阅读说明：本技术 一种无磷锅炉水处理剂及其制备与应用 (Phosphorus-free boiler water treatment agent and preparation and application thereof ) 是由 梁华强 于 2019-09-03 设计创作，主要内容包括：本发明涉及一种无磷锅炉水处理剂及其制备与应用,所述处理剂由以下组分及质量百分含量的原料制备而成：改性聚天冬氨酸16-30%,3-丙烯酰胺基多巴胺10-20%,pH调节剂10-16%,除氧剂3-8%,成膜助剂2-6%,余量为去离子水；制备时,按质量百分含量将去离子水加入反应釜中,加入改性聚天冬氨酸和3-丙烯酰胺基多巴胺,充分搅拌均匀,随后依次加入除氧剂、成膜助剂、pH调节剂,加热至50-65℃,恒温搅拌20-30min,自然冷却至室温,即可；在实际应用时,所述处理剂在加药时,按锅炉实际水容积计算,投加量为10g/t-20g/t。与现有技术相比,本发明用于中、高压锅炉水系统,克服了使用磷酸盐带来的各种负面影响,锅炉排污率降低,节约能源,具有很好的应用前景。(The invention relates to a phosphorus-free boiler water treatment agent and preparation and application thereof, wherein the treatment agent is prepared from the following raw materials in percentage by mass: 16-30% of modified polyaspartic acid, 10-20% of 3-acrylamide dopamine, 10-16% of pH regulator, 3-8% of deoxidant, 2-6% of film-forming additive and the balance of deionized water; the preparation method comprises the steps of adding deionized water into a reaction kettle according to the mass percentage, adding the modified polyaspartic acid and the 3-acrylamido dopamine, fully and uniformly stirring, then sequentially adding the deoxidant, the film-forming aid and the pH regulator, heating to 50-65 ℃, stirring at a constant temperature for 20-30min, and naturally cooling to room temperature; in actual application, when the treating agent is added with chemicals, the adding amount is 10g/t-20g/t according to the actual water volume of the boiler. Compared with the prior art, the invention is used for medium and high pressure boiler water systems, overcomes various negative effects caused by using phosphate, reduces the boiler pollution discharge rate, saves energy and has good application prospect.)

1. The phosphorus-free boiler water treatment agent is characterized by being prepared from the following raw materials in percentage by mass: 16-30% of modified polyaspartic acid, 10-20% of 3-acrylamide dopamine, 10-16% of pH regulator, 3-8% of deoxidant, 2-6% of film-forming additive and the balance of deionized water.

2. The phosphorus-free boiler water treatment agent according to claim 1, wherein the modified polyaspartic acid is diethyl malonate modified polyaspartic acid, and the preparation method comprises the following steps:

1) in a water solvent, maleic anhydride and ammonium salt react for 1-2h at 72-80 ℃, then the temperature is raised to 168-180 ℃ and the reaction is carried out for 1-1.5h, thus obtaining polysuccinimide;

2) purifying the polysuccinimide prepared in the step 1), putting the purified polysuccinimide into an alkaline aqueous solution, adding diethyl malonate, reacting at 35-42 ℃ for 12-18h, then adjusting the pH of the system, and then purifying and drying to obtain the modified polyaspartic acid.

3. The phosphorus-free boiler water treatment agent according to claim 2, wherein the molar ratio of the maleic anhydride to the ammonium salt in step 1) is 1:1.2-1.5, wherein the molar amount of the ammonium salt is calculated by ammonium ions.

4. The phosphorus-free boiler water treatment agent according to claim 2, wherein the ammonium salt is one of ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium sulfate or ammonium nitrate.

5. The phosphorus-free boiler water treatment agent according to claim 2, wherein the alkaline aqueous solution of step 2) is an aqueous sodium hydroxide solution, and the molar ratio of polysuccinimide to diethyl malonate to sodium hydroxide is 1:0.6-1: 1-2.

6. The phosphorus-free boiler water treatment agent according to claim 1, wherein the pH regulator comprises one or more of 2, 2-diethylamino-1-butanol, triethanolamine, 2-dimethylamino-2-ethyl-1, 3-propanediol, or 2-methylamino-2-ethyl-1-propanol.

7. The phosphorus-free boiler water treatment agent according to claim 1, wherein the oxygen scavenger comprises one or more of 1-aminopyrrolidine, 1-amino-4-methylpiperazine, N-ethylaminomorpholine, 3-hydroxymethyl-5-pyrazolone, and 5, 6-dimethylamino-1-hydroxy-3-ethyluracil.

8. The phosphorus-free boiler water treatment agent according to claim 1, wherein the film forming aid comprises one or more of ethylene glycol, propylene glycol, dodecyl carbonate, dipropylene glycol monomethyl ether, propylene glycol methyl ether acetate, and hexylene glycol butyl ether acetate.

9. The method for preparing the phosphorus-free boiler water treatment agent according to any one of claims 1 to 8, wherein deionized water is added into a reaction kettle according to the mass percentage, modified polyaspartic acid and 3-acrylamidodopamine are added, the mixture is fully and uniformly stirred, then an oxygen scavenger, a film forming aid and a pH regulator are sequentially added, the mixture is heated to 50-65 ℃, the mixture is stirred at a constant temperature for 20-30min, and the mixture is naturally cooled to room temperature.

10. The use of the phosphorus-free boiler water treatment agent according to any one of claims 1 to 8, wherein the treatment agent is added in an amount of 10g/t to 20g/t, calculated on the basis of the actual water volume of the boiler, when the treatment agent is added.

Technical Field

The invention belongs to the technical field of boiler water treatment, and relates to a phosphorus-free boiler water treatment agent and preparation and application thereof.

Background

As is well known, a boiler is an energy conversion device, and the energy input to the boiler is chemical energy in fuel or electric energy, and the boiler outputs steam, high-temperature water or an organic heat carrier with certain heat energy. The hot water or steam generated in the boiler can directly provide heat energy for industrial production and people life, and can also be converted into mechanical energy through a steam power device, or the mechanical energy is converted into electric energy through a generator. In practical application, a small amount of colloid, calcium, iron and other impurities in the boiler water used as an energy transfer medium are easy to deposit and form dirt under a high-temperature and high-pressure environment, and the dirt is deposited on the surface of equipment to cause corrosion of the equipment and damage to the equipment. Especially, under the special working environment of high temperature and high pressure, the surface stress of boiler equipment is very large, and corrosion damage can bring certain potential safety hazard, so that under the conventional condition, the boiler water needs to be treated by adding chemicals to adjust the water quality, and the generation of dirt of the high-pressure boiler is delayed or reduced as much as possible.

The existing conventional high-pressure boiler water treatment agent is a phosphorus reagent, after the phosphorus reagent is added into boiler water, phosphate and calcium ions in the boiler water form calcium hydroxy phosphate which is insoluble salt and is in a dispersed and soft water slag shape, and the phosphate can be discharged out of a boiler body along with system sewage. However, such agents present certain drawbacks: the system has higher requirement on system load, and the phenomenon of phosphate disappearance can occur when the system load is increased, actually, phosphate indissolvable substances are deposited on a furnace wall, and the problem of alkali corrosion caused by the increase of local free alkali can be caused.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a green environment-friendly phosphorus-free boiler water treatment agent (product code YG 800) which can effectively replace the traditional phosphate treatment method, has good scale inhibition and dispersion effects, is convenient to store and transport, long in validity period, small in dosage and less in pollution discharge.

Another object of the present invention is to provide a preparation scheme of the phosphorus-free boiler water treatment agent.

It is still another object of the present invention to provide use of the phosphorus-free boiler water treatment agent.

The purpose of the invention can be realized by the following technical scheme:

a phosphorus-free boiler water treatment agent is prepared from the following raw materials in percentage by mass: 16-30% of modified polyaspartic acid, 10-20% of 3-acrylamide dopamine, 10-16% of pH regulator, 3-8% of deoxidant, 2-6% of film-forming additive and the balance of deionized water.

As a preferred technical scheme, the modified polyaspartic acid is polyaspartic acid modified by diethyl malonate, and the preparation method comprises the following steps:

1) in a water solvent, maleic anhydride and ammonium salt react for 1-2h at 72-80 ℃, then the temperature is raised to 168-180 ℃ and the reaction is carried out for 1-1.5h, thus obtaining polysuccinimide;

2) purifying the polysuccinimide prepared in the step 1), putting the purified polysuccinimide into an alkaline aqueous solution, adding diethyl malonate, reacting at 35-42 ℃ for 12-18h, then adjusting the pH of the system, and then purifying and drying to obtain the modified polyaspartic acid.

The molar ratio of the maleic anhydride to the ammonium salt in the step 1) is 1:1.2-1.5, wherein the molar amount of the ammonium salt is calculated by ammonium ions.

Preferably, the ammonium salt is one of ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium sulfate and ammonium nitrate.

The alkaline aqueous solution in the step 2) is an aqueous solution of sodium hydroxide, and the molar ratio of the polysuccinimide to the diethyl malonate to the sodium hydroxide is 1:0.6-1: 1-2. Wherein sodium hydroxide is used as a catalyst for the reaction.

Purifying the polysuccinimide obtained in the step 2) by adopting the following method: dissolving polysuccinimide in with N, N-dimethylformamide, stirring at 40-50 deg.c for 4-6 hr and suction filtering; and adding ethanol, precipitating for 20-40min, and vacuum filtering to obtain the purified polysuccinimide as the filter cake.

As a preferable technical scheme, the pH regulator comprises one or more of 2, 2-diethylamino-1-butanol, triethanolamine, 2-dimethylamino-2-ethyl-1, 3-propanediol or 2-methylamino-2-ethyl-1-propanol.

As a preferable technical scheme, the oxygen scavenger comprises one or more of 1-aminopyrrolidine, 1-amino-4-methylpiperazine, N-ethylaminomorpholine, 3-hydroxymethyl-5-pyrazolone and 5, 6-dimethylamino-1-hydroxy-3-ethyluracil.

As a preferable technical scheme, the film forming auxiliary agent comprises one or more of ethylene glycol, propylene glycol, dodecyl carbonate, dipropylene glycol monomethyl ether, propylene glycol methyl ether acetate and hexanediol butyl ether acetate.

The preparation method of the phosphorus-free boiler water treatment agent comprises the steps of adding deionized water into a reaction kettle according to the mass percentage, adding modified polyaspartic acid and 3-acrylamide dopamine, fully and uniformly stirring, then sequentially adding a deoxidant, a film-forming aid and a pH regulator, heating to 50-65 ℃, stirring at a constant temperature for 20-30min, and naturally cooling to room temperature.

When the phosphorus-free boiler water treatment agent is applied, the adding amount is 10g/t-20g/t calculated according to the actual water volume of a boiler. When the water is supplemented, the adding amount is calculated according to the water supplementing amount in operation, and the adding amount is 10g/t-20g/t, or the adding amount is calculated according to the actual water quality condition.

Compared with the prior art, the invention has the following characteristics:

1) the modified polyaspartic acid is prepared by taking diethyl malonate as a modifier and sodium hydroxide as a catalyst for grafting reaction, has stable and proper viscosity-average molecular weight, has excellent scale inhibition and corrosion inhibition performances, and can promote the dispersibility of 3-acrylamide dopamine in a formula system;

2) the molecules of the 3-acrylamide dopamine adopted in the phosphorus-free boiler water treatment agent (product code No. YG 800) of the invention contain pi bonds, the pi bond can be combined with the d-vacant orbit of the metal atom to form a coordination piece, so that the 3-acrylamide dopamine molecule can be adsorbed on the metal surface, and the 3-acrylamide dopamine molecule contains a polar group (amide group) which is close to the pi bond, the large pi bond is formed due to the conjugation, the adsorption force of the 3-acrylamide dopamine molecule on the metal surface can be obviously improved, under the synergistic effect of the modified polyaspartic acid, the dispersibility of the 3-acrylamide dopamine is obviously improved, and a film-forming auxiliary agent is used for assisting, so that a homogeneous and stable protective film is formed on the metal surface of the boiler, and the corrosion inhibition performance of a formula system is obviously improved;

3) the phosphorus-free boiler water treatment agent (product code YG 800) is suitable for medium-pressure and high-pressure boiler water systems, overcomes various negative effects caused by using phosphate, reduces discharge, has stable parameter control, can effectively prevent scaling in a boiler and deposition of iron, copper and silicon, further can keep the interior of the boiler clean for a long time, has no corrosion, does not need additional unplanned shutdown and cleaning operation, reduces the boiler pollution discharge rate, saves energy, and has good application prospect.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but should not be construed as limiting the scope thereof. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out under conventional conditions or conditions recommended by the manufacturers.