燃料油中硫化物的选择性吸附研究进展

综述了不同吸附剂脱硫和选择性吸附两方面的机理及研究进展。在燃料油选择性吸附脱硫研究的吸附剂中,使用最多的是金属阳离子改性的Y型分子筛,以Cu、Ni和Ce改性的Y型分子筛最为成熟。其吸附脱硫机理主要包括π-络合吸附和金属S—M键作用。燃料油（以汽油和柴油为主）组成复杂,含大量烯烃、芳烃、烷烃及少量的氮化物、氧化物、水及胶质,影响吸附剂的吸附脱硫效果,而烯烃和芳烃严重影响吸附剂的选择性吸附脱硫性能。各种吸附剂对富含烯烃或芳烃的燃料油中的硫化物选择性和硫容量不同,但都不高。研究吸附剂与燃料中的硫化物的选择性吸附机理,对研发具有高选择性和高吸附容量的吸附剂起推动作用。     

燃料油吸附脱硫的研究进展

与传统的加氢脱硫技术相比,吸附脱硫技术在超低硫燃料油生产方面具有明显优势,近年来得到了迅速发展。综述了吸附法脱除燃料油中有机硫化物的研究进展,重点介绍了反应吸附脱硫和选择性吸附脱硫两种类型的吸附脱硫方法以及分子筛基吸附剂、金属氧化物基吸附剂、活性炭基吸附剂和粘土基吸附剂在吸附脱硫方面的应用。指出选择性吸附脱硫技术是近期最有希望实现零硫目标的脱硫技术。     

金属改性分子筛吸附脱硫研究新进展

从分子筛金属改性的方式、吸附脱硫机理、吸附剂再生等方面综述了近几年国内外关于金属改性的微、介孔分子筛在燃料油液相吸附脱硫中的应用,分析了微、介孔分子筛作为脱硫吸附剂的优势和存在的问题,指出如何提高吸附剂的硫容量和选择性仍是未来研究的主要方向。     

脱硫吸附剂与吸附脱硫技术

综述国内外原料气和燃料油吸附脱硫技术在吸附脱硫材料和吸附脱硫工艺方面的研究与开发进展。介绍分子筛类、金属氧化物类、活性炭类等脱硫吸附剂。分别评述物理吸附、活化吸附、选择性吸附等燃料油吸附脱硫技术的机理和工艺．     

车用燃料油固体脱硫吸附剂的研究进展

吸附脱硫的优势是投资成本低、操作条件温和,其技术关键在于研发吸附硫容量大、选择性高和再生性能好的固体吸附剂。本文综述了车用燃料油固体脱硫吸附剂的研究进展,包括常规的分子筛、活性炭、金属氧化物吸附剂以及一种新型金属-有机骨架（MOFs）材料脱硫吸附剂。从吸附机理、制备方法、脱硫效果等方面分析了上述吸附剂的优缺点和改进方向。提出今后的固体脱硫吸附剂可从吸附机理出发在分子尺度上设计和组装新材料的观点。     

脱硫吸附剂与吸附脱硫技术

综述了国内外原料气和燃料油吸附脱硫技术在吸附脱硫材料和吸附脱硫工艺方面的研究与开发进展。介绍了分子筛类、金属氧化物类、活性炭类等脱硫吸附剂。分别评述了物理吸附、活化吸附、选择性吸附等燃料油吸附脱硫技术的机理和工艺。     

燃油选择性吸附脱硫的多孔材料研究进展

吸附脱硫技术具有操作条件温和、节能、不改变燃油品质和成本低等特点而备受关注。针对噻吩类难脱除硫化物的深度脱除和转化问题,综述了近年来应用多孔吸附材料选择性吸附超深度脱除燃油中噻吩类硫化物的作用机理及最新研究进展。重点分析了分子筛、金属有机骨架、多孔炭材料、复合材料等不同吸附剂的研究现状,并探讨了各种吸附材料的吸附机理、改性方式和优缺点。本文指出分子筛因优异的热稳定性、高比表面积、均一的孔道结构、低成本和易于工业化等特点,是目前最具优势的吸附剂材料。未来研究应着重阐明吸附机理、提高合成便捷性、脱硫性能以及再生能力,更全面系统的研究将为开发具有理想选择性和再生能力的高效吸附剂奠定基础。     

柴油吸附脱硫工艺条件影响

研究了吸附工艺条件对柴油中硫化物,特别是对二苯并噻吩（DBT）的脱除效果。实验在常压下,采用静态吸附法,以FCC柴油和DBT模型物为原料,用燃灯法测定脱硫前后油品的硫含量,考察了模型物溶剂、油品中含有的芳烃以及吸附温度对吸附剂脱硫率的影响。得出溶剂黏度越大吸附脱硫率越差;油品中含有芳烃时,吸附剂脱硫率减小,温度对脱硫率的影响不大。考察了高温氮气、有机溶剂和水蒸汽这3种再生方法对吸附剂的再生效果,结果表明,水蒸汽600℃再生4h和有机溶剂苯洗涤24h的再生效果较好,基本可以恢复吸附剂的吸附性能。     

燃煤烟气中单质汞吸附与氧化机理研究进展

燃煤电厂汞排放控制是当前的研究热点,实现燃煤烟气中汞的脱除涉及两个非常重要的过程：吸附与氧化。本文概述了汞在吸附剂表面吸附的相关理论和单质汞的催化氧化机理,结合碳基和非碳基吸附剂相关吸附特性的研究现状,对汞的吸附机理进行了讨论,回顾了SCR、碳基、以及金属和金属氧化物三种常见催化剂对单质汞的催化氧化性能并总结了其可能存在的机理。指出吸附剂表面活性位是决定其对汞吸附效果的关键因素,异相反应是单质汞氧化的重要途径,吸附和氧化是相辅相成的,不同催化剂不同气氛下氧化机理不同。并提出通过氯化物等物质改性能够提高吸附剂的吸附效果,深入研究汞的异相反应机理并开发经济有效的汞脱除方法是今后的研究方向。     

吸附法柴油脱硫技术进展

本文从吸附剂改性、吸附脱硫机理和吸附剂再生等方面综述了以活性炭、金属氧化物、分子筛等为吸附材料吸附脱除柴油中硫化物的最新进展。柴油中的含硫化合物主要包括无机硫和有机硫,其中有机硫占80％以上。在活性炭表面,金属氧化物或分子筛上负载过渡金属都可提高其对硫的吸附能力,π键配位吸附脱硫技术是脱除噻吩类硫化物的有效方法。吸附脱硫是一项具有发展潜力的脱硫技术,然而,要加速这一技术的工业化进程,开发对稠环噻吩类硫化物具有高选择性、高吸附量、易再生的吸附剂是当前面临的重要挑战。     

Studies on adsorptive desulfurization by zirconia based adsorbents

This study reports usage of laboratory prepared zirconia samples (normal dried zirconia (ZD383), zirconia calcined at 893 K (ZC893), zirconia sulfated and calcined at 893 K (SZC893)) as adsorbents for the removal of sulfur from model oil (dibenzothiophene, DBT in iso-octane). Bulk densities of adsorbents were found to be in the range of 0.896–0.987 kg/m³. Optimum adsorbent dose was found to be 10 g/l. The adsorption of DBT on zirconia based adsorbents was found to be gradual process with quasi-equilibrium condition reached in 22 h. Brunauer–Emmett–Teller (BET) isotherm best represented the equilibrium adsorption data. The heat of adsorption and change in entropy for DBT adsorption onto zirconia based adsorbents were found to be −165.3 (ZD383), −125.5 (ZC893), −96.7 (SZC893) kJ/mol, and −509.9 (ZD383), −379.4 (ZC893), −284.1 (SZC893) J/mol K, respectively.     

Adsorption removal of thiophene and dibenzothiophene from oils with activated carbon as adsorbent: effect of surface chemistry

Commercial coconut-based activated carbons (AC), before and after being treated using 65 wt% HNO₃ at different temperatures (termed as AC–Hs), were used as adsorbents to remove thiophene (T) or dibenzothiophene (DBT) from model oils. The fresh AC sample and all of the AC–Hs samples were characterized by Boehm titration, Fourier-transform infrared spectroscopy, and thermal analysis, which yield the information of the surface chemistry properties of the carbon materials. The results show that in comparison to the fresh AC sample, the quantity of oxygen-containing functional groups on the surface of AC–Hs samples increases as the pretreatment temperature of the fresh AC sample increases. The adsorption capabilities of the AC samples for removal of T and DBT from model oils were evaluated in a batch-type reactor. It has been found that the refractory DBT can be removed easily over the untreated commercial AC with the removal efficiency even being higher than that of T. In the case of acid modified AC–Hs samples, the efficiency for removal of T has been greatly improved, but this is not the case for the removal of DBT. The possible mechanism for adsorption removal of T and DBT over activated carbons is discussed in terms of the quantity of surface oxygen-containing functional groups of adsorbents and the chemical structure of sulfur compounds. The effect of olefin (1-octene) and aromatic hydrocarbons (benzene) in the model oils on the selective adsorption DBT over AC is also evaluated, revealing that in the case of DBT, the competitive adsorption is involved in the process, and the removal efficiency levels off at a level over 80%.     

Adsorption of dibenzothiophenes on activated carbons with copper and iron deposited on their surfaces

Three polymer-derived carbons with iron and different amounts of copper on the surface were investigated as adsorbents of dibenzothiophene (DBT) and 4, 6-dimethyldibenzothiophene (DMDBT) from simulated diesel fuel. To characterize the initial and exhausted carbons nitrogen adsorption, elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal analysis (TA) were applied. The selectivities for DBT and DMDBT were calculated with reference to naphthalene. In spite of the enhancement in selectivity for DBT and DMDBT removal caused by iron and copper species, the results indicate that the volume of micropores is the main factor governing the amount adsorbed. Oxidation of benzothiophenes is likely promoted by iron oxide and copper/copper oxide highly dispersed on the surface. The oxidation products are then selectively adsorbed on the surface of carbon in larger pores where metal species and heteroatoms are the active centers for adsorption of polar species.     

改性吸附剂脱除燃油中二苯并噻吩的研究

采用浸渍法将5种金属离子Zn2+,Cu2+,Fe3+,Pb2+,Hg2+负载于活性炭和γ-氧化铝上,制备出一系列改性的吸附剂;用静态吸附法测定了燃料油中二苯并噻吩在不同吸附剂上的吸附等温曲线。结果表明,活性炭对97#汽油中二苯并噻吩吸附能力显著高于氧化铝;活性炭表面负载Zn2+,Cu2+,Fe3+,可以提高其对97#汽油中的二苯并噻吩的吸附量(摩尔质量浓度),其中负载Zn2+的活性炭吸附能力最大,硫饱和吸附量为478.3mmol/kg;γ-氧化铝上Pb2+的最佳负载质量分数为5.0%。     

Metal‐organic frameworks for highly efficient adsorption of dibenzothiophene from liquid fuels

By taking desulfurization of liquid fuels as a demonstrative example, a bottom‐up selection was performed to find the metal‐organic frameworks (MOF)‐type adsorbents with highly efficient adsorption performance of large molecules. Through carefully analyzing the adsorption mechanism for typical S‐heterocyclic compounds like dibenzothiophene (DBT), PCN‐10 was selected in consideration of the simultaneous inclusion of several kinds of interactions in the framework. Experimental results demonstrate that this MOF exhibits extraordinary high DBT adsorption capacity (75.24 mg S g^?1), showing record uptake among all the reported porous materials for the removal of thiophenicsulfur from fuels (below 1000 ppm_wS), to the best of our knowledge. Moreover, the removal rate for the low sulfur concentration (50 ppm_wS) can reach beyond 99%. This strategy can be conveniently extended to the screening and design of MOFs for the efficient removal of other important large guest molecules. © 2016 American Institute of Chemical Engineers AIChE J, 62: 4491–4496, 2016     

Role of phosphorus in carbon matrix in desulfurization of diesel fuel using adsorption process

Adsorptive removal of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel with 20 ppmw total concentration of sulfur was investigated on polymer-derived carbons with incorporated heteroatoms of oxygen, sulfur and phosphorus. The materials before and after exposure to model diesel fuel were characterized using adsorption of nitrogen, thermal analysis, potentiometric titration, XPS and elemental analysis. The selectivities for DBT and DMDBT adsorption were calculated with reference to naphthalene. The results indicated that the presence of phosphorus, especially in the form of pyrophosphates and P₂O₅, increases the capacity and selectivity for removal of dibenzothiophenes. It also affects the adsorption mechanism. Phosphorus suppresses oxidation reactions of DBT and DMDBT. Owing to a possible location of bulky phosphorus groups in pore with sizes between 1 and 3 nm thiophenic molecules are strongly adsorbed there via dispersive forces. Acidic environment also enhances adsorption via acid–base interactions. Physical adsorption mechanism and stability of surface make these carbons attractive candidates for thermal regeneration.     

基于有序多孔材料磷酸盐吸附剂的研究进展

过量的磷流入水体易导致水体富营养化等环境问题,吸附法由于操作方便、经济高效等特点被广泛应用于水体磷酸盐的去除。有序多孔材料具有孔道规则,比表面积大,孔容大等特点,其作为载体可有效提高活性物种的分散性,从而提高吸附剂吸附磷酸盐的效率。综述了基于不同有序多孔材料的吸附剂应用于水体磷酸盐去除的进展,主要包括有序多孔碳材料、有序多孔硅材料和金属有机框架。讨论了基于有序多孔材料吸附剂的磷酸盐吸附性能、主要吸附机理、影响因素及回收利用。总结了基于有序多孔材料吸附剂吸附磷酸盐存在的问题,展望了其未来研究方向及应用前景。     

基于有序多孔材料磷酸盐吸附剂的研究进展

过量的磷流入水体易导致水体富营养化等环境问题。吸附法由于操作方便、经济高效等特点被广泛应用于水体磷酸盐的去除。有序多孔材料具有孔道规则，比表面积大，孔容大等特点，其作为载体可有效提高活性物种的分散性，从而提高吸附剂去除磷酸盐的效率。该文综述了基于不同有序多孔材料合成的吸附剂应用于水体磷酸盐去除的进展，主要包括有序多孔碳材料、有序多孔硅材料和金属有机框架。讨论了基于有序多孔材料吸附剂的磷酸盐吸附性能、主要吸附机制、影响因素及回收利用等。总结了基于有序多孔材料吸附剂吸附磷酸盐存在的问题，展望了其未来研究方向及应用前景。