The ethanol content in crude methanol is 2.5%, while it is 5% in the crude methanol storage tank. What is the reason for this?
Thread Content
I have personally seen an ethanol content of 2.5% in crude methanol, and 5% in the crude methanol storage tanks. The reasons for this phenomenon are complex. First, as for the 5% ethanol content in the crude methanol tank: since the ethanol content in crude methanol is 2.5%, the distillation system only extracts methanol from the pressurized column; the ethanol content in what is extracted from the atmospheric column exceeds 1000 ppm, forcing it to be returned to the crude methanol tank. Ethanol gradually accumulates in the crude methanol storage tank.
Solution: 1. The ethanol content in the crude methanol storage tank is 5%. 1) Starting with the structure of the atmospheric pressure tower, adjust the feed position of this tower from 19 trays to the lowest feed point, which is at 13 trays； 2) Enhance the extraction of fusel oils from the atmospheric pressure column, by extracting them from 15 or 17 tray levels. 3) Gradually extract pure methanol from the atmospheric pressure column. Effectively reduces the ethanol content in crude methanol storage tanks.