Why is the wastewater at the bottom of the methanol-water separation tower acidic? What is the reason for this? Some expert who knows this could please explain it to me?
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Why is the wastewater at the bottom of the methanol-water separation tower acidic? What is the reason for this? Is methanol an acid or a base?
The bottom of the tower is almost entirely water, containing only 0.05% methanol; since methanol is neutral, this wastewater should also be neutral
Are you referring to the low-temperature methanol washing process? Acidic gases dissolve in methanol, giving it an acidic nature; generally, soda ash is added at this stage to adjust the pH value.
During the methanol synthesis process, formic acid is produced, which results in a certain level of acidity; therefore, an appropriate amount of alkali must be added before the material enters the distillation tower
Acidic substances in the feed gas, such as HCN, dissolve in water, causing the wastewater to become acidic
It is mainly the HCN in the crude syngas that causes this issue; generally, sodium hydroxide is added in the wastewater tower
The water coming from the exhaust gas scrubber contains CO2, so it is acidic.