The rate of ionic mass transfer at the limiting current density was measured in two-dimensional flows both laminar and turbulent, through a channel between a pair of ion-exchange membranes. The results obtained were independent of the properties of the membranes, because the mass transfer rate at the limiting current density was mainly controlled by the transport process through the boundary layers in the desalting cell. (9) JOURNAL OF CHEMICAL ENGINEERING OF JAPAN

No abstract

No abstract

The high performance catalysts of hydrophobic carrier with fully dispersed platinum were used to measure the isotope separation performance of hydrogen by the chemical exchange method. The continuous injection of oxygen on the order of 103 ppmwas effective in regenerating catalyst activity and in maintaining high performance for a long time.The separation performance in a trickle bed column should be evaluated by using two parameters, Kg and A,. These two parameters were unified to the overall transfer coefficient Kfg9 which may be sufficient in the estimation of overall performance or the design of a separation plant by the chemical exchange method. Whenone wants to increase the transfer rate in a chemical exchangecolumn, the improvementof Kxrather than Kgmay be more effective in increasing the overall transfer rate (its coefficient is expressed by Kfg in this paper).

The moles of CO2absorbed into an amine-nonaqueoussolvent mixture were measuredby using the stirred-cell method. The test solutions were the mixtures of amine such as butylamine, terf-butylamine, dibutylamine, diethylamine and dipropylamine, and solvents such as octane, triethylamine and methanol. The equilibria of the reactions between CO2and amine in nonaqueous solvent were studied by examining the pressure dependency of the absorption of CO2at lower temperatures, and could be described by the following reactions:where R is the alkyl group. The equilibrium constants, K19K2 and K3, were estimated simultaneously by the method of least squares with respect to the pressure dependency of the absorption of CO2. The equih'bria of the reactions in a nonpolar solvent were mainly described by Eqs. (1) and (2). Those in a polar solvent were described by Eqs. (1) and (3). The proposed reactions, Eqs. (1) to (3), were supported by enthalpies estimated from the Arrhenius plot of the equilibrium constant.