等离子体荷电干式喷钙脱硫工艺实验研究

将等离子体技术与传统干式喷钙脱硫技术相结合,利用脉冲电晕放电技术产生等离子体,对脱硫剂颗粒进行处理,脉冲放电脱硫反应器电极结构采用线筒式电极,正极性窄脉冲高电压供电,实验烟气流量为100m3/h~300m3/h.主要研究了脉冲放电脱硫的运行参数对脱硫效果的影响,目的是为脉冲放电烟气脱硫工业应用提供科学依据.实验结果表明:烟气中SO2浓度在1000mL/m3~2000mL/m3范围内,烟气温度在60℃~80℃范围内,氧化钙加入量按摩尔比CaO∶SO2=2∶1加入,能耗3(W·h)/m3~5(W·h)/m3,SO2脱除率达到85%以上.     

配NO2调节NOx氧化度双循环一塔硫硝同脱研究

以石灰浆液作吸收液,在筛板塔双循环模式下开展了模拟烟气同时脱硫脱硝实验,并通过配加NO2调节NOx氧化度来提高脱硝率.主要研究了液气比、吸收液温度、NO2/NOx (体积比)、SO2浓度等因素对脱硝率的影响.实验结果表明:当烟气量20 m3/h,SO2和NO进气体积分数分别为5.5×10-4和3×10-4,NO2/NOx为0.5,液气比4 L/m3,温度298 K的石灰浆液吸收烟气时,SO2和NOx的吸收率分别可达到96.63％和88.36％,实现了脱硫脱硝同塔完成.     

自由基簇射电催化氧化同时脱硫脱硝过程反应特性及机理研究

应用一种新型的电催化氧化技术??电晕放电自由基簇射技术进行了烟气同时脱硫脱硝实验,重点分析了SO2和NOx脱除的反应特性和相互影响机理.结果表明:在0.042 L(min(1的氨气注入下,50%的SO2在放电前被脱除,但放电过程仍对SO2的脱除有一定的促进作用.而NOx的脱除取决于放电过程,放电前的脱除几乎可以忽略不计.在脱除过程中,适量的SO2能够提高NOx的脱除,最大能使NOx脱除率提高25%,但过高的SO2又使NOx的脱除趋于减少.不同SO2初始浓度下NOx脱除率的变化主要归因于SO2和NO2之间的反应.NO初始浓度的变化对SO2的脱除影响较小.烟气成分的变化对SO2和NOx的脱除影响也不明显.在脱硫脱硝过程中,观察到的白色晶体状物质主要成分是硫酸铵和硝酸铵.     

FeⅡ(NTA)吸收结合生物还原脱除烟气中NO研究

以FeⅡ(NTA)为络合吸收剂,在恒温摇床中考察了微生物还原络合吸收液的特性,并进一步在填料塔中进行了连续脱除NO的工艺研究.结果表明添加葡萄糖比醋酸钠、柠檬酸钠、甲醇、乙醇等更适合于作为该体系的碳源;在较低碳源用量下,还原速率随其用量的增加而增加,达到一定量以后再增加对还原反应没有促进作用;在进气量1000 ml·min1,NO浓度200 cm3·m-3,O2含量3%的实验条件下,当系统达到稳定运行后,NO脱除率可保持在95%左右;烟气中O2含量增大至4%以后,NO脱除率会随之增加而下降.     

水泥窑炉烟气SNCR 脱硝工艺参数的优化研究

伊犁青松南岗建材有限责任公司的伊犁水泥厂拥有一条2　500t/d熟料生产线,主要设备为Φ4m×60m回转窑,带单系列五级低压损旋风预热器和 HFC分解炉组成,分解炉直径为 Φ6　000mm,生产线带有低温余热发电系统, 装机容量为6MW。其预分解炉C1筒出口烟气量最大2.6×105Nm3/h,温度在350～400℃,烟气中NOx浓度为800mg/Nm3左右。为满足窑炉烟气NOx的达标排放,公司于2013年投资建成SNCR系统,系统采用浓度25%的氨水作为还原剂。其工艺流程为氨水储罐中浓度25%的氨水经水稀释混合、计量后,由喷枪高压喷入分解炉,其中的NH3与烟气中的 NOx发生还原反应生成N2和H2O排放。     

低床层烟炱吸附法烟气脱硫试验研究及机理探讨

研究了以锅炉烟气沉降物为吸附剂的烟炱吸附法脱除SO2的工艺条件，结果表明该法较适宜的工艺条件为SO2浓度小于2400mg/L，烟气流速小于36m/h，烟气温度低于100℃，此时脱硫效率可达30%以上，并且还初步探讨了烟炱吸附法脱硫的作用机理。     

氨吸收法同时脱硫脱硝的实验研究

在自行设计的吸收塔反应器中,以氨水作为吸收剂,研究其对SO2和NOx的脱除效果,在氨法脱硫的工艺条件下对SO2的脱除率为100%,NOx脱除率可达72%。对SO2和NOx的吸收条件进行了研究,发现吸收液中SO32-浓度是影响脱硫脱硝率的重要因素。提出了选择性催化氧化(SCO)和氨法烟气脱硫相结合的氨吸收法同时脱硫脱硝技术,此法可用于改造现有氨法烟气脱硫设备,达到SO2和NOx同时脱除的目的。     

活性焦联合脱硫脱硝工艺试验研究

为了开发活性焦联合脱硫脱硝工艺,选取一种商用活性焦在微型反应器上进行NH3对NO、SO2脱除影响及NO和SO2脱除交互影响试验,提出了活性焦联合脱硫脱硝工艺路线,并在实验室搭建的模拟装置上进行了工艺路线的模拟试验验证。结果表明,活性焦脱硝是低温SCR反应,NH3的存在使SO2吸附量提高约18%,说明NH3与SO2发生化学反应,有利于SO2脱除,但生成的硫铵会降低工业装置的稳定性;当活性焦无吸附NH3时,NO对SO2脱除无影响,当活性焦吸附NH3时,通入NO前后,SO2出口体积分数由0.15%降至0.13%左右,说明NO对SO2脱除有促进作用;通入SO2气体后,NO出口体积分数由0.045%迅速增至0.065%,说明SO2与NO争抢NH3,不利于脱硝。通过工艺路线模拟试验发现,当联合脱硫脱硝空速为400 h-1时,脱硫效率≥95%,脱硝效率≥70%,验证了活性焦联合脱硫脱硝工艺的可行性。     

SCR脱硝氨转化、吸附及飞灰氨脱除技术研究现状

随着国家对燃煤电厂污染物排放要求愈加严格,燃煤电厂几乎都安装了SCR烟气脱硝装置处理烟气中NO_x。正常运行的SCR烟气脱硝装置脱硝效率为80%～90%。但在超低排放要求下,部分燃煤机组锅炉SCR运行实际脱硝效率高达95%,导致氨逃逸控制难度急剧增大。综述了国内外燃煤电站锅炉SCR脱硝后飞灰中NH₄HSO₄的形成与脱除,分析其形成机制以及脱除方法,对其工业应用进行了展望。研究表明粉煤灰对单质氨的吸附能力有限,但烟气中SO₃与H₂O的存在可促使灰中氨含量升高,NH₃、SO₃浓度和煤种是影响灰中氨含量的主要因素。粉煤灰脱氨技术按原理可分为加热法、氧化法、水洗法以及加碱法等。204℃下,粉煤灰中氨的脱除十分缓慢,处理80 min,氨脱除率小于50%,因而加热法需在260℃进行,能耗较高。灰中含水量高于3%时,氨脱除速率很高,但在随后的干燥阶段,灰中含水量降至2%以下后,氨脱除速率迅速下降,同时水洗法会产生额外的废水;氧化法是选取合适的催化剂安...     

活性炭辅助低温等离子体脱除燃煤烟气中NO

燃煤烟气中氮氧化物以NO为主,其大量排放对自然环境和人类健康危害极大。针对低温等离子体(Nonthermal plasmas, NTPs)技术脱除NO效率低、能耗高的问题,系统研究不同气体流量、O₂含量和NO初始浓度等因素对低温等离子体过程中NO去除效果的影响。结果表明,在N₂/NO混合气体条件下,NO脱除率为90%、气体流量为5 L/min对应的单位能耗NO处理量最高,为4.17 g/kWh。O₂的存在对于NO转化具有一定抑制作用,且在高O₂含量下,升高电源的输出功率反而不利于NO脱除。研究发现,O₂体积分数6%条件下,NO脱除率低于46%,对应单位能耗NO处理量仅为2.29 g/kWh。为实现有氧条件下NO的低能耗高效脱除,在低温等离子体反应段前添加活性炭吸附氧化工艺。首先利用活性炭对高浓度NO进行吸附氧化预处理,降低进入低温等离子体反应器中的NO浓度;随后,采用低温等离子体技术对剩余NO进行深度氧化处理,实现NO的低能耗高效脱除。结果表明,采用该耦合工艺,活性炭吸附氧化N...     

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。