液氯生产中出现的问题及解决办法

从人为因素、工艺因素和设备因素分析液氯生产过程中液氯产量低、品质差的原因,提出增加1根DN150的原氯管道,使原氯管道由1根增加为2根,并将氯气分配台由0.8 m3改为16 m3,保证了氯气量的充足和均匀分配,更好提高了冷冻机的能效,将液氯产量从2 300 t/月提高到3 000 t/月,可新增产值1 260万元/a;电耗由126 kW.h/t降低到92 kW.h/t,年节约电成本75.89万元/a。     

氯气液化新工艺研究

前言液化工段是氯碱生产过程中动力电消耗盼主要工段之一,生产1t液氯的动力电耗约为110kw·h;使用氟利昂冷冻制液氯工艺,使吨液氯电耗降至75kw·h左右,同时氟利昂工艺的开发为分级冷冻制液氯工艺奠定了基础,这将使氯气液化工艺产生更大的变革,电耗进一步降低,随着氟利昂制液氯新工艺的推广应用,传统的“氨—氯化钙”法冷冻制液氯工艺受到了一定的冲击;对于中     

液氯生产中应注意的几个问题

从原氯纯度、压力、液化温度、液化过程、包装等方面，说明在液氯的生产中，应采取降低氯气中的含水量、合理控制液化温度、原氯压力、增加排污次数等手段，来确保安全生产。     

烧碱装置液氯冷冻单元节能优化运行

针对离子膜装置液氯冷冻单元运行干氯和尾氯压力波动,螺杆机老化热能效比低,能耗高等问题,结合上、下游装置工艺要求,提出增加干氯换热器,通过干氯与液氯换热,降低干氯温度,提高液氯温度。此外,部分干氯直送环氧氯丙烷装置,减少干氯液化;并通过更换热能效比较高的约克机替代螺杆机,降低电耗。     

高压常温制液氯工艺研究

讨论了高压常温法制备液氯的工艺，介绍了液化温度、原料氯气纯度等对工艺的影响及对液化温度、氯压机输出压力的控制方法。通过对比，认为一级压缩与二级压缩在能耗上无大的差别，高压常温法氯气液化工艺安全性较高。     

液氯生产的节能降耗措施

从选用FLY氯气液化装置 ,高压氯、余氯、废氯各尽其用 ,纳氏泵集中设置在氯氢处理 ,氯气输送选用透平氯压机等方面阐述设计中型氯碱厂液氯装置时可采用的节能降耗措施。纵观世界氯碱技术发展 ,应借鉴吸收节能新技术、新工艺 ,促进我国氯碱生产持续发展。     

降低氯气含水量新举措

通过对氯气泵酸的二次冷却和用液氯洗涤原氯,解决了氯气含水量超标的难题。同 时也解决了硫酸渣堵塞氯气液化槽排管以及三氯化氮的富集爆炸问题。     

液氯系统涨压的原因分析及解决办法

在生产中出现液氯系统涨压,不但降低了液氯的液化效率、增加了电耗,而且严重威胁公司的安全生产。本文通过认真分析确定了氯气水分超标、液化蛇管氯水结晶是造成液氯系统涨压的主要原因,并提出了采取系统升温、干燥空气吹扫消除氯水结晶和污垢的办法,解决了液氯系统涨压问题,消除了安全生产隐患。并制定相应的管理措施确保干燥氯气水分稳定达标,对今后公司的安全稳定、优质低耗生产也具有重要的指导意义。     

关于氯碱厂氯气加工与净化

由于液氯加工工业倾向于提高干燥氯压力,有机合成时对高质量液氯的要求和对液化效率等经济效果的要求,如何在加工工艺过程中设法降低氯中的有害杂质含量是必要的,这些在国内外比较先进的氯碱行业中正在实践着。一、氯气中的有害杂质及除去办法由电解进入氯气工段的氯气中,可能含有的杂质水、氢、氧、氮、二氧化碳、有机物(氯仿、四氯乙烯、六氯乙烷)食盐及三     

优化氯气处理工艺提高装置效率

配合烧碱产能由3万t/a扩产至6万t/a，改进氯气处理工艺，改造洗涤、冷却、干燥、压缩、过滤及液化、包装工序。改造后生产装置效率大大提高，液化效率由79％提高到85％以上，实现了多产液氯、少产盐酸的目的。     

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。