Thermal Conductivity of Porous Catalyst Pellets.

Abstract

Even though these data include a threefold change in $teaming rate, there is no steaming rate parameter. This is a condition of equilibrium. Since carbon dioxide is formed in the hydrolysis of Na2C03, equilibrium considerations indicate that increasing the pressure on the system would hinder the formation of NaOH. However. studies have shown that increasing the temperature increases the conversion. Since the system must be maintained in the liquid phase, high pressure is a necessary condition. Presumably, there may exist a temperature and pressure condition beyond which there can be no improvement in conversion. Such conditions actually do exist as is shown by the data in Figure 5 . These data are for initially 1.0 and 2.57 NazCO3 solutions and a steaming rate of 1000 ml./hr. and show that in most cases increases in temperature with the associated increases in pressure result in higher total conversion. However, for the lCC Na2CO; solutions, while an increase in temperature from 410 to 550 F. and the resulting higher pressure improves the conversion considerably, further increase to 594 F. and 1000 p s.1.g. results in no further advantage for the ICc N a 2 C 0 solutions. Figure 5 also shows the effect of the initial concentration of carbonate on conversion a t 593 F. and 1400 p.s.i.g. This is simply another means of looking a t the data in Figure 3. Increasing the concentration from 15 to 2 . 5 7 equivalent Na2C03 results in less than a twofold decrease in conversion. Conversion is not proportional to initial carbonate concentration because the NaOH concentration is different a t different initial concentrations. As equivalent NaXO? concentration increases, conversion decreases in an exponential manner.