低温甲醇洗工艺降低甲醇损耗的研究

目前低温甲醇洗工艺被普遍应用于合成氨等气体净化装置中,但我们公司在运行中发现甲醇消耗过多,严重影响设备正常运行。本论文就低温甲醇洗工艺运行中出现甲醇消耗过多问题分析原因,并提出了解决方法,降低了甲醇的消耗,每年节省100t甲醇,生产效率提高5%。     

低温甲醇洗装置运行中的设备问题及处理

在低温甲醇洗装置运行过程中,可能会出现一些问题对装置的运行造成不利影响,影响低温甲醇洗装置的应用效果,因此需要加强低温甲醇洗装置运行情况的研究,分析运行中出现问题的原因,采取措施及时的进行处理。本文以某煤化工公司的低温甲醇洗装置为例,介绍了该公司低温甲醇洗装置运行过程中出现的问题,对导致问题的原因进行了分析,提出了针对性的解决策略。     

全贫液、半贫液低温甲醇洗工艺技术比较

系统分析比较了全贫液低温甲醇洗吸收流程与半贫液低温甲醇洗吸收流程之间的流程设置特点、关键运行参数、消耗、技术经济指标,得出2种流程的优势和劣势。低温甲醇洗工艺吸收流程的选择需综合考虑能耗、装置规模和投资、可操作性等因素。全贫液低温甲醇洗流程适合中、小规模的合成气装置,半贫液低温甲醇洗流程适合中、大规模的合成气装置。     

低温甲醇洗装置甲醇消耗问题探讨

煤化工行业进入了变革期,传统的生产工艺存在着非常大的能耗,影响了煤化工企业的生产效益。甲醇脱硫脱氮工艺环节,低温甲醇洗装置不可或缺,虽然这一装置在运行的过程中,有效去除了气体中的二氧化碳、硫化氢等气体,使酸性气体得以回收,减轻了传统工艺下的环境污染现象,但是,这一装置同样存在着一定的技术缺陷,就是甲醇消耗非常严重,因此,甲醇消耗控制是低温甲醇洗装置应用的关键。基于此,本文重点分析了在低温甲醇洗装置甲醇消耗方面的控制策略。     

低温甲醇洗总硫运行控制措施分析

低温甲醇洗装置是化工工艺装置中利用低温甲醇对H2S、CO2的超强吸收能力,脱除原料气体中酸性气体成分的一种高效的物理吸收工艺方法。低温甲醇洗工艺在化工企业生产中,能耗低,运转费用低,生产运行稳定、可靠。甲醇装置在开车接气过程和系统运行操作过程中经常出现总硫超标问题,严重影响了后系统催化剂的使用寿命,为企业的生产造成了巨大的消耗,增加了生产成本。因此,对林德低温甲醇洗装置在开车接气过程中的总硫控制方法及系统正常运行过程中的操作控制进行了总结分析。     

低温甲醇洗工艺甲醇消耗高问题探讨

本文简要介绍了粉煤气化配套装置低温甲醇洗工艺,对装置运行过程中的甲醇消耗过高问题进行分析并改造,结果表明：放空尾气夹带甲醇是消耗高的主要原因,工艺参数的控制也是甲醇消耗高的重要原因之一。通过技术改造和工艺参数优化降低了甲醇消耗。     

低温甲醇洗甲醇消耗偏高的分析及操作思路

本文介绍了低温甲醇洗的工艺装置,对生产过程低温甲醇洗消耗偏高的问题进行分析,并提出相应的操作思路,从操作上达到降低甲醇消耗大的目的。     

以低温甲醇与聚醇醚为溶剂的工业气净化工艺对比

介绍了低温甲醇洗流程和聚醇醚流程的应用现状,评述了低温甲醇洗流程和聚醇醚流程的工艺特点,分析比较了2种工艺的主要技术指标,着重比较了2种工艺的关键运行参数如溶液消耗、冷量消耗、消耗指标、设备以及投资费用等,并对2种工艺流程的适应性进行了分析。分析和比较后认为:酸性气体吸收流程的选择需综合考虑能耗、装置规模、投资、可操作性、装置稳定性等因素;低温甲醇洗适用于净化度要求高、高压、大规模的工业化装置;聚醇醚工艺适用于净化度要求较低的装置,如IGCC多联产装置,可降低能耗,节省投资。     

低温甲醇洗系统存在问题分析及解决办法

结合义马气化厂低温甲醇洗工艺运行情况,从低温甲醇洗工艺原理出发,就低温甲醇洗在生产中暴露出的问题进行物理化学分析,总结解决问题的方法。逐步提高对低温甲醇洗认识,保障实际生产中低温甲醇洗装置平稳运行,充分发挥低温甲醇洗装置的先进性、经济性及其环保性。同时,为提高企业的生存竞争力打下坚实的基础。     

低温甲醇洗工艺甲醇消耗高问题探讨

介绍了粉煤气化配套装置低温甲醇洗工艺,对装置运行过程中出现的甲醇消耗过高的问题进行分析并改造。分析表明,放空尾气夹带甲醇和工艺参数控制不当是甲醇消耗高的重要原因。通过技术改造和工艺参数优化,甲醇消耗由改造前的40～50t/d下降至3t/d。     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。