吸附法脱除柴油中噻吩类含硫化合物的研究进展

综述了吸附法脱除柴油中噻吩类含硫化合物的常用吸附剂、吸附脱硫的机理及吸附脱硫过程动力学研究的最新进展。阐述了近来研究较多的吸附剂主要有分子筛、活性炭和金属有机骨架（MOFs）材料。目前传统的加氢脱硫（HDS）技术虽然可以满足当前柴油中硫含量的国家标准,但是其需要高温高压、成本高且对二苯并噻吩类硫化物脱硫率低,而吸附脱硫技术由于成本低、操作条件温和、易脱除加氢脱硫难以脱除的硫化物、对油品品质影响小等优点成为当前柴油脱硫的研究热点。吸附脱硫主要包括反应型吸附脱硫和非反应型吸附脱硫,反应吸附脱硫关键是有旧键的断裂与新键的生成,而非反应吸附脱硫则是通过分散力使硫化物上的硫原子与吸附剂之间相互作用,从而达到吸附脱硫的作用。本文对吸附脱硫机理和吸附脱硫过程的动力学加以讨论,为以后的研究提供一定的理论基础,并提出了脱硫吸附剂今后的研究方向。     

吸附工艺脱除噻吩类有机硫的研究进展

概述了吸附法脱除噻吩类有机硫工艺的研究进展。详细介绍了分子筛、金属氧化物、活性炭及其他吸附剂。探讨了吸附脱硫在油品精制和焦化苯处理中的应用和发展。今后研究的主要方向将定位于吸附工艺的设计优化和高效吸附剂的研发。     

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。     

吸附脱硫及分子模拟计算应用的研究进展

综述了采用各种吸附方法脱除汽油、柴油中硫的研究进展。认为天然矿物及未改性商业分子筛具有价格便宜的优点,但本身脱硫性能不是很好;改性活性炭在硫化物吸附容量方面比较优良,但机械强度不高;金属氧化物及负载金属氧化物的多孔复合材料对硫化物的选择性较高,但吸附容量不大;以过渡金属离子改性分子筛,尤其是利用π络合脱硫的研究为以后柴油深度脱硫开拓了方向。指出吸附法结合其他脱硫工艺将是深度脱硫的重要研究方向之一;分子模拟应用于吸附脱硫的研究,将为脱硫吸附剂的开发提供新的途径。     

FCC汽油吸附脱硫剂研究新进展

对FCC汽油进行吸附脱硫,吸附剂的选择是关键。论述了分子筛类吸附剂、金属氧化物类吸附剂、活性炭、黏土类吸附剂和其他一些吸附剂在吸附机理、改性、脱硫效果、再生等方面的研究进展,特别是各类吸附剂改性后对硫化物的脱除效果。指出吸附剂吸附选择性及吸附容量的提高和吸附机理的深入研究是今后研究的重要方向。     

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。     

活性炭用于柴油深度脱硫研究进展

综述了活性炭作为吸附剂和催化剂在柴油深度脱硫方面应用的新进展。通过表面热氧化和负载金属离子对活性炭表面进行化学性能改性,有效提高对柴油中噻吩类硫化物的吸附性能。活性炭作为催化剂,能有效催化过氧化氢和氧化柴油中的噻吩类硫化物而达到催化氧化脱硫。活性炭在柴油深度脱硫方面具有广阔的应用前景,但要真正实现其在脱硫上的工业化应用,尚需加强其表面化学性能改性、再生、吸附和催化氧化机理等方面的研究。     

焦化苯脱硫用吸附剂研究进展

焦化苯的选择吸附脱硫(SARS)技术以脱硫精度高、操作简单、设备投资小等优点而被看好。综述了焦化苯脱硫用分子筛吸附剂、金属氧化物吸附剂、活性炭吸附剂的研究进展,其中,分子筛吸附剂主要介绍了微孔吸附材料、介孔吸附材料和碳分子筛吸附材料,通过分析可知,吸附剂的孔道结构对硫化物吸附选择性的作用明显,Y型分子筛和ZSM-5分子筛是比较理想的吸附剂。并指出,要获得脱硫精度好、硫容高的焦化苯脱硫吸附剂,先制备孔径孔容较大、性质稳定、活性位丰富的多孔材料,然后对其进行酸性改性或金属离子改性是一条较好的途径。     

吸附法脱除芳香含硫化合物的研究进展

吸附法可以脱除加氢汽油、柴油中的芳香含硫化合物,是超低硫油品的一种具有工业前景的脱硫方法.详细介绍了分子筛吸附剂、氧化物吸附剂、络合吸附剂、分子印迹吸附剂和化学吸附吸附剂等的设计、再生的最新研究进展.吸附脱硫目前的主要问题在于对硫化物的吸附选择性低和再生与重复使用效果不好.     

焦化苯中噻吩类硫化物脱除技术研究进展

我国焦化苯粗品中噻吩含量普遍偏高,脱除焦化苯中的噻吩类硫化物,可提高焦化苯的质量,有利于其进一步的深加工利用。目前,焦化苯中噻吩类硫化物脱除技术主要有萃取精馏法、选择吸附法、选择氧化法、催化加氢法、酸洗精制法等;另外,Friedel-Crafts反应脱硫法和氯甲基化脱硫法也可将焦化苯中纯苯与噻吩类硫化物分离。选择吸附法脱硫技术具备硫酸酸洗精制法操作简单和催化加氢法脱硫精度高、以及萃取精馏法可回收噻吩的优点,具有较大的工业化推广应用价值,提高吸附剂吸附容量以及吸附剂的稳定性将是选择吸附法今后研究的重点。近年来,离子液体已用于催化裂化汽油中硫化物的脱除,这对将来采用离子液体脱除焦化苯中噻吩的技术研究具有重要的借鉴意义。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.