What are the issues that affect the quality of methanol products during the production process? ?
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There are many factors during the production process that can affect or cause refined methanol to fail quality standards. I would like to ask what these main factors are ? What are the minor aspects? ? It would be great if relevant information could be provided; thank you very much for everyone’s help!
1. Insufficient amount of extraction water, resulting in an excessive content of high-molecular-weight alkane components. 2. Improper temperature control in the pre-column top condenser. 3. Backflow control of the main tower, etc
Factors causing excessive moisture content in pure methanol product: ① Low reflux ratio, leading to the upward movement of heavier components; ② Leaks in the condenser at the top of the distillation tower; ③ Damage to the internal components of the distillation tower, resulting in reduced separation efficiency; ④ Abnormally high temperature at the bottom of the tower. Measures to take: ① Increase the reflux ratio and maintain proper temperature levels; ② Stop the operation to fix the leaks; ③ Increase the reflux ratio and shut down the tower periodically for maintenance; ④ Adjust the temperature at the bottom of the tower to normal levels
Factors contributing to the unsatisfactory water solubility of pure methanol: ① Low amount of water added for extraction in the pre-tower; ② Low vent temperature in the pre-tower’s TIC2101 unit; ③ Low reflux rate of the product stream, resulting in the upward movement of heavier components. Measures to take: ① Increase the amount of water used for extraction; ② Raise the vent temperature; ③ Increase the reflux rate
The oxidation value of the pure methanol product is not up to standard, and there are excessive reducing impurities in the product: ① Improper treatment in the pre-treatment tower results in light components entering the product; ② A low reflux ratio in the pressure or atmospheric pressure tower leads to heavy components entering the product; ③ The amount of isobutyl oil extracted from the stripping tower is insufficient. Measures to take: ① Control all process parameters in the pre-treatment tower properly; ② Increase the reflux ratio and maintain an appropriate temperature at the top of the tower; ③ Increase the amount of isobutyl oil extracted
The increase in the content of low-boiling components in pure methanol is due to the excessively low temperature at the bottom of the pre-tower; it is necessary to raise this temperature appropriately (by increasing the steam flow to the reboiler)
1. A low temperature in the pre-tower reactor leads to incomplete separation of low-boiling-point components. 2. Improper control of the reflux ratio and bottom temperature in the distillation column, as well as faults in the top condenser, can all result in a decrease in product purity
All of this relates to distillation; let me talk about synthesis instead. During synthesis at high temperatures, the product contains mostly higher alcohols and hydrocarbons. When synthesis is carried out at low temperatures, the product consists mainly of paraffins along with various by-products, and the methanol content is only around 80%. The normal low-temperature methanol synthesis method can achieve a methanol content of 85%, but in practice it might be 5% lower than that.