粒径对煤温和气化特性的影响

用神木煤在鼓泡流化床反应品中进行了两个粒往下煤温和气化特性研究,结果表明：当不添加氧化钙时,由于在热解过程中形成了基本相同的煤层厚度,传热和传质条件都很接近,所以此时颗粒尺寸与温和气化产物关系不大．添加氧化钙后,由于氧化钙减少了温和气化过程中煤的熔聚性,防止了煤样团聚,从而使煤样粒径对温和气化过程发生了影响．在450℃～650℃范围内,粒径增大气态产率增加．650℃～750℃范围内,粒径增大气态产率减小．最后,对两种粒径下所得半焦进行了工业分析和元素分析,并对所得结果进行了讨论．     

氧化铁与碳酸钾对煤温和气化的影响

对神木煤进行了流化床煤温和气化研究,考察了氧化铁、碳酸钾对煤温和气化产物产率,气体组成,半焦组成的影响。试验结果表明：添加氧化铁后,煤气中Ｈ２产率显著增加,ＣＯ产率明显下降,添加碳酸钾后,Ｈ２产率增幅较小,ＣＯ,ＣＨ４及其它气态烃产率基本不变,表明碳酸钾对烃类裂解反应无明显催化作用。通过对所得半焦组成分析,发现添加碳酸钾所得半焦中硫,氮含量比原煤热解半焦有所增加,添加氧化铁的得半焦中硫,氮含量无明     

氧化钙催化活性在焦油裂解过程中的变化规律

在以循环床锅炉循环灰为热载体、部分气化产生的半焦为锅炉燃料的煤的部分气化技术中,循环灰中的氧化钙对降低焦油产率、提高煤气产率是有利的。以焦油中的苯和甲苯为对象,用固定床反应器实验研究了焦油裂解过程中反应对氧化钙催化活性的影响,测定了失活系数,探讨了失活机理。实验结果表明,随着积碳量的增加,氧化钙颗粒的比表面积和空隙率减小,裂解反应速率下降,裂解产物中碳的总产率增加。     

配煤比例及温度对气化反应特性影响

为降低制气成本,实现用煤当地化,文中以工程示范项目所用广汇煤为原煤,掺混当地气化活性低、气化过程中易结渣的红沙岗煤,利用热重分析仪考察配煤比例和气化温度对混煤气化特性的影响,采用等转化率法计算气化反应表观活化能。研究结果表明:碳转化率、气化速率以及反应性指数R随混煤中红沙岗煤质量分数增加而降低,随气化温度升高而增加;配煤质量比为10%和20%时反应性指数增加率在1 050℃最小,配煤比为40%和60%时反应性指数在1 000℃时增加率最大,而配煤比为30%和50%时反应性指数在950℃时增加率最大;混煤气化反应表观活化能与配煤比不成线性关系,广汇煤和红沙岗煤在气化过程中存在相互作用,混煤的相互作用与配煤比及碳转化率有关。     

褐煤与煤直接液化残渣共气化研究

褐煤与煤直接液化残渣共气化可充分利用二者的资源特性和反应特性。本研究对不同比例的胜利褐煤与神华煤直接液化残渣在800℃下进行水蒸气气化实验,探讨了混料比对褐煤与煤直接液化残渣共气化的影响规律。结果表明当液化残渣掺混比较低时,液化残渣的添加对焦油和气体逸出、碳转化率的提高均有较好的促进作用,半焦产率相应下降,当液化残渣掺混比在30%左右时,共气化表现出良好的协同作用,之后随着原料中液化残渣掺混比的增加,促进效果下降。     

高温煤焦油加氢裂解反应动力学研究

在360℃～400℃,氢气初压1MPa～2.5MPa,5min～40min以及0.5～3剂油比条件下,在自制的间歇式反应器上对高温煤焦油在超临界二甲苯中加氢裂解的宏观反应动力学进行了研究,建立起三集总宏观反应动力学模型.结果表明,该模型能较好反应高温煤焦油在超临界二甲苯中加氢裂解行为.在本实验条件下高温煤焦油在超临界二甲苯中加氢裂解反应时裂化反应的表观压力指数为-0.2111,表观剂油比指数为0.4033,表观活化能为15.765kJ/mol,指前因子为2.722min-1.MPa(0.2111);缩合反应的表观压力指数为-0.2884,表观剂油比指数为-0.4459,表观活化能为30.762kJ/mol,指前因子为18.952min-1.MPa(0.2884);总反应的表观压力指数为0.1609,表观剂油比指数为0.2265,表观活化能为39.049kJ/mol,指前因子为204.226min-1.MPa(-0.1609).     

含锌铅粉尘配碳球团中氧化铁还原动力学

在氮气气氛和１０５０～１３００℃温度范围内，采用化学分析方法研究了还原温度、过量碳及煤粉粒度对含锌铅粉尘配碳球团中氧化铁还原速率的影响．结果表明：还原温度对氧化铁还原速度有显著影响，过量碳和煤粉粒度对还原速率没有影响．在不同还原程度和还原温度下，得出了氧化铁还原的表观活化能，由活化能结果和还原动力学模型对实验结果进行分析，确定了氧化铁在不同还原程度和还原温度下的还原限制性环节．     

稀土元素对炼焦煤热分解特征的影响

研究了配合煤及脱灰配合煤添加0.2%稀土元素后的热解行为,结果表明,添加稀土元素后炼焦煤热分解特征发生显著变化,相同温度下最终失重量增大,快速热分解温度区间延长.DTG曲线表现为热解峰个数增加,塑性胶质体生成阶段(500～700 ℃)热解速率明显增大;550℃开始二次热解加剧;第三热解峰值向高温区移动.动力学分析结果也表明,在热解的三个阶段中,500℃以前反应活化能略升高;处于塑性阶段的第二、三阶段平均反应活化能降低,添加稀土元素后炼焦煤低温下显示出较高的催化作用.     

煤在铜渣熔融还原铁尾渣降温中的热解特性

通过动力学计算,结合XRD和气相色谱分析,对降温条件下单煤及以铜渣熔融还原尾渣为载体的煤的热解行为进行了研究. 结果表明,在初始温度1200℃、降温速率6.667 K/min条件下,煤混渣中煤热解最大速率较单煤增大,时间提前6~7.5 min,失重增加4.51%~11.43%;煤混渣热解气体中H2含量增高,原因为渣中CaO组分对煤中芳香环的脱氢效应;单煤及煤混渣样在降温过程中热解及气化反应均属一级反应,煤混渣样初始热解及气化反应表观活化能低于单煤,但主热解区表观活化能大于单煤,原因为主热解区还原性气氛增强,同步发生渣中高价铁氧化物的还原,反应类型增加,表观活化能变大.     

高温下兖州煤焦/CO2气化反应性

在常压、温度为950 ℃～1 400 ℃范围内,以二氧化碳为气化剂,用等温热重法研究了我国兖州煤的高温气化反应性.主要考察了反应温度、热解终温和热解速率对兖州煤焦高温反应性的影响,并把兖州煤焦的高温反应性和神府煤焦的高温反应性作了比较.结果表明:随气化温度的提高,兖州煤焦反应性的总体趋势增强;快速热解焦的反应性优于慢速热解焦;热解温度对兖州煤焦反应性的影响甚微;在低温段,兖州煤焦的反应性比神府煤焦略差,但在高温段,兖州煤焦的反应性与神府煤相近.     

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。