Optimized methionine preparation method based on carbon dioxide acidification method

Abstract

The invention relates to the field of methionine production, in particular to an optimized methionine preparation method based on a carbon dioxide acidification method. Compared with the prior art, the optimized methionine preparation method based on the carbon dioxide acidification method is more environment-friendly, economical and safe, the single yield is increased by extracting methionine in crystallization mother liquor, the single hydrolysis hydantoin amount in the follow-up circulation is increased by extracting alkaline potassium, formic acid and oil phase impurities are enriched and then extracted respectively, the hydrolysis circulation can be carried out for more times, impurities in the saponification liquid in the DL-methionine production process are effectively removed, and a large amount of impurities cannot be accumulated in the continuous methionine production process to affect the quality of methionine.

Description

technical field [0001] The invention relates to the field of methionine production, in particular to an optimized preparation method of methionine based on a carbon dioxide acidification method. Background technique [0002] D, L-methionine, as an amino acid feed additive in feed, is an animal growth promoter, used for protein synthesis, and can improve feed conversion rate, animal growth rate and poultry egg production rate. It can promote the growth of poultry and livestock, increase the amount of lean meat, and shorten the feeding cycle. Animal feed added with methionine can help animals grow rapidly in a short period of time, saving about 40% of feed. [0003] At present, the production methods of D,L-methionine mainly include chemical synthesis, biological fermentation, and enzyme catalysis, among which chemical synthesis is the most common. The known production process of methionine is to synthesize 5-(β-methylthioethyl)hydantoin from 3-methylthiopropionaldehyde, hydr...

AI Technical Summary

Problems solved by technology

Within the acceptable time and energy consumption of industrial production, electrodialysis cannot achieve this goal well; methionine will enter the anolyte due to osmotic pressure or potential difference, and the anolyte still needs further treatment; moreover, the crystallization mother liquor is enriched with impurities, May clog the membrane, eventually leading to poor electrodialysis efficiency or even breakdown

[0008] CN401693082A points out that methionine will produce impurities such as dimethyl disulfide, allylamine, and 3-methylthiopropylamine during heating, but does not mention the heating time, frequency and temperature

But there are following defects: the chromatographic separation technology needs to introduce a large amount of water additionally, so that the concentration of methionine solution becomes low; the investment of chromatographic separation is large, and the separation efficiency is low. The impurity produced by thermal decomposition) is the key to deal with; moreover, the separation effect of chromatography on bicarbonate and methionine is worth considering

But there are also the following defects: first, the solubility of methionine is limited, so it must be diluted with water, and the separated methionine solution needs to be concentrated and crystallized or crystallized at low temperature; second, the mixed solution contains many impurities, which have an impact on the electron utilization efficiency of the bipolar membrane and affect The life of the membrane itself is also affected; third, the use of bipolar membranes to produce low-concentration alkali still needs to be concentrated and used; fourth, the carbon dioxide produced is a neutral molecule, resulting in increased solution resistance and low electrodialysis efficiency, which is used in the main process Large equipment investment and high operating costs

[0017] (4) After the treatment of the methionine crystallization mother liquor, a part of the crystallization mother liquor still needs to be discarded, and the beneficial substances cannot be recovered;

[0018] (5) For the waste of part of the crystallization mother liquor, use beneficial resources to treat it as low-value substances, and the cost will increase twice

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