多元耦合低氮燃烧技术在蒸汽锅炉中的应用

采用低氮燃烧器、烟气外循环、分级分区燃烧多元耦合低氮燃烧技术,将两台75 t/h蒸汽锅炉进行技术改造措施。改造后烟气中NO_x浓度由改造前的104.2 mg/m³降至40.6 mg/m³,烟尘浓度由改造前的5.6 mg/m³降至4.1 mg/m³,SO₂浓度为9.6 mg/m³,年均减少NO_x排放50.9 t/a,年均减少颗粒物排放0.7 t/a,烟气中SO₂、NO_x及颗粒物含量均满足《锅炉大气污染物排放标准》(DB61/1226—2018)排放浓度限值。     

甲乙酮装置热媒炉低氮燃烧技术改造

甲乙酮装置热媒炉烟气中NO_x的含量大约为130 mg/m³，从NO_x生成机理出发，采用分级燃烧技术、助燃空气-烟气内循环技术、燃料-烟气内循环技术和二次风布置技术相结合的改造方案，可显著降低热媒炉烟气中NO_x排放浓度。NO_x排放浓度从改造前的130mg/m³下降至45 mg/m³以内，满足当地环保部门超低NO_x排放限值的要求。     

催化裂化烟气NOx含量高原因分析及应对措施

2018年以来,洛阳市多次启动《重污染天气应急预案》,要求催化裂化装置脱硫脱硝烟气排放指标按ρ(NO_x)≤100mg/m³,ρ(SO_x)≤50mg/m³,ρ(粉尘)≤30 mg/m³执行。操作中,发现双脱烟气NO_x含量很不稳定,时有发生超标甚至NO_x含量长时间居高不下造成环保事件的情况。从日常操作和脱硝剂、助燃剂作用机理入手,分析了双脱烟气NO_x超标的五种原因,并针对这些原因提出了解决方法,实践证明效果不错。     

工业煤粉锅炉采用不同煤质时NOx排放特性研究

对某项目中工业煤粉锅炉中NO_x生成及排放量进行了简要研究，结果表明：煤质对NO_x的生成和排放有影响，燃用神府东胜高氮煤时，炉内NO_x生成量较高，达到225.28 mg/m³,SCR出口NO_x排放量也较高，达到了21.55 mg/m³;燃用设计的低氮低热值煤时，炉内NO_x生成量较低，为213.37 mg/m³,SCR出口NO_x排放量也较低，为16.74 mg/m³。     

SNCR精准脱硝技术在水泥生产中的实践应用

LHK公司在今年节能降碳改造后，熟料产量上升，NOx排放本体浓度增大，而原有脱硝系统使用时间久，设备老化，喷枪位置少，覆盖面小等，在满足NOx环保排放指标达到100 mg/m3以下时，吨熟料氨水用量在3.1 kg/t左右，经过SNCR精准脱硝改造后，进行多层多点布置氨水喷枪位置，精确计量每组喷枪的氨水流量和压缩空气量，动态调节喷枪的雾化效果，控制烟囱NOx排放（标况下）低于100 mg/m3，吨熟料氨水用量降至2.14 kg/t，氨水用量节约了30.96%。     

尘硝一箱化SCR脱硝技术的探索与实践

中材株洲水泥有限责任公司5 000 t/d水泥生产线采用SNCR+分级燃烧技术进行脱硝，虽能满足现有排放标准，但随着国家环保形势日趋严峻，企业面临巨大的环保压力。为彻底解决NO_x排放问题，中材株洲联合河南中材环保采用尘硝一箱化SCR脱硝技术，并在中材株洲生产线顺利建成投运。项目投运后窑尾烟囱NO_x排放浓度稳定控制在100 mg/Nm³以内，氨逃逸控制在2.5 mg/Nm³以内，达到超低排放要求，同时脱硝氨水用量降低约75%,NO_x排污总量降低约1 100 t/a，可为水泥企业实现NO_x超低排放提供参考借鉴。     

5000 t/d水泥熟料生产线智能化精准脱硝系统开发与应用

唐山冀东水泥三友有限公司5 000 t/d水泥熟料生产线配有非催化还原脱硝系统(SNCR)系统实际可以控制NOx浓度在50 mg/m³以下,但存在氨水用量偏高,氨水用量波动较大,氨逃逸数值不稳定等问题。为此,公司对#2水泥熟料生产线现有的SNCR脱硝系统进行了优化升级改造,采用智能化精准脱硝技术,实现NO_x和氨水用量同时降低。     

预分解窑SNCR脱硝系统技术改造的实践

本文以我单位4800t/d熟料生产线现有的SNCR脱硝系统作为改造研究对象,结合CFD计算流体仿真模拟技术的应用以及我厂长期实际运行数据资料的综合分析,于2019年底检修期间对我厂脱硝系统的氨枪类型和喷氨位置进行了重新选择,经过两年多的生产实践表明,NO_x排放控制指标在满足山东省关于氮氧化物排放浓度限值100 mg/m³的基础上,氨水用量方面得到了大幅降低,技改后的应用效果显著,同时也为进一步实现NO_x超低排放进行了新的探索。     

管道炉脱硝技术在熟料生产线中的应用

介绍了管道脱硝炉的工作原理及技术特点，并对原有生产线进行了脱硝改造，通过增加管道脱硝炉，改造烟室(增大横截面积、调整斜坡角度、拉大月亮门与斜坡间的垂直距离、合理布置喷枪等改造措施)，经过生产实践与调试，现已实现控制水泥窑尾烟气NO_x排放浓度<50 mg/Nm³。     

煤基乙醇装置燃气加热炉NOx减排技改总结

陕西兴化集团有限责任公司100 kt/a煤基乙醇装置于2017年建成投产，2021年12月咸阳市环保部门发文要求燃气加热炉尾气NO_x排放指标按特别排放限值(NO_x含量<100 mg/m³)执行，煤基乙醇装置加热炉尾气无法实现达标排放，NO_x减排改造迫在眉睫。为此，从NO_x产生机理入手，通过深入分析与调研市场现有低氮燃烧改造技术的优劣，结合装置的实际情况，决定对3台燃气加热炉进行改造——将加热炉燃烧器更换为一种融合了高分级燃料和烟气内循环技术的超低氮燃烧器。改造后，经测算，年可减排NO_x 2.308 t、减排烟气992.4 km³,年节约燃气(天然气)费用13.69万元，带来良好生态效益的同时还产生了一定的经济效益。     

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。