CN113755179A

CN113755179A - Method for preparing liquid soil conditioner by using amino acid waste liquid

Info

Publication number: CN113755179A
Application number: CN202111048344.6A
Authority: CN
Inventors: 刘元涛; 赵兰坤; 王小平; 孙钦波; 侍述志; 封慧戎; 张婷婷; 张传松
Original assignee: Hulunbeier Northeast Fufeng Biotechnologies Co ltd
Current assignee: Hulunbeier Northeast Fufeng Biotechnologies Co ltd
Priority date: 2021-09-08
Filing date: 2021-09-08
Publication date: 2021-12-07

Abstract

The invention belongs to the technical field of lysine production, and discloses a method for preparing a liquid soil conditioner by using amino acid waste liquid, which comprises the following steps: step 1) adding chitosan into glutamic acid fermentation liquor, then setting a high-speed disc separator for separation, and collecting clear liquid and mycoprotein precipitation; step 2) taking clear liquid separated by the high-speed disc separator, concentrating, adding sulfuric acid to adjust the pH value, cooling and standing; centrifuging to obtain glutamic acid crystals; adding sodium carbonate aqueous solution into the glutamic acid crystal for dissolving and neutralizing, evaporating and crystallizing, and centrifugally separating monosodium glutamate; step 3) evaporating the mycoprotein precipitation to a dryness with a substance content of 25% by weight, and granulating in a fluidized bed spray granulator to obtain protein granules; and 4) adding the waste liquid generated in the protein concentration process into the concentrated isoelectric residual waste liquid to prepare the liquid soil conditioner.

Description

Method for preparing liquid soil conditioner by using amino acid waste liquid

Technical Field

The invention relates to a method for recovering ammonium sulfate in lysine ion exchange waste liquid, and belongs to the technical field of lysine production.

Technical Field

Sodium glutamate is commonly called as monosodium glutamate, has the effects of increasing freshness and enhancing flavor as a food seasoning, is widely popular in the market along with the gradual improvement of the living standard of people, particularly rises in emerging markets such as Europe and America, ensures that the demand of sodium glutamate is kept up, and has good market prospect. At present, the method for industrially producing glutamic acid by various large enterprises is mainly a biological fermentation method, namely, a strain is cultivated by a microbial fermentation method to prepare fermentation liquor containing glutamic acid, then the glutamic acid is extracted from the fermentation liquor by an isoelectric ion exchange method, and sodium glutamate is regenerated after neutralization. The process has high energy consumption and pollution, is an important problem for limiting the development of the glutamic acid industry, and has been studied for many years at home and abroad for treatment.

A large amount of mycoprotein is generated in the fermentation production process of the glutamic acid, on one hand, the traditional process generally extracts the glutamic acid directly, and the extraction yield of the glutamic acid is low due to the influence of the mycoprotein; in addition, the addition of sulfuric acid in the isoelectric extraction process leads mycoprotein to be denatured, although the subsequent extraction is carried out by a flocculation and sedimentation plate-frame separation method, the nutritional value is greatly reduced, and the added value of the product is low; on the other hand, a large amount of high-concentration wastewater is generated in the technical process, the wastewater has the characteristics of high COD (chemical oxygen demand), high BOD (biochemical oxygen demand), high thallus content, high ammonia nitrogen content, high sulfate radical content and low pH value, and the prior art is difficult to treat. At present, a treatment mode of producing granular fertilizer by evaporating and concentrating waste liquid and then spraying and granulating is generally adopted, but the energy consumption is large, the process is complex, a large amount of burnt odor gas is generated in the spraying and granulating process, the treatment difficulty is large, and the problem is always the bottleneck problem of industrial production. Therefore, a plurality of enterprises introduce leading new technical equipment in industries such as plasma deodorization, ozone generator deodorization and the like. The method for removing the peculiar smell by adopting the terminal treatment has good effect, but has large investment and complex process, greatly increases the production cost, and is not widely accepted.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a method for preparing a liquid soil conditioner by using amino acid waste liquid.

The invention is realized by the following technical scheme:

a method for preparing a liquid soil conditioner by using amino acid waste liquid comprises the following steps:

step 1) adding chitosan into glutamic acid fermentation liquor, stirring at 500rpm for 30s, standing for 3min, then separating by a high-speed disc separator, and collecting clear liquid and mycoprotein precipitates;

step 2) taking clear liquid separated by the high-speed disc separator, concentrating by 2 times, adding sulfuric acid to adjust the pH value to 3.2 +/-0.2, gradually cooling to 10 ℃, and standing for 12 hours; centrifuging to obtain glutamic acid crystals; adding sodium carbonate aqueous solution into glutamic acid crystal for dissolving and neutralizing, controlling the neutralizing temperature at 62 ℃ and the pH value at 6.5, then evaporating and crystallizing, and centrifugally separating monosodium glutamate;

step 3) evaporating the mycoprotein precipitation to a dryness with a substance content of 25% by weight, and granulating in a fluidized bed spray granulator to obtain protein granules;

step 4) adding waste liquid generated in the protein concentration process into the concentrated isoelectric residual waste liquid, adjusting the Baume degree of the mixture to 20Be +/-2, and adding soluble phosphorus and potassium to enable the liquid soil conditioner to reach the organic matter content of more than or equal to 100 g/L; n is more than or equal to 50 g/L; p is more than or equal to 20 g/L; k is more than or equal to 10g/L and pH is as follows: 4.0-5.0; na is less than or equal to 30 g/L; the water insoluble substance is less than or equal to 50 g/L; the product is qualified.

Preferably, the first and second electrodes are formed of a metal,

the addition amount of the chitosan is 100g/m³。

Preferably, the first and second electrodes are formed of a metal,

the rotating speed of the high-speed disc separator is 5000r/min, and the feeding flow rate is 300-.

Preferably, the first and second electrodes are formed of a metal,

the sulfuric acid adjusted the pH to 3.2.

Preferably, the first and second electrodes are formed of a metal,

in the step 2), a sodium carbonate aqueous solution with the mass fraction of 10% is added in a weight ratio of five times.

The beneficial effects achieved by the invention mainly comprise but are not limited to the following aspects:

the invention starts from the source of fermentation liquor extraction, and firstly separates mycoprotein from glutamic acid fermentation liquor through a high-speed disc separator, on one hand, the extracted mycoprotein is evaporated, concentrated, sprayed and granulated to produce a granular fine glutamic acid residue new product, and the value of a byproduct is improved; on the other hand, the influence of protein on the subsequent glutamic acid extraction is avoided. The clear liquid without mycoprotein is concentrated and then continuously isoelectric to extract glutamic acid, so that the content of sulfuric acid is greatly reduced, the isoelectric conditions are strictly controlled, the extraction rate of the glutamic acid is obviously improved, the separated mycoprotein is used for producing a fine glutamic acid residue feed protein new product by a method of evaporation, concentration, spray granulation, the product is granular and is convenient to be used as a feed additive, the protein content is about 20 percent higher than that of common protein, the palatability is strong, and the product is widely popular in the market. The waste liquid produced in the extraction process and the waste liquid produced in the evaporation and concentration of the mycoprotein are mixed in a proper proportion and added with auxiliary materials such as phosphorus, potassium and the like to produce a new product of the liquid soil conditioner, and the liquid soil conditioner is acidic, is specially suitable for saline-alkali soil in northeast regions, and has a good effect. The invention changes the problems of energy consumption and flue gas treatment in the production of the granular soil conditioner by the traditional process of wastewater spraying granulation.

Drawings

FIG. 1: the tall fescue is used for carrying out a gradient safety test on the liquid soil conditioner.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the present invention will be described more clearly and completely below with reference to specific embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

1. High speed disc separation of fermentation broth

Exploring feasibility of disc separation fermentation liquor, taking 1000L of fermentation liquor, adding 100g of chitosan, stirring at 500rpm for 30s, standing for 3min, setting the rotating speed of a high-speed disc separator to be 5000r/min, detecting the content of dry protein in clear liquid under different feeding flows by changing the rotating speed of the feeding flows, and testing the optimal feeding flow under the rotating speed of 5000 r/min. See table 1 specifically:

TABLE 1

Comprehensive experiment analysis shows that the optimal feeding speed is 300-400L/h at the rotating speed of the high-speed disc separator of 5000r/min, and the speed has more protein dry matters, less time consumption and less energy consumption.

The removal rates of the cells with and without chitosan were 98.5% and 87.1%, respectively. The invention does not need to add a large amount of chitosan to form large floccules, only needs a small amount of chitosan, leads the thalli to form small floccules and is more suitable for the separation rate of a high-speed disc separator.

2. Continuous isoelectric concentration of glutamic acid

Glutamic acid is extracted by adopting a concentration continuous isoelectric method, and the influence of concentration on isoelectric extraction is explored. Respectively taking 1000L of clear liquid obtained after disc separation under the same conditions of fermentation liquor in the same tank, concentrating by different times, adding sulfuric acid to adjust the pH value to 3.2 +/-0.2, and measuring the acid consumption and the extraction rate. See table 2 specifically:

TABLE 2

Through test comparison, the higher the concentration multiple of the fermentation clear liquid after disc separation is, the lower the sulfuric acid consumption is, and when the concentration multiple is 2, the lower the sulfuric acid consumption is, and the extraction rate is highest.

3. Spray granulation of mycoprotein

The influence of the mycoprotein liquids with different dry matter contents entering the fluidized bed on granulation is explored by controlling the evaporation concentration of the mycoprotein, and the optimal concentration of the mycoprotein liquids entering the fluidized bed spray granulator is selected. The effect of the dry matter content on the fluidized bed spray granulation is shown in Table 3.

TABLE 3

Through experiments, mycoprotein with dry matter content of 25% is selected to enter a fluidized bed spray granulation system.

4. Preparation of liquid soil conditioner

Adding waste liquid generated in the protein concentration process into the concentrated isoelectric residual waste liquid, adjusting the baume degree of a mixture to 20Be +/-2, and adding soluble phosphorus and potassium to enable the liquid soil conditioner to reach that the organic matter is more than or equal to 100 g/L; n is more than or equal to 50 g/L; p is more than or equal to 20 g/L; k is more than or equal to 10g/L and pH is as follows: 4.0-5.0; na is less than or equal to 30 g/L; the water insoluble matter is less than or equal to 50g/L, the product is qualified, and the liquid soil conditioner is subjected to gradient safety test by adopting the herbaceous plant festuca arundinacea (10 g, 100g and 1000g are applied to each kg of soil, and each concentration is six basins).

As shown in figure 1, tall fescue fully emerged and grew well, demonstrating the feasibility of the liquid soil conditioner.

The process can obtain two new products, namely refined glutamic acid residue and a liquid soil conditioner, wherein the refined glutamic acid residue is granular and has the protein content of more than 85 percent. The organic matter of the liquid soil conditioner is more than or equal to 100 g/L; n is more than or equal to 50 g/L; p is more than or equal to 20 g/L; k is more than or equal to 10g/L and pH is as follows: 4.0-5.0; na is less than or equal to 30 g/L; the water insoluble matter is less than or equal to 50 g/L. The extraction rate of glutamic acid is improved by 1 percent, and the consumption of sulfuric acid is reduced by 40 percent.

The new process produces two high-value new products of refined glutamic acid residue and liquid soil conditioner. The selling price of the fine glutamic acid residues is about 2000 yuan higher than that of the original common protein, 1.8 million tons of fine glutamic acid residues are produced every year according to the annual production of 20 million tons of sodium glutamate, and the annual estimated profit can be improved by 3500 million yuan; the liquid soil conditioner is calculated according to the original 20 ten thousand tons of granular soil conditioners produced by spraying and granulating in the company, the annual production cost of steam, equipment, manpower and the like can reach 1500 ten thousand yuan, and the economic benefit is very obvious.

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for preparing a liquid soil conditioner by using amino acid waste liquid comprises the following steps:

step 1) adding chitosan into glutamic acid fermentation liquor, stirring at 500rpm for 30s, standing for 3min, separating by a high-speed disc separator, and collecting clear liquid and mycoprotein precipitates;

2. The method of claim 1, wherein the chitosan is added in an amount of 100g/m³。

3. The method as claimed in claim 1, wherein the high-speed disk separator has a rotational speed of 5000r/min and a feed flow rate of 300-400L/h.

4. The method of claim 1, wherein the sulfuric acid adjusts the pH to 3.2.

5. The method according to claim 1, characterized in that in step 2) an aqueous solution of sodium carbonate with a mass fraction of 10% is added in a proportion of five times the weight.