压力对于油脂氢化的影响

国内硬化油生产已有近六十年的历史，长期以来主要采用铜、镍二元触媒常压氢化工艺。近年来很多厂纷纷改用中压加氢先进工艺，已经形成了趋势。我厂在汲取大连油脂化工厂中压氢化经验的基础上，于1975年7月建成了年产5000吨硬化油的中压管道连续氢化车间，并已投入生产。因此，进一步探讨压力对于油脂氢化反应的影响，从而选择适宜的反应压力，有着重要的实际意义。油脂氢化是一多相催化反应。反应是在催化剂表面进行，由以下三个过程构成：①氢气向催化剂表面吸附，②油脂和氢在催化剂表面反应，③反应产物从催化剂表面解吸。     

中压操作在甲醇制烃领域的应用可行性探讨

随着国内煤化工的迅猛发展,甲醇制烃(MTH)领域也得到了快速发展。当前该领域工业装置均采用较低压力操作,造成部分管道及设备尺寸较大,在装置大规模化趋势下,如何有效降低装置投资及运行成本是甲醇制烃领域需要解决的问题。文中以某10万t/a、50万t/a产能的固定床MTG装置为例,从反应过程、管道及设备尺寸、节能及投资成本四方面对比分析,深入探讨了中压操作的可行性。结果表明:中压操作在显著降低设备尺寸及减少设备数量的同时,还有效地降低了能耗,具备良好的经济性。研究结论为未来大规模甲醇制烃装置的设计及建设提供了参考依据。     

优化操作,降低中压系统压力

尿素装置2005年扩能改造后,中压系统压力PT-3202总是在高限浮动,本文对中压系统两个参数的控制及系统优化操作方面进行了阐述,通过降低中压系统压力,使中压系统能够在生产中达到甚至超过了设计生产能力。     

斯那姆氨气提工艺高、中压系统水联动试车总结

新建尿素工厂试车时如能实施以水为介质使整个工艺系统模拟正常操作压力的分段循环，对保证化工投料试车成功无疑是一个很好的促进。针对斯那姆尿素工厂操作手册中无高、中压系统水联动试车的情况，本公司通过实践，成功地实现了高、中压系统水联动试车，不仅消除了设备的隐患，而且进一步训练了操作队伍     

低温甲醇洗中压闪蒸系统的节能研究

为了提高低温甲醇洗中压闪蒸系统的运行效率,采用一台小的氨冷器和甲醇循环泵,对传统的低温甲醇洗的中压闪蒸系统进行了优化,考察了不同的中压闪蒸系统的操作压力,对中压闪蒸气中CO2的摩尔分数,以及长期消耗指标,即中压闪蒸气压缩机和水冷器的负荷的影响。研究结果表明:采用小股的低温甲醇循环后,相对于传统工艺,优化后的中压闪蒸系统的气体压缩机及与其所对应水冷器节能分别为56.48%和73.41%。同时,由于中压闪蒸气压缩机和对应水冷器的负荷降低了一半以上,与其相应的固定设备投资也会因此降下来。所以,优化工艺可以在不增加传统低温甲醇洗单元的整体能量消耗和低的设备投资的前提下,降低中压闪蒸系统的能耗。     

松香连续氢化设备的安全技术问题

松香在高温高压和催化剂存在下与氢气发生加成反应而制得氢化松香。目前我国氢化松香生产采用了连续化工艺,在高温高压设备中完成的。高温高压设备与其他工业设备相比有其独特的地方,这主要是它的设计和使用条件都比较严格,而且万一发生事故就有可能造成生命财产的巨大损失,因此不论是设计、制造、还是操作上,对高压设备的安全技术问题都必须予以充分的注意。一、设计上的考虑松香加氢是在270℃、200公斤/平方厘米压力下进行的。对于这种高温高压设备,仅仅是机械破裂就能造成重大事故,而且这是造成气体爆炸的主要原因。为了抵抗高温高压下设     

天然气富氧空气部份氧化法制合成氨原料气新工艺

天然气加压催化富部分氧化法生产合成氨原料气新工艺其工艺先进，技术可靠、节能显著，特别是流程短，占地少，设备简单，设备材质要求不高，投资省、易操作，推进了天然气化工生产 市场竞争能力，经过连续运行，状况良好。     

KDF连续压滤机发展与应用

ＫＤＦ连续压滤机发展与应用四川省江北机械厂张剑鸣所谓连续压滤机指的是操作压力高于大气压，操作连续不停机卸料的是操作压力高于大气压，操作连续不停机卸料的一类过滤设备￣［１］。最早的连续压滤机是１９５７年出现的Ｍｃ－Ｇａｓｋｅｌｌ旋转压滤机￣［２］。６０...     

蒽醌法过氧化氢装置中氢化塔三塔串联探索及应用

在蒽醌法生产过氧化氢的工艺中,氢化塔是整个生产工艺中的核心设备,设备内钯触媒的活性高低直接制约了装置的产量及消耗,介绍蒽醌法生产过氧化氢装置氢化塔三塔串联生产工艺的应用、生产管理操作要点及生产过程中工艺安全注意事项。     

U-GAS气化工艺配套空分方案分析

针对U-GAS气化炉操作压力下空分界区氧气和氮气的压力要求,可供选择的空分流程较多,选取了双泵-中压膨胀流程、单泵-中压膨胀流程、单泵-低压膨胀流程、外压缩流程以及自增压-外压缩流程5种空分方案进行对比。简述了空分部分的工艺流程,介绍了5种空分方案流程的异同,并对5种空分装置的运行能耗、投资、占地等进行了对比,为不同工艺流程的配套最优空分方案选择提供了参考。     

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.     

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。     

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.