What impurities in methanol does the methanol purifier in the etherification unit specifically remove?
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May I ask what specific impurities in methanol are removed by the methanol purifier in the etherification unit? What is the principle of evolution?
It is to remove the trace amounts of alkaline substances present in methanol, mainly NH3 ions. The principle behind this is acid-base neutralization. . .
Should water be purified or not? Does water have an effect on the etherification catalyst?
Purifying alkaline substances is intended to prevent the deactivation of the large-pore, strong-acid cation resin catalyst in the reactor!
How can it purify water? It mainly purifies alkaline substances. The raw material must not contain water; if there is too much water, the resin will absorb it, and since water is immiscible with tetrahydrocarbon, this will lead to an increase in the pressure drop across the bed. . . Water must be removed by other methods.
Part of the methanol in the etherification reaction is recovered through washing after ether formation; therefore, it was initially thought that this was to remove water. Also, may I ask what the basic substance in methanol is? Ammonia? How can there be alkaline substances in methanol?
What’s installed in our methanol purifier is the catalyst from the etherification reactor; before entering the reactor, the methanol first passes through the purifier
During the production process, methanol inevitably contains some metal ions similar to those of iron. What is used in methanol purifiers are catalysts for the etherification reaction; through the contact between methanol and these catalysts, the metal ions are replaced by hydrogen ions present in the catalysts. In other words, the performance of part of the catalyst is sacrificed in order to achieve methanol purification.
The purification mainly targets the methanol that enters the reactive distillation column, and the catalyst used in this column is required to have a longer service life than that in the reactor. The catalyst at the upper part of the first section of the reactor acts as a purifier.
The designed service life of the catalyst inside the reactor is shorter than that in the catalytic distillation column; therefore, the purpose of designing the methanol purifier is to purify the catalyst that enters the catalytic distillation column.
One of the reasons for catalyst deactivation is that, in our case, such a problem doesn’t occur. After deactivation, the resin loses hydrogen atoms, which means it can no longer participate in reactions; as a result, the quality and yield of the product decrease, right?