Questions about distillation?
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Pine acetate oil decomposed during vacuum distillation and purification. What is the cause of the decomposition? How can I prevent decomposition? Thank you in advance, friends!
It should contain a certain amount of water. The distillation process is high temperature, and high temperature is also conducive to hydrolysis.
When the temperature at the top of the tower is 100 degrees Celsius, the initial components are distilled out, and the distillate does not have a strong sour smell. Ours is sour when the transitional fraction comes out, and the more the transitional fraction is distilled, the more the ester is decomposed, and it cannot reach the product output section. The temperature at the top of the tower is over 100 degrees, and there is a small amount of water. It should probably come out. ； We also suspected that there was water. We later filtered the water with salt and distilled it, but it still decomposed in the same way. This post was last written by x_Edited by yuan on 2009-4-18 21:43 ]
I don’t understand your product. I made an ester before and it was similar to yours. The purity just couldn’t be improved. I got it right after strictly removing the water. You’d better measure the moisture in the crude product first and then take a look. Or you could try increasing the vacuum to lower the boiling point.
It is necessary to understand the properties of the medium in detail and control the temperature.
We have now unloaded the tower, and if we continue trial production like this, the losses will be too serious. We have considered all the situations mentioned above. During the trial production, the materials were washed to neutrality, water was removed, and the vacuum degree was increased, but the decomposition was still the same. Now we will focus on these situations and use small tests to troubleshoot them bit by bit to find the reasons, hoping to solve them quickly. Thank you friends for your enthusiastic replies.
First of all, you need to carefully analyze the composition of your raw materials. If there is moisture or hydroxyl-containing materials in the raw materials, the ester will undergo hydrolysis reaction or transesterification reaction to generate the corresponding acid under acidic or alkaline conditions. In addition, if the material is easy to decompose at high temperatures, in order to obtain a high-purity material, the vacuum must be increased to lower the temperature. Our factory also has a 200°C material, but the material will decompose above 130°C. We also use controlled vacuum to lower the temperature. The purity is above 99.9%, and there is no decomposition at all.
I also encountered this problem during vacuum distillation, but what I did was refined urea. I hope experts can give me some advice.