液化石油气脱硫技术研究进展

介绍了液化石油气(LPG)中含硫化合物的种类及其危害,并指明了脱硫的必要性。分别介绍了脱硫化氢、脱硫醇、脱羰基硫以及脱硫醚的常用技术,重点对比了几种常见脱硫醇技术(Merox抽提-氧化技术、纤维膜法脱硫技术、吸附脱硫技术、催化氧化-吸附法脱硫技术、络合脱硫技术以及等离子体法脱硫技术)的优缺点。对未来LPG脱硫技术的发展方向进行了展望,即需结合多种技术联合进行脱硫,利用各自技术的优势,在高效脱除LPG中硫化物的同时确保技术节能环保。     

Merox抽提-氧化脱硫醇工艺研究进展

针对液化石油气(LPG)中硫醇的一系列严重危害,指出LPG脱硫醇的必要性,同时介绍了目前应用最为广泛的Merox抽提-氧化脱硫醇工艺的原理和流程,并总结了该技术存在的主要问题和缺陷以及综述了氨水取代苛性碱进行原料预处理、固体碱工艺、反抽提工艺等各种改进的方法,最后指出了该技术的发展方向。     

油品中硫醇的催化氧化脱除

脱硫醇是提高汽油等油品质量的重要环节。综述了油品脱硫醇工艺在碱性介质、酞菁钴等方面的研究进展,并展望催化氧化脱硫醇的发展方向。     

固定床脱除液化石油气中的硫醇

综述了有关固定床脱除液化气中硫醇的新技术，指出了各种方法的优缺点，并认为催化氧化吸收法是液化气脱硫醇的发展方向。     

催化汽油选择性加氢脱硫技术通过鉴定

由石油化工科学研究院、上海石化股份公司、中国石化工程建设公司共同承担的中国石化“十条龙”攻关项目“催化裂化汽油选择性加氢脱硫技术RSDS的开发及工业应用试验”,近日通过了股份公司科技开发部组织的技术鉴定。RSDS技术是将催化裂化汽油切割为轻重组分,轻馏分碱抽提脱硫醇,重组分经选择性加氢脱硫处理,固定床氧化脱硫醇处理,然后与轻组分混合,达到了选择性脱硫的目的。     

除臭精制液在液化气脱硫醇装置的应用研究

原液化气脱硫醇过程采用传统的催化氧化法,使用2×10-4磺化钛氰钴催化剂配置的约12%的NaOH碱液进行脱硫醇,尤其当原料总硫>300 mg/m3时,存在脱后总硫含量高、废渣处理费用高、能耗高、后续MTBE装置总硫含量高等问题,采用河北精制科技有限公司生产的高效工艺助剂——除臭精制液代替磺化酞菁钴进行液化气脱硫醇,提高了装置平稳运行周期及液化气脱后总硫合格率,降低了装置能耗及职工劳动强度,减少了碱渣排放量,提高了综合经济效益。     

用煤制催化剂脱除油品中硫醇硫的研究

一、引言油品中的硫醇不仅产生令人恶心的臭味,并会使油品的安定性变坏。硫醇还有腐蚀性,并且影响油品对添加剂的感受性。因而在油品加工过程中往往要脱除油品中的硫醇。由于硫醇随着它分子量增大,在碱液中的溶解度减小,故不能只用简单的碱洗方法除去硫醇。脱硫醇的方法大致可分为氧化法、抽提法和抽提——氧化法三类。其中抽提——氧化法被广泛地采用。它是将抽提法和氧化法     

液化气脱硫醇技术方案研究

通过对液化气脱硫醇专有技术三家单位在液化气脱硫醇的技术方案、投资、运行参数、能耗、运行成本等方面进行对比分析,最终确定采用专利商一专有技术作为中石化天津分公司新建液化气脱硫脱硫醇技术方案,为石化企业新建液化气脱硫脱硫醇工艺选择提供参考和借鉴。     

DME/LPG混合体系的氧化反应与热稳定性

采用加速量热仪(ARC)分别测定了液化石油气(LPG)及其DME/LPG的氧化反应初始温度(To)和活化能(Ea),考察了添加剂对氧化反应的稳定性效应,用气相色谱-质谱联用仪(GC-MS)分析热分解产物。结果表明,LPG和DME/LPG的To分别为180℃和150℃,反应活化能Ea分别为203.2kJ·mol-1和188.6kJ·mol-1。氧的存在是导致LPG及其DME/LPG热稳定性下降重要因素,特别是有过氧化物存在下,由于自由基的引发,显著降低LPG、DME/LPG氧化反应的初始温度和反应活化能,在氧化反应体系中添加Fe、Al时,To和Ea值减小,稳定性降低,抗氧剂能提高它们的热稳定性。DME/LPG氧化产物主要有HCHO,CH3OH,HCOOCH3,HCOOH,CH3OCH2CH2OCH,H3CH(OH)CH3,CH3C(O)CH3,CH3CH2CH2OH,(CH3)2CHCH2OCH3,CH3CH2CH2CH2OCH3等20种化合物。     

炼油过程中的脱硫技术讨论分析

本文分析了脱硫的技术的应用情况,选择性的研究分析了汽油氧化、脱硫醇尾气冷凝-蓄热燃烧技术的优缺点,并结合实际对其设备改进,增加我们副产品的可行性研究,同时减少或者避免环境污染,达到绿色化工的目的。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。