火炬排放管网系统设计

火炬用来处理石油化工装置中无法收集和再加工的可燃气体或蒸气的特殊燃烧设施,是保证安全生产、减少环境污染的重要措施。火炬排放管网将装置排放的火炬气安全输送到火炬,是火炬系统的重要组成部分。本文介绍火炬管网系统的设计方法,可供设计参考。     

高架火炬高效点火操作研究

火炬系统是化工企业重要的安全与环保设施,主要用于处理各个装置在开停工、正常以及事故工况下排放的可燃气体,负责及时、稳定、充分地将排放的易燃和有害气体转变为符合环保要求的不燃和无害物质。为使火炬长明灯保持常燃状态,需要在日常操作时进行火炬的点火操作,而在实际点火过程中,存在一定的安全隐患和点不燃的问题,所以必须采取有效的控制措施,设计最佳的点火方式。因此,研究火炬点火操作及注意事项,提高火炬点火的安全系数,是非常必要的。     

吉化公司乙烯厂兴建火炬回收利用工程

吉化公司乙烯厂火炬回收利用工程在 2 0 0 0年大检修期间完成 ,预计 3季度投运。吉化设计院承担了火炬系统改造工程设计 ,装置设计处理能力 1 80 0ｍ3/ｈ,利用压缩机直抽方式回收正常生产排放的火炬气 ,为了保证乙烯等车间的气体在事故状态下能安全排放 ,采用了自动点火系统。其主要工艺过程为乙烯和聚乙烯车间排放的火炬气、油品车间以及丙烯装车栈台排放的置换气汇集于火炬气总管 ,然后由总管将火炬气引入湿式螺杆压缩机 ,通过压缩将火炬气的压力升高至0 .5ＭＰａ后进入气液分离器 ,经螺杆叶片和金属丝网分离 ,去除冷却液 ,再经出口气体止…     

新建(改扩建)海上油气田开发项目温室气体排放特点分析

以新建(改扩建)海上油气田开发项目为边界,结合海上油气开发生产的特点,对温室气体排放进行了系统的分析研究,结论为:燃料燃烧排放、火炬燃烧排放、放空与逃逸排放以及用电产生的排放是新建(改扩建)海上油气田开发项目温室气体的主要排放源。随着开发年限增长,油气田碳排放强度呈增长趋势。海上油气田用电/供电方式以自发电为主,岸电比例较小,用电产生的温室气体排放量大。海上火炬气回收利用困难,火炬燃烧排放仍是海上油气田生产的重要排放源之一。海上生产生活运输供应系统消耗化石燃料产生的温室气体排放不可忽视。     

降低放空系统的携液量

在天然气生产及加工过程中,需要及时处理生产装置中排放的多余、有害、不平衡的废气,并能处理试车、开停车时产生的不合格气体,以及事故时瞬时放出的大量气体,保证装置正常、安全运行。所以天然气处理及加工过程中,均会设置火炬放空系统。同时,由于气田采用湿气输送工艺,进入处理厂的原料气中还有大量凝液,如分离不及时,在放空时会被带入放空火炬系统,严重时形成火雨,威胁生产及周边居民的生命安全。本文主要从放空分液及火炬运行过程中携液量较大进行研究,分析问题,解决问题,以此降低天然气处理厂放空火炬液体携带量,保证厂区安全放空。     

关于化工企业低热值废气综合利用的研究

化工企业低热值气体主要特点为压力低、热值低、气量不稳定、易燃易爆,在单独的企业难以实现资源的综合利用,主要排放至火炬系统燃烧,造成资源浪费。系统要根据气体特性、热值,利用园区的优势实现资源综合利用。     

火炬排放管道负压影响分析及处理措施

石油化工企业火炬系统的主要作用是及时燃烧各装置开停工或事故状态下排放的可燃性气体或含有H₂S的酸性气,避免引起安全和环保事故。当事故工况下大量火炬气排放结束后,随着温度的降低,火炬排放管道内的压力也随之降低,形成负压状态。常用的防负压措施包括设置水封罐、设置补气措施。本文分析了火炬排放系统的负压形成原因,应用气体状态方程和小孔泄漏模型计算负压影响,给出了防负压水封量和补气量的计算方法。     

高架火炬冷缩情况下空气回流的数值模拟

石油化工企业的高架火炬系统中,当高温火炬气排放结束后,如果遇到冷空气、强降雨等天气,火炬筒体内的高温气体将会迅速受冷造成负压,此时外界的冷空气将侵入筒体内部,与高温火炬气混合。此种情况下,火炬气-空气的混合物可能会引发闷烧、回火等现象,极大威胁设备的使用寿命和企业生产安全。文章以某石油化工企业高架火炬筒体为研究对象,采用ANSYS Fluent仿真软件进行了动态模拟,研究了火炬筒内气体温度骤降过程中的空气回流现象,为高架火炬发生冷缩的情况下补气设计提供了理论指导。     

电石法制乙炔装置散排乙炔回收利用

电石法乙炔生产过程中,因系统置换,富含乙炔的气体排至大气中,对环境造成污染,产生异味,影响周边居民。如果活泼的乙炔气体达到爆炸极限,将形成安全风险。通过改造,将散排乙炔气体收集回收后作为燃料送至锅炉,在事故状态下送至高空火炬进行无烟燃烧安全排放,该改造取得了较好的经济效益和社会效益。     

山西焦化苯精制装置VOCs治理方法研究

通过采用装置区真空尾气、放散气保持原有处理工艺继续进地面火炬燃烧排放,罐区各槽罐氮封后单独收集送管式炉燃烧,解决了苯精制罐区放散气无组织排放现象,从而在实现安全、环保的同时,改善了现场作业环境,产生了巨大的社会效益。     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

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。