Solid-liquid-vapor dioxide system

Davis, J.A., N. Rodewald, and F. Kurata. 1962. "Solid-Liquid-Vapor Phase Behavior of the Methane-Carbon Dioxide System", AlChE )., 8 537-539. 

Figure 2. Experimental and predicted solid-liquid-vapor locus for the methane-carbon dioxide system (O), Davis et al. (13) (A), Donnelly ir Katz (14) ( ), Sobocinski 6- Kurata (15) (-), P-R prediction.

Figure 3. Liquid composition at the solid-liquid-vapor condition in the methane-ethane-carbon dioxide ternary system ( ), —84.9°F (A), -90°F (M), —100°F ( ), -I29.9°F ( ), -I<50°F.

B Carbon dioxide is liquid at 60 atm and 25° C. When it is released into a room at 1 atm and 25° C, as the pressure lowers, the system reaches the liquid-vapor boundary, at which pressure the liquid is changed to vapor. The vaporization absorbs sufficient heat to cool the C02 to below its sublimation temperature at 1 atm. As a result, fine particles of solid C02 snow are produced. 

The hydrate and phenol clathrate equilibrium data of the water-carbon dioxide, phenol-carbon dioxide, and water-phenol-carbon dioxide systems are presented in Table 1 and depicted in Figure 2. In order to establish the validity of the experimental apparatus and procedure the hydrate dissociation pressures of carbon dioxide measured in this work were compared with the data available in the literature (Deaton and Frost [7], Adisasmito et al. [8]) and found that both were in good agreement. For the phenol-carbon dioxide clathrate equilibrium results, as seen in Figure 2, the dramatic increase of the dissociation pressures in the vicinity of 319.0 K was observed. It was also found in the previous study (Kang et al. [9]) that the experimental phenol-rich liquid-phenol clathrate-vapor (Lp-C-V) equilibrium line of the binary phenol-carbon dioxide system could be well extended to the phenol clathrate-solid phenol-vapor (C-Sp-V) equilibrium line (Nikitin and Kovalskaya [10]). It is thus interesting to note that a quadruple point at which four individual phases of phenol-rich liquid, phenol clathrate, solid... 

The mechanism of a sublimation process can be described with reference to the pressure-temperature phase diagram in Figure 8.28. The significance of the P-T diagram applied to one-component systems has already been discussed in section 4.2. The phase diagram is divided into three regions, solid, liquid and vapour, by the sublimation, vaporization and fusion curves. These three curves intersect at the triple point T. The position of the triple point in the diagram is of the utmost importance if it occurs at a pressure above atmospheric, the solid caimot melt under normal atmospheric conditions, and true sublimation, i.e. solid vapour, is easy to achieve. The triple point for carbon dioxide, for... 

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