In a previous investigation in 1963 Wang and Shen et al found that the well known flow equation for pulsed sieve plate column given by J.D.Thornton should be modified and written as Vd/x+Vc/(1-x)=Vo(1-x)n.n=2.2±0.2 was obtained for kerosene-water system in a standard sieve plate column of 1 inch in diameter. This paper is a continuation of the previous works. Four kinds of liq-liq system were used in this study. The parameters n and Vo, the sauter mean diameter of dispersed droplets (D3,2) are correlated in terms of physical properties of the systems and operation variables:These correlations are Flooding velocities calculated by equations obtained are close to experimental values with deviation within(+)15%

Experimental studies of emulsion and suspension polymerisation of styrene at 50℃ are reported. It is apparent that the classical model for Stages I and I of an emulsion polymerisation is not valid for the case of low emulsifier concentrations or for the case of high impeller speeds at low or intermediate emulsifier concentrations. A mathematical model for a batch emulsion polymerisation in an unbaffled reactor is proposed which overcomes this problem by taking into account the effect of the adsorption of the emulsifier onto themonomer droplet surfaces. The model is extended into Stage I by incorporation of the effect of the autoacceleration of the conversion rate through reduced radical translational mobility, i. e. the gel-effect. The model presented in this paper for Stage I of an emulsion polymerisation demands knowledge of the total surface area of the dispersed monomer droplets. An existing relationship between dispersed phase droplet diameter and impeller speed and impeller diameter has been incorporated into the model. The predictions of the particle size, particle number and reaction rate obtained via the current model are in good agreement with the experimental data for Stage I and subsequently for Stage I of the reaction. During Stage I of the emulsion polymerisation the increase in polymer particle viscosity reduces the translational mobility of the radicals with the result that the termination rate constant of radicals increases dramatically. The analogous behaviour in a suspension polymerisation of styrene has been investigated and the following relationship between termination rate constant and the level of monomer conversion has been developed. Kt=exp(A1 + A2Xp+A3Xp2+A4Xp3+A5Xp4) where A1=29.5873, A2=-7.4332, A3=45.8577, A4=-95.9184, A5=47.4095. When this relationship is incorporated into the model for emulsion polymerisation, it allows the determination of the average number of radicals per particle. It is apparent that during Stages I and I this value is close to 0.5 as suggested by the Smith and Ewart case II (instantaneous termination)model but for Stage III the average number of radicals per particle increases with increasing conversion. The predictions of the current model are in good agreement with experimental data of emulsion polymerisation of styrene at 50℃ over most of the conversion range.

This paper studies water soluble disperse dyes containing carboxy-methyl-sulfonyl group (-SO2CH2COOH). Monoazo dyes with the carboxy-methyl-sul-fonyl group in diazo component and the anthraquinone derivatives of the same group have been synthesized. The azo dye(I) was prepared as follows: The other azo dyes were similarly prepared. The anthraquinone dyes were prepared as follows- Ammonium salts of this type of dyes are water soluble. These dyes are suitable for pad dyeing or printing on polyester fiber and polyester/cotton blends in either weak acid, neutral or weak alkali medium without a dispersing agent. The solubilizing carboxyl group is believed to be decarboxylized at thermal fixation temperatures during dyeing. The formation of methyl sulfonyl group(-SO2CH3)from carboxy-methyl-sulfonyl group after fixing on the fiber was proved by thin-layer chromatography and infrared spectra. Their fastness properties are good and the fastness to sublimation is -excellent.

The kinetics of oxidative dehydrogenation of butene-2 to butadiene on the multiconponent molybdates catalyst, Mo12Bi1.5Fe3Co1Ni4.5Cr0.5K0.3/SiO2 (atomic ratio), has been investigated in a flow-recirculation glass reactor. It was found that the butene conversion was m-order with respect to butene and n-order with respect to oxygen, m and n depended on the reaction temperature and concentration, m increased and n decreased with the rise of reaction temperature, and m+n=1. According to the steady state Redox mechanism: 1 ) The reduction of catalyst by butene and the reoxidation of reduced catalyst by oxygen were in steady state; 2 ) Butadiene reversibly adsorbed on the fraction of sites of the oxidized catalyst inhibited the butene conversion, the rate equation, was derived. The activation energy of catalyst reduction step E1 was 4.53 kcal/g-mole, the activation energies of catalyst reoxidation E2 were 21 kcal/ g-mole (>400℃) and 60 kcal/g-mole (<400℃). The Arrhenius figure of k2 appeared a broken-line and the turning point was at about 400℃.Under the condition of insignificant inhibition of butadiene, i. e. small partial pressure of butadiene or higher temperature, the above equation could simplify as:

The cobalt catalyzed oxidation of cyclohexane in acetic acid solution to adipic acid by pure oxygen has been studied. Under the following conditions of investigation:reaction temperature 80-95℃;concentration of cyclohexane 1.08-2.97 mol/1;concentration of Co(OAc)2.4H2O 0.0301-0.0803 mol/l; acetic acid/cyclohexane 10-20(by weight) and oxygen pressure, 5-30 kg/cm2, it is shown that the kinetics of adipic acid formation can be expressed by the following equation where r-rate of formation of adipic acid [C6H12]-concentration of cyclohexane [Co]-concentration of cobaltic ion [Co#]- concentration of cobaltous ion [po2]-pressure of oxygen k-rate constant of reaction.The temperature dependance of the rate constant can be correlated with the Arrhenius equation The apparant activited energy △E is 32.74 kcal/g-mol. A tentative reaction mechanism is offered to explain the phenomena observed, in which the rate determining step is the formation of cation radical species through the interaction of Co and cyclohexane molecules with Co and Co serving as chain carriers.

In order to eliminate the effect of mass transfer the kinetics of o-xylene oxidation in liquid phase was studied in a stirring batch reactor. Experimentaldata indicate that the effect of mass transfer can be eliminted, when the stirring velocity is≥1200 rpm and the superficial velocity is≥1.5 cm/s at 130℃ under the experimental conditions. This paper recommends rate expression (suitable for conversion of o-xylene<50%)as kinetic model for scaling up gas-liquid reactors. The results of chemical reaction kinetics of o-xylene oxidation which involves both main and side reactions and contains seven components in total are presented. As with the bubbling reactor, the o-xylene oxidation reaction is composed of seversl consecutive and competitive 1-st order reactions.

A new equation for calculating the heat of vaporization was derived For alkanes, monoolefines, ethers (nonring) , nitrils, ketones (ring and nonring), organic acids and organic anhydrides, K2 = 4.358 For alkylbenzenes and polyphenyls(biphenyls, terphenyls) K2 = 4. 435 For cyclitols, alcohols(except diols, aromatic alcohols), K2 = 4.581 For all other compounds and gases, Where Tt - normal boiling point, K Tc - -critical temperature, K Pc - critical pressure, atm. This equation applies to nonpolar and polar liquids at their normal boiling points and gives average and maximum errors of 1.65% and 12. 2% respectively for 157 compounds.

The tube-grid jet is a novel, simple and efficient device for mass-transfer. fts construction is shown in Fig. 1. The main experimental equipment employed in this study consists of a tube-grid jet unit, an absorption section and a separation section. The diameter of the absorption section is 150mm. The ratio of height to diameter of the absorption section is 10.7, and thearea ratio of tube-grid slits to absorption section 0.113. The schematic diagram of the apparatus employed in this study is given in Figure 2. The fluid-dynamic experiments have been carried out with the air-water system and the mass-transfer experiments with the ammonia-air-water system. The conditions of the present work were- the gas velocity calculated over the whole cross-sectional area of the absorption section w=2-9m/s, the gas velocity at the slits of the tube-grid w0=17-76m/s, the liquid-gas ratio w=3-501/m3. Two flow patterns were observed in the fluid-dynamic experiments. The transition of the two flow patterns occurs at where m - liquid-gas ratio, 1/m3, Wo- gas velocity at the tube-grid slits, rn/s, u- viscosity of the gas, kg-s/m2, density of the gas, kg/m3, and de - equivalent diameter of the tube-grid slits, m.the pressure drop across the wet-drained tube-grid jet unit can be calculated from where La is the Lagrangian number Two operating regions for the different mass-transfer characteristics were also observed. Empiric regression equations for the number of overall gas transfer units NOG based on the tube-grid jet unit are N oo = 0. 027 W-W8 when zw<475 l/m2s, and when Mvw>475 l/m2s. It should be pointed out that the maximum deviation of all the experimental data from the above empiric correlations is ?0%. It is important to see that the pressure drop across the tube-grid unit is about 30% less than that across the cup- jet unit, and the gas mass-transfer coefficient per unit pressure drop Ky,/AP of the tube-grid jet unit is higher than that of the cup-jet unit. Besides, the construction of the tube-grid jet is simple and it is very easy to manufacture. Hence the tube-grid jet, in general, is superior to the cup- jet.

It is an important problem to select the most ideal model which characterizes a given process from several rival models. In this paper, an account of the various discrimination criteria for the screening rival models is recommended, such as posterior probability, F ratio test, homogeneity test and likelihood ratio test. Besides, their theoretical foundations and merits are discussed. Based on the above criteria, different viewpoints concerning the relevant parts in"a sequential procedure for optimal discrimination among rival rate models for the reaction of synthesis of ammonia on A catalysts" are also presented.