Method for recovering glycerin in production of pentanediol
A recovery method, pentylene glycol technology, applied in 2 fields, can solve the problems of long time consumption, environmental pollution, insufficient recycling of glycerin, etc., and achieve the effect of reducing production costs and preventing environmental pollution
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0029] Add 86g KBH to the 2000ml reaction bottle 4 , 660mL H 2 O. 160mL of methanol, stirring and cooling down to 0°C, dropwise adding a mixture of 240g of 2,4-pentanedione and 160g of methanol at a temperature below 20°C, and reacting at room temperature for 2 hours after the addition is complete; distill out the methanol under reduced pressure and water, and then 1000 g of glycerin was added; fractional distillation obtained 234 g of the product 2,4-pentanediol with a content of 98.3% and a yield of 92.1%. Add H to the remaining raffinate 2 O 1000ml and after stirring and mixing, add 150g of 98% concentrated sulfuric acid to make the pH of the reaction solution 4.0, and stir and react at 50°C for 2 hours, then cool down to 0-5°C, crystallize out, filter, and concentrate the filtrate to remove water. Recover glycerin 850g.
Embodiment 2
[0031] Glycerol 847g is recovered in the same manner as in Example 1, the only difference is that the material used in Example 2 is: the combination of 850g of glycerol recovered in Example 1 and fresh glycerin 150g, adding 30% concentrated hydrochloric acid to make the pH of the reaction solution: 4.0. Among them, 95.3 g of 2,4-pentanediol was obtained with a content of 99.87%.
Embodiment 3
[0033] Glycerin 835g was recovered in the same manner as in Example 1, except that the material used in Example 3 was a combination of 847g of glycerol recovered in Example 2 and 153g of fresh glycerin, and acetic acid was added to make the pH of the reaction solution 4.0. Among them, 93.0 g of 2,4-pentanediol was obtained, with a content of 100%.
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 