阅读说明：本技术 一种由氨基葡萄糖废酸液制备醋酸酯和氯化钙的方法 (Method for preparing acetate and calcium chloride from glucosamine waste acid solution ) 是由 乔旭 崔咪芬 徐希化 陈献 刘清 费兆阳 张竹修 汤吉海 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种由氨基葡萄糖废酸液制备醋酸酯和氯化钙的方法,包括：氨基葡萄糖废酸液通过蒸馏得到馏出液和馏余液,实现废酸液与高沸物的分离；馏出液与脂肪醇进行无催化酯化反应得到醋酸酯,经过反应精馏回收浓盐酸；馏余液依次经氧化钙中和处理、催化裂解反应,得到TOC含量低于10mg/kg的氯化钙产品。本发明不仅实现了盐酸的资源化再利用,盐酸的回收率达到99％以上,而且使废醋酸得到高值化利用,产出醋酸酯产品,醋酸的回收率达到83％以上,使氨糖盐酸盐的废酸液变废为宝,提高了企业的经济效益和市场竞争力。(The invention discloses a method for preparing acetate and calcium chloride from glucosamine waste acid solution, which comprises the following steps: distilling the glucosamine waste acid solution to obtain distillate and raffinate, so as to realize the separation of the waste acid solution and high-boiling-point substances; carrying out non-catalytic esterification reaction on the distillate and fatty alcohol to obtain acetic ester, and recovering concentrated hydrochloric acid through reaction rectification; and (3) sequentially carrying out calcium oxide neutralization treatment and catalytic cracking reaction on the raffinate to obtain a calcium chloride product with the TOC content lower than 10 mg/kg. The invention not only realizes the resource recycling of the hydrochloric acid, the recovery rate of the hydrochloric acid reaches more than 99 percent, but also enables the waste acetic acid to be utilized with high value, produces acetic ester products, and the recovery rate of the acetic acid reaches more than 83 percent, changes the waste acid liquid of the glucosamine hydrochloride into valuable, and improves the economic benefit and market competitiveness of enterprises.)

1. A method for preparing acetate and calcium chloride from glucosamine waste acid solution is characterized by comprising the following steps: distilling the glucosamine waste acid solution to obtain distillate and raffinate, so as to realize the separation of the waste acid solution and high-boiling-point substances; carrying out non-catalytic esterification reaction on the distillate and fatty alcohol to obtain acetic ester, and recovering concentrated hydrochloric acid through reaction rectification; and (4) sequentially carrying out calcium oxide neutralization treatment and catalytic cracking reaction on the raffinate to obtain a calcium chloride product.

2. The method for preparing acetate and calcium chloride from glucosamine pickle liquor as claimed in claim 1, which comprises the following steps:

step (1), distillation: distilling the glucosamine waste acid solution to obtain distillate and raffinate, wherein the distillate accounts for 50-70% of the total mass of the waste acid solution, and the distillate is acidic wastewater with the acetic acid content of 5-10% and the hydrochloric acid content of 10-20%;

step (2), non-catalytic esterification: carrying out non-catalytic esterification reaction on the distillate obtained in the step (1) and fatty alcohol, controlling the esterification conversion rate of acetic acid to be more than 99.5% by adopting a reactive distillation method, obtaining a mixture of fatty alcohol, acetic ester and water at the tower top through reactive distillation, and obtaining concentrated hydrochloric acid at the tower bottom;

step (3), catalytic cracking: neutralizing the pH value of the raffinate obtained in the step (1) with calcium oxide to 8-10, carrying out catalytic cracking reaction on the neutralized material under the action of a catalyst, and separating the catalyst and calcium chloride after the reaction is finished to obtain a calcium chloride product; and (3) allowing water vapor and organic vapor generated by the catalytic cracking reaction to enter an oxygen-critical cracking device for oxygen-critical cracking reaction.

3. The method for preparing acetic ester and calcium chloride from glucosamine pickle liquor as claimed in claim 1 or 2, wherein the pickle liquor contains 3-10% acetic acid, 5-15% hydrochloric acid, and 10-15% water-soluble organic impurities.

4. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution according to claim 1 or 2, wherein the molar ratio of the fatty alcohol to the acetic acid in the distillate is 5/1-10/1; the aliphatic alcohol is methanol.

5. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution according to claim 1 or 2, wherein the temperature of the esterification reaction is 55-65 ℃; the concentration of the concentrated hydrochloric acid is 20-30%, and the content of acetic acid in the concentrated hydrochloric acid is lower than 0.01%.

6. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution as claimed in claim 1 or 2, wherein the acetic ester product and the fatty alcohol are obtained by rectifying and separating the mixture of fatty alcohol, acetic ester and water, and the rectified wastewater enters an oxygen cracking device for oxygen cracking reaction.

7. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution according to claim 1 or 2, wherein a catalyst for catalytic cracking reaction takes Y molecular sieve, HZSM, MCM41 and alumina as carriers and metal oxide as active ingredients, and the loading capacity of the metal oxide is 10-25%; the metal oxide is 1-3 oxides of copper oxide, iron oxide, nickel oxide, manganese oxide, cobalt oxide, chromium oxide, cerium oxide, zirconium oxide and lanthanum oxide.

8. The method for preparing acetic ester and calcium chloride from glucosamine acid pickle according to claim 1 or 2, wherein the amount of catalyst used in the catalytic cracking reaction is 0.1-10% of the mass of the raffinate; the temperature of the catalytic cracking reaction is 300-500 ℃.

9. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution according to claim 1 or 2, wherein water is added into the materials obtained by catalytic cracking reaction to obtain a mixture of calcium chloride aqueous solution and catalyst, solid-liquid separation is performed to obtain catalyst and calcium chloride aqueous solution, the calcium chloride aqueous solution is evaporated and dried to obtain calcium chloride product, and TOC in the calcium chloride product is lower than 10 mg/kg.

10. The method for preparing acetic ester and calcium chloride from glucosamine waste acid solution according to claim 2 or 6, wherein the temperature of the temporary oxygen cracking reaction is 250-450 ℃, and the total gas phase space velocity is 2000-20000 h^-1The gas phase VOC at the gas outlet of the near-oxygen cracking device is lower than 15mg/m³And the liquid phase COD at the liquid outlet is lower than 40 mg/L.

Technical Field

The invention belongs to the field of treatment of glucosamine waste acid liquid, and relates to a method for preparing acetate and calcium chloride from the glucosamine waste acid liquid.

Background

The glucosamine hydrochloride has various physiological effects of antibiosis, anti-inflammation, liver protection, tumor resistance, oxidation resistance and the like, is an important basic raw material for synthesizing a plurality of medicaments, and is widely applied to the fields of chemical industry, food, medicine and the like. When glucosamine (called glucosamine for short) hydrochloride is prepared from chitin, 0.8-1 ton of glucosamine waste acid liquid is produced when 1 ton of chitin is consumed, the waste acid liquid is dark black in color and viscous, contains a large amount of waste hydrochloric acid and acetic acid, needs a large amount of alkali for neutralization treatment, is high in treatment cost, and seriously affects the production cost of the glucosamine.

Patent CN101993257A discloses a method for preparing a high-activity compound organic fertilizer by using waste acid generated in the ammonia sugar production process as a raw material, which comprises the steps of concentrating the waste acid liquor to recover hydrochloric acid, neutralizing the slag and the slurry with alkaline liquor containing potassium hydroxide, adding chitosan into the neutralized solution, stirring for dissolving, adding mixed enzyme for enzymolysis, and sterilizing to obtain the solid fertilizer. Patent CN1467227A utilizes the waste acid solution in the production of ammonia sugar to extract chitin, and the secondary waste liquid generated is used for producing amino acid microelement chelate. Patent CN105753914A neutralizes the waste acid in the production of glucosamine hydrochloride with ammonia water, and adds monoammonium phosphate, potassium nitrate and organic compounds of trace elements to obtain high-quality agricultural fertilizer. The above method has a possibility that organic contaminants which are not separated may contaminate the soil. In patent CN101993041A, dichloromethane is added to the waste acid in the production of glucosamine hydrochloride, acetic acid in the waste acid is extracted into a lower layer separation liquid, then dichloromethane is recovered from the lower layer separation liquid, hydrogen chloride gas is introduced into an upper layer separation liquid to prepare concentrated hydrochloric acid with the concentration of more than 31%, and the content of the acetic acid in the recovered hydrochloric acid is lower than 0.5%. In the method, the content of acetic acid in the recovered concentrated hydrochloric acid is too high, so that the possibility of product pollution is brought to the glucosamine production when the concentrated hydrochloric acid is repeatedly used.

Disclosure of Invention

The waste acid liquor generated in the glucosamine production process contains a large amount of hydrochloric acid solution, acetic acid, glucosamine hydrochloride and other high boiling point (the boiling point exceeds the boiling point of acetic acid), and the acetic acid and water are extremely difficult to separate and recycle due to the azeotropic phenomenon of the acetic acid and the water. The invention provides a method for preparing acetic ester and calcium chloride from waste acid liquor in a glucosamine production process, which realizes high-value utilization of acetic acid and simultaneously purifies the waste acid liquor.

The purpose of the invention is realized by the following technical scheme:

a method for preparing acetate and calcium chloride from glucosamine waste acid liquor comprises the following steps: distilling the glucosamine waste acid solution to obtain distillate and raffinate, so as to realize the separation of acetic acid, hydrochloric acid and high-boiling-point substances in the waste acid solution; carrying out non-catalytic esterification reaction on distillate and low-boiling-point fatty alcohol, recovering concentrated hydrochloric acid through reactive distillation, returning the concentrated hydrochloric acid to a glucosamine production working section, rectifying acetic ester obtained through the esterification reaction to obtain an acetic ester product and fatty alcohol, and treating obtained rectification wastewater through an oxygen cracking device to reach the standard and discharge; and (4) sequentially carrying out calcium oxide neutralization treatment and catalytic cracking reaction on the raffinate to obtain a calcium chloride product.

A method for preparing acetate and calcium chloride from glucosamine waste acid solution specifically comprises the following steps:

step (1), distillation: the glucosamine waste acid solution is distilled under normal pressure to obtain distillate and raffinate, the distillate accounts for 50-70% of the total mass of the waste acid solution, and the distillate is clear and transparent acidic wastewater with the acetic acid content of 5-10% and the hydrochloric acid content of 10-20%; the raffinate is a brownish black high-boiling residue;

step (2), non-catalytic esterification: carrying out non-catalytic esterification reaction on the distillate obtained in the step (1) and low-boiling-point fatty alcohol, controlling the esterification conversion rate of acetic acid to be more than 99.5% by adopting a reactive distillation method, obtaining a mixture of fatty alcohol, acetic ester and water at the tower top through reactive distillation, and obtaining concentrated hydrochloric acid at the tower bottom; rectifying and separating a mixture of fatty alcohol, acetic ester and water to obtain an acetic ester product and fatty alcohol, returning the fatty alcohol to an esterification reaction working section, and allowing rectification wastewater containing a small amount of alcohol and ester to enter an oxygen cracking device for oxygen cracking reaction so as to discharge the wastewater up to the standard;

step (3), catalytic cracking: neutralizing the pH value of the raffinate obtained in the step (1) with calcium oxide to 8-10, performing catalytic cracking reaction on the neutralized material under the action of a catalyst to convert organic matters in the raffinate into inorganic small molecular substances such as carbon dioxide, water, hydrogen chloride and the like, separating the catalyst and the calcium chloride after the reaction is finished to obtain a calcium chloride product, recycling the catalyst, and allowing water vapor and organic vapor generated by the catalytic cracking reaction to enter an oxygen cracking device for oxygen cracking reaction.

The waste acid liquid contains 3-10% of acetic acid, 5-15% of hydrochloric acid and 10-15% of water-soluble organic impurities, wherein the water-soluble organic impurities are hydrochlorides such as glucosamine hydrochloride.

The distillation temperature is 110-130 ℃.

The residual liquid is brownish black high-boiling residue and accounts for 50-30% of the total mass of the original waste acid liquid.

The non-catalytic esterification reaction means that acetic acid and fatty alcohol are subjected to acid-alcohol esterification reaction in the absence of any catalyst to obtain acetic ester, and the temperature of the esterification reaction is 60-80 ℃. The low boiling point aliphatic alcohol is methanol; the molar ratio of the fatty alcohol to acetic acid in the distillate is 5/1-10/1. The acetate is methyl acetate.

The concentration of the concentrated hydrochloric acid is 20-30%, the content of acetic acid in the concentrated hydrochloric acid is lower than 0.01%, and the concentrated hydrochloric acid can be directly returned to a glucosamine production section.

The catalyst for catalytic cracking takes Y molecular sieve, HZSM, MCM41 and alumina as carriers and metal oxide as active ingredients, and the loading capacity of the metal oxide is 10-25%; the metal oxide is 1-3 oxides of copper oxide, iron oxide, nickel oxide, manganese oxide, cobalt oxide, chromium oxide, cerium oxide, zirconium oxide and lanthanum oxide. The catalyst is prepared by a conventional impregnation method.

The dosage of the catalyst is 0.1-10% of the mass of the raffinate.

The temperature of the catalytic cracking reaction is 300-500 ℃.

Adding water into the material obtained by catalytic cracking reaction to obtain a mixture of a calcium chloride aqueous solution and a catalyst, carrying out solid-liquid separation to obtain the catalyst and the calcium chloride aqueous solution, recycling the catalyst, evaporating and drying the calcium chloride aqueous solution to obtain a calcium chloride product, wherein the TOC (total organic carbon) in the calcium chloride product is lower than 10mg/kg, and the calcium chloride product can be sold as a common byproduct.

The catalyst used for the temporary oxygen cracking reaction is the same as that used for the catalytic cracking reaction. The temperature of the near-oxygen cracking reaction is 250-450 ℃, the reaction pressure is normal pressure, and the total space velocity of the gas phase is 2000-20000 h^-1The gas phase VOC at the gas outlet of the near-oxygen cracking device is lower than 15mg/m³And the liquid phase COD at the liquid outlet is lower than 40 mg/L.

The invention has the beneficial effects that:

the invention controls the proportion of distillate, firstly, the liquid is evaporated as little as possible, the energy consumption is saved, secondly, only acetic acid and hydrochloric acid are required to be evaporated, the resource recycling is realized, and other materials are not required to be evaporated. And reaction rectification is adopted to control the esterification of acetic acid as much as possible, so that the problem of separation of acetic acid in a subsequent water phase is avoided. By adopting the treatment method, the resource recycling of the hydrochloric acid is realized, the recovery rate of the hydrochloric acid reaches more than 99 percent, the waste acetic acid is utilized in a high-value manner, an acetate product is produced, the recovery rate of the acetic acid reaches more than 83 percent, the waste acid liquid of the glucosamine hydrochloride is changed into valuable, and the economic benefit and the market competitiveness of enterprises are improved.

Drawings

FIG. 1 is a process flow diagram of a method for preparing acetate and calcium chloride from glucosamine pickle liquor according to the present invention.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.