Discussion on the Taga alkali issue

This is our first alkali addition method; as for which one is better, no tests have been conducted. That’s how the design institute planned it from the start.

It is better to add it before the crude methanol preheater, to prevent corrosion of the preheater and the pipeline fittings.

Adding it directly at the lower part of the tower prevents the acidic substances in crude methanol from causing corrosion to the tower components. It is also possible to add it before the crude methanol preheater, but this would result in waste and the effect would not be significant

Can those upstairs explain how it’s wasted and why the effect isn’t noticeable? I think adding it before the crude methanol preheater would yield better results due to the uniform mixing effect, and it would also be more suitable for extractive distillation.

I also believe it is better to add it before the preheater; firstly, to prevent corrosion of the preheater and the pipelines along its path, and secondly, to facilitate better pH regulation. . . .

In terms of current processes, there are two-tower and three-tower distillation methods, as well as four-tower systems. Whether it is single-tower distillation or the addition of alkali, it is usually done directly in the pre-distillation tower; in some cases, two pipelines are used for this purpose. Regardless of the method used, it still works effectively, and there are no issues related to corrosion. This is just my personal opinion for reference only.

There are different opinions regarding the position of the pre-taga base. 1. Adding it to the feed pipeline is beneficial, as it facilitates thorough mixing of methanol and the alkaline solution ； 2. It is better to add it in the middle and lower part of the pre-heater; there are two reasons for this: a) Adding it to the feed pipeline causes alkaline corrosion of the internal components of the tower pre-heater as well as the pipelines ； b. The alkali added to the feed pipeline reacts with certain organic impurities to form salts, which decompose again at the high temperatures inside the main tower, releasing these impurities and resulting in excessive levels of light components in the methanol product, or excessive levels of organic acids. I suggest adding it directly to the tower; waiting at least until the light-component impurities have been removed first can save some effort :)

All under heaven converge yet take different paths; they share a common goal yet have myriad thoughts. It doesn’t matter where you add it; there’s no need to strive excessively for a better effect! There’s no need for that

It is better to add it to the pipeline leading to the crude methanol reactor, as this allows for uniform mixing； If added at the bottom of the pre-tower, it cannot neutralize all of the acidic gases in crude methanol, and this will still cause corrosion of the tower internals.

Our company adds crude methanol before the crude methanol preheater