Method of preparation of pentaerythritol and co-production of sodium oxalate

Abstract

The invention relates to a method for preparation of pentaerythritol and co-production of sodium oxalate. The method comprises the following steps: dissolving formaldehyde, acetaldehyde and sodium hydroxide, carrying out condensation reaction, adding an oxalic acid solution into a reaction liquid after heat preservation of the reaction, cooling, crystallizing, filtering to obtain a first filter material, washing the filtered first filter material, drying to obtain sodium oxalate, removing formaldehyde and methanol from filtered first mother liquor, concentrating, cooling, crystallizing, then centrifugally separating to obtain a second filter material, and washing and drying the second filter material to obtain the pentaerythritol; settling second mother liquor obtained by centrifugal separation, filtering, combining the filtered filter cake into the first mother liquor, adding an oxalic acid solution into the filtered filtrate to adjust the pH value, crystallizing, filtering to obtaina third filter material, and washing and drying the filtered third filter material to obtain the sodium oxalate. The yield of the pentaerythritol in the method provided by the invention is more than or equal to 90%, and the purity of the pentaerythritol in the product is greater than or equal to 95%, the ash content is less than or equal to 0.03%, and the chromaticity of the platinum-cobalt coloris less than or equal to 50; the yield of the sodium oxalate reaches more than 98%, and the purity of the sodium oxalate in the product is greater than 98.5%.

Description

technical field [0001] The invention relates to the technical field of chemical engineering, in particular to a preparation method of pentaerythritol co-production sodium oxalate. Background technique [0002] At present, the production routes of pentaerythritol at home and abroad basically use formic acid as the neutralizing liquid after the condensation reaction. The following problems exist in this kind of production process: [0003] 1. In the actual production process, 88% formic acid solution is generally used, which has strong acidity and requires high mechanical strength and corrosion strength of the reactor; [0004] 2. The condensation reaction in the pentaerythritol production process is an exothermic reaction, and the neutralization reaction of formic acid is also an exothermic reaction. A large amount of heat release causes formic acid in the formic acid solution to escape in the form of gas, which reduces the utilization rate of formic acid and easily causes e...

AI Technical Summary

Problems solved by technology

[0003] 1. In the actual production process, 88% formic acid solution is generally used, which has strong acidity and requires high mechanical strength and corrosion strength of the reactor;

[0004] 2. The condensation reaction in the pentaerythritol production process is an exothermic reaction, and the neutralization reaction of formic acid is also an exothermic reaction. A large amount of heat release causes formic acid in the formic acid solution to escape in the form of gas, which reduces the utilization rate of formic acid and easily causes environmental pollution;

[0005] 3. The traditional production of sodium formate requires a lot of heat energy for evaporation