冷凝水闪蒸汽的回收利用

分析了三效顺流烧碱蒸发系统存在的蒸发汽耗高的原因,通过制订工艺优化方案,控制闪蒸罐液位,回收冷凝水闪蒸汽,每年可节约蒸汽费用97.01万元。     

碳铵液贮槽液位对系统稳定性的影响及处理措施

锦西天然气化工有限责任公司短期停车后重新开车,碳铵液贮槽(300V06)一直处于液位高超限状态,期间蒸发系统和中压系统运行不稳定,就此分析其原因,并采取一系列措施来降低300V06液位。300V06液位正常后,蒸发和中压系统运行稳定。     

合成氨装置工艺冷凝液电导率波动原因分析及处理措施

2017年以来中国石油天然气股份有限公司塔里木油田石化分公司450 kt/a合成氨装置工艺冷凝液汽提塔出口冷凝液电导率不断上涨,超出允许值20μS/cm,同时伴随工艺冷凝液汽提塔压差上下宽幅波动的现象,造成汽提塔出口冷凝液无法回收至脱盐水系统,只能排入循环水系统。对此,塔石化结合2019年冬季检修发现的问题,对汽提塔出口工艺冷凝液电导率逐年升高的原因进行了分析和探究,在工艺冷凝液汽提塔检修和操作中采取了相应的措施,使汽提塔出口工艺冷凝液电导率稳定在了15～17μS/cm,汽提塔压差也恢复至正常的80～90 kPa区间,保证了系统的优质运行和工艺冷凝液的有效回收利用。     

影响PA6萃取水蒸发效果的因素探讨

讨论了在己内酰胺聚合过程中,三效蒸发工艺对PA6萃取水浓缩液浓度的影响,为蒸发系统节能降耗提供依据。结果表明:温度和真空度相互制约,温度98～118℃,真空度0．040～0．085 MPa,一效蒸发塔底部物料温度与二效蒸发塔的二次蒸汽温度差为6～8℃,回流水量75～105 L/h,调节浓度梯度,控制蒸汽调节阀开度为55%～80%,可得到己内酰胺质量分数约80%的萃取水浓缩液,且一效蒸发塔出料温度稳定,有利于节能。     

三效MVR系统的流程模拟及性能研究

基于多效蒸发与MVR技术的优点,将2种工艺进行结合,提出多效MVR节能工艺的新思路,介绍了三效MVR蒸发系统的工作原理。通过Aspen Plus模拟了整个系统的工艺流程,并对三效MVR进行了性能分析。为了减少换热强度,应该尽量降低蒸发压强,这样原料需要预热的温度也会减小;压缩机的蒸汽压缩比维持在1. 6～2. 0比较合适;进料浓度不宜过大,高浓度进料液需适当稀释后再进行蒸发;为了提高此蒸发系统的制热能效比,需适当地减小压缩比;考虑到整个系统的节能效果,此系统在低温低压下运行较为合适。     

聚己内酰胺切片萃取水回用直接聚合工艺探讨

己内酰胺聚合装置回收萃取水中的己内酰胺采用“三效蒸发”、“真空蒸馏”的方法 ,回收率只有 60 %。改用高压前聚、常压后聚的工艺 ,将 85 %浓缩液按 10 %的比例与己内酰胺混合加入 ,前聚压力0 .3MPa以上 ,温度 2 60℃ ,回收率可以达到 90 %以上 ,己内酰胺单耗下降到 10 10 kg/t,聚合时间从 2 3h缩短到 18h     

基于LabVIEW多效逆流蒸发工艺液位控制的研究

针对多效逆流蒸发工艺中液位非线性、大惯性和时滞性的特点,将BP神经网络与增量式PID算法相结合,以LabVIEW为开发平台,实现了多效逆流蒸发过程液位控制的动态仿真。基于物料衡算和热量衡算,建立三效逆流蒸发液位的数学模型,通过液位仿真证明基于LabVIEW实现BP神经网络PID控制系统在多效蒸发液位控制中具有良好的自适应性和鲁棒性。     

晶体硅生产废水零排放工程实例

对于含有大量NaCl、Ca2+及一定量SiO2的化工废水,设计采用混凝沉淀-超滤-弱酸阳床-膜浓缩-三效蒸发结晶-单效蒸发结晶的组合工艺进行废水零排放处理,淡水和NaCl回收,杂盐外运.工程运行结果表明,系统运行稳定,未进行废水外排,淡水水质及NaCl固体品质均满足设计要求.     

己内酰胺聚合装置萃取蒸发系统节能改造技术经济分析

以60kt/a己内酰胺聚合装置萃取蒸发系统为例,探讨了影响萃取蒸发系统蒸汽消耗的因素,分析了装置节能改造的方案和效果.结果表明:影响己内酰胺聚合装置萃取蒸发系统蒸汽消耗的因素包括萃取水量、萃取水温度、蒸发回流量、蒸发浓缩液固含量;采用三效蒸发+浓缩液闪蒸技术对60 kt/a己内酰胺聚合装置进行改造,同时控制萃取水浴比为...     

高速电镀银漂洗水的近零排放技术

利用逆流漂洗和逆流蒸发联合装置实现高速电镀银漂洗水的近零排放.该联合装置中逆流漂洗由三级漂洗槽组成,而逆流蒸发包含电镀槽、填料蒸发器、过滤机和风机等.实际镀液实验表明,在保持一定的液位水平和第三槽漂洗水的浓度小于20 mg/L的前提下,系统运行稳定,没有向外界排放含银漂洗废水,新鲜漂洗水用量比原来节省超过90%,实现电镀银过程的节水高效和漂洗水近零排放.     

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。