Facile synthesis of highly porous hyper-cross-linked polymer for light hydrocarbon separation

Light hydrocarbon separation is a crucial process associated with high energy expenditure in the petrochemical industry. The utilization of porous organic materials as solid porous adsorbents for light hydrocarbon separation has found widespread attention because of the advantages of low cost, excellent stability, and good recyclability. Here, we present the facile synthesis of a porous organic material, constructed from pyridine-triphenylborane by using a Friedel-Crafts alkylation coupling reaction, affording the hyper-cross-linked polymer, HCP-B. HCP-B features significant thermal stability, and high surface area. Gas adsorption experiments show that this material adsorbs much larger amounts of ethane, ethylene, and acetylene than that of methane. Ideal adsorbed solution theory (IAST) calculations also predict that HCP-B selectively adsorbs ethane, ethylene, and acetylene over methane. Both are indicative of the great potential of HCP-B in light hydrocarbon separation.     

基于MOFs材料的低碳烃（C1~C3）分离研究进展

低碳烃（C₁~C₃）混合物的分离和纯化是化工过程中最重要且耗能最大的过程单元之一,开发温和条件下低能耗高选择性吸附分离C₁~C₃分子的固体吸附材料迫在眉睫。金属有机框架材料（MOFs）作为一类相对新颖的多孔有机-无机杂化材料,因其可控的拓扑结构和多样的化学微环境,在低碳烃分离和纯化领域受到广泛关注。本文概述了MOFs作为分离和纯化低碳烃气体吸附剂的特性,重点关注了MOFs材料在C₁（CO₂/CH₄）、C₂、C₃烯/烷烃以及烯/炔烃分离领域的应用进展。首先归纳了MOFs材料在C₁~C₃烃类物质分离过程中的三种常见分离机制,并据此回顾了近年来MOFs材料对常见C₁~C₃烃类分子的吸附及分离性能;分析了MOFs材料在C₁~C₃烃类物质分离过程中的构效关系,总结了MOFs材料的孔道尺寸/形状、骨架柔性和表面功能的调控理念与方法,并提出MOFs材料成本高、水热稳定性差、主客体关系难以精准探测等制约其应用发展的现状。文章指出未来研究重点为开发低成本多样化专一性的新型配体,构造复合型吸附剂,并明确吸附分离过程中分离体系主客体性质,为MOFs材料用于低碳烃分离的定向设计提供了探索方向。     

金属有机骨架材料（MOFs）用于气态轻烃的高效分离研究进展

气态轻烃（C₁～C₃）如甲烷、乙烯、丙烯分别作为应用最广的清洁燃料和大宗化工产品，在国民经济中占据重要的地位。然而，在其生产过程中广泛存在着分离与提纯能耗较高的问题。金属有机骨架材料（MOFs）作为第三代新型多孔材料，近年来在轻烃分离领域显示出巨大的应用潜力。本文综述了MOFs用于气态轻烃分离的现状和机理，总结了本文作者课题组针对不同轻烃产物的分离要求，对MOFs进行了精确的孔径调控、配体功能化修饰、构筑吸附位点、调变柔性结构“开口压力”等，实现了多种气态轻烃组分的高效分离。最后，针对低碳烃工业分离过程中存在的关键问题，对MOFs材料的吸附分离机理进行了深入分析，以及MOFs工业化应用所面临的结构稳定性与分离工艺匹配等进行了展望。     

金属有机框架材料分离低碳烃的研究进展

烯烃、烷烃和炔烃等结构相似物的高效分离是石油化学工业可持续发展的关键过程之一。低碳烃化合物结构和性质相近,仅在碳数和不饱和度存在微小差异,传统低温精馏过程选择性低、能耗高。金属有机框架材料/多孔配位聚合物（MOF/PCP）的结构多样性及可设计性使其可以精确识别相似物分子间的微小差异,在低碳烃分离领域取得重要进展。综述了金属有机框架材料在碳二/碳三的烯烃、炔烃和烷烃分离体系中取得的最新进展以及分离机理,探讨了金属有机框架材料在低碳烃吸附分离研究中存在的问题和发展方向。     

锆基MOF次级结构单元调控及轻烃吸附分离性能增强

从天然气中回收C₂/C₃轻烃组分具有重要的工业价值,吸附分离技术可在常温常压下实现轻烃的回收。对MOF材料进行次级结构单元（SBU）调控,可在继承其晶体结构和发达孔道的同时,优化孔道化学微环境并引入新的吸附位点。使用三嗪（TZ）取代Zr-TBAPy(NU-1000)SBU中的配位水分子,在其孔道内构筑对轻烃吸附质具有更强限域作用的碱性表面化学微环境,得到了高选择性的新型TZ@Zr-TBAPy吸附剂。TZ的引入在分子尺度上提高了孔道的表面粗糙度,同时强化对轻烃吸附质的限域作用,提高材料对烷烃的吸附容量和选择性。常温常压下,TZ@Zr-TBAPy对丙烷和乙烷的吸附容量分别为10.08和4.19 mmol?g^-1,比Zr-TBAPy提高了27%和9%,是目前国际上已报道的丙烷吸附容量最高的吸附剂之一。此外,丙烷/甲烷的IAST选择性为1518,是原材料的6.27倍;乙烷/甲烷的IAST选择性为11.7,比原材料提高了22%。更为重要的是,以TZ@Zr-TBAPy吸附剂为核心的固定床吸附过程可实现在常温常压天然气中乙烷和丙烷的一步分离回收。     

Mass transfer behavior of methane in porous carbon materials

The low mass transfer rate in porous materials hinders the use of adsorbed natural gas as vehicle fuel. Fundamentally, the mass transfer rate depends on the structures of the adsorbents and the operating conditions. Therefore, in this study, the effects of adsorbent (activated carbons) structure and operating conditions on the mass transfer rate of methane (main component of natural gas) were investigated quantitatively, providing a theoretical basis for the synthesis of efficient adsorbent materials. By performing Monte Carlo and molecular dynamics simulations and utilizing a nonequilibrium thermodynamic linearization transfer model, the mass transfer behavior of methane in porous carbon materials was quantitatively evaluated, specifically focusing on the material structure, operating conditions, and feasibility of using natural gas as vehicle fuel. The proposed linear nonequilibrium thermodynamic mass transfer model is applicable to interfacial gas species and provides a valuable tool for gas separation.     

Structuring adsorbents and catalysts by processing of porous powders

Microporous materials such as zeolites, metal organic frameworks, activated carbons and aluminum phosphates are suitable for catalysis and separation applications. These high surface area materials are invariably produced in particulate forms and need to be transformed into hierarchically porous structures for high performance adsorbents or catalysts. Structuring of porous powders enables an optimized structure with high mass transfer, low pressure drop, good heat management, and high mechanical and chemical stability. The requirements and important properties of hierarchically porous structures are reviewed with a focus on applications in gas separation and catalysis. Versatile powder processing routes to process porous powders into hierarchically porous structures like extrusion, coatings of scaffolds and honeycombs, colloidal processing and direct casting, and sacrificial approaches are presented and discussed. The use and limitations of the use of inorganic binders for increasing the mechanical strength is reviewed, and the most important binder systems, e.g. clays and silica, are described in detail. Recent advances to produce binder-free and complex shaped hierarchically porous monoliths are described and their performance is compared with traditional binder-containing structured adsorbents. Needs related to better thermal management and improved kinetics and volume efficiency are discussed and an outlook on future research is also given.     

分子筛基CH4-N2分离材料的研究进展

实现CH₄-N₂高效分离能够极大地推动常规天然气和非常规天然气这一类绿色低碳能源的利用,分子筛基吸附剂和膜材料具有优良的气体分离特性,而且对CH₄-N₂的分离颇具应用潜力。本文从对N₂具有优先选择性吸附的N₂/CH₄分离（高浓度CH₄纯化脱氮）和对CH₄具有优先选择性吸附的CH₄/N₂分离（低浓度CH₄富集脱氮）两方面综述了国内外分子筛吸附剂及分子筛膜的研究进展。详细地分析了分子筛骨架和平衡阳离子与其CH₄-N₂吸附分离性能之间的构效关系,并结合本文作者课题组的工作,提出了电中性（近中性）骨架分子筛对CH₄-N₂分离具有较好的分离效果。最后总结和展望了CH₄-N₂分离用分子筛吸附剂及分子筛膜的未来发展趋势。     

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。     

金属有机骨架材料用于吸附分离CH4和N2的研究进展

非常规天然气的利用不仅可以有效缓解常规天然气不足带来的能源问题,而且可以降低其肆意排放带来的温室效应,无论是低浓度煤层气的提浓还是低品质天然气的提质都需要解决甲烷与氮气的分离难题。基于金属有机骨架（MOFs）材料结构和功能均呈多样化的特色,本文主要从CH₄选择型MOFs吸附材料和N₂选择型MOFs吸附材料两个方面,综述了近年来MOFs材料在CH₄与N₂吸附分离方面的研究进展,讨论了影响二者分离的影响因素,并对吸附与分离机理与MOFs结构和性能关联进行了详细的总结与分析,提出了CH₄与N₂选择性提升的方法,即需要合适的孔道尺寸与弱极性表面性质或有利骨架结构的协同作用,最后展望了MOFs材料在甲烷富集和纯化领域的应用前景和发展趋势。     

Porous Adsorbents for Vehicular Natural Gas Storage: A Review

Methane adsorption data (both experimental and simulated) under conditions of direct relevance for vehicular natural gas storage, i.e., at 500 psig and ambient temperature, has been compiled from the literature for various microporous adsorbents and discussed in this work. Characterization of microporosity has been briefly reviewed, followed with a discussion on the porous structure of natural gas adsorbents. A common trend of gravimetric methane adsorption capacity scaling with surface area among the diverse microporous adsorbents (viz., coals, carbons, zeolites, silica gel and an MCM-41 type material) is demonstrated. Further, it is substantiated and emphasized that increasing the adsorbent surface area on a volumetric basis is very important for vehicular natural gas storage where the fuel storage volume is a constraint. The effect of other adsorbent properties such as heat of adsorption and heat capacity on the natural gas storage capacity is also discussed.     

N掺杂多孔碳材料研究进展

通过掺杂氮原子对多孔碳材料进行功能化,可强化多孔碳材料固有的优异性能并赋予其新功能,从而拓宽其在各领域的应用范围。近年来,研究者相继开发了一系列技术方法,已制备得到多种结构特异、性能优异的氮掺杂多孔碳材料。本文基于氮掺杂多孔碳材料的最新研究进展,详细介绍了利用液相模板法、化学气相沉积法、氨气后处理法、化学活化法和水热法等制备氮掺杂多孔碳材料的方法,评述了各种方法的特点及局限性,并简要介绍了该类材料在电池催化、气体吸附分离、储氢及污染气体脱除等方面的应用,指出了氮掺杂多孔碳材料工业应用的规模化制备发展方向。     

CO2和N2吸附的研究札记

Experiments were made for the adsorption of CO2 and N2 on typical adsorbents to investigate the effects of porous structure and surface affinity of adsorbents as well as those of adsorption temperature and pressure that might cause the variation of adsorption mechanism. It is shown that polar surface tends to enlarge the adsorption difference between CO2 and N2, and the difference is more sensitive to temperature than the adsorbents with non-polar surface. The adsorbents with non-polar surface are not much sensitive to the effect of water vapor, though the water vapor interferes the separation remarkably. The separation coefficient linearly increases with the micropore volume per unit surface area of activated carbons, but no rule is shown on mesoporous silicon materials. The function of adsorption mechanism on the separation is not as much as expected.     

S-enriched porous polymer derived N-doped porous carbons for electrochemical energy storage and conversion

Porous polymers have been recently recognized as one of the most important precursors for fabrication of heteroatom-doped porous carbons due to the intrinsic porous structure, easy available heteroatom-containing monomers and versatile polymerization methods. However, the heteroatom elements in as-produced porous carbons are quite relied on monomers. So far, the manipulating of heteroatom in porous polymer derived porous carbons are still very rare and challenge. In this work, a sulfur-enriched porous polymer, which was prepared from a diacetylene-linked porous polymer, was used as precursor to prepare S-doped and/or N-doped porous carbons under nitrogen and/or ammonia atmospheres. Remarkably, S content can sharply decrease from 36.3% to 0.05% after ammonia treatment. The N content and specific surface area of as-fabricated porous carbons can reach up to 1.32% and 1508 m²·g⁻¹, respectively. As the electrode materials for electrical double-layer capacitors, as-fabricated porous carbons exhibit high specific capacitance of up to 431.6 F·g⁻¹ at 5 mV·s⁻¹ and excellent cycling stability of 99.74% capacitance retention after 3000 cycles at 100 mV·s⁻¹. Furthermore, as the electrochemical catalysts for oxygen reduction reaction, as-fabricated porous carbons presented ultralow half-wave-potential of 0.78 V versus RHE. This work not only offers a new strategy for manipulating S and N doping features for the porous carbons derived from S-containing porous polymers, but also paves the way for the structure-performance interrelationship study of heteroatoms co-doped porous carbon for energy applications.     

低浓度煤层气提纯的研究现状

煤矿开采过程中排放出大量低浓度煤层气,提纯利用这部分煤层气对我国能源开发利用和环境保护意义重大,其难点是经济高效地分离CH4和N2.本文从CH4/N2分离技术、变压吸附分离CH4/N2吸附剂和制备新型炭分子筛3个方面逐层对低浓度煤层气提纯进行了综述和展望.介绍了CH4/N2分离技术研究进展,对其在低浓度煤层气提纯中的应用前景进行了对比.概述了常用变压吸附剂分离CH4/N2的研究现状,分析了它们在低浓度煤层气提纯应用中的优缺点,并提出了制取适合低浓度煤层气提纯用的新型炭分子筛的方法.     

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.     

吸附剂特性对CO2/CH4吸附分离的影响分析

用于CO2/CH4二元混合体系吸附分离的吸附剂种类较多,效果参差不齐,而吸附剂的各种特性是影响分离效果的主要原因。本文从吸附剂特性出发,总结了孔结构、可交换阳离子、表面化学以及吸附剂湿度4个因素对吸附分离效果的影响,并解释了造成各种影响的原因。得出结论：中孔有利于该二元体系的分离和胺基嫁接;在吸附剂骨架之外引入合适的可交换阳离子可促进吸附剂与CO2四极矩之间吸引力,提升分离效果;吸附剂的表面羟基也是影响胺基嫁接的重要因素;水分既有利于该体系的吸附分离,又可以促进胺基吸附剂再生。     

煤层气在活性炭和炭分子筛上变压吸附分离

变压吸附分离是有效的气体分离提纯方法,采用合适的吸附剂可对煤层气(CH4/N2混合气体)进行高效分离,节约能耗。在单床吸附装置上测量了CH4/N2混合气体在3种活性炭和4种炭分子筛吸附柱上的穿透曲线,并进行实验研究再生条件对吸附剂分离性能的影响。实验结果表明,7种吸附剂均对CH4/N2混合气具有一定程度的分离能力,且高温真空再生后吸附效果更好;但仍需开发出更有效的吸附剂。     

煤层气回收及CH4/N2分离PSA材料的研究进展

我国煤层气蕴藏丰富,在面临能源危机时代煤层气可作为天然气能源的有效补充。本文介绍了低浓煤层气回收即CH₄/N₂分离几种常见技术：低温技术、水合物技术、溶解技术、膜分离和变压吸附技术（PSA）的分离原理、技术开发和研究的现状,并分析了各项技术目前存在的问题。讨论了多孔材料,如活性炭、碳分子筛、沸石分子筛和新型金属有机骨架材料（MOFs）等对CH₄/N₂吸附分离效果的研究进展,由于MOFs材料的吸附性能随温度或压力的改变出现飞跃,预示了其在PSA领域广阔的应用前景。     

偏氯乙烯聚合物基多孔炭的制备及应用研究进展

叙述了以偏氯乙烯聚合物为碳源,通过高温直接炭化制备微孔为主的多孔炭,及炭化、催化活化和模板法制备中孔-微孔复合多孔炭的研究进展,归纳了影响2种新型多孔炭制备过程中炭材料孔隙的主要因素.介绍了偏氯乙烯聚合物基微孔和中孔-微孔复合多孔炭材料在超级电容器电极、催化剂负载和吸附分离等方面的应用.认为偏氯乙烯聚合物基多孔炭属新型...