合成甲醇铜系催化剂硫中毒机理与该催化剂上CO、H_2吸附机理的研究

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CO、H_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CO、H_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。

层状La-Ba-Cu复合氧化物在CO还原NO反应中活性的研究

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...

合成醇Cu-CO催化剂中第Ⅲ组分对其催化性能的影响

在一般金属催化剂上,由CO和H_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

燃料气中H_2、N_2、O_2、CH_4、CO、O_2的全分析

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。

高温气冷堆He载气中H_2和CO转化实验研究

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。

Anomalous Thermal Stability of Nd-Fe-Co-Al Bulk Metallic Glass

The thermal stability of Nd60Fe20Co10Al10 bulk metallic glass (BMG) has been studied by differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), isochronal dilatation and compression tests. The results show that the glass transition of the BMG takes place quite gradually between about 460 and 650 K at a heating rate of 0.17 K/s. Several transformation processes are observed during continuous heating with the first crystallization process beginning at about 460 K, while massive crystallization takes place near the solidus temperature of the alloy. The positive heat of mixing between the two major constituents, Nd and Fe, and, consequently, a highly inhomogeneous composition of the attained amorphous phase are responsible for the anomalous thermal stability in this system. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

Flame Propagation of H_2-Air in a Semi-Open Obstructed Tube

针对氢／空气混合物,通过实验研究了其预混火焰在半开口管道中的火焰传播加速现象,结果表明,火焰传播状态随着氢气当量比的变化而发生改变。当氢／空气混合物被点燃后,由于障碍物的扰动,火焰在管道中不断加速传播,并最终到达一准稳态传播。在氢气当量比0.31附近时,火焰速度发生跃变。当氢气当量比足够大时,火焰传播由爆燃态转变为爆轰态。在本实验条件下,爆燃转准爆轰的临界条件是d/Lambda>=2.6（d是圆环形障碍物内径,人是爆轰格胞尺度）。障碍物阻塞比的变化对最大火焰速度和压力提升的影响不明显。

Numerical Simulation of Gaseous Detonation of H_2-O_2 Mixture with Detailed Chemical Reaction Model

采用高精度的ENO格式和基于基元化学反应的真实化学反应模型求解氢氧混合气体一维爆轰波的精细结构。采用直接起爆方法得到稳定传播的爆轰波,计算的爆轰波阵面参数和实验相当符合。对爆轰波反应区化学反应的研究表明,参与反应的不同组分具有不同类型的变化特征。网格尺寸影响的研究表明,计算结果的精度随着网格尺寸的增加而增加,并能保持较好的收敛性。移动网格研究结果表明,网格运动速度和爆轰速度接近时,两者的相互作用对计算结果产生一定影响。

Interactions of CO, HCl, and Sox in Pulverised Coal Flames

The effect of HCl and SO_2 on CO oxidation in pulverised coal flames was investigated experimentally and kinetically in an entrained flow combustion reactor. Two bituminous coals (German 'Goettelborn' and a Polish coal) were used as fuels with a feeding rate of 1 or 1.5 kg/h. HCl or SO_2 is introduced into the reactor premixed with the primary air. Experimental results indicate that HCl addition may inhibit CO oxidation in coal flames and increases CO emission. Reducing temperature in the reactor will enhance the inhibitory effect of HCl on CO oxidation. The measured CO profiles along the reactor height clearly show that the addition of HCl may inhibit CO oxidation. In the experimental range of SO_2 addition. The inhibiting effect of SO_2 on CO oxidation is less significant than HCl. A detailed kinetic mechanism is used to model the reactions. And the controlling reactions are analysed.

流化床中RDF焚烧时CO、SO_2和HCl的生成

垃圾衍生燃料 (Refuse-Derived Fuels-RDF)具有热值高、易燃烧的优点。RDF的一个潜在应用是与煤进行混烧，替代一部分锅炉燃烧用煤。由于RDF挥发份相当高，因此燃烧时的污染物排放不易控制。本文在非均匀布风流化床中进行了RDF与煤的混烧试验，测量了H_2O、CO、CO_2、NO、N_2O、HCl、SO_2等污染物质的排放特性。结果表明与单纯燃烧RDF相比，混烧时的CO生成量大大下降；SO2生成浓度较低，而HCl的生成量比单纯烧煤时明显增加。

Practical Criterion for Universal Laws and Practical Methods for Construction of Co-variance Sets

给出相对论力学中普遍定律的实用判别法和协变集的实用构造法,还给出实现非普遍定律的“可导出性”的一种实用方法．

Quantum Monte Carlo study of the CO interaction with a dimer model surface for Cr(110)

The chemisorption of CO on a Cr( 110) surface is investigated using the quantum Monte Carlo method in the diffusion Monte Carlo (DMC) variant and a model Cr2CO cluster. The present results are consistent with the earlier ab initio HF study with this model that showed the tilted/ near-parallel orientation as energetically favoured over the perpendicular arrangement. The DMC energy difference between the two orientations is larger (1.9 eV) than that computed in the previous study. The distribution and reorganization of electrons during CO adsorption on the model surface are analysed using the topological electron localization function method that yields electron populations, charge transfer and clear insight on the chemical bonding that occurs with CO adsorption and dissociation on the model surface.

Studies on two-phase co-current air/non-Newtonian shear-thinning fluid flows in inclined smooth pipes

In this work. co-current flow characteristics of air/non-Newtonian liquid systems in inclined smooth pipes are studied experimentally and theoretically using transparent tubes of 20, 40 and 60 turn in diameter. Each tube includes two 10 m lone pipe branches connected by a U-bend that is capable of being inclined to any angle, from a completely horizontal to a fully vertical position. The flow rate of each phase is varied over a wide range. The studied flow phenomena are bubbly, plug flow, slug flow, churn flow and annular flow. These are observed and recorded by a high flow. stratified flow. -speed camera over a wide range of operating conditions. The effects of the liquid phase properties, the inclination angle and the pipe diameter on two-phase flow characteristics are systematically studied. The Heywood-Charles model for horizontal flow was modified to accommodate stratified flow in inclined pipes, taking into account the average void fraction and pressure drop of the mixture flow of a gas/non-Newtonian liquid. The pressure drop gradient model of Taitel and Barnea for a gas/Newtonian liquid slug flow was extended to include liquids possessing shear-thinning flow behaviour in inclined pipes. The comparison of the predicted values with the experimental data shows that the models presented here provide a reasonable estimate of the average void fraction and the corresponding pressure drop for the mixture flow of a gas/ non-Newtonian liquid. (C) 2007 Elsevier Ltd. All rights reserved.

高温下CF_4在H_2中解离的反应动力学研究

用单脉冲激波管研究了有少量ＣＦ３Ｃｌ参予下的ＣＦ４与Ｈ２的混合物在高温下的反应动力学，发现主要产物为Ｃ２Ｆ４和ＣＦ３Ｈ．对实验结果的分析表明，反应过程为一个双中心链反应。始发反应为ＣＦ３Ｃｌ的Ｃ—Ｃｌ键的断裂，继之以由Ｈ２和ＣＦ４为媒介的双中心链传递，最后测得温度由１０００至１０８０Ｋ，压力为０．１ＭＰａ下的ＣＦ４表观分解速率常数为Ｋｅｆｆ＝１０１３．７ｅｘｐ（－５５０００／ＲＴ）１１／２ｍｏｌ－１ｓ－１对这一结果进行分析，得到以下相关的反应速度常数ｋ（ＣＦ３Ｃｌ→ＣＦ３＋Ｃｌ?）＝１０１５ｅｘｐ（－８１０００／ＲＴ）ｓ－１ｋ（ＣＦ３＋Ｈ２→ＣＦ３Ｈ＋Ｈ?）＝１０８．６ｅｘｐ（－８８００／ＲＴ）１?ｍｏｌ－１?ｓ－１ｋ（ＣＦ４＋Ｈ?→ＣＦ３?＋ＨＦ）＝１０１１．４ｅｘｐ（Ｇ２００００／ＲＴ）１?ｍｏｌ－１?ｓ－１ｋ（ＣＦ３?＋Ｈ?→ＣＦ３Ｈ）＝１０８．０１?ｍｏｌ－１?ｓ－１

用量子Monte Carlo方法计算氢分子H_2基态(Χ~1∑_g~+)势能曲线

本文用量子MontoCarlo方法中优化试探波函数Ψ_T计算氢分子H_2基态(X~1∑_g~+)势能曲线.文中采用相当简单的波函数形式,并用固定样点优化技术优化试探波函数的参数.确定优化试探波函数后,分别用变分Monte Carlo及固定节面M0nte Carlo计算势能曲线各点能值.二种方法先后得95%和100%的相关能.因此,在量子M0nte Carlo方法中,用本文作者提出的试探波函数计算分子势能面,将会获得很好的结果.从而对分子散射和动力学的研究有重要意义.