Changes in stripping pressure and the acid value of the material
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Could someone explain the relationship between stripping pressure and the acid value of materials in ester production?
I only know the mechanism by which too low a stripping pressure leads to an increase in the acid value of the material; I am not aware whether too high a stripping pressure can also cause an increase in the acid value.
During the stripping process, due to the low stripping pressure, the impact force of the steam is weak, which prolongs the time taken for the steam to reach the liquid surface. This increases the contact time between the ester molecules and water. Under high temperature conditions (150–180 degrees), the ester molecules react with water molecules, resulting in hydrolysis (emulsification), which is the reverse reaction of esterification. One of the products of hydrolysis is monoester acid, thereby increasing the acid value. If there are trace amounts of alkali present in the material, it will further react with the alkali to form monoesterates. Both monoester acids and monoester salts reduce the resistivity of the material. But I’m not sure what will happen if the stripping pressure is too high. Fellow professionals, please share your opinions
Gentlemen, come and share your insights.
:(Your steam pressure is low; not only does the processing time increase, but the higher water content also constitutes a major cause of hydrolysis. An excessive level of water will likely lead to increased problems as well. When your steam pressure is high, the local temperature is certainly high as well, and the hydrolysis rate of lipids is directly proportional to temperature. Moreover, if you use a high processing temperature, the stability of the oils will decrease. As for exactly what level counts as excessive, it’s hard to say – it requires experimental testing. This is just my personal opinion; I’ve never worked with oils myself, only had them stored for a few days.)
What is the typical pressure control for air tanks?
It is generally controlled at 0.2–0.45 MPa, with adjustments made according to different periods, liquid levels, and vacuum degrees.