The solubility of NH_3 in water in multicomponent systems under high pressure is of extreme importance to the new integrated ammonia and urea process. This paper proposes a new method for calculating the vaporliquid equilibria for aqueous ammonia solutions under high pressure. Based on the experimental data of the binary system of NH_3-H_2O in the high concentration range, a model has been established for the activity coefficients of NH_3 and H_2O to describe the non-ideality of the liquid phase; and the modified SIRK equation of state for polar compounds has been used to describe the non-ideality of the vapor phase under high pressure. The reliability of this model has been examined in the light of the experimental data of the solubility of NH_3 in H_2O under high pressure in the systems of NH_3-H_2O-N_2, NH_3-H_2O-N_2-H_2-Ar-CH_4 and NH_2-H_2O-N_2-H_2, the last being from Guerreri et al. Both the accuracy of calculation and the concentration range for applicability of this model have been found to surpass those of Guerrerl’s model.

A simple, easy-to-use approximate equation, in the form of normal probability distribution function, was derived and proposed for breakthrough curves of fixed bed reactors and adsorbers. The equation predicts breakthrough curves and evolution in time of concentration and temperature distribution in fixed bed with accuracy higher than or comparable to the best of the other equations previously proposed.

Two equations of (γ/χ)χ=0 ——a modified Kikic-Renon equation and a Valentin-Guiochon equation——have been studied. Values of γ_1~∞and (dlnγ_1/dχ_1)χ=0 by these two equations for 29 binary systems have been calculated from GLC data, the parameters in some models of excess Gibbs free energy evaluated and the vapor-liquid equilibrium date predicted. The results are satisfactory.

Three methods to determine UNIFAC parameters by chromatography have been compared. The method of multiple activity coefficients at irlfinited dilution has been found inferior to the other two methods, According to an analysis on the sensitivities of UNIFAC parameters to γ~∞and (dγ/dχ)χ=0, it has been discovered that the effect of γ~∞is greater than that of (dγ/dχ)χ=0. Estimates of parameters and their ranges of values above, an appropriate confidence level are discussed.

The kinetics of extraction of cobalt with P5709 was studied in a Lewis cell. In the extraction system the aqueous phase was the solution of CoSO_4 (8.8×10~(-4)—3.4×10~(-2)M) and Na_2SO_4 (0.63M.) at pH 5.5; the organic phase was 15% (v/v) P5709 in kerosene (saturated with hydrogen).In order to determine the control regime of extraction of cobalt, the stirring speed, the interracial area between the two phases and the operating temperature were varied in the experiments. Experimental results showed that the extraction process of cobalt was predominantly governed by the diffusion process, and the overall mass transfer coefficients were found to be as follows:_((a)): (2-5)×10~(-3)cm/s, _((o)): (0.3-1)×10~(-3)cm/s.The results of the experiments and calculations indicated that K did not remain constant during the extraction process, Reasons for the variations in K were discussed.

The maximum-profit problem in the operation of a batch distillation column separating a binary mixture is studied. From the objective function made in this paper, such problem can be transformed under special condition, into either maximum-distillate or minimum-time problem. Reflux ratio is chosen as control variable. Digital method is worked out by using optimal control theory to find the condition of optimal operation. In deriving present mathematic model, the liquid hold-up in plates and in condenser as well as the plate efficiency are taken into account. The proposed optimal operation is compared theoretically with the conventional constant reflux ratio and constant overhead composition policies and the results show that the proposed optimal operation can lead to/nuch higher profits. To demonstrate the practical usefulness of the proposed optimal policy, experimental work is carried out in a 4 sieve trays 0.17M diameter batch distillation column with ethanolwater system. Agreement is found between the experimental data and the computed results from present model.

A double hot-wire method is adopted to separate the mixed signal of temperature fluctuation and velocity fluctuation appearing in high temperature turbulences. The relationships among the various coefficients in the sensitivity equation for measuring turbulent fluctuations with constant temperature hot wire anemometer are deduced. Once these equations are being related to the temperature fluctuation sensitivity equation of a constant current hot wire anemometer, the temperature fluctuation signal may be taken out from the mixed signal, then the turbulent velocity fluctuation signal and other main turbulent parameters may be obtained.

The relation between the gravimetric liquid concentration (χ_(10)) and equilibrium one (χ_1) is developed for the system within an ebulliometer or a still operating steadily. From the relation, the necessary and sufficient condition for χ_(10)→χ_1, and a new equation for calculating limiting activity coefficient (γ~∞) are deduced. This equation proves more accurate than that proposed by previous researchers. The leaning ebulliometer, a new apparatus, is designed to measure bubble points and γ~∞without composition analysis, its operating line (T, P, χ_(10)) proves a good approximation to the bubble-point line (T, P, χ_1): |(χ_(10)-χ_1)/χ)|<0.005|K_1-1|, where K_1=y_1/χ_1 is the K-value.

An exergy balance equation which relates to heat and mass transfer on distillation stages was derived from the theory of non-equilibrium thermodynamics. This equation was used to analyze an ethylene distillation column, and the result checked satisfactorily with that of equilibrium thermodynamic exergy analysis.In a multiphase discontinuous system, each phase may be considered as a subsystem, and all subsystems are separated by interfaces. With appropriate hypotheses, the equation of exergy loss relating to energy and mass transfer through interfaces may be expressed as follows:D=T_o[J_q·Δ(1/T)-sum from k to n J_k·Δ(μ_k/T)] Thus, profound insight into distillation process could be gained to provide ideas for further improvement of the distillation scheme.

In this paper, the principles of mass and heat transfer for a non-isothermal gas absorption with chemical reaction have been described. The examples of carbon monoxide complexing with aluminum cuprous tetrachloride solution and carbon dioxide absorbed by monoethanolamine aqueous solution in packed column have been simulated and computed with a mathematical model which considered of both mass and heat transfer, gas and liquid resistance. The fundamental differential equations of the process are treated with forth order Runge-Kutta method. Through simulating and computing, the temperature profiles and concentration profiles of both gas and liquid phase along the packed height have been visualized. The results are reasonably accurate and conform with pilot plant experimental data.

A series of Methine Type Disperse Dyes of Benzthiophen-one derivatives for polyester fiber was devised and prepared. The adsorption spectra of these disperse dyes in solution were measured. The relation between the molecular structures of these dyes and their adsorption spectra was studied and discussed.

Based on absolute-rate theory, a new equation has been derived to correlate the binary liquid diffusion coefficient with concentration:D_(AB)=C_VC_η(D_(BA)~0)φ_A(D_(AB)~0)φ_Bβwhere C_V=(V_A~(φ_A)V_B~(φ_B)/V)~(1/3), C_η=(η_A~(φ_A)η_B~(φ_B)/η). It has been applied to 16 systems with 176 experimental points. The grand average percent deviation in comparison with those obtained by using three other equations is as followsThe results of calculation show that the present equation proposed has higher generaliity and better applicability.