sshep
Chemical
- Feb 3, 2003
- 761
One of our processes involves spray drying of an alumina slurry (Al2O3) in water. It has been proposed to saturate the slurry with CO2 to reduce the viscosity. A series of test runs was performed and indeed the viscosity of a 10.88wt% Al2O3 slurry was reduced in viscosity from 1170cP to 10cP. Conditions of 10psig and 40C were sufficient to saturate the slurry in a reasonable time, and the viscosity of 10cP was obtained upon draining the reactor contents.
When I inquired into the mechanism for how this reduced the viscosity, the experimenter and plant engineer did not seem to know anything beyond the fact that it worked. This idea came from a site outside our company, and apparently there was anecdotal evidence that formic acid was also used at some site- from an engineering standpoint I am thankful that such an alternative was rejected.
There is little need to know why this works in order to design equipment to meet the conditions desired, however, I am extremely curious as to how such a significant viscosity reduction can occur. Any insight is appreciated- i.e. is this an effect of the gas in liquid, a surface effect on the solid, an electrochemical effect, etc?
When I inquired into the mechanism for how this reduced the viscosity, the experimenter and plant engineer did not seem to know anything beyond the fact that it worked. This idea came from a site outside our company, and apparently there was anecdotal evidence that formic acid was also used at some site- from an engineering standpoint I am thankful that such an alternative was rejected.
There is little need to know why this works in order to design equipment to meet the conditions desired, however, I am extremely curious as to how such a significant viscosity reduction can occur. Any insight is appreciated- i.e. is this an effect of the gas in liquid, a surface effect on the solid, an electrochemical effect, etc?
