May I ask everyone: are there any control parameters for methanol-depleted fluid after thermal regeneration?
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May I ask everyone: Are there any control parameters for lean methanol after thermal regeneration? Such as: the levels of hydrogen sulfide, ammonia, and hydrocyanic acid, as well as the turbidity of the recycled methanol!
Yes, the total sulfur level is below 100 ppm; of course, the lower the better. Our values are usually in the range of a few dozen ppm. The ammonia content is below 500 ppm. There is no specific threshold for hydrogen cyanide – it generally cannot be detected through analysis. It’s best to conduct comparative tests regarding the turbidity of methanol. I’m not sure if what I said is correct; please feel free to offer your criticism and suggestions!
There are indicators for control. The methanol content in the water at the bottom of the tower is not more than 2%, and the ammonia content is not more than 50 mg/l. There are no specific requirements regarding hydrocyanic acid.
May I ask at what concentration of sulfur in methanol can it be detected? Is it possible to tell that it’s that low under normal circumstances? The water content in methanol at our factory is <1%
The total sulfur content in the thermoregeneratively purified methanol is 100 ppm; how can we ensure that the total sulfur content in the purified gas at the top of the absorption tower is less than 0.1 ppm? 100 ppm is too high!
The Henry coefficient can be used to calculate the concentration of a certain component in a gas under constant conditions.
The total sulfur content in the thermoregeneratively treated methanol-poor stream is 100 ppm, while the purified gas at the top of the absorption tower is required to have a sulfur content of less than 0.1 ppm. One measurement is taken for the liquid phase and another for the gas phase; moreover, the temperature at the top of the absorption tower is relatively low, so the requirements should be met. In my previous factory, the target for water content was generally less than 0.5%. If the water content in methanol is too high, its absorption capacity drops significantly; I’ve forgotten the exact figures, but it seems that when the water content increases from 0.5% to 1%, the absorption capacity decreases by about one-tenth. The typical design limit for hydrocyanic acid is below 5 ppm; otherwise, an alkaline neutralization unit must be installed in the separation tower. If the concentration exceeds 20 ppm, a pre-washing tower is required for treatment.
Reply to 8# lzp-ap: What level do you keep the total sulfur content in lean methanol at in your factory?
The total sulfur content in the thermoregeneratively treated methanol-poor stream is 10 ppm, while the purified gas at the top of the absorption tower is required to have a sulfur content of less than 0.1 ppm; carbon dioxide is present in both the liquid and gas phases