裂解炉炉管内壁的蒸汽-空气烧焦操作是一个反应温度和浓度沿空司变化的动态过程。此过程可以用一组非线性双曲型偏微分方程描述。为了便于求解及积分的收敛，采用迎风差分格式计算。在烧焦过程模拟中，根据裂解炉炉管高温成焦的特点，采用了沿炉管不变的烧焦反应动力学参数和反应热，模拟计算20h内裂解炉炉管不同时刻的焦层厚度、气固相温度、氧气和水蒸气分压沿炉管的变化，计算结果与工业测量结果相符合，为开发先进的裂解炉在线烧焦技术提供了更加可靠的基础。

Hydrogenation of benzene to cyclohexane was conducted in an adiabatic fixed-bed reactor under a phase transitional condition. In which process, a mixture of benzene and cyclohexane was fed into the reactor at the bottom under the liquid condition, however, the liquid phase disappeared and turned into gas phase at the reactor outlet through vaporization. It follows from this novel idea that the problems associated with reaction heat removal and low catalyst efficiency of the liquid-filled catalyst could be solved simultaneously with emptying of the liquid from the catalyst. However, the benzene concentration in the mixture should not exceed 14% if simple phase transition is employed, since the reaction heat is seven times the liquid vaporization heat. To optimize this primitive operation, a side stream quenching operation was proposed and attempted experimentally, and it was found that the side stream quenching with double injection points could be an acceptable operating strategy.

The paper presents theoretical analysis and experimental results of dilute SO2 oxidation over activated carbon coupled with partial liquid phase evaporation. A dynamic model has been first developed for this combination of reaction with vaporization of liquid in the packed bed. The model reveals the interactions among the exothermic reaction, endothermic vaporization and partial internal wetting of activated carbon pellets. Reliability of the model is verified by the experiments. Secondly, the effects of the two different operation modes and the states of the wetted catalysts on SO2 oxidation are compared. The results have demonstrated that this method has an increased SO2 removal efficiency and a higher sulfuric acid concentration.

Based on theoretical analysis and experimental results, a new attempt has been made to characterize the dynamics of the fluid flowing under conditions of pulsing flow in a trickle-bed reactor (TBR). Two kinds of correlation are proposed for the dynamic liquid holdup under pulsing flow, which can predict the dynamic liquid holdup for a given packing type and given operating conditions.

The effect of partial internal wetting of catalyst pellets on apparent reaction kinetics at elevated temperatures and pressures is investigated experimentally and by modeling for benzene hydrogenation. A new method that combines adsorption and chemical reaction is introduced to study the kinetics influenced by capillary condensation ofreagents at steady-state conditions. It is shown that the extent ofliquid filling in the pellet interior has a critical effect on the global kinetics, and the current state of the catalyst depends on the history. Under certain conditions two steady states ofthe effectiveness factor exist. Moreover, either a decrease in temperature or increase in total pressure can increase the effectiveness factor. The model exhibits good agreement with experimental results.

A numerical method is developed for the initial guesses of heat transfer and kinetic parameters in a wall-cooled fixed-bed reactor accompanied with side-stream analysis in both the axial and radial directions. The differential method is found to be the only way to decouple the heat and mass transport equations, and thus enables the estimation of the heat transfer and kinetic parameters by separate steps. Compared with simultaneous estimation by the integral methods, the differential method possesses a unique advantage arising from the separate estimation of the parameters, because the pararnetric correlation can be reduced since the parameter number in the separate estimating process is less than that in the integral process. Numerical analysis and experimental studies reveal that the most appropriate method for presenting the axial derivative is by the Pade approximation, and that for the radial derivatives is by the orthogonal collocation with one point.

Reactor performance of a trickle-bed reactor (TBR) concurrently under gas-liquid downward flow and that of a flooded-bed reactor (FBR) concurrently under gas-liquid upward flow was experimentally investigated under an elevated temperature and pressure (150℃ and 1.0MPa) for benzene ydrogenation. It was shown that the different hydrodynamics of TBR and FBR could result in quite different reactor behaviors, as typically observed from the temperature profiles along the reactor. The reason for this is because the present reaction is controlled by the supply of hydrogen in the liquid phase, thus external partial wetting of the catalyst pellets could increase the reaction rate. Moreover, the pronounced vapor pressure of benzene under the prescribed temperature would make the reaction remarkable over the non-wetted catalysts. Operation in the FBR is superior to the TBR, considering the operational safety. However, TBR should be considered when the catalyst partial wetting is negligible under liquid flow rates higher than 0.58 cm/s as shown in this work.

The hydrodynamic properties in a trickle bed reactor under forced pulsing flow are studied. It has been demonstrated by the experiments that the axial and radial liquid distributions become more uniform than those of the natural pulsing fkow regime. The thickness of the liquid film over the particles is sharply thinned by the induced liquid flow. Eects of the operating conditions on liquid holdup are studied in detail. The frequency of the forced pulsing flow is found to be the most significant parameter affecting the liquid holdup.

The Ergun equation based on the effective spherical diameter is universally valid for various shapes of granular packings. It, however, was derived from the assumption of infinite tube-to-particle diameter ratio without considering the wall effect. Although some improvements were made by Mehta and Hawley (1969) to correct this, the application of the Ergun equation is still restricted to cylindrical columns with a packing porosity of less than 0.5. To modify, the Ergun equation to noncylindrical flow space with or with-out a wall, it was substituted into the empty tube pressure drop equation by introducing an effective tube diameter so that the pressure drop can be predicted just from the free flow space and the wetted area involved. This treatment offers the basis for a new method in velocity distribution prediction.