Steam produces different results in different reactors
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This post was last edited by zdl1966 on 2017-10-21 at 20:32. In the plasticizer production process, steam stripping is used in the alcohol removal stage; generally, back-acidification does not occur, with either only a slight increase in the acid value (acidity) or no significant increase at all. In the esterification reactor, if steam leaks from the coil, the acid value of the material inside the reactor cannot be reduced. When steam enters the material as well, different results occur – what is the mechanism behind this?
Why isn’t anyone sharing their opinions?
Steam stripping is used in the dealcoholization section. And inside the esterification reactor. The processes for these two steps need to be explained in detail; without understanding them, it’s impossible to participate
The esterification reactor is where phthalic anhydride reacts with excess isooctanol in the presence of butyl titanate as a catalyst. The dealcoholization tank is used to remove excess isooctanol through vacuum and stripping distillation.
Heating of the esterification reactor: steam in the inner coil, heat transfer oil in the inner coil, heat transfer oil in the outer coil. Steam leakage from the inner coil causes the end-point acid value (acidity) to not decrease, meaning the reaction cannot reach its completion.
During esterification, steam from the coil leaks into the material; the catalyst will hydrolyze, the pressure in the reactor increases, and the water produced by the reaction cannot escape, so the acid value certainly will not decrease. Stirring extraction is carried out under negative pressure, where the alcohol and steam form an azeotrope that is removed under vacuum; however, if the steam contains a high amount of water, acid reflux occurs – hydrolysis of the ester takes place, resulting in an increase in both the acid value and the alcohol content.