二氯乙烷裂解生产氯乙烯技术的改进

介绍了二氯乙烷裂解生产氯乙烯工艺,阐述了影响二氯乙烷裂解的因素,对改造后的裂解炉进行了热量衡算。技术改进后,裂解炉的生产能力增加20％、节能31％。     

二氯乙烷裂解炉设计的探讨

随着石油化工的迅速发展,乙烯成本逐渐下降,国外采用电石法制氯乙烯的方法逐步被乙烯氯化生成二氯乙烷裂解制氯乙烯的方法所代替。因此,1.2二氯乙烷裂解制氯乙烯的技术成了目前生产氯乙烯的重要一环。国内,已有不少研究院和工厂对二氯乙烷裂解技术做了不少的工作,並从西德引进了8万吨氯乙烯生产装置。但对二氯乙烷裂解炉辐射段设计计算尚无资料,因此,本文想利用有关试验数据和别洛康的设计方法采用动力学方程作一些探讨和分析。     

影响二氯乙烷裂解反应的因素

1　 1 ,2 -二氯乙烷转化率在裂解的工艺操作中 ,提高二氯乙烷的转化率 ,必须提高反应温度 ,但是 ,过高的反应温度会使副反应和结焦加剧 ,导致氯乙烯产品收率下降、生产周期缩短、消耗增加及氯乙烯产品质量的下降。为满足 VCM产品纯度高、副产物少、裂解生产周期长及消耗低的要求 ,1 ,2 -二氯乙烷裂解的最佳转化率为 55%左右。但随着 EDC裂解转化率的增加 ,VCM产品中的杂质量也随着增加。其杂质主要是乙炔、氯甲烷、氯乙烷、1 ,3 -丁二烯和氯丁二烯等。二氯乙烷转化率过高 ,裂解炉炉管结焦加剧、裂解炉的使用周期缩短。2　原料纯度原料纯…     

二氯乙烷裂解炉对流段出口工艺改造

针对1,2-二氯乙烷裂解炉对流段出口管线及自控阀经常堵塞的实际情况,对1,2-二氯乙烷裂炉对流段出口进行了工艺改造,改造后裂解炉运行周期和氯乙烯产量均得到了提高。     

二氯乙烷裂解反应停留时间的计算

对二氯乙烷裂解炉炉管按平推流反应器进行了计算,并根据PFD数据进行估算。计算出二氯乙烷裂解反应的停留时间,为裂解炉的长周期稳定运行提供了指导。     

新型乙烯法VCM热能的回收与利用

描述了乙烯和氯气发生氯化反应生成二氯乙烷（EDC）及二氯乙烷（EDC）在高温下裂解生成氯乙烯（VCM）的工艺流程，在二氯乙烷合成、精制和二氯乙烷高温裂解过程中将高温氯化反应器与精馏塔合二为一、EDC裂解生产的高温裂解混合气作为循环EDC精馏塔和HCl精馏塔再沸器热媒，有效利用了其热量，对降低冷量和蒸汽用量等方面进行了探讨分析。     

1,2-二氯乙烷催化裂解制氯乙烯催化剂及反应工艺研究

本文在固定床反应装置上,考察了以SAPO-34分子筛为活性组分制备的催化剂催化裂解1,2-二氯乙烷(EDC)制氯乙烯的催化反应性能,考察了空速、反应温度、载体对催化裂解1,2二氯乙烷制氯乙烯的影响,得到了优化的反应工艺条件：在350℃,常压,EDC空速为2 h^-1时,EDC转化率达到57%,氯乙烯选择性达98.5%。     

乙炔与二氯乙烷反应体系热力学分析

对乙炔与1,2-二氯乙烷反应体系进行了热力学计算,使用AspenPlus11.0中的RGibbs反应器模块,并结合灵敏度分析工具,对不同情况下各产物在100～450℃下的平衡收率进行了计算;采用REquil反应器模块并结合灵敏度分析工具对1,2-二氯乙烷裂解反应、乙炔氢氯化反应以及二者协同反应在100～600℃下的平衡收率进行了计算。结果表明,1,2-二氯乙烷裂解反应为强吸热反应,在标准状态下不能自发进行。乙炔与1,2-二氯乙烷协同反应为微放热反应,反应在标准状态下能自发进行;乙炔平衡转化率随温度提高逐渐降低。非聚合副反应对氯乙烯收率影响很小,但聚合副反应对氯乙烯收率影响很大,主要生成氯丁二烯。二氯乙烷裂解与乙炔氢氯化协同反应氯乙烯收率随着温度上升而降低。     

二氯乙烷裂解过程模拟研究

建立了二氯乙烷裂解制氯乙烯过程的数学模型，进行了裂解过程的模拟研究；为实现生产操作条件的优化，考察了操作参数对裂解过程的影响。模拟结果不仅可以计算沿裂解反应管的物料分布，能同时得到裂解管壁温度分布、管内物流温度分布及压力分布等，可作为设计、操作分析及优化的依据。     

二氯乙烷裂解炉的模拟与分析

建立了二氯乙烷裂解炉的数学模型,采用别洛康法计算辐射室的传热,利用四阶龙格-库塔法求解管内微分方程.计算结果验证了数学模型及参数选择的正确性,在此基础上分析了操作条件的改变对EDC裂解转化率的影响,为进一步提高二氯乙烷裂解炉的效率和降耗节能打下了基础.     

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。