extraction of Uranium from Seawater Using Magnetic Adsorbents

Abstract

A new process for the extraction of uranium from seawater was developed. In the process, uranium adsorption is effected using powdered magnetic adsorbents; the adsorbents are then separated from seawater using magnetic separation technology. This process is superior to a column method using a granulated hydrous titanium oxide adsorber bed in the following ways: (1) a higher rate of adsorption is realized because smaller particles are used in the uranium adsorption; and (2) blocking, which is inevitable in an adsorber bed, is eliminated.

The composite hydrous titanium-iron oxide as a magnetic adsorbent having high uranium adsorption capacity and magnetization can be prepared by adding urea to a mixed solution of titanium sulfate and ferrous sulfate. Adsorption and desorption of uranium and the removal of the adsorbent using a small-scale uranium extraction plant (about 15 m³/d) is reported, and the feasibility of uranium extraction from seawater by this process is demonstrated.     

Shaping of metal-organic frameworks through a calcium alginate method towards ethylene/ethane separation

The separation of ethylene and ethane is a crucial, challenging and cost-intensive process in chemical engineering. Metal-organic frameworks (MOFs) are a class of novel porous adsorbents used for the separation of ethylene/ethane mixtures. However, MOFs are normally crystalline powders that cause multiple problems, such as dust, abrasion and heat/mass loss, as well as significant pressure drops on the adsorption bed resulting in a sudden stop in production. To solve these issues, we have prepared four different sphere-shaped adsorbents, including Mg-gallate, Co-gallate, MUV-10(Mn) and MIL-53(Al) using a calcium alginate method to achieve excellent ethylene/ethane separation performance. The performance of the sphere-shaped adsorbents has been validated using mechanical strength measurements, powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, gas adsorption isotherms and dynamic breakthrough experiments. The excellent mechanical strength of these sphere-shaped adsorbents meets the criteria for industrial application in gas separation. Thus, the energy consumption and operating cost will be further reduced in the ethylene production process. We believe that this shaping method will open a prosperous route to the development of MOFs toward higher technology levels and their commercial application.     

载金属离子的13X分子筛对噻吩的吸附性能研究

采用Zn2+,Cu2+,N i2+,Ag+分别负载到13X分子筛制得吸附剂,考察了它们对噻吩的吸附能力,发现Ag+-13X吸附效果最好,与软硬酸碱理论解释的结果一致。测定了噻吩在Ag+-13X上的吸附动力学数据,并测定了其不同温度下的吸附平衡数据,采用Langmu ir模型进行拟合,与平衡数据吻合得很好,说明Langmu ir模型能够描述本体系的特征,从微观上探讨了其吸附机理,是分子尺寸和化学键的共同作用;考察了Ag+-13X对真实汽油的脱硫性能,结果表明对汽油中的噻吩类硫化物都有脱除效果,为其工业设计提供基础数据。     

含氧煤层气分离提纯技术的研究进展

分别从直接分离与先脱氧再分离技术两个方面,介绍了含氧煤层气分离提纯的研究现状及存在的问题,并指出今后的发展方向。同时,针对低甲烷浓度含氧煤层气的真空变压吸附分离技术的研究进展进行了评述,指出高容量、高选择性吸附剂的研发是该技术工业化应用的关键。     

镧改性材料对水中磷酸盐去除的研究进展

在各种除磷技术中,吸附法因其成本低、操作简单、设计简单而受到广泛关注;稀土镧由于对磷酸盐具有特异性而被广泛运用于复合吸附剂中,以增强吸附磷酸盐的能力。文中综述了近几年来用于磷酸盐去除的镧改性复合材料吸附剂的研究进展,主要包括镧氧化物/氢氧化物、镧改性铝/铁、镧改性黏土矿物、镧改性碳材料和镧改性其他材料,考虑了镧改性后吸附剂的吸附容量、pH及回收情况等。在进一步的研究中,应考虑镧改性复合材料吸附剂在复杂条件下的稳定性和潜在风险,以及其高效分离和再生的能力。     

吸附制冷用复合吸附剂的吸附性能

固体吸附式制冷因具有环保和节能两大优势,成为国内外竞相开发的热点,尤其是将其用于新型空调系统和太阳能应用产品方面的开发研究备受关注．但从实用化研究成果来看,还远不满足工业化条件,其主要原因之一是受吸附制冷工质对（吸附剂-制冷剂）的性能制约．目前,国内外关于吸附制冷工质对的研究报道比较多,所采用的吸附（工）质仍然以水、甲醇、乙醇和氨为主,对于吸附剂的研究进展比较快,已从当初单一组分吸附剂的选用发展到目前多组分、复合吸附剂的研制．研制性能优良的吸附剂被认为是推动固体吸附式制冷工业化的关键之一．     

The Pore Mouth Tailoring of Coal and Coconut Char Through Acid Treatment Followed by Coke Deposition

Carbon Molecular Sieves (CMS) obtained by coke deposition through deep cracking of hydrocarbons on the wide pore mouths of coal and coconut char are important adsorbents for separation of, difficult to separate, gaseous as well as liquid mixtures. The adsorption studies on these CMS show a high selectivity towards the adsorption of one or the other component from its mixture. In this work, CMS is prepared from pre treated raw materials like bituminous coal and coconut shell. The product samples are characterized in terms of kinetic adsorption and equilibrium adsorption of various gas adsorbents. It is observed that, all these samples are very good for CO₂ removal from mixtures containing CH₄ or H₂ in it. The CMS prepared from coconut shell showed an uptake ratio 4, for adsorption of O₂ and N₂, indicating that separation of nitrogen from air is viable by choosing suitable conditions in Pressure Swing Adsorption (PSA) Technique.     

Effektive Stofftrennung in Gas‐ und Flüssigphase durch selektive Adsorption

Adsorption is a versatile tool for the separation of low abundant molecules from complex mixtures. The affinity and selectivity of the adsorbents are crucial parameters for the efficiency of the separation process. This work provides an overview of the basic adsorption mechanisms and illustrates their relevance for technical applications based on own experimental data in bioprocess, environmental and safety engineering. Distinctive features between the adsorption from the gas and fluid phase, respectively, the differences between small molecules and interacting biomacromolecules are presented.     

Adsorption desalination: Advances in porous adsorbents

With the continuous growth of the world population, the demand for fresh water is ever increasing. Water desalination is a means of producing fresh water from saline water, and one of the proposed solutions in the scientific community for solving the current global freshwater shortage. Adsorption is foreseen as a promising technology for desalination due to its relatively low energy requirements, low environmental impact, low cost and high salt removal efficiency. More importantly, chemicals are not required in adsorption processes. Active carbons, zeolites, carbon nanostructures, graphene and coordination framework materials are amongst the most investigated adsorbents for adsorption desalination, which show different performances regarding adsorption rate, adsorption capacity, stability and recyclability. In this review, the latest adsorbent materials with their features are assessed (using metrics) and commented critically, and the current trend for their development is discussed. The adsorption mode is also reviewed, which can provide guidance for the design of adsorbents from the engineering application point of view.     

金属-有机骨架材料制备及其吸附净化挥发性有机物应用

吸附技术是控制净化挥发性有机化合物(Volatile Organic Compounds,VOCs)常用且有效的方法之一,其核心和关键是具有高比表面积和孔容的高效吸附材料。金属-有机骨架材料(Metal-Organic Frameworks,MOFs)是一类具有超高比表面积和孔容的新型高效吸附材料,在VOCs吸附净化领域具有广阔的应用前景。概述了MOFs材料的发展历程,重点介绍了MOFs材料合成制备方法及其对VOCs的吸附研究进展,讨论了相关研究工作尚存在的科学技术问题并展望了未来研究方向。     

多孔液体在CO2捕集与利用领域的研究进展

为助力中国早日实现“双碳目标”，深入落实化工领域绿色低碳可持续发展的重要举措，吸附-吸收耦合有望成为气体分离的绿色变革性分离技术，其关键是高性能吸附（收）材料的开发。多孔液体（PLs）作为一类具有永久孔隙的液体材料，兼具了液体吸收剂的易于管道输送、传质传热效果好等优点和固体吸附剂的高比表面积、高孔隙率等优点，有望成为新一代CO2捕集的绿色变革性介质。该文首先简单介绍了多孔液体发展脉络；然后，重点聚焦于多孔液体在CO2的吸附/吸收、膜分离、催化转化等领域的应用展开探讨，并对多孔液体性能和优缺点进行分析归纳。最后，对多孔液体目前面临的挑战和未来发展趋势进行了展望。