沼气净化提纯制备车用燃气技术

由于能源和生态的危机,沼气利用逐渐从传统的低附加值生产向可再生车用燃气转变。但沼气中含有的二氧化碳、硫化氢等杂质会降低沼气的热值,腐蚀设备,污染环境,影响沼气的规模化利用,因此杂质的去除是沼气用作车用燃气的关键。阐述了变压吸附法、水洗法、有机物理吸收法、化学吸收法(胺吸收法)和膜法等净化提纯工艺的流程和特点等,对比分析了各种工艺的优缺点、发展概况和经济性,总结与展望了中国车用沼气的发展现状与前景。     

煤与生物质共气化制甲烷实验研究

以烟煤和高粱秸秆为研究对象,在小型加压固定床反应器上考察了压力3.5MPa及温度700℃条件下制焦方式、煤/生物质混合比和气固接触时间对煤与生物质共气化制取富甲烷气体过程中水蒸气气化反应和甲烷化反应的影响.结果表明,对于水蒸气气化反应,煤焦和生物质焦共气化时不能观察到明显的协同作用;对于甲烷化反应,高粱秸秆焦的甲烷化反应活性高于煤焦的甲烷化反应活性,当对高粱秸秆水洗后,高粱秸秆焦的甲烷化反应活性降低至与煤焦的甲烷化反应活性相当,分析表明,水洗后高粱秸秆焦碱金属钾的含量显著降低,说明高粱秸秆焦中碱金属钾的存在是高粱秸秆焦甲烷化反应活性较高的主要原因.增加气固接触时间,有利于提高甲烷产率.     

沼气重整制氢方法选择

生物质经厌氧发酵产生的沼气富含甲烷与二氧化碳,两者都是主要的温室气体,然而经适当净化后,沼气又是可再生的清洁能源,可以有多种利用方式。从沼气中分离出甲烷并通过催化重整可以制取氢气,具有环境与经济的双重效益。本文对比了沼气重整制氢的各种方法,指出通过干重整是沼气重整制氢的最优途径。     

红外气体分析器进样多点切换装置

我厂合成氨一车间用加压水洗的方法去除原料气中的CO_2,对水洗塔出口气中CO_2含量的分析,采用了一台北京分析仪器厂的QGS—04型红外分析器。该车间有四个水洗塔,一般开三个,由于各塔负荷及操作情况不同,其出口气中CO_2含量高低各异,因此有必要分别对各塔出口气进行分析,以便操作人员及时加以调节。     

基于Aspen Hysys的沼气中N_2对净化工艺的影响

沼气净化技术主要包括脱硫、脱水、脱碳等工艺,而很少涉及N_2对净化工艺的影响。系统地研究了沼气中氮含量对其净化效果的影响。利用化工过程模拟软件,对沼气虚拟临界性质、热值、定压比热容等进行了物性分析,以及对压缩机功耗进行了模拟计算。研究发现,随着N_2含量从0%增至9%时,沼气的临界温度下降12.53℃,热值下降9.03%;N_2含量的增加,也使得在脱碳工序中,对沼气进行冷却降温时所需的换热量增加,且冷却效率明显降低;在相同排气压强工况下,随着N_2含量的增加,压缩机功耗增加明显。     

神东矿区选煤厂水洗矸石干选效果分析

阐述了水洗矸石再处理的必要性,从理论上提出采用干选技术回收可燃物的可行性。以神华煤制油选煤厂水洗矸石分选为例,通过分析煤矸石可选性特点及主流干选机的分选原理,显示了干选水洗煤矸石的优越性。研究表明：IDS型X射线智能分选机分选上湾选煤厂大于50 mm块矸石可以节省矸石破碎成本,ZM型复合式干选机分选小于50 mm末矸石有利于提高分选效率,有利于低热值精煤的回收。分别对补连塔选煤厂和神华煤制油公司小于50 mm水洗矸石采用ZM型复合式干选机成功进行了半工业性干选试验,补连塔煤矸石入料热值4.51 MJ/kg,精煤产率26.74%,精煤热值12.79 MJ/kg,分选后热值提高了8.28 MJ/kg;神华煤制油公司煤矸石入料平均热值为6.22 MJ/kg,精煤产率36.98%,精煤平均热值为14.60 MJ/kg,干选提高热值约8.37 MJ/kg。采用IDS型X射线智能分选机对神东上湾煤矿选煤厂50 mm以上的矸石进行了分选试验,分选密度为1.8 g/cm³时,可回收28.13%的精煤产品,煤中含矸2.43%,矸石带煤1.97%,排矸率达99.04%。     

炭黑尾气综合利用示例

采用水洗塔对炭黑尾气进行降温脱湿处理,提高炭黑尾气热值和火焰燃烧温度,将尾气用于替代炼焦煤气,置换出焦炉煤气用于制取甲醇,社会和经济效益明显。     

关于提高厌氧系统去除效率的研究

通过分析某公司IC厌氧反应器处理效率下降沼气中甲烷含量偏低的原因,提出通过增加厌氧出水的循环量、降低沼气柜配重、补充厌氧颗粒污泥等方法改善厌氧去除效率,增加沼气中甲烷含量,从而提高厌氧系统的运行效率。     

我院中型硫酸装置设计中的技术进展

本文介绍湖南化工设计院近年来在中型硫酸装置设计中所采用的一些新设备和新工艺。诸如:硫精矿烘干尾气采用水洗;增加硫精矿烘干后返库流程;半封闭水洗净化工艺;全塑电除雾器;干吸塔采用新型塔拱和填料;采用金属丝网除沫器;转化用远红外电炉升温等新设备和新技术。     

生物质燃气净化除尘技术研究

研究了生物质气化燃气中固相物质的组成,分析了燃气中灰尘粒径分布及飞灰中碱金属氧化物含量。根据生物质燃气飞灰特点,设计了适合生物质气化燃气的耐腐蚀性强、净化效率及精度高的分级干式高温净化除尘装置。该装置避免了水洗除尘带来的二次水污染,同时通过实验验证了该装置的可靠性及稳定性。     

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。