INTRAPARTICLE CONVECTION, DIFFUSION AND ZERO ORDER REACTION IN POROUS CATALYSTS

An assessment is made of the influence of convective effects in the behaviour of calalyst pellets with large pores

Concentration profiles and effectiveness factors are calculated for zero order reactions in isothermal regimes using a model which involves convective transport as well as diffusion and reaction processes in the pellet

Errors made in current reactor design are discussed. A predictive method for calculating the intraparticle fluid velocity in industrial cases is reported. Finally, the analysis is applied to the design of biological reactors.     

Kinetics of Methanol Oxidation on Supported and Unsupported Pt/Ru Catalysts Bonded to PEM

The kinetics and mechanism of methanol adsorption and oxidation on real Pt/Ru (1:1) electrodes were investigated. In model electrode systems, the addition of supporting proton-conducting electrolyte is necessary. Therefore, the influence of sulphuric acid on the kinetics of methanol adsorption and oxidation was also investigated. It turns out that the steady state adsorption is not significantly affected by the addition of sulphuric acid. However, if sulphuric acid is used as an additional electrolyte, the rate of methanol adsorption and steady state oxidation decreases, whereas the active surface of the catalyst increases. The mechanism of methanol oxidation is not affected by the addition of sulphuric acid. At low potentials, the adsorption of methanol is found to be much faster than its oxidation. Hence, the oxidation of the methanol intermediate species is believed to be the rate-determining step under these conditions. This result is confirmed by apparent orders of reaction of about 0.5. At potentials in the range of 0.3–0.5 V, a mixed activation-adsorption control is supposed, whereas at potentials more positive than 0.5 V, the adsorption of methanol is probably the rds. This is supported by the apparent reaction orders and apparent activation energies of methanol oxidation.     

地下水热催化裂化降粘开采稠油新技术研究

针对辽河油田的3种稠油,筛选陋一种合适的水热裂解催化剂（过渡金属盐）,确定了水热裂解的最佳条件,在0．2％该催化剂顾在下,3种稠油样在240℃经水热裂解反应24h后,50℃粘度分别下降89．9％－77．7％,饱和烃和芳香烃含量大幅上升,胶质,沥青质含量下降,烃碳数分布移向低碳数方向,产生大量气体和少量固体,在辽河油田曙光采油3口蒸汽吞吐井进行的地下稠油催化剂水热裂解降粘开采现场试验获得成功,采出的稠油粘度大同度降低。