Gasifier ash water scale inhibitor and preparation method thereof

Abstract

The invention relates to the technical field of scale inhibition, and provides a gasifier ash water scale inhibitor and a preparation method thereof. The ash water scale inhibitor is prepared from the following components in parts by weight: 22 to 35 parts of polycarboxylic acid, 21 to 28 parts of polysulfonate, 5 to 12 parts of phosphate, 8 to 12 parts of phosphonic acid, 3 to 9 parts of azoles, 22 to 30 parts of an auxiliary agent, 15 to 25 parts of alcohols, 25 to 30 parts of a suspending agent and 200 to 220 parts of water, the auxiliaries comprise 2-picolinic acid and 6-aminonicotinic acid. Through the technical scheme, the problem of poor scale inhibition performance of a scale inhibitor in related technologies is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of scale inhibition, and specifically, to a scale inhibitor for gasifier ash water and a preparation method thereof. Background Art

[0002] In the modern industrial system, gasifiers play a crucial role and are key equipment indispensable to industries such as coal, chemical engineering, and energy. Its working principle is to carry out a chemical reaction between solid fuels (such as coal) and gasifying agents (such as oxygen, steam, etc.) under high temperature and high pressure conditions to convert them into syngas, and the syngas can be further used to produce various chemical products such as methanol and synthetic ammonia, or as fuel gas for power generation, etc., playing a fundamental role in the energy supply and product manufacturing of industrial production.

[0003] During the operation of the gasifier, the ash water system is an important link to maintain its stable operation. Ash water is mainly composed of ash generated by the gasification reaction, flushing water, and various impurities carried during the reaction, with extremely complex components, including various metal ions (such as calcium, magnesium, iron, etc.), aluminosilicates, and other soluble salts. Under the high temperature, high pressure, and specific pH environment of the gasifier, these complex components are extremely likely to undergo chemical reactions and precipitate crystals, thus forming a hard scale layer on the inner walls of equipment and pipelines.

[0004] For a long time, the problem of ash water scaling has been like a cancer, severely restricting the efficient production of relevant enterprises. Although traditional scale inhibitors can alleviate the scaling phenomenon to a certain extent, their effects are very limited in the face of such complex ash water components and working conditions. With the rapid development of industry, the production scale of enterprises has been continuously expanding, and the requirements for production efficiency have become increasingly strict. The existing scale inhibition technologies are increasingly difficult to meet the growing production demands.

[0005] The harms brought about by ash water scaling are various and extremely serious. From the perspective of equipment performance, the presence of the scale layer greatly reduces the heat transfer efficiency of the equipment, hindering heat transfer. To maintain the temperature required for production, enterprises have to consume more energy, resulting in a significant increase in energy consumption. At the same time, the gradual thickening of the scale layer will also cause the inner diameter of the pipeline to become smaller until it is blocked, which will not only affect the normal transportation of ash water but also may cause safety hazards such as equipment overpressure. In severe cases, it may even lead to equipment damage and production shutdown for maintenance. Frequent equipment repairs and production shutdowns will not only generate high maintenance costs but also disrupt the entire production plan, affecting the supply of upstream and downstream products, causing inestimable losses to the economic benefits and market reputation of enterprises.

[0006] In summary, it is crucial to develop a scale inhibitor for gasifier ash water that can significantly improve the scale inhibition performance. Summary of the Invention

[0007] The present invention provides a scale inhibitor for gasifier ash water and a preparation method thereof, which solves the problem of poor scale inhibition performance of scale inhibitors in the related art.

[0008] The technical solution of the present invention is as follows: The present invention provides a scale inhibitor for gasifier ash water, which comprises the following components in parts by weight: 22-35 parts of polycarboxylic acid, 21-28 parts of polysulfonate, 5-12 parts of phosphate, 8-12 parts of phosphonic acid, 3-9 parts of azole, 22-30 parts of auxiliary agent, 15-25 parts of alcohol, 25-30 parts of suspending agent, and 200-220 parts of water; The auxiliary agent includes 2-pyridinecarboxylic acid and 6-aminonicotinic acid.

[0009] As a further technical solution, the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid is 15:7-9.

[0010] In the present invention, by adjusting the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid to 15:7-9, the scale inhibition performance of the scale inhibitor for gasifier ash water is further improved.

[0011] As a further technical solution, the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid is 15:8.

[0012] In the present invention, by adjusting the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid to 15:8, the scale inhibition performance of the scale inhibitor for gasifier ash water is further improved.

[0013] As a further technical solution, the alcohol includes 1,3-cyclohexanediol and 1,2-pentanediol.

[0014] In the present invention, a mixed solvent of 1,3-cyclohexanediol and 1,2-pentanediol is used for the alcohol. 1,3-cyclohexanediol and 1,2-pentanediol produce a synergistic effect to form a denser adsorption film, improving the corrosion inhibition performance of the scale inhibitor for gasifier ash water.

[0015] As a further technical solution, the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol is 2:5-7.

[0016] In the present invention, by adjusting the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol to 2:5-7, the corrosion inhibition performance of the scale inhibitor for gasifier ash water is further improved.

[0017] As a further technical solution, the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol is 1:3.

[0018] In the present invention, by adjusting the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol to 1:3, the corrosion inhibition performance of the scale inhibitor for gasifier ash water is further improved.

[0019] As a further technical solution, the polycarboxylic acid includes one of polyaspartic acid, polyacrylic acid, and polymethacrylic acid; The polysulfonate includes sodium poly(p-styrenesulfonate); The suspending agent includes one of polyethylene glycol, polyethylene oxide, and sodium carboxymethyl cellulose.

[0020] As a further technical solution, the phosphate includes one of sodium hexametaphosphate and sodium pyrophosphate; The phosphonic acid includes one of ethylenediaminetetramethylenephosphonic acid and aminotrimethylenephosphonic acid; The azoles include one of benzotriazole and methylbenzotriazole.

[0021] The present invention also provides a preparation method of the gasifier ash water scale inhibitor, comprising the following step: mixing each component evenly to obtain the gasifier ash water scale inhibitor.

[0022] As a further technical solution, the temperature of the mixing is 25~35°C.

[0023] The working principle and beneficial effects of the present invention are as follows: 1. In the present invention, polycarboxylic acid is added to the scale inhibitor. Polycarboxylic acid has excellent dispersion performance and can adsorb on the surfaces of various metal ions in the ash water, disperse them, effectively prevent the metal ions from combining with each other to form insoluble salt precipitates, thereby inhibiting the formation of scale layers. At the same time, it can also disperse the already formed tiny scale crystals to prevent them from further aggregating and growing, maintaining the cleanliness of the ash water system.

[0024] 2. In the present invention, phosphate is added to the scale inhibitor. Phosphate can react with metal ions in the ash water to form stable complexes. These complexes can reduce the concentration of metal ions and reduce the possibility of their combination with other anions to form scale. In addition, phosphate can, to a certain extent, form a protective film on the surface of the equipment to prevent the attachment of scale.

[0025] 3. In the present invention, phosphonic acid is added to the scale inhibitor. Phosphonic acid has a strong chelating ability for common scale-forming metal ions such as calcium and magnesium, can chelate these ions, and make them lose the activity of combining with other anions to form scale. At the same time, phosphonic acid can destroy the crystal lattice structure of the scale crystals, making it difficult for the scale crystals to grow and aggregate, playing a good scale inhibition role.

[0026] 4. In the present invention, azoles are added to the scale inhibitor. Azoles mainly play a corrosion inhibition role, can form a dense protective film on the surface of metal equipment, prevent corrosive substances in the ash water from corroding the equipment. At the same time, it also has a certain inhibitory effect on the precipitation of some metal ions, helping to reduce the scale formed due to the participation of metal corrosion products in the reaction.

[0027] 5. In the present invention, the additives include 2-pyridinecarboxylic acid and 6-aminonicotinic acid. The two different acids have different selectivities for metal ions in water and can chelate with different metal ions. At the same time, the use of 2-pyridinecarboxylic acid and 6-aminonicotinic acid produces a synergistic effect, improving the scale inhibition performance of the gasifier ash water scale inhibitor.

[0028] 6. In the present invention, alcohols are added to the scale inhibitor. The polar groups contained in the alcohol molecules adsorb the molecules on the metal surface through intermolecular forces, facing the hydrophobic non-polar groups towards the medium and aggregating to form an adsorption film, hindering the contact between the metal surface and the outside world, thereby achieving the corrosion inhibition effect.

[0029] 7. In the present invention, a suspending agent is added to the scale inhibitor. The suspending agent prevents particle aggregation and growth, avoiding pipeline blockage. Specific Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0031] In the following examples and comparative examples, polyaspartic acid was purchased from Shandong Weiyuan Environmental Protection Technology Co., Ltd., with the product number P02; the weight average molecular weight of sodium poly (styrene sulfonate) was 80,000; the weight average molecular weight of polyacrylic acid was 20,000; the weight average molecular weight of polymethacrylic acid was 80,000; the model of polyethylene glycol was PEG-2000; the model of polyethylene oxide was WSR-205; the model of sodium carboxymethyl cellulose was FVH9.

[0032] Example 1 A gasifier ash water scale inhibitor, comprising the following components in parts by weight: 35 parts of polycarboxylic acid, 28 parts of polysulfonate, 12 parts of phosphate, 12 parts of phosphonic acid, 9 parts of azole, 30 parts of additives, 25 parts of alcohols, 30 parts of suspending agent, and 220 parts of water; The additives include 2-pyridinecarboxylic acid and 6-aminonicotinic acid; The mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid is 15:11; The alcohols are 1,3-cyclohexanediol; The polycarboxylic acid is polyaspartic acid; The polysulfonate is sodium poly (styrene sulfonate); The suspending agent is polyethylene glycol; The phosphate is sodium hexametaphosphate; The phosphonic acid is ethylenediaminetetramethylenephosphonic acid; The azole is benzotriazole; A preparation method of a gasifier ash water scale inhibitor, comprising the following steps: mixing each component evenly at 35°C to obtain the gasifier ash water scale inhibitor.

[0033] Example 2 A gasifier ash water scale inhibitor, comprising the following components in parts by weight: 22 parts of polycarboxylic acid, 21 parts of polysulfonate, 5 parts of phosphate, 8 parts of phosphonic acid, 3 parts of azole, 22 parts of auxiliary agent, 15 parts of alcohol, 25 parts of suspending agent, and 200 parts of water; The auxiliary agent includes 2-pyridinecarboxylic acid and 6-aminonicotinic acid; The mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid is 3:1; The alcohol is 1,3-cyclohexanediol; The polycarboxylic acid is polyacrylic acid; The polysulfonate is sodium poly(p-styrenesulfonate); The suspending agent is polyethylene oxide; The phosphate is sodium pyrophosphate; The phosphonic acid is aminotrimethylenephosphonic acid; The azole is methylbenzotriazole; A preparation method of a gasifier ash water scale inhibitor, comprising the following steps: mixing each component evenly at 25°C to obtain the gasifier ash water scale inhibitor.

[0034] Example 3 A gasifier ash water scale inhibitor, comprising the following components in parts by weight: 25 parts of polycarboxylic acid, 27 parts of polysulfonate, 9 parts of phosphate, 9 parts of phosphonic acid, 6 parts of azole, 27 parts of auxiliary agent, 20 parts of alcohol, 28 parts of suspending agent, and 210 parts of water; The auxiliary agent includes 2-pyridinecarboxylic acid and 6-aminonicotinic acid; The mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid is 3:2; The alcohol is 1,3-cyclohexanediol; The polycarboxylic acid is polymethacrylic acid; The polysulfonate is sodium poly(p-styrenesulfonate); The suspending agent is sodium carboxymethyl cellulose; The phosphate is sodium hexametaphosphate; The phosphonic acid is ethylenediaminetetramethylenephosphonic acid; The azole is benzotriazole; A preparation method of a gasifier ash water scale inhibitor, comprising the following steps: mixing each component evenly at 30°C to obtain the gasifier ash water scale inhibitor.

[0035] Example 4 The difference between this example and Example 3 is only that the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid in this example is 5:2.

[0036] Example 5 The difference between this example and Example 3 is only that the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid in this Example 2 is 15:7.

[0037] Example 6 The difference between this example and Example 3 is only that the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid in this Example 2 is 15:8.

[0038] Example 7 The difference between this example and Example 3 is only that the mass ratio of 2-pyridinecarboxylic acid to 6-aminonicotinic acid in this Example 2 is 5:3.

[0039] Example 8 The difference between this example and Example 3 is only that the alcohol in this example is 1,2-pentanediol.

[0040] Example 9 The difference between this example and Example 3 is only that the alcohol in this example is a mixed solvent of 1,3-cyclohexanediol and 1,2-pentanediol, and the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol is 1:2.

[0041] Example 10 The difference between this example and Example 8 is only that the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol in this example is 1:4.

[0042] Example 11 The difference between this example and Example 8 is only that the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol in this example is 2:5.

[0043] Example 12 The difference between this example and Example 8 is only that the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol in this example is 1:3.

[0044] Example 13 The difference between this example and Example 8 is only that the mass ratio of 1,3-cyclohexanediol to 1,2-pentanediol in this example is 2:7.

[0045] Comparative Example 1 The difference between this comparative example and Example 2 is only that the auxiliary agent in this comparative example is 2-pyridinecarboxylic acid.

[0046] Comparative Example 2 The difference between this comparative example and Example 2 is only that the auxiliary agent in this comparative example is 6-aminonicotinic acid.

[0047] Comparative Example 3 The difference between this comparative example and Example 2 is only that no auxiliary agent is added in this comparative example.

[0048] Experimental Example 1 The scale inhibition performance of the gasifier ash water scale inhibitors prepared in Examples 1-7 and Comparative Examples 1-3 was tested according to the method in GB / T 16632-2019 "Determination of Scale Inhibition Performance of Water Treatment Machines - Calcium Carbonate Deposition Method". The experimental water temperature was 80 °C, and the experimental dosage of the gasifier ash water scale inhibitor was 30 mg / L. The test results are shown in Table 1.

[0049] Table 1 Test Results of Scale Inhibition Performance

[0050] Comparing Example 2 with Comparative Examples 1-3 shows that the use of 2-pyridinecarboxylic acid and 6-aminonicotinic acid in the present invention produces a synergistic effect, improving the scale inhibition performance of the gasifier ash water scale inhibitor.

[0051] Comparing Examples 5-7 with Examples 3-4 shows that when the mass ratio of 2-pyridinecarboxylic acid and 6-aminonicotinic acid is 15:7-9, the scale inhibition performance of the gasifier ash water scale inhibitor is further improved.

[0052] Experimental Example 2 The corrosion inhibition performance of the gasifier ash water scale inhibitors prepared in Example 3 and Examples 8-13 was tested according to the method in GB / T 18175-2014 "Determination of Corrosion Inhibition Performance of Water Treatment Agents - Rotating Hanging Specimen Method". The experimental water temperature was 80 °C, the rotation speed was 75 r / min, the running time was 72 h, and the experimental dosage of the gasifier ash water scale inhibitor was 30 mg / L. The test results are shown in Table 2.

[0053] Table 2 Test Results of Corrosion Inhibition Performance

[0054] Comparing Examples 9-13 with Example 3 and Example 8 shows that the use of 1,3-cyclohexanediol and 1,2-pentanediol in the present invention produces a synergistic effect, improving the corrosion inhibition property of the gasifier ash water scale inhibitor. Comparing Examples 11-13 with Examples 9-10 shows that when the mass ratio of 1,3-cyclohexanediol and 1,2-pentanediol is 2:5-7, the corrosion inhibition property of the gasifier ash water scale inhibitor is further improved.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gasifier ash water scale inhibitor, characterized in that, It comprises the following components in parts by weight: 22 - 35 parts of polycarboxylic acid, 21 - 28 parts of polysulfonate, 5 - 12 parts of phosphate, 8 - 12 parts of phosphonic acid, 3 - 9 parts of azole, 22 - 30 parts of auxiliary agent, 15 - 25 parts of alcohol, 25 - 30 parts of suspending agent, and 200 - 220 parts of water; The auxiliary agent includes 2 - pyridinecarboxylic acid and 6 - aminonicotinic acid.

2. The scale inhibitor for gasifier ash water according to claim 1, wherein The mass ratio of 2 - pyridinecarboxylic acid to 6 - aminonicotinic acid is 15:7 - 9.

3. The scale inhibitor for gasifier ash water according to claim 2, wherein The mass ratio of 2 - pyridinecarboxylic acid to 6 - aminonicotinic acid is 15:

8.

4. The scale inhibitor for gasifier ash water according to claim 1, wherein The alcohol includes 1,3 - cyclohexanediol and 1,2 - pentanediol.

5. The scale inhibitor for gasifier ash water according to claim 4, wherein, The mass ratio of 1,3 - cyclohexanediol to 1,2 - pentanediol is 2:5 - 7.

6. The scale inhibitor for gasifier ash water according to claim 5, wherein The mass ratio of 1,3 - cyclohexanediol to 1,2 - pentanediol is 1:

3.

7. The scale inhibitor for gasifier ash water according to claim 1, wherein The polycarboxylic acid includes one of polyaspartic acid, polyacrylic acid, and polymethacrylic acid; The polysulfonate includes sodium poly(p - styrenesulfonate); The suspending agent includes one of polyethylene glycol, poly(ethylene oxide), and sodium carboxymethylcellulose.

8. The scale inhibitor for gasifier ash water according to claim 1, wherein The phosphate includes one of sodium hexametaphosphate and sodium pyrophosphate; The phosphonic acid includes one of ethylenediaminetetra(methylenephosphonic acid) and aminotrimethylenephosphonic acid; The azole includes one of benzotriazole and methylbenzotriazole.

9. The preparation method of a gasifier ash water scale inhibitor according to any one of claims 1 to 8, characterized in that, It includes the following steps: Mix the components evenly to obtain the scale inhibitor for gasifier ash water.

10. The preparation method of a gasifier ash water scale inhibitor according to claim 9, characterized in that, The temperature of the mixing is 25 - 35 °C.

Images