我厂合成氨“七改十”净化系统改造

我厂建于1970年,原设计合成氨年产量6万吨,硝酸铵年产量13万吨。由于设备能力不配套,投产后几经改造,1990年达到年产合成氨7万吨。1992年建成一套年产尿素4万吨的生产装置,氨加工能力与氨生产能力不相匹配,为了充分利用已有氨加工能力,切实增加工厂的综合效益,我厂于95年提出对氨生产系统进行扩产改造,将氨生产能力扩大至10万吨/年。本次改造充分利用现有工艺、设备及公用设施,在原工艺流程不做大的变动情况下,采用国内先进成熟的工艺技术、节能设备扩大合成氨装置的生产能力,氨生产能力改造的难点在净化车间,净化属单系统流程,工艺采用:常…     

全低变改中中低低变换工艺总结

该文介绍了以中中低低变换工艺对全低变工艺进行改造 ,克服了全低变工艺催化剂易失活、阻力上升快和设备腐蚀严重等缺点 ,改造后系统压差 0 0 5MPa ,吨氨蒸汽消耗 2 40kg以下 ,节能效果显著。     

氨合成塔改造及运行情况小结

氨合成塔改造及运行情况小结张名兴，石志富（本溪化肥厂辽宁本溪市１１７００１）我厂是１９７０年建成投产的年产６万吨合成氨、１１万吨尿素的中型氮肥厂。氨合成塔内件为三套管结构。根据生产发展和技术进步的需要，我厂对氨合成塔进行了８万吨规模的节能增产改造，于...     

冰机氨冷凝器故障分析

我公司氨合成系统冰机氨冷凝器原设计为单台每小时耗水量200余吨。在2001年5月化肥系统填平补齐改造结束后，冰机氨冷凝器串联了一台原甲烷化换热器(旧设备)作冰机上氨冷凝器，用循环水冷却，下氨冷凝器用新鲜水。投用后可满足工艺要求，并且每小时节水70余吨。     

全低变工艺在我公司合成氨装置上的应用

1改造背景 2001年6月，我公司采用中低低工艺对原合成氨厂常压变换工艺进行了改造。改造后，节能效果明显，吨氨蒸汽消耗降至300kg以下，但由于工艺条件及其他一些因素的影响，运行过程中发生了一系列设备腐蚀问题，热交换器、水加热器、一调温和二调温损坏频繁，平均运行周期不到0．5a，给企业造成了很大的经济损失。为此，公司组织技术人员对国内各种变换工艺的腐蚀情况进行了系统的研究，并与有关厂家进行了技术交流，比较一致的看法是设备腐蚀由湿态硫化氢应力腐蚀引起。为此，决定将中低低变换工艺改为全低变工艺，以期改变操作工况，扭转生产的被动局面。[第一段]     

南农化肥厂2.5×10~4tNH_3/a工程改造合成节能流程特点简介

该厂2.5×10~4tNH_3/a的改造工程中,其合成节能流程是在收集、吸收国内有关的大、中、小型合成氨生产厂的合成工段的工艺特点、先进经验和节能措施的前提下制订出来的。投运后,吨氨节能达5620.85MJ。本文介绍了该合成节能流程的九大特点。     

中变后串耐硫低变技术小结

为了节能降耗，该厂采用化工部上海研究院开发的SB－3型耐硫低变催化剂，实现了“中变串耐硫低变”工艺。投入运行后，中变炉出口气CO4．6％左右，低变炉出口气CO0．5％左右，节省了大量高压蒸汽，节能效果显著，吨氨节能1．34兆千焦，年直接经济效益146万元。     

450 t/d醇氨联产装置回收大甲醇弛放气可行性分析

1450t／d醇氨联产装置简介 我公司合成一车间合成氨装置设计产能为100kt／a，20世纪60年代从英国引进，以天然气为原料，采用2．0MPa蒸汽转化、中低温变换、热钾碱脱碳、铜碱洗净化、高压合成工艺生产液氨及二氧化碳。1989年公司利用世界银行贷款对该装置进行增产节能技术改造后，装置的生产能力扩大了50％，吨氨能耗下降了30％。采取的改造措施有：一段炉加旁路，二段炉加入过量空气，系统的氢氮比靠返氢（来自合成二车间的普里森装置）维持，脱碳改为两段吸收、两段再生加蒸汽压缩机的低能耗工艺，氨合成改为13．0MPa低压合成等。     

变换系统设备改造小结

河北宣化化肥厂年产合成氨100kt、尿素140kt，1996年6月利用大修机会，将变换系统中串低变工艺改造为全低变工艺。改造后，变换系统吨氨蒸汽消耗由1．1t下降到0．5t，系统阻力下降0．1MPa左右，腐蚀明显减轻，操作弹性变大。但随着生产负荷逐渐加大，部分设备出现了“小马拉大车”的现象，     

水溶液全循环法尿素生产蒸汽系统节能改造

介绍了水溶液全循环尿素装置节能改造方案,对中压分解吸收系统、低压分解吸收系统、蒸发系统和蒸汽系统等进行了技改。改造后,吨尿素平均汽耗1.199 t、氨耗0.519 t,比改造前同期同负荷水平吨尿素蒸汽消耗降低116 kg、氨耗降低2 kg,改造效果显著。     

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。