Reasons for the high pressure difference at the inlet and outlet of the desulfurization and purification bed before the methanol synthesis tower

The catalyst is no longer effective; it’s possible that the space velocity is too high, which has caused the catalyst to break down

I guess you added too much process gas along with water; the substances in the purification tank lost their strength after absorbing water, which caused them to compress and clump together.

Do you add the desulfurization tank in front of the synthesis tower or in front of the synthesis compressor? Generally, it is the catalyst absorbing water and getting crushed, or impurities entering earlier causing blockages, which leads to an increase in pressure difference!

How does the desulfurization tank placed in front of the synthesis tower remove sulfur? What is the principle?

I know there are two processes for the desulfurization tank before the synthesis tower; in the purification tank, from top to bottom, there are a hydrolyzer, activated carbon, and a desulfurization agent. Another approach is to install a spray device in front of the purification tank, using boiler water to spray onto the process gas in order to convert organic sulfur into inorganic sulfur. The relevant reactions are: COS + H2O → H2S + CO2, CS2 + 2H2O → H2S + CO2. The desulfurizing agent used in the purification tank is zinc oxide; the reaction is H2S + ZnO → ZnS + H2O. Installing a purification tank before synthesis serves mainly for thorough desulfurization, which is what is referred to as dry desulfurization (while low-temperature methanol washing belongs to wet desulfurization). This is because the copper-based catalysts used in the synthesis tower are extremely sensitive to high sulfur levels, as such levels can poison the catalysts and reduce or eliminate their activity.