中药渣催化热解特性与产物分布规律

本研究探索了一系列用于中药渣快速热解的Al MCM-41、β30、HY、ZSM-5商业分子筛类催化剂,进行了热重分析(TGA),Py-GC/MS联用仪分析,对中药渣原样和不同分子筛掺杂中药渣快速热解液相产物的化学组分进行了测定,重点讨论了热解温度、催化剂种类等参数对热解油组成分布的影响规律。与中药渣原料直接热解相比,加入分子筛催化剂在中药渣快速热解中生产芳烃的效率更高,且更有效抑制了酚类和酮类化合物的生成。当热解温度为700℃时,4种催化剂对应热解油中酚类含量分别为9.9%、11.8%、11.3%和16.9%,酮类含量分别为10.9%、10.6%、20.2%和13.4%。分析结果表明,ZSM-5芳烃相对含量可达到7.2%,更加适用于中药渣的催化热解。     

喷动-载流床中Co/ZSM-5分子筛催化剂对煤热解的催化作用

在喷动-载流床中考察了Co/ZSM-5分子筛催化剂对煤热解气、液、固产物产率及组成变化的影响,分析了催化剂失活的原因及催化剂的再生使用寿命. 结果表明,在550~600℃的热解温度范围内,Co/ZSM-5分子筛催化剂提高煤热解总转化率达70%以上. 而在650℃时,煤热解正己烷可溶物产率最大,其中酚类、脂肪烃类和芳香烃类的产率比无催化剂时分别增加203%, 51%和78%. 因积碳失活的Co/ZSM-5分子筛催化剂经过500℃焙烧后再生使用6次,活性下降不到5%. Co/ZSM-5分子筛催化剂的结构表征结果说明,Co进入了ZSM-5分子筛骨架. Co的催化加氢活性促进了H·与煤热解焦油片断的结合,减少了焦油聚合成大分子的几率,从而提高了煤热解油品的产率和品质.     

Fe-Mo/ZSM-5催化剂对生物质热解产物分布的影响

使用固定床管式热解炉进行了果树枝(GSZ)、玉米秸秆(YUJG)两种生物质的催化热解实验,考察了热解温度、加热速率、停留时间、催化剂对生物质热解产物分布的影响,并通过XRD和FT-IR对催化剂以及热解生物质焦进行分析表征.结果表明:未引入催化剂时,反应温度对生物质热解焦油收率影响最大,催化剂的加入,提高了热解产物各组分收率,且随着催化剂种类、添加比例和添加方式不同,YUJG热解产物收率有所变化,其中5Fe-Mo/ZSM-5催化剂加入使得生物质转化率提高了4.8％,焦油收率提高了1.75％,当催化剂与生物质比例为1:1且填料方式为TL-2时,焦油收率达到了最佳值,为30.2％.     

半焦基催化剂裂解煤热解产物提高油气品质

利用上段热解下段催化的两段固定床反应器,针对府谷煤研究了半焦和半焦负载Co催化剂对煤热解产物的催化裂解效果。结果表明,半焦和半焦负载钴对热解产物催化裂解后,热解气收率增加,焦油收率降低,但焦油中沸点低于360℃的轻质组分含量提高,轻质焦油收率基本保持不变或略有增加。与煤在600℃直接热解相比,在热解和催化温度均为600℃,采用煤样质量20%的半焦为催化剂时焦油中轻质组分质量含量提高了约25%,轻质组分收率基本不变,热解气体积收率增加了31.2%;在热解温度600℃,催化温度500℃时,采用煤样质量5%的半焦负载钴催化剂,焦油中轻质组分质量收率和含量分别提高了约8.8%和28.8%,热解气体积收率增加了21.5%。煤热解产物的二次催化裂解的总体效果是将焦油中重质组分转化为轻质焦油和热解气。     

改性ZSM-5对神东煤热解行为的影响

以自制的ZSM-5为载体,制备了NiW/ZSM-5及磷改性PNiW/ZSM-5负载型催化剂,通过XRD,ICP,BET,NH3-TPD和SEM等检测手段对催化剂进行系列表征.结果表明:绝大部分Ni,W和P活性组分被引入到载体上,且分散均匀,改性后分子筛的强酸性位数量明显减少.利用热重-红外联用(TG-FTIR)装置对神东煤在不同催化剂上的热解性能进行评价.结果显示,与原煤热解相比较,催化剂NiW/ZSM-5和PNiW/ZSM-5均使神东煤热解的最大失重峰温提前了8℃,失重率分别增加了1.2%和2.0%.FTIR谱显示,在ZSM-5作用下气相产物析出量无明显增加,而在NiW/ZSM-5和PNiW/ZSM-5催化剂作用下,CH_4、CO、NH_3、轻质脂肪烃和芳香烃的析出量增加明显,其中以PNiW/ZSM-5催化剂效果最佳.     

水合CaO对微拟球藻催化热解制备生物油的影响

以水合CaO为催化剂,在管式炉内研究了微拟球藻的催化热解.考察了催化剂用量对微拟球藻热解产物及油品组成的影响,并通过直接再生和强化再生研究了催化剂的再生特性.结果表明:随着水合CaO用量逐渐加大,生物油性能明显改善.在催化剂/藻质量比为1:3时催化热解得到的生物油产率为28.5%,具有含氧量低、热值高、运动黏度低、含水率低等优点.与直接热解油相比,催化热解油中羧基化合物和羟基化合物含量均有明显下降,而脂肪烃和芳香烃含量均显著增加.第1次和第2次循环再生实验中,直接再生催化剂依然具有较高的催化活性.通过在直接再生过程中引入水洗强化步骤,可对再生催化剂表面进行更新,并降低其表面的碱金属含量,明显改善再生催化剂所催化热解的油品质量,提高再生催化剂活性.     

Fe-Zn共改性ZSM-5催化作用下生物质快速热解特性研究

选取木屑和花生壳作为原料进行生物质热解，研究有机产物分布，催化剂使用Fe、Zn两种金属元素进行改性。通过X射线衍射（XRD）、扫描电镜（SEM）、傅里叶红外（FT-IR）、比表面积测试（BET）对Fe-Zn改性的ZSM-5进行分析。使用闪速裂解-气质联用仪（PY-GC/MS）对原料进行热解，探究生物质催化热解的产物分布变化。催化剂的使用使得芳烃类产物产率获得较大提升，在木屑热解中，Fe负载的分子筛催化获得了酚类的最高产率，比ZSM-5催化热解产率提升18.30%。金属改性催化剂在花生壳热解中，大幅提升了芳烃类产物产率，其中Zn负载催化剂芳烃类产物产率最高，Zn负载催化热解比直接热解的酚类产率降低了18.92%。Zn负载催化获得了最低的酮类产率，与直接热解相比酮类产率降低19.74%，显示出较强的脱羟基效果。此外Zn负载催化和Fe-Zn双金属负载催化在花生壳热解中都大幅降低了酸类产物产率，与直接热解相比酸类产率分别降低了30.46%、36.71%。     

废旧轮胎热解及热解产物研究展望

热解作为废旧轮胎处置的重要技术手段,可以有效实现其减量化、无害化和资源化利用。本文综述了废旧轮胎热解的影响因素以及热解产物的研究进展,对废旧轮胎热解的经济、环境和社会效益进行了说明,指出当前工业化热解废旧轮胎存在的问题,并展望了未来节能环保式热解工艺的应用前景。结合现有的工业化热解设备,优化工艺条件和反应器结构型式,进一步分析了热解产物即热解气、热解油及热解炭的成分结构与应用,通过对热解产物改性活化与提质处理,创造更大的经济效益。提出应基于环境法规要求和绿色发展理念,糅合多种处理技术,研制适合废旧轮胎热解的工艺装备,开发集收集/预处理/热解/产物回收与提质于一体的废旧轮胎处置技术,实现废旧轮胎高效清洁转化和高值利用。     

模板法调控多级孔ZSM-5催化褐煤挥发分制备轻质芳烃的研究

在相同的水热合成条件下,以氧化炭黑为硬模板和十六烷基三甲基溴化铵（CTAB）为软模板,经一步结晶法分别制得了一系列以晶内介孔为主和以无定形介孔为主的多级孔ZSM-5分子筛。通过采用次氯酸钠、双氧水和硝酸来氧化改性商业炭黑,以增加其亲水性及分散性,进而促进了ZSM-5在晶化过程中分子筛前体与炭粒之间的相互作用。重点阐述了不同碳源和CTAB对合成的多级孔ZSM-5物化结构特性的影响,并将该催化剂用于褐煤热解挥发分催化重整制备轻质芳烃的反应中。结果表明,成功构筑的孔径均一的微-介孔梯度的ZSM-5在催化重整褐煤热解挥发分提质过程中有效地解决了催化剂的扩散传质问题,抑制了催化剂失活。引入硝酸氧化改性炭黑晶化合成的ZSM-5分子筛在褐煤热解挥发分的催化重整反应中表现出了很好的催化性能,其中轻质芳烃含量达到27.0 mg/g,选择性为81.7%。此外,在氢气气氛下,该催化剂能够有效降低积炭的碳含量。     

废旧轮胎热解的动力学研究与特性分析

热解作为一种清洁有效的废旧轮胎处理工艺,被广泛研究与应用。本文基于化学动力学理论建立热解动力学模型,并结合热重分析实验得到了低温(400℃以下)和高温(400℃以上)废旧轮胎热解的反应速率与失重率之间的关联式和热解动力学参数。对热重实验结果分析表明废旧轮胎热解过程可以分为有机添加剂析出阶段(295℃)、以天然橡胶热解为主的低温热解阶段(295~400℃)和以合成橡胶热解为主的高温热解阶段(400℃),因此在温度区间300~400℃和450~500℃会分别出现1个失重峰。而升温速率对热解结果的分析显示升温速率虽不改变废轮胎最终热解失重率,但可改变热解的最大失重速率,从而影响最终产物。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。