Why is methanol unqualified? (Urgent)
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Our plant uses three-column distillation for methanol purification; the methanol produced in the pressurized column is of satisfactory quality, but why is the moisture content too high in the purified methanol obtained from the atmospheric pressure column? Many reasons were analyzed, such as internal leakage in the condenser (which has been fixed), problems inside the atmospheric pressure tower; however, nothing unusual was found when the manholes were opened. Let’s discuss this.
Please describe the current specific operational conditions of the atmospheric tower
Try to reduce the load and increase the backflow to see
We’ve tried increasing the reflux rate – isn’t the atmospheric pressure tower now turned on? Try to analyze what problems exist in the atmospheric pressure tower that are causing the moisture level to be unsatisfactory Thank you for your attention
Didn’t there just be a problem with the conversion process at your factory? How is it that there are problems with distillation again so soon?
Our factory uses two sets, costing 151,800 each
The reason lies in synthesis and distillation. The H/C imbalance during synthesis leads to an increase in moisture content of the crude methanol impurities. Temperature. The pressure is not at the required level, resulting in an excessive production of alkane compounds. In this way, during distillation, issues such as overpressure, overheating, or an excessively low reflux ratio that lead to substandard product quality can be easily detected and corrected promptly. The trace amounts of impurities were not detected, resulting in the product’s water solubility and oxidizing capacity failing to meet the required standards. . Furthermore, improper handling in the pre-distillation tower caused organic impurities to enter the middle section of the main tower, rendering the extraction using fusel oil ineffective. This part should be extracted. When the reflux ratio is too high, the light components move downward, resulting in substandard product.
Has the contents in the return tank been analyzed? Have you ruled out the possibility that there is a problem with the produced water cooler? Your problem should be solvable!
Does your plant have a liquid seal tank before venting the gas from the atmospheric pressure tower top? Also, is the pressure at the tower top negative? If both of these conditions are present, it may be the negative pressure that causes backflow of water in the liquid-sealing tank, resulting in unacceptable levels of moisture in the methanol. Also, is there a problem with the water cooler?
The detachment of internal components in the tower should lead to an excessive water content. However, by increasing the recirculation, it should also be possible to prevent the water level from exceeding the limit. Please tell me about your operating conditions. Has the internal leakage in your heat exchanger been completely fixed? Check more often, okay?