How to dry with methanol?
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Dear friends, what can I use for drying with methanol? Are calcium chloride, calcium oxide, and silica gel good?
1. How much moisture does it depend on? 2. Can it be used directly after drying? Or re-distill it and use it again? for example: Potassium carbonate can be used for drying, but it will bring alkalinity to methanol and needs to be re-distilled before use. The calcium chloride mentioned by the poster is not acceptable.
1. Under slight boiling conditions, use a small amount of iodine to initiate the reaction between magnesium and methanol to generate magnesium methoxide, then add a larger amount of methanol, reflux, and use the generated magnesium methoxide to react with water to generate magnesium hydroxide to remove the moisture in the alcohol. 2. Use sodium to remove water, specific process: According to the water content (trace amount), add a certain amount of sodium to the alcohol. After refluxing for 1 hour, add a certain amount of dimethyl phthalate (can be 1 with sodium).: 1), continue to reflux for 30 minutes, and then distill at room temperature. 3. Dry with anhydrous sodium sulfate or magnesium sulfate overnight and then re-evaporate. 4. If the amount is large, distillation can be considered.
1) Distillation, can reach below 300ppm； 2) Add magnesium and reflux to remove water, which can be reduced to less than 100ppm.
It has less moisture, but it also contains a small amount of ammonia!
3A molecular sieve is mainly used for drying unsaturated hydrocarbons such as petroleum cracked gas, ethylene, butadiene and acetylene.； Drying of polar liquids such as methanol and ethanol ； Refrigerant drying ； Deep drying of kerosene and aviation engine fuels ； Drying of ammonia cracked nitrogen-hydrogen mixture. It is a desiccant for industrial use in chemical, pharmaceutical, insulating glass and other industries.
1. Distillation and rectification can be used. 2. Can be used dry. 3. Chemical reactions can be used
1. Distillation 2. Using molecular sieves works well (laboratory usage)
This post was last edited by astrodog on 2009-8-26 11:38 In terms of production, a certain amount of caustic soda or sodium methoxide (28-30% wt) can be added to the distillation tower, and the effect is very good. Methanol recovery in chemical plants basically uses this method to remove water from the 1# huangchune
Distillation and drying are not very suitable, and they are easy to azeotropically evaporate!