胜利煤与木屑共液化研究

以胜利煤与木屑为原料,采用Fe2O3催化剂和S助催化剂,用高压反应釜,研究了配比、温度、反应时间及初始氢压等因素对两者共液化的影响.研究结果表明,木屑能促进煤的转化,当木屑与煤的质量比为1∶9时,油产率达到最大值;在实验条件范围内,转化率和油产率均随反应温度、反应时间和初始氢压的增大而增大.     

温度和时间对神东煤直接液化转化率和收率的影响

采用高压反应釜,研究了反应温度和反应时间对神东煤直接液化性能的影响。结果表明,在不同的反应时间下,煤转化率大体上随着反应温度的升高而增加,其中当反应时间较短时,煤转化率增加的幅度较大;当反应时间较长时,煤转化率增加的幅度较小。在不同的反应时间下,随着反应温度的升高,大体上油收率逐渐增大,沥青质收率逐渐减小,水收率变化不明显,气收率逐渐增大。在不同的反应温度下,随着反应时间的延长,煤转化率和油收率都先是快速增大,然后缓慢增大,在反应温度太高时,随反应时间继续延长,煤转化率增加到最大值后基本不变甚至略有减小,油收率增加到最大值后开始减小。当反应温度为460℃,反应时间为90 min时,煤转化率和油收率达到最大值,分别为90.7%和61.8%。     

温度和时间对神东煤直接液化转化率和收率的影响

采用高压反应釜,研究了反应温度和反应时间对神东煤直接液化性能的影响。结果表明,在不同的反应时间下,煤转化率大体上随着反应温度的升高而增加,其中当反应时间较短时,煤转化率增加的幅度较大;当反应时间较长时,煤转化率增加的幅度较小。在不同的反应时间下,随着反应温度的升高,大体上油收率逐渐增大,沥青质收率逐渐减小,水收率变化不明显,气收率逐渐增大。在不同的反应温度下,随着反应时间的延长,煤转化率和油收率都先是快速增大,然后缓慢增大,在反应温度太高时,随反应时间继续延长,煤转化率增加到最大值后基本不变甚至略有减小,油收率增加到最大值后开始减小。当反应温度为460℃,反应时间为90 min时,煤转化率和油收率达到最大值,分别为90.7%和61.8%。     

秸秆与兖州煤共液化反应条件的研究

在高压反应釜内,以四氢萘为供氢溶剂,Fe2O3＋S为催化剂,研究了温度、反应时间、初始氢压、配比对兖州煤与秸秆共液化的影响。结果表明,提高反应温度,转化率、油产率增加;延长反应时间对转化率、油产率的影响较小;升高初始氢压,转化率、油产率刚开始增加,6 MPa以后增幅趋缓;在m（秸秆）∶m（兖州煤）=0.5∶9.5时,共液化的油产率为60.45%,比兖州煤单独液化的油产率提高了4.17%;在m（兖州煤）∶m（秸秆）=9.5∶0.5,440℃,8 MPa,90 min的条件下,共液化转化率和油产率达到最大,分别为83.58%和63.1%。     

新疆淖毛湖煤直接液化反应行为研究

为研究新疆淖毛湖煤直接液化反应特性和产品分布规律,在0.5 L间歇式高压釜中,以四氢萘为溶剂,纳米氧化铁为催化剂及S为助剂,考察了不同反应温度、反应时间条件对煤转化率和液化产物收率的影响。结果表明:淖毛湖煤易液化,在反应器温度刚加热到425℃时,煤转化率和液化油收率已分别达到96.6%、56.68%;随着反应温度的升高以及反应时间的延长,煤转化率、氢耗、气体产率、油收率逐渐增加,而沥青类物质产率下降,水产率基本保持不变;当反应温度进一步增加以及反应时间继续延长,轻质油将会发生裂解,导致气体产率进一步增加,而油收率有所降低。当反应温度为455℃、反应时间为80 min时,煤转化率达到99.6%,油、沥青和气体收率分别为73.42%、1.64%、16.61%,氢耗为4.85%。基于液化试验结果,建立了5集总的反应动力学模型,采用优化算法获得动力学模型参数,煤转化率、沥青类物质和油气收率的模拟值和试验值的相对误差分别为0.5%、1.0%、8.0%。     

不同热解因素对污泥热解生成气相产物的影响

采用外热式反应釜加热装置,以CH3COOK为催化剂对污泥进行了热解实验,研究了不同热解终温、催化剂的质量分数、反应时间、升温速率对热解气相产物的产率及气相产物组成的影响。结果表明:随着热解温度升高,气相产率不断增大,H2的体积分数在增大,气体的热值先增大后减小,500℃时气体热值达到最大值,为26.05 MJ/m~3;随着催化剂质量分数和升温速率的增大,气产率先增大后减小,催化剂质量分数为6%时达到最大值,而热值变化呈减小趋势;随着反应时间增大,气产率不断增大,H_2体积分数在增大,而热值先增大后减小,在90 min时达到最大值,为30.19 MJ/m~3。     

惰质组含量对上湾煤液化性能的影响

对不同惰质组分含量的上湾煤样进行了高压釜煤液化实验。在反应温度440～465℃,氢初压7～11 MPa条件下,研究了5种不同惰质组含量的上湾煤的液化性能。结果表明:在反应温度为440～465℃内,随着温度的升高,除惰质组含量最高的5号煤样在温度高于465℃时转化率开始下降以外,其余不同惰质组含量的4种煤的转化率、油产率、气产率和氢耗均随着温度的升高而增加,沥青烯产率随温度的升高而减小;随着氢初压的增加,不同显微组含量的煤的转化率和油产率增加,沥青烯产率减小。惰质组含量越高,煤的转化率和油收率越低。     

甲烷气氛下铁基催化剂对低阶煤温和液化的影响

针对煤直接液化的高温高压苛刻反应条件和高昂的氢气成本问题,通过降低煤液化反应温度、压力和更换供氢气氛等方法来优化工艺过程。选用四种铁基催化剂研究低阶煤在甲烷气氛下温和液化的反应特性,研究结果表明：神华黑山长焰煤HS在温度350℃、初始压力3 MPa的甲烷气氛下液化产物为轻质气体、液化油和沥青质;以FeSO₄为催化剂时沥青质的产率最高达到8.03%,并将煤液化的转化率提升了6.10%;以FeS为催化剂时油气产率提升了3.48%;助剂硫元素的加入对煤液化反应总转化率的提升有着重要作用;Fe粉、Fe+S和FeS催化剂的加入有助于提升煤液化油中单环芳烃的含量。     

煤与生物质共液化的催化反应

有效性和经济角度考虑,选定硫铁化物为煤与生物质加氢共液化的催化剂.在不同条件下制备的催化剂对反应有不同的催化效果.硫铁催化剂可降低反应苛刻度,在300～400℃范围内可明显提高反应转化率和油产率.建议合适的反应条件为:温度350℃,反应时间20min,初始冷氢压3.40MPa.     

胜利褐煤在CO+H_2O系统中液化的研究

在500 mL的间歇式高压反应釜中进行了胜利褐煤铁基催化剂条件加氢液化实验,考察了H2O+CO系统中温度、压力、煤水质量比对总转化率、油气产率和沥青质产率的影响。结果表明,随着反应温度的提高,液化总转化率和油产率增加,沥青质产率降低;随着煤水质量比的增加,总转化率先降低后增加,在1∶1.2处出现拐点,油产率有相同的变化趋势,但低煤水质量比条件下油产率较高,高压有利于加氢液化反应。通过红外、核磁共振分析,证明液化产物中存在大量酚和醇类物质。     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.