Methanol section: One question per day. What are the reasons for the unsatisfactory water solubility of pure methanol? How to handle it? 2016.04.12
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Methanol section: One question per day. What are the reasons for the unsatisfactory water solubility of high-purity methanol? How to handle it? 2016.04.12 What are the reasons for the product’s poor water solubility? How to handle it? Answer: Water solubility is also known as turbidity. When pure methanol contains organic impurities that are insoluble or poorly soluble in water, upon adding water, these impurities precipitate as gel-like particles, resulting in turbidity. 1) Water extraction distillation in the pre-column is the best method for removing these impurities; the amount of water added generally should not exceed 20% of the feed volume. Adding more water certainly helps to remove organic impurities, but it reduces the production capacity of the pre-column, so it must be done in an appropriate manner. 2) The control of the pre-tower top temperature also has a significant impact on the water solubility of the product; it is generally maintained at 30–40°C. As the catalyst in the synthesis tower is used for an extended period, the top temperature of the tower also needs to be adjusted accordingly. 3) Properly control the operation of the main tower; based on the results of sampling and analysis, it is necessary to continue removing fusel oils, thereby preventing them from ending up in the product and affecting its clarity.
Answer: 1. The light components at the top of the tower are relatively high; therefore, the initial distillate should be taken off appropriately from the pre-tower condenser； 2. The reflux ratio is low; increase the reflux volume ； 3. High production temperature; reduce the production temperature ； 4. Less middle distillate is extracted, increasing the extraction of fusel oils.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.
Reason: ① High content of higher alcohols or paraffins in crude methanol； ②In a pressurized or atmospheric distillation column, if the reflux ratio is set too low, the heavier components move upward within the column and exit along with the product from the top of the column ； ③The amount of heating steam supplied to the reboiler of the pressurized distillation tower is too high, resulting in fogging or entrainment in the pressurized distillation tower or the atmospheric distillation tower ； ④Incomplete removal of alkanes in the pre-distillation tower ； ⑤The amount of fusel oil obtained from the side stream of the atmospheric distillation column is low. Solutions: ① Control the operating temperature of the synthesis tower properly. ②Increase the reflux ratio. ③Reduce the reboiler steam volume. ④Control the operating temperatures of the pre-tower condenser and the expansion gas cooler. ⑤Strictly control the extraction of fusel oils.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.
What are the reasons for the product’s unsatisfactory water solubility? How to handle it? Answer: The reasons are as follows: 1 ； Improper pretreatment led to some alkanes that form azeotropes with methanol being carried over into the product, affecting its water solubility. Treatment measure: Adjust the amount of extraction water appropriately based on the quality of crude methanol, and remove alkane impurities through extraction. Control the pre-column condensation temperature to enable light components to be discharged from the system smoothly 2; improper treatment in the main column results in heavy components entering the product, affecting its water solubility. Treatment measures: Strictly control the operating conditions inside the tower; by adjusting the heat load and reflux rate, maintain an appropriate temperature of the sensitive plate to prevent the upward movement of heavier components. How to handle it: ① Control the operating temperature of the synthesis tower properly. ②Increase the reflux ratio. ③Reduce the reboiler steam volume. ④Control the operating temperatures of the pre-tower condenser and the expansion gas cooler. ⑤Strictly control the extraction of fusel oils.
Water solubility is also known as turbidity. The product quality requirements for pure methanol specify that it can be mixed with water in any proportion without becoming cloudy. If the pure methanol product contains organic impurities that are insoluble or poorly soluble in water, upon addition of water, these impurities precipitate as gel-like particles, resulting in turbidity. The process of water extraction distillation is an important method for separating and removing these impurities. However, the amount of water added generally does not exceed 20% of the crude methanol feed volume. Increasing the amount of water added will certainly help in removing organic impurities, but it will reduce the production capacity of the pre-distillation tower, increase energy consumption in terms of heat and kinetic energy, and also pose certain difficulties in controlling other process conditions of the tower.