A kind of method for removing sulfate radical in lactic acid

Abstract

The invention discloses a method for removing sulfate radicals from lactic acid. The method comprises the following steps: sulfuric acid and calcium lactate undergo a metathesis reaction in the process of fermenting lactic acid by a calcium salt technology, the obtained solution is filtered to obtain a filtrate which is a lactic acid solution containing a small amount of sulfate radicals, barium hydroxide is added, a reaction is performed, and filtration is performed to separate barium sulfate in order to remove the sulfate radicals from the lactic acid. The method allows the removal rate of the sulfate radicals from the lactic acid to be about 90%, and the exchange load of anion resin is greatly reduced although the sulfate radical removal still needs anion resin exchange, so the servicecycle of an anion resin exchange column is prolonged by 1.9-2.1 times. The investment of the anion exchange column and anion resin is reduced by 2 / 3, the amount of liquid 30 wt% sodium hydroxide consumed by every ton of the finished lactic acid is reduced by 0.06 t, the amount of tap water consumed by every ton of the finished lactic acid is reduced by 2.6 t, the amount of pure water consumed by every ton of the finished lactic acid is reduced by 1.0 t, the yield of the fermented lactic acid increases by 2%, the amount of produced wastewater is reduced by 3.0 t, and the comprehensive benefit is increased by 220-240 yuan.

Description

technical field [0001] The invention belongs to the field of biochemical industry, and in particular relates to a method for removing sulfate radicals in lactic acid. Background technique [0002] Lactic acid, scientific name 2-hydroxypropionic acid, molecular formula CH 3 CHOHCOOH. It has a wide range of applications in food, medicine, cosmetics, textiles, agriculture and other industries. It is a renewable resource product and is irreplaceable in industrial applications. Among them, it is the most widely used as a food additive. At present, the production of domestic lactic acid is obtained by using glucose as raw material and fermenting it by calcium salt method. National standards limit the content of various inorganic salt impurities in finished lactic acid. Such as chloride ≤ 0.002%, sulfate ≤ 0.005%, iron salt ≤ 0.001%, etc. In order to make the finished lactic acid meet the specified standards, domestic manufacturing units all adopt the following basic productio...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for removing sulfate radicals in lactic acid, which can effectively remove the sulfate radical content in lactic acid, and solve the problem that the sulfate radical removal process load of anion exchange resin is relatively large and the use efficiency is low