1000 resultados para CO H_2


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合成甲醇铜系催化剂是广泛用于工业反应的高活性催化剂。但对含硫气体十分敏感,易硫中毒。本论文通过常压、220 ℃反应温度下硫中毒对催化活性、反应物吸附性质、催化剂表面组成与体相结构、孔分布的影响探讨了铜系催化剂硫中毒机理。同时通过考察COH_2在米中毒铜系催化剂上咐附、脱附、程脱及竞争吸附的性质,探讨了COH_2吸附机理。得到以下结果。常压下,铜系催化剂遇含硫气体引起不可逆中毒。当硫浓度较低时,H_2S占据了铜活性中心,使CO不能在该吸附中心吸附,造成失活。由于H_2S吸附引起催化剂表面铜晶相冲长也是失活的直接原因。中毒时,硫并非均匀吸附,而主要是吸附在50~80A孔内。H_2S浓度较高时,硫与催化剂反应形成硫化物是失活的主要原因。H_2在铜系催化剂上的吸附当吸附温度为225 ℃时可分为两部分,可逆吸附与不可逆吸附。可逆吸附中心属铜吸附中心,不可逆吸附中心是H_2与部分吸附的CO共同的竞争的咐附中心。CO在该温度下的可逆吸附发生在催化剂铜活性表面上。

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氮氧化物是严重的空气污染物,催化消除氮氧化物是环保催化研究的热点问题,在已有报道的催化剂体系中复合氧化物和含铜分子筛受到人们的普遍关注,文献中已有报道ABO_3(A=Ln;B=Cr,Mn,Fe,Co,Ni)型复合氧化物作为CO还原NO反应的催化剂.但迄今尚未见有合成LaCuO_3的报道,有关含铜复合氧化物作催化剂的大多是A_2BO_4型的.呈ABO_3结构的含铜复合氧化物只有成层状的超导体如YBa_2Cu_3O_7,本文为了探讨复合氧化物晶体结构对催化活性的影响,首次研究了3种层状ABO_3结构的La-Ba-Cu复合氧化物对CO还原NO反应的活性,发现它们均具有较高的活性,并首次提出了Ba离子在此反应中的作用.1 实验方法催化剂的制备和Cu价态分析见文献[4,5]CO还原NO反应在固定床流动反应体系中进行,反应管为内径6mm石英管,催化剂粒度为40~80目,用量0.2g,空速为7000h~(-1),原料气为NO7.5×10~(-3),CO8.0×10~(-3),He平衡.采用英国产的Pyc Pan气相色谱分析检测N_2O,CO_2,0.5nm分子筛色谱柱检测NO,CO转化率. H_2-TPR在自制装置上...

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在一般金属催化剂上,由COH_2选择合成高级醇是合成气化学的重要研究方向。IFP在1982年提出的Cu-Co催化剂至今还是重要的体系,对合成C_2醇有较好的选择性,但这类催化剂存在热稳定性差、活性低的缺点,为改善催化剂的性质需添加热稳定性高的载体和助剂。有关Cu-Co催化剂体系的研究已有不少报道,但加入第Ⅲ组分对其性质的影

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从生物质汽化制取的燃料气,其主要成份是 CO_2、H_2、O_2、N_2、CH_4、CO 六种气体。但在不同的工艺条件下,各组份的含量差异很大。在工艺试验中,需要及时监测各种组份含量的变化,摸索最佳工艺条件,这就要求缩短分析周期。为此我们改装了一台 SP-2307色谱仪。用 Ar 作载气,只用一个热导检测器,一次进样就可完成上述六种气体的分析。改装时增加气体自动进样系统,提高了分析的准确度。

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研究了H_2和CO在CuO-ZnO_Al_2O_3催化床中转化成H_2O和CO_2的实验装置和实验结果,论证了不同床层工作温度、系统压力、杂质浓度、流量及露点温度等因素对氧化铜床工作性能的影响;测得了H_2和CO在CuO-ZnO-Al_2O_3床上的转化特性曲线等变化规律,获得了转化容量、工作周期和转化效率等实验数据,确定了最佳运行参数。结果表明,使用CuO_ZnO-Al_2O_3床可使净化后的H_2和CO的体积分数都小于2×l0 ̄(-6),满足高温气冷堆的净化要求。为高温气冷堆中氧化铜床装置提供了可靠的设计数据。

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We report on the solution of the Hartree-Fock equations for the ground state of the H_2 molecule using the finite element method. Both the Hartree-Fock and the Poisson equations are solved with this method to an accuracy of 10^-8 using only 26 x 11 grid points in two dimensions. A 41 x 16 grid gives a new Hartree-Fock benchmark to ten-figure accuracy.

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This paper considers the question, ‘what is co-creative media, and why is it a useful idea in social media research’? The term ‘co-creative media’ is now used by Creative Industries researchers at QUT to describe their digital storytelling practices. Digital storytelling is a set of collaborative digital media production techniques that have been used to facilitate social participation in numerous Australian and international contexts. Digital storytelling has been adapted by Creative Industries researchers at QUT as a platform for researching the potential of vernacular creativity in a variety of contexts, including social inclusion of marginalized and disadvantaged groups; inclusion in public histories of narratives that might be overlooked; and articulation of voices that otherwise remain silent in the formulation of social and economic development strategies. The adaption of digital storytelling to different contexts has been shaped by the reflexive, recursive, and pragmatic requirements of action research. Amongst other things, this activity draws attention to the agency of researchers in facilitating these kinds of participatory media processes and outcomes. This discussion serves to problematise concepts of participatory media by introducing the term ‘co-creative media’ and differentiating these from other social media production practices.

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ABSTRACT. The phenomenon of consumer co-creation is often framed in terms of whether either economic market forces or socio-cultural non-market forces ultimately dominate. We propose an alternate model of consumer co-creation in terms of co-evolution between markets and non-markets. Our model is based on a recent ethnographic study of a massively multiplayer online game through its development, release and ultimate failure, and cast in terms of two explanatory models: multiple games and social network markets. We conclude that consumer co-creation is indeed complex, but in ways that relate to both emergent market expectations and the evolution of markets, not to the transcendence of markets.

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This article discusses the ways in which the relations among professional and non-professional participants in co-creative relations are being reconfigured as part of the shift from a closed industrial paradigm of expertise toward open and distributed expertise networks. This article draws on ethnographic consultancy research undertaken throughout 2007 with Auran Games, a Brisbane, Australia based games developer, to explore the co-creative relationships between professional developers and gamers. This research followed and informed Auran’s online community management and social networking strategies for Fury (http://unleashthefury.com), a massively multiplayer online game released in October 2007. This paper argues that these co-creative forms of expertise involve co-ordinating expertises through social-network markets.