A new thermodynamic model for gas hydrates was established by combining the modified Patel-Teja equation of state proposed for aqueous electrolyte systems and the simplified Holder -John multi -shell hydrate model. The new hydrate model is capable of predicting the hydrate formation/dissociation conditions of natural gas systems containing pure water/formation water (brine) and polar inhibitor without using activity coefficient model. Extensive test results indicate very encouraging results.

Diffusion coefficients were determined for benzene, toluene, ethylbenzene, p-xylene, o-xylene, 1, 3, 5-trimethylbenzene in n -heptane and in n-octane at 303.2K to 333.2K. A new predictive equation for liquid diffusion coefficients, based on Eyring’s absolute rate theory, was proposed. The active energy of diffusion was determined from the active energy of viscosity. It had the advantage of being based entirely on theoretical considerations and involved no experimental curve-fitting parameters.

A generalized compartmental modelling method for the derivation of reduced-order models for multicomponent staged separation columns is presented. In contrast to the one proposed by Benallou, this method uses dynamic state relationships, rather than steady state ones, such that superfluous composition variables resulting from the compartmental representation of staged separation columns may be eliminated. The accuracy of transient responses of the resulting model is, therefore, substantially improved. Furthermore, the phenomena of initial inverse responses, usually encountered in the development of reduced-order methods, has also been deleted completely. Simulations of a deethanizer have been conducted to evaluate this modelling method. Results indicate high efficiency and robustness in minimizing the dimensionality and computation time of the staged separation column model.

This criterion is based on the occurrence of an extremum of hot spot parameters with respect to any of the input parameters of the reactor. The critical operation trajectory, the critical isoconcentration curve and the supercritical operation trajectory are defined. Applying the relationship between the hot spot of the critical operation trajectory and the inflection point of the supercritical, an approximate expression of the critical inlet conditions is derived. The computed results show that the influence of the cooling medium on the parametric sensitivity region is related to the heat capacity ratio α. And the greater α is, the more sensitive the reaction systems would be.

In this work, Temperature-Programmed Reduction Processes of iron oxide and 12 other kinds of promoted iron oxides were investigated. It is suggested that the reduction activation energy can be expressed as a normal distribution. The distribution parameters were obtained by kinetic data fitting, which depends on the chemical and geometric characteristics of both the iron oxide and the promoter.

The dynamic behavior of gas stripping during ethanol fermentation (GSEF) in a CSTR for a combined product-substrate inhibition case has been investigated in terms of bifurcation and regional stability theory. The region of optimal operating steady states and the effect of initial concentration on the attraction region have been established. The analytical results can be used to predict and promote the GSEF system moving towards an optimal operating steady state.

The hydrodynamic and mass transfer characteristics of a downflow liquid jet loop reactor (D-JLR) were studied experimentally with water/air and CMC (carboxymethyl cellulose) solution/air systems. The effects of the geometry, the operating parameters and the physical properties of the liquid phase on gas hold-up and mass transfer coefficient were measuered. Compared with other types of gas-liquid reactor, D-JLR shows higher mass transfer coefficient and lower energy dissipation rate, the optimum diameter ratio was found to be about 0.42-0.6. A model for gas hold-up in D-JLR with Newtonian and non-Newtonian fluids has been developed on the basis of the equation of motion and the concept of average mixing length. The prediction of gas hold-up with the model agreed with the experimental results of this work.

Thin layer polycrystal oxides (amorphous and micro-crystalline) TiO₂(Fe₂O₃, SnO₂ and ln₂O₃ · Sn) are prepared by the organometallic chemical vapor deposition (MO-CVD) technique at 300-410℃ . Their structures, surface states and photoelectrochemical properties are described by X-ray diffraction (XRD), electron microscopy and three electrode methods. The experiments indicate that these thin layer oxides are suitable for formly transparent conductive coating to serve as photoelectrodes and photocatalysts for splitting of water