CN114082288B - New application of folic acid wastewater - Google Patents

Abstract

The present invention relates to a new application of folic acid wastewater, and specifically to an application of folic acid wastewater in the preparation of a desulfurization and denitrification agent. The desulfurization and denitrification agent prepared by the folic acid wastewater has good desulfurization and denitrification effects, and also significantly reduces the consumption of sodium carbonate and urea, realizes the reuse of folic acid wastewater, saves the use of water resources, and has the characteristics of sustainable green environmental protection.

Description

New application of folic acid wastewater

Technical Field

The invention relates to the field of chemical industry, and in particular to a new application of folic acid wastewater.

Background technique

Desulfurization and denitrification agents are mainly used in the treatment of tail gas from high-temperature kilns such as cement plants, brick and tile plants, ceramic plants, and thermal power plants. Under high temperature conditions, if _SO2 and nitrogen oxides produced by kilns are discharged into the air, they will pollute the atmosphere and produce acid rain. Under the high temperature conditions of the kiln itself, desulfurization and denitrification agents solidify _SO2 into sulfates and reduce nitrogen oxides into non-toxic and harmless gases such as _N2 .

Folic acid, also known as vitamin B9, is a water-soluble vitamin. It was named after American scholar Mitchell et al. separated and extracted it from spinach leaves in 1941. Folic acid is a substance necessary for the growth and reproduction of body cells and plays an important role in human metabolism. If the human body lacks folic acid, it can cause megaloblastic anemia and leukocytopenia. In particular, pregnant women, nursing mothers and infants, who account for a large proportion of the population, need folic acid supplementation. When animals lack folic acid, they will suffer from growth retardation, deformity, anemia and other diseases. Therefore, folic acid is widely used in food, feed, medicine and health care products and other industries.

The production process of folic acid is generally divided into three stages: crude product synthesis, acid dissolution and water precipitation, and alkaline dissolution and refining. The crude product synthesis stage mainly uses trichloroacetone, N-(4-aminobenzoyl)-L-glutamic acid and 2,4,5-triamino-6-hydroxypyrimidine sulfate as raw materials for crude product synthesis. The synthesis routes are basically the same for enterprises in the industry. Folic acid wastewater generally refers to the mixed wastewater generated at various stages of production. Usually the parameters of wastewater are pH value of about 1 and COD value of about 8000-10000 mg/L. The existing production process of folic acid uses a lot of water and the ammonia organic matter contained in the wastewater generated during the production process is not easy to be treated by biodegradation. Therefore, the conventional production process will produce a large amount of difficult-to-treat wastewater. Folic acid wastewater contains a large amount of acid and carbon-nitrogen compounds, which has high treatment costs and great treatment difficulties. This is also the main reason why the production capacity of most companies is restricted when producing folic acid.

Summary of the invention

Based on this, the purpose of the present invention is to provide a new application of folic acid wastewater in the preparation of desulfurization and denitrification agents.

The specific technical solutions are as follows:

The invention discloses an application of folic acid wastewater in preparing a desulfurization and denitrification agent.

In some of the embodiments, in the folic acid wastewater, the mass percentage of carbon source is 0.05-5%, the mass percentage of nitrogen source is 0.05-5%; the mass percentage of sulfate ion is 10-15%, the mass percentage of chloride ion is 0.05-5%, and the mass percentage of sodium ion is 1-5%.

In some of the embodiments, in the folic acid wastewater, the mass percentage of carbon source is 3-5%, the mass percentage of nitrogen source is 3-5%; the mass percentage of sulfate ion is 10-15%, the mass percentage of chloride ion is 0.1-1%, and the mass percentage of sodium ion is 1-5%.

In some embodiments, the mass percentage of carbon source in the folic acid wastewater is 3-4.5%, the mass percentage of nitrogen source is 3-5%, the mass percentage of sulfate ion is 12-14%, the mass percentage of chloride ion is 0.1-0.5%, and the mass percentage of sodium ion is 2.5-4%. The existing synthesis route of folic acid is basically the same for enterprises in the industry, and the content of the above substances in folic acid wastewater is relatively stable.

Another object of the present invention is to provide a method for preparing a desulfurization and denitrification agent, comprising the following steps:

(1) adjusting the pH of the folic acid wastewater to alkaline using a pH regulator, filtering, and taking the filtrate as nitrogen-containing wastewater;

(2) adding an ammonia source and a sodium source to the nitrogen-containing wastewater in step (1) and mixing them until the mass percentage of the carbon source in the obtained mixture is 1 to 15%, the mass percentage of the nitrogen source is 5 to 15%, and the mass percentage of the sodium ion is 3 to 10%;

The ammonia source is at least one of urea, ammonia water, ammonium carbonate and N-methylethanolamine; the sodium source is at least one of sodium carbonate and sodium bicarbonate.

In some embodiments, in step (2), the ammonia source is urea, and the sodium source is sodium carbonate; 5-15 kg of urea and 1-10 kg of sodium carbonate are added to every 100 kg of nitrogen-containing wastewater.

In some of the embodiments, in step (2), 5-15 kg of urea and 2-5 kg of sodium carbonate are added to every 100 kg of nitrogen-containing wastewater.

In some of the embodiments, before preparing the desulfurization and denitrification agent, the folic acid wastewater is first analyzed for its components. Generally, the mass percentage of the carbon source in the folic acid wastewater is 0.05-5%, the mass percentage of the nitrogen source is 0.05-5%, the mass percentage of the sulfate ion is 10-15%, the mass percentage of the chloride ion is 0.05-5%, and the mass percentage of the sodium ion is 1-5%.

In some embodiments, the alkaline pH of step (2) is 8-13, further, the alkaline pH is 8-10, and further, the alkaline pH is 8-9.

In some of the embodiments, in step (1), the folic acid wastewater is first settled and filtered, and then the pH of the resulting filtrate is adjusted to alkaline using a pH regulator.

In some embodiments, the pH adjuster in step (2) is a base, and the base is at least one of calcium oxide, calcium hydroxide, barium oxide and barium hydroxide.

In some embodiments, steps (1) to (3) are performed at room temperature, which is 0 to 40°C.

Another object of the present invention is to provide a desulfurization and denitrification agent prepared by the above preparation method.

Another object of the present invention is to provide an application of the above-mentioned desulfurization and denitrification agent in desulfurization and denitrification.

Compared with the prior art, the present invention has the following beneficial effects:

The present invention discovers for the first time that folic acid wastewater is used to prepare desulfurization and denitrification agents. On the basis of ensuring good desulfurization and denitrification effects, not only the folic acid wastewater is reused and the treatment cost of folic acid wastewater is reduced, but also the addition amount of sodium carbonate, urea and water in the desulfurization and denitrification agents can be significantly reduced, thus saving the use of water resources in the desulfurization and denitrification agents, and the invention has the characteristics of sustainable green environmental protection.

The present invention only needs to remove sulfate ions in folic acid wastewater with a pH regulator, and then mix it with a small amount of ammonia source and sodium source to prepare a desulfurization and denitrification agent with good desulfurization and denitrification effects. It does not need to add additional water sources, the raw material cost is very low, and resources are recycled, thereby achieving the purpose of reducing costs and increasing efficiency, and is suitable for industrial promotion.

Detailed ways

The experimental methods in the following examples of the present invention without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

The terms "include" and "have" and any variations thereof of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment comprising a series of steps is not limited to the listed steps or modules, but may optionally include steps not listed, or may optionally include other steps inherent to these processes, methods, products or equipment.

In the present invention, the term "plurality" refers to two or more than two. "And/or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character "/" generally indicates that the associated objects are in an "or" relationship.

The present invention is further described in detail below with reference to specific embodiments.

Example 1

1. Identification of components of folic acid wastewater

20L of folic acid wastewater from three different batches was taken for component analysis. The analysis results showed that the components and mass percentages in the folic acid wastewater were: carbon source 0.05-5%; nitrogen source 0.05-5%; sulfate ion 10-15%, chloride ion 0.05-5%, sodium ion 1-5%, as shown in Table 1.

Table 1

2. Preparation of nitrogen-containing wastewater

The folic acid wastewater is stored in a sedimentation tank, and after solid-liquid separation, it is filtered with a filter bag or a filter membrane. The filtrate is taken, stirring is started, calcium oxide is added to the filtrate of the folic acid wastewater, and the pH value is adjusted to 8-9 to obtain calcium sulfate precipitate. Filter and take the filtrate to obtain nitrogen-containing wastewater.

3. Analysis of nitrogen-containing wastewater components

The components in the nitrogen-containing wastewater were analyzed, and the results showed that the mass percentage range of each component in the nitrogen-containing wastewater was: carbon source 0.05-4%, nitrogen source 0.05-4%, sulfate ion 0.03-0.5%, chloride ion 0.05-5%, calcium ion 1-2%, sodium ion 1-5%. The details are shown in Table 2:

Table 2

4. Preparation of desulfurization and denitrification agents

Urea and sodium carbonate are added to the nitrogen-containing wastewater. The addition amount of urea and sodium carbonate per 100 kg of nitrogen-containing wastewater is shown in Table 3:

Table 3 The amount of urea and sodium carbonate added to 100 kg of nitrogen-containing wastewater

Urea/kg Sodium carbonate/kg Sodium ion/wt% Batch 1 8.12 3.38 5 Batch 2 10.12 3.38 5 Batch 3 12.12 3.38 5

Comparative Example 1

The standards of commercially available desulfurization and denitrification agents are generally (mass percentage): carbon source 1-10%, nitrogen source 5-15%, sulfate ion less than 0.2%, calcium ion 0.05-5%, sodium ion 3-10%.

Three batches of commercially available desulfurization and denitrification agents were taken and tested to find that their main components were urea, sodium carbonate and sodium bicarbonate. Component analysis of three commercially available desulfurization and denitrification agents (mass percentage, as shown in Table 4):

Batch 1: carbon source 5%, nitrogen source 8.55%, sulfate ion 0.03%, calcium ion 0.05%, sodium ion 5%.

Batch 2: carbon source 5%, nitrogen source 9.63%, sulfate ion 0.04%, calcium ion 0.1%, sodium ion 6%.

Batch 3: carbon source 8%, nitrogen source 11.33%, sulfate ion 0.04%, calcium ion 0.1%, sodium ion 5%.

The component analysis of commercially available desulfurization and denitrification agents is shown in Table 4, and the addition amounts of urea and sodium carbonate of commercially available desulfurization and denitrification agents are shown in Table 5.

Table 4 Component analysis of commercially available desulfurization and denitrification agents (mass percentage)

Carbon source/% Nitrogen source/% Sodium ion/% Commercial batch 1 5 8.55 5 Commercial batch 2 5 9.63 6 Commercial batch 3 8 11.33 5

Table 5 Urea and sodium carbonate addition in 100kg commercial desulfurization and denitrification agent

Urea/kg Sodium carbonate/kg Sodium ion/% Commercial batch 1 15 11.52 5 Commercial batch 2 17 13.82 6 Commercial batch 3 20 11.52 5

Desulfurization and denitrification effect verification:

Test 1:

Desulfurization and denitrification aqueous agent formula: Batch 2 desulfurization and denitrification aqueous agent prepared in Example 1.

This test is used in a dry cement production line. The feeding method is atomization spraying in the kiln smoke chamber, the feeding temperature is 70-120℃, direct multi-point atomization spraying, and the addition amount is 800L/hour (about 0.15% of the cement raw material feed amount). The real-time monitoring data is shown in Table 6 below:

Table 6

Conclusion: This implementation example can control _SO2 emissions to less than 30mg/ ^m3 and _NOx emissions to less than 30mg/ ^m3 , which meets the national cement industry air pollutant emission standards.

Test 2:

Desulfurization and denitrification aqueous agent: Batch 2 desulfurization and denitrification aqueous agent prepared in Example 1.

This implementation example is used in a brick kiln production line. The feeding method is atomization spraying in the kiln smoke chamber, the feeding temperature is 70-120℃, direct multi-point atomization spraying, and the addition amount is 200L/hour. The real-time monitoring data is shown in Table 7 below:

Table 7

It can be seen from the results of Table 6 and Table 7 that the desulfurization and denitrification agent prepared from folic acid wastewater in the present invention can control _SO2 emissions to within 30 mg/ ^m3 and _NOx emissions to below 30 mg/ ^m3 , which meets the national industrial air pollutant emission standards for brick kilns.

The desulfurization and denitrification agent of the present invention greatly reduces the usage of sodium carbonate and urea while maintaining good desulfurization and denitrification effects, saves water, and efficiently reuses resources of industrial folic acid wastewater. It is green and environmentally friendly, has important promotion significance, and can be widely used as a desulfurization and denitrification agent in the electric power and building materials industry, and as a desulfurization and denitrification agent for kilns in cement plants, brick plants, ceramic plants, etc.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims (9)

1. A method for preparing a desulfurization and denitrification agent, characterized in that it comprises the following steps: (1) Using a pH regulator to adjust the pH of folic acid wastewater to alkaline, filtering, and taking the filtrate as nitrogen-containing wastewater; in the folic acid wastewater, the mass percentage of the carbon source is 0.05-5%, the mass percentage of the nitrogen source is 0.05-5%, the mass percentage of the sulfate ion is 10-15%, the mass percentage of the chloride ion is 0.05-5%, and the mass percentage of the sodium ion is 1-5%; (2) adding an ammonia source and a sodium source to the nitrogen-containing wastewater in step (1) to mix until the mass percentage of the carbon source in the obtained mixture is 1-15%, the mass percentage of the nitrogen source is 5-15%, and the mass percentage of the sodium ion is 3-10%; the pH regulator is at least one of calcium oxide, calcium hydroxide, barium oxide and barium hydroxide; The ammonia source is at least one of urea, ammonia water, ammonium carbonate and N-methylethanolamine; the sodium source is at least one of sodium carbonate and sodium bicarbonate. 2. preparation method according to claim 1, is characterized in that, in the folic acid wastewater, the mass percentage of carbon source is 3-5%, the mass percentage of nitrogen source is 3-5%; the mass percentage of sulfate ion is 10-15%, the mass percentage of chloride ion is 0.1-1%, and the mass percentage of sodium ion is 1-5%. 3. preparation method according to claim 2, is characterized in that, in the folic acid wastewater, the mass percentage of carbon source is 3~4.5%, the mass percentage of nitrogen source is 3~5%; the mass percentage of sulfate ion is 12~14%, the mass percentage of chloride ion is 0.1~0.5%, and the mass percentage of sodium ion is 2.5~4%. 4. The preparation method according to claim 1, characterized in that in the step (2), the ammonia source is urea, and the sodium source is sodium carbonate; 5-15 kg of urea and 1-10 kg of sodium carbonate are added to every 100 kg of nitrogen-containing wastewater. 5. The preparation method according to claim 1, characterized in that the alkaline pH in step (2) is 8-13. 6. The preparation method according to claim 5, characterized in that the alkaline pH in step (2) is 8-9. 7. The preparation method according to any one of claims 1 to 6, characterized in that in step (1), the folic acid wastewater is first settled and filtered, and then the pH of the obtained filtrate is adjusted to alkaline using a pH regulator. 8. The desulfurization and denitrification agent prepared by the preparation method according to any one of claims 1 to 7. 9. Use of the desulfurization and denitrification agent according to claim 8 in desulfurization and denitrification.