The ethanol content in the methanol distillation product is high

What is the ethanol content in pure methanol after distillation?

Increase the reflux in each column, as this may affect the yield

The analysis shows that the level in the phenol tank is around 0.12

The ethanol content in the crude alcohol is around 0.2, while it’s about 0.12 in the refined alcohol tank. What is the unit of measurement? Is it a % figure? With the increase in the reflux flow rate in the pressurized tower and the atmospheric pressure tower, the extraction of fusel oils should increase as well.

1. The CO2 content in the raw gas used for methanol synthesis is also an important parameter; if the CO2 level is too low, the synthesis reaction dominated by CO will produce ethanol. This is because CO2 inhibits the reaction of ethanol. At the same time, if the methanol content in the syngas is high, side reactions of methanol occur; when the residence time is too long, more by-products are generated (especially ethanol and dimethyl ether), which ultimately affects the quality of the product. 2. Lower temperatures and pressures during methanol synthesis are more favorable for ethanol production, but they cannot be too low; otherwise, higher alcohols will be formed. 3. The temperature of the non-condensable gases in the pre-distillation tower affects the ethanol content in methanol. 4. Extracting water is added to the pre-distillation tower to remove ethanol azeotropes. In the pressurized column, the reflux ratio can be increased appropriately to control the ethanol content in methanol, while in the atmospheric pressure column, the recovery rate of the product stream can be increased

The ethanol content in the rectifier tank is indeed high; increasing the flow rate of water used for pre-column extraction, raising the reflux ratios in both the pressurized column and the atmospheric column, and increasing the output from the atmospheric column can have some effect. The key is still to control the issue at its source by analyzing the reasons starting from the synthesis process

There is a problem with the distillation process; it’s not clear whether it involves two, three, or four columns for distillation. Even in the case of two-column distillation, this shouldn’t be the result.

The carbon monoxide content in the gas entering the tower is high; when it exceeds 18%, the ethanol content in crude methanol is also high.

I have seen personally that the ethanol content in crude methanol is 2.5%, while it is 5% in the crude methanol storage tanks.

In that case you’re describing a situation where the catalyst is at the end of its life... when there are the most by-products