Diffusion Coefficient and Solubility of Isobutene and trans-2-Butene in Aqueous Sulfuric Acid Solutions

Abstract

The diffusion coefficient and the physical solubility of isobutene and trans-2-butene in aqueous sulfuric acid solutions cannot be determined experimentally due to the occurrence of fast chemical reactions. In the present contribution these physicochemical parameters are estimated. For the solubility an isobutaneisobutene analogy is applied for the range 0-100% H 2 SO 4 . A correlation technique, initially proposed by Rudakov et al., 11 was used for describing the experimental data at low acid concentrations and for estimation purposes for more concentrated solutions. Diffusion coefficients for inert gases in electrolyte solutions were measured using a modified diaphragm cell. It was found for CO 2 and N 2 O in KCl solutions that the diffusion coefficient is not a function of the ionic strength of the electrolyte solution and therefore not a function of the activity coefficient of the diffusing component. It appears that the correlation Dη 0.6 ) constant holds up to 80 mass % sulfuric acid, as is the case for several other aqueous electrolyte solutions. Diffusion coefficients for butenes in sulfuric acid solutions (up to 96 mass %) are estimated from CO 2 coefficients in these solutions.

Characterization of potassium glycinate for carbon dioxide absorption purposes

“…Many authors studied the dependence of the diffusion coefficient on the temperature and on the concentration of the absorbent solution and concluded that it can be related to the solution viscosity, , through a modified Stokes-Einstein equation (Brilman et al, 2001;Joosten and Danckwerts, 1972;Kumar et al, 2001;Versteeg and Van Swaaij, 1988).…”

Carbon dioxide absorption kinetics in potassium threonate

“…It is generally accepted that the diffusion coefficient of a diffusant in solution can be related to the solution viscosity, , through modified Stokes--Einstein equation (Brilman et al, 2001;Joosten and Danckwerts, 1972;Kumar et al, 2001;Versteeg and Van Swaaij, 1988):…”

“…= 0.8 can be considered to estimate the diffusion coefficient of N 2 O in the aqueous solutions of potassium threonate (Versteeg and Van Swaaij, 1988;Joosten and Danckwerts, 1972;Brilman et al, 2001) and = 0.6 to estimate the diffusion coefficient of the amino acid salt in solutions (Versteeg and Van Swaaij, 1988;Snijder et al, 1993). Gubbins et al (1966) found that the ratio of the diffusivity of a gas in an electrolyte solution to the diffusivity of the same gas in water does not vary significantly with the nature of the diffusant.…”

Diffusivities in Aqueous Solutions of the Potassium Salt of Amino Acids

“…Several investigators have correlated the diffusivity of an absorbed gas in an aqueous salt solution to the viscosity or the salt concentration. [19][20][21][22][23] Ratcliff & Holdcroft, 19 Brilman et al, 22 and Kumar et al 23 correlated the diffusivities to the viscosities by a modified Stokes-Einstein relation…”