微波氧化脱除煤中有机硫

采用微波联合超声波分别对潞安煤、西山煤、云南煤和阳泉煤进行脱硫研究.考察了氧化剂配比、微波辐照时间、超声波联合微波等条件对煤中有机硫脱除效果的影响.实验结果表明,不同氧化剂配比有不同的脱有机硫效果.其中,V(HAc):V(H2O2)=1∶1时,脱硫效果最佳;微波辐照时间对脱硫率有明显的影响,随着微波辐照时间的延长,有机...     

微波协同化学助剂强化脱除煤中硫

硫是煤中主要有害元素,煤炭利用过程中硫的排放是酸雨的重要成因,脱硫是煤炭洁净利用的研究热点之一。微波具有促进反应发生、加快反应速率的作用,微波协同化学助剂脱硫是煤炭脱硫的重要手段。本文通过微波辐照结合3种化学助剂研究煤中硫的脱除效果,利用正交试验考察微波辐照时间、化学助剂种类和煤种对脱硫效果的影响。结果表明,煤种对微波协同不同助剂的脱硫效率影响较大,所选3种煤样的最佳辐照时间各不相同;硝酸与微波联合的脱硫效果最好,其中贵州(GZ)煤在微波协同硝酸作用下,全硫脱除率可达71. 2%。形态硫测试分析表明煤样经脱硫后无机硫脱除效率较高,最高可达90. 5%,有机硫脱除效率在20%～40%。XRD谱图分析显示微波协同化学助剂脱硫后,煤中主要矿物和煤质结构没有明显变化,微波在脱除煤中硫分的同时可保持煤炭基质稳定。XPS谱图分析表明,煤样硫醚(醇)类有机硫脱除效果较好,脱除率可达49. 4%,亚砜类略低,脱除率为23%～28%,噻吩类有机硫脱除效果最差,脱除率在10%～20%。     

不同方式辅助H2O2脱硫结果的比较

分别采用磁力搅拌(J)、超声辅助(U)、超声-微波联合(U-M)三种方式辅助H2 O2体系对宁夏宁东煤(YYH)和河南洛阳煤(LY)进行氧化脱硫处理,测定脱硫前后煤样中全硫及形态硫的含量并计算脱硫率.利用扫描电子显微镜(SEM)、比表面及孔隙度分析仪(BET)、傅立叶变换红外光谱仪(FTIR)和X射线光电子能谱仪(XP...     

高硫煤的微波脱硫研究

考查了高硫煤直接微波处理、浸渍不同浓度NaOH溶液后微波处理及其与磁选相结合的手段对脱硫效率的影响,结果表明:高硫煤样直接经微波辐照处理具有一定的脱硫效果,但脱硫率较低。原煤经不同NaOH溶液浸渍后,再经微波处理,其脱硫效果明显提高。在采用2 mol/L NaOH溶液浸渍后,经700W微波功率处理60s,其脱硫率达到最大,为45.2%。磁选对脱硫效率的影响受微波功率的影响较大。在本实验条件下,采用900W微波功率处理,经磁选后脱硫率明显提高。     

硫酸铁氧化浸出脱除煤中硫研究

采用硫酸铁溶液氧化浸出法脱除贵州某矿煤中的硫,考察了硫酸铁溶液浓度、浸出温度、浸出时间及液固比对脱硫率的影响. 实验结果表明,在浸出温度100℃,浸出时间8 h,硫酸铁溶液浓度1 mol/L,液固比10:1时,能有效脱除煤中硫份,脱硫率达到48.56%. 脱硫前后煤样的对比分析结果表明,硫酸铁氧化浸出煤中硫的同时,不仅没有破坏煤中的有效成分,而且提高了煤样的热值,提升了煤的质量.     

DDS脱硫技术在焦炉煤气脱硫中的应用

DDS脱硫技术是一种湿法生化脱硫技术,用含DDS催化剂和亲硫好氧菌的碱性水溶液吸收焦炉煤气中的H2 S和有机硫,然后在DDS催化剂和亲硫好氧菌的共同作用下,用空气氧化再生,将H2 S和有机硫转化成单质硫,再生后的脱硫液循环使用.分别测定DDS脱硫技术和PDS脱硫技术对焦炉煤气中的H2 S、CS2、COS、硫醇和噻吩的脱...     

高硫煤的H2O2-CH3COOH溶液体系脱硫研究

采用H2O2-CH3COOH溶液体系对高硫煤进行了脱硫研究,结果表明,H2O2-CH3COOH的溶液体系可有效脱除煤中的硫铁矿硫和有机硫,实验获得的较佳脱硫条件是溶液初始的H2O2质量分数为10%,n(H2O2)∶n(CH3COOH)为10,温度为室温,反应时间60min,液固比为3∶1,搅拌速率300r/min;在此条件下,煤中硫铁矿硫的脱出率和有机硫的脱出率均可达到65%以上.对该体系的脱硫机理分析表明,H2O2的氧化性在CH3COOH的催化作用下得以加强,促使反应生成更多的羟基自由基(·OH)和过氧羟基自由基(·OOH),这些自由基具有较高的电负性或电子亲和能,能够加速脱硫反应的进行,从而实现硫铁矿硫或有机硫从煤中的脱除.     

酸性体系H_2O-NaBr混合溶剂中煤的电化学脱硫研究

对贵州地宗高硫煤在酸性条件下 ,H2 O- Na Br混合溶剂中电化学脱硫规律进行了研究 ,讨论了电解电流、温度、煤浆浓度、Na Br浓度、p H值及电解时间等主要因素对煤的脱硫率的影响 ,获得无机硫脱除率为 5 6 .71% ,有机硫脱除率为 38.0 3% ,硫的总脱除率为 4 5 .6 2 %的较好效果     

碱性体系中煤中有机硫的电化学脱除研究

以高硫煤为原料,用化学法将其无机硫脱除后,再以此作为电解煤样,在碱性条件下研究了煤中有机硫的电化学脱硫规律。讨论了电解电流、煤浆浓度、NaOH浓度等主要因素对煤中有机硫脱硫率的影响,并确定了适宜电解脱硫条件:NaOH质量浓度4.0mol/L,煤浆质量浓度0.04g/mL,反应温度70℃,电流强度1.0A,电解时间5h,获得了有机硫脱除率为32.50%的较好效果。     

水溶液对光催化煤脱硫实验的影响

为提高燃煤中硫的脱除率，采用光催化氧化法脱硫，利用30%过氧化氢(H₂O₂)作为氧化剂、SiO₂作为光催化剂，加入1 g水溶液，使其在紫外灯照射下反应，或者在紫外光照射后加入1 g水溶液，观察煤中硫含量的变化。结果表明：水溶液可以增加氧化物质，提高溶剂的氧化性，H₂O₂-SiO₂-H₂O光催化处理后煤样的无机硫脱除率达到40%左右，有机硫脱除率最大可以达到9.69%。加入过氧化氢会优先去除无机硫，但是过量的过氧化氢反而会捕获羟基自由基导致体系的氧化性减弱，脱硫率降低；光照结束后加入水溶液时煤的有机硫脱除率提高，说明水溶液在一定程度上可以促进光催化煤脱硫。FTIR和XPS分析表明光催化对噻吩、砜和亚砜的脱除效果好；模拟分析表明水溶液可以在紫外光辐射下产生羟基自由基；而噻吩内部为负电性区域，外部区域呈正电性，羟基自由基的氧原子附近所在区域呈负电性，所以高电负性羟基自由基容易攻击噻吩等高电子云密度点，使其氧化成极性更大的物质，最后通过萃取将...     

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。