CN113562857A

CN113562857A - Salt inhibitor for salt-containing wastewater back-spraying quenching tower process and using method thereof

Info

Publication number: CN113562857A
Application number: CN202110863130.8A
Authority: CN
Inventors: 张金山; 夏志先
Original assignee: SHANGHAI FENGXIN ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD
Current assignee: SHANGHAI FENGXIN ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2021-10-29
Anticipated expiration: 2041-07-29
Also published as: CN113562857B

Abstract

The invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized by being prepared by mixing the following components: wherein, the component 1 is a mixture containing ethoxylated alkyl sulfate, long-chain alkyl benzene sulfonate and p-toluene sulfonate; the component 2 is a mixture containing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt; component 3 comprises 2, 2-dibromo-3-nitrilopropionamide and polyethylene glycol silicate; wherein the component 1: the mass ratio of the component 2 is 1-10: 1; the dosage of the component 3 is 1-10 per mill of the total weight of the salt inhibitor. The salt inhibitor can form loose crystals and has ideal salt inhibiting effect.

Description

Salt inhibitor for salt-containing wastewater back-spraying quenching tower process and using method thereof

Technical Field

The invention relates to the field of salt inhibitors, in particular to a salt inhibitor for a salt-containing wastewater back-spray quenching tower process and a using method thereof.

Background

In the caustic tower of the hazardous waste incineration project, the sodium hydroxide solution is generally used for washing acidic gases (hydrogen chloride, sulfur dioxide, hydrogen fluoride and the like) in the flue gas. When the pH value of the alkaline washing liquid is reduced to about 9.0, adding alkali again to increase the pH value, and continuously recycling. As the recycling is continued, the salt content in the lye is higher and higher, and the salt concentration can be as high as 18 percent or even higher. The higher and higher salt content causes that a large amount of near-white miscellaneous salt is separated out from the filling material and the nozzle of the alkaline washing tower in the circulation process of the alkaline washing liquid, thereby causing blockage.

In the prior art, to the phenomenon that alkaline tower filler and nozzle are appeared, in the current product, mostly for using circulating water to mix with the scale inhibitor and the ferrocyanide and hinder the salt, increase the ion concentration solubility in water, some then add the ferrocyanide salt on above basis and play and change the crystal shape, reach the purpose of hindering the salt, use current salt inhibitor can play certain effect, can not only reduce the volume of appearing of crystal on filler and nozzle, can also be better disperse the salinity, make the salt of crystallization more easily wash.

However, the salt inhibitor in the current market has a large dosage, and in the practical application process, the dosage of the salt inhibitor generally reaches the level of 200-300ppm when the salt content is 1%, and the higher the salt content is, the larger the dosage is. In particular, most products containing potassium ferrocyanide as the main component are added in an amount exceeding the above-mentioned addition concentration.

In addition, the research of the invention finds that the scale after crystallization is very stable for the mixture of sulfate crystal and silicon dioxide crystal based on the crystal form. However, the conventional salt inhibitor design fails to take the problem into consideration, and a device for destroying or changing the crystal form of the crystalline salt cannot be provided, so that although the salt inhibitor is added, the crystallization period can be prolonged, the conventional crystal form cannot be changed, and most crystals cannot be changed in shape after use (as shown in fig. 2). The cleaning based on the mixed salt is very difficult, the product is generally alkalescent, bacteria are easy to breed, the quality guarantee period is not long, and some products can generate toxic and harmful substances after cyanide is added and are subjected to high temperature, so that secondary pollution is caused.

For example: patent application No. CN202010506511.6 introduces a salt inhibitor, a preparation method and application thereof, and a salt inhibitor with patent No. CN202011243019.0 applied to hazardous waste incineration environment, wherein the main components of the two patents are conventional scale inhibitor raw material components, and are common scale inhibitor raw materials in the market for compounding, so that the application is changed. Which still present the above problems after forming the product.

Also for example: the patent CN202010941070.2 is a salt inhibitor prepared by mixing ferrocyanide with polyaspartic acid, polyepoxysuccinic acid, polyacrylate and the like, and is prepared by mixing a scale inhibitor and ferrocyanide according to a certain proportion, although the property of salt can be better changed by using the formula, toxic and harmful substances can be generated due to cyanide at high temperature.

Disclosure of Invention

The invention aims to overcome the defects, solves the problem that the crystal form cannot be changed in the prior art by using various components capable of changing salt to separate out crystals and adopting surface active components, and preferably compounds the scale inhibition components of calcium sulfate and silicon dioxide to finally form the salt inhibitor which has strong pertinence, high solid content, obvious salt inhibition effect, low dosage, no cyanide and long shelf life and does not contain cyanide.

The invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized by being prepared by mixing the following components:

wherein, the component 1 is a mixture containing ethoxylated alkyl sulfate, long-chain alkyl benzene sulfonate and p-toluene sulfonate;

the component 2 is a mixture containing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt;

component 3 comprises 2, 2-dibromo-3-nitrilopropionamide and polyethylene glycol silicate;

wherein the component 1: the mass ratio of the component 2 is 1-10: 1;

the dosage of the component 3 is 1-10 per mill of the total weight of the salt inhibitor.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the mass ratio of the ethoxylated alkyl sulfate to the long-chain alkylbenzene sulfonate to the p-toluene sulfonate is 1-5: 0.5-1: 1-20.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the mass ratio of the ethoxylated alkyl sulfate to the long-chain alkyl benzene sulfonate to the p-toluene sulfonate is 2-3:0.5-1: 5-10.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the mass ratio of the polyamino polyether methylene phosphonic acid sodium salt to the diethylenetriamine pentamethylene phosphoric acid sodium salt to the ethylene diamine tetraacetic acid sodium salt is 5-15: 4-10:1-2.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the mass ratio of the polyamino polyether methylene phosphonic acid sodium salt to the diethylenetriamine pentamethylene phosphoric acid sodium salt to the ethylene diamine tetraacetic acid sodium salt is 10-12: 5-6:1-2.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the mass ratio of the component 1 to the component 2 is 2-3: 1.

further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the dosage of the 2, 2-dibromo-3-nitrilopropionamide is 1/4-1/2 of polyethylene glycol silicate.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the long-chain alkyl benzene sulfonate is selected from one or more of long-chain alkyl benzene sulfonates with 8-20 carbon atoms.

Further, the invention provides a salt inhibitor for a salt-containing wastewater back-spray quenching tower process, which is characterized in that: the polyethylene glycol silicate is one or more selected from polyethylene glycol silicate with molecular weight of 400-4000.

In addition, the invention also provides a use method of the salt inhibitor for the salt-containing wastewater back-spray quenching tower process, which is characterized by comprising the following steps:

when the content of sulfate and silicon dioxide in the wastewater accounts for less than 10% (excluding) of the total salt content, the dosage is 50-80ppm when the salt content is 1%;

when the content of sulfate and silicon dioxide in the wastewater accounts for 10 percent (inclusive) to 30 percent (exclusive) of the total salt content,

adding 80-150ppm of medicine per 1% of salt content;

when the content of sulfate and silicon dioxide in the wastewater accounts for more than 30 percent (including) of the total salt content,

the addition amount is 150-300ppm per 1 percent of salt content.

The invention has the following functions and effects:

1. through the compounding of the component I, the formed salt is powdered, and meanwhile, the gaps among the powder can be increased, so that the powder is bulked.

2. Through the compounding of the second component, the silicon dioxide salt and the sulfate can effectively change the crystal structure of the silicon dioxide salt and the sulfate, so that the silicon dioxide salt and the sulfate are not easy to harden and are easy to fall off during cleaning.

3. The third component can be well compatible with the two components, so that the mildew of the third component is prevented, and the effective period of the product is prolonged from 1 year to 2 years.

Drawings

FIG. 1 is a state diagram before dosing;

FIG. 2 is a state diagram after addition of the salt inhibitor of comparative example 1;

FIG. 3-1 is a state diagram after addition of the salt inhibitor of example 1;

FIGS. 3-2 are diagrams of the state after addition of the salt inhibitor of example 1;

FIGS. 3-3 are diagrams of the state after addition of the salt inhibitor of example 1;

FIG. 4 is a state diagram after addition of the salt inhibitor of comparative example 2;

FIG. 5 is a state diagram after addition of the salt inhibitor of comparative example 3;

FIG. 6 is a state diagram after addition of the salt inhibitor of comparative example 4;

FIG. 7 is a state diagram after the salt inhibitor of comparative example 5 is added.

Detailed description of the invention

Examples 1,

The preparation process of the salt inhibitor provided in this example 1 is as follows:

s1, configuring a component 1: mixing ethoxylated sodium alkyl sulfate AES, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 2: 0.5: and 5, compounding.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene sodium phosphate and ethylene diamine tetraacetic acid sodium salt according to the proportion of 10: 5:1 for compounding.

S3, mixing the component 1 and the component 2 according to a mass ratio of 2: 1, adding DBPNA accounting for 1 per mill of the total weight and polyethylene glycol silicate (400) accounting for 3 per mill of the total weight.

The using method comprises the following steps:

when the sulfate and the silicon dioxide in the wastewater account for 10 percent of the whole salt content,

adding 50-80ppm of medicine every time the salt content is 1%, and so on;

when the sulfate and the silicon dioxide in the wastewater account for 10-30 percent of the whole salt content,

adding 80-150ppm of medicine every time the salt content is 1%, and so on;

when the sulfate and the silicon dioxide in the wastewater account for more than 30 percent of the whole salt content,

the addition amount is 150-300ppm every time the salt content is 1%, and so on.

Specific use examples:

after mixing sulfate and sodium silicate with different contents respectively, three wastewater samples with different compositions are prepared, namely wastewater samples with sulfate and silicon dioxide accounting for 8%, 25% and 38% of the whole salt content.

The liquid medicine is added according to the above rules, and the results of the evaporation of the solution after the full mixing are respectively shown in fig. 3-1, fig. 3-2 and fig. 3-3, and it can be found from the three figures that the crystal after treatment is in a flour powder state, the whole is loose and soft, the separation effect can be realized by lightly knocking the surface of the container, and the removal effect is excellent.

Comparative example 1

Wastewater containing 25% of sulfate and silica from the same source was treated in the same manner as in example 1 using a commercially available salt inhibitor containing phosphate as a main component. Based on the addition of 300ppm of the compound at a salt content of 1%, the results are shown in FIG. 2.

Comparative example 2

The preparation process of the salt inhibitor provided by the comparative example 2 is as follows:

mixing ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 2-3:0.5-1:5-10 to compound.

The results of experiments on wastewater containing 8%, 25% and 38% of the total salt content of sulfate and silica, respectively, based on 1% of the total salt content and 300ppm of the chemical agent, are shown in FIG. 4.

Comparative example 3

The preparation process of the salt inhibitor provided by the comparative example 3 is as follows:

s1, configuring a component 1: mixing ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 2-3:0.5-1:5-10 to compound.

S2, adding DBPNA accounting for 1 per mill of the total weight and polyethylene glycol silicate (400) accounting for 3 per mill of the total weight.

Wastewater containing 25% of sulfate and silica from the same source was treated in the same manner as in example 1. Based on the addition of 300ppm of the compound at a salt content of 1%, the results are shown in FIG. 5.

Comparative example 4

The preparation process of the salt inhibitor provided by the comparative example 4 is as follows:

Wastewater containing 25% of sulfate and silica from the same source was treated in the same manner as in example 1. Based on the addition of 300ppm of the compound at a salt content of 1%, the results are shown in FIG. 6.

Comparative example 5

The preparation process of the salt inhibitor provided in the comparative example 5 is as follows:

s1, configuring a component 1: and a nonionic surfactant PEG 200.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt according to the proportion of 10-12: 5-6: 1-2.

S3, mixing the component 1 and the component 2 according to a mass ratio of 2-3: 1, adding DBPNA accounting for 1 per mill of the total weight and polyethylene glycol silicate (400) accounting for 3 per mill of the total weight.

Wastewater containing 25% of sulfate and silica from the same source was treated in the same manner as in example 1. Based on the addition of 300ppm of the compound at a salt content of 1%, the results are shown in FIG. 7.

From the above comparative examples, it was found that neither the conventional products nor the similar formulation scheme to the present invention could achieve the similar effects to the present invention, but the final crystals of the wastewater treated by the comparative products were mainly agglomerated or partially agglomerated and adsorbed on the surface of the container, and the crystals were uniformly and loosely in the form of powder, which resulted in the difficulty of the desalting process.

Examples 2,

The preparation process of the salt inhibitor provided in this example 2 is as follows:

s1, configuring a component 1: mixing ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 2: 1: and 5, compounding.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt according to the proportion of 10: 6:1 for compounding.

S3, mixing the component 1 and the component 2 according to a mass ratio of 3:1, adding DBPNA accounting for 1 per mill of the total weight and polyethylene glycol silicate (400) accounting for 3 per mill of the total weight.

Examples 3,

The preparation process of the salt inhibitor provided in this example 3 is as follows:

s1, configuring a component 1: mixing ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 3: 0.5: 8, compounding.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt according to the proportion of 11: 6:1 for compounding.

S3, mixing the component 1 and the component 2 according to a mass ratio of 2.5: 1, adding DBPNA accounting for 2 per mill of the total weight and polyethylene glycol silicate (800) accounting for 3 per mill of the total weight.

Examples 4,

The preparation process of the salt inhibitor provided in this example 4 is as follows:

s1, configuring a component 1: ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluene sulfonate are mixed according to the mass ratio of 1: 0.5: 1, compounding.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt according to the proportion of 2: 3:1 for compounding.

S3, mixing the component 1 and the component 2 according to a mass ratio of 1: 1, adding DBPNA accounting for 1 per mill of the total weight and polyethylene glycol silicate (800) accounting for 4 per mill of the total weight.

Examples 5,

The preparation process of the salt inhibitor provided in this example 5 is as follows:

s1, configuring a component 1: mixing ethoxylated sodium alkyl sulfate, sodium dodecyl benzene sulfonate and sodium p-toluenesulfonate according to a mass ratio of 5: 0.5: 3, compounding.

S2, configuring a component 2: mixing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene phosphoric acid sodium salt and ethylene diamine tetraacetic acid sodium salt according to the proportion of 1: 3: 6.

S3, mixing the component 1 and the component 2 according to a mass ratio of 2: 1, adding DBPNA accounting for 0.5 per mill of the total weight and polyethylene glycol silicate (200) accounting for 1 per mill of the total weight.

Based on the same test conditions and methods as in example 1, the products of examples 2 to 5 were subjected to the effect test in the same manner as in example 1. The same effect, i.e., the formation of loose crystals as shown in fig. 3-1 to 3-3, is desirable.

Claims

1. A salt inhibitor for a salt-containing wastewater back-spray quenching tower process is characterized by being prepared by mixing the following components:

the component 2 is a mixture containing polyamino polyether methylene phosphonic acid sodium salt, diethylenetriamine pentamethylene sodium phosphate and ethylene diamine tetraacetic acid sodium salt;

wherein the component 1: the mass ratio of the component 2 is 1-10: 1;

2. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the mass ratio of the ethoxylated alkyl sulfate to the long-chain alkylbenzene sulfonate to the p-toluene sulfonate is 1-5: 0.5-1: 1-20.

3. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the mass ratio of the ethoxylated alkyl sulfate to the long-chain alkyl benzene sulfonate to the p-toluene sulfonate is 2-3:0.5-1: 5-10.

4. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the mass ratio of the polyamino polyether methylene phosphonic acid sodium salt to the diethylenetriamine pentamethylene sodium phosphate to the ethylene diamine tetraacetic acid sodium salt is 5-15: 4-10:1-2.

5. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the mass ratio of the polyamino polyether methylene phosphonic acid sodium salt to the diethylenetriamine pentamethylene sodium phosphate to the ethylene diamine tetraacetic acid sodium salt is 10-12: 5-6:1-2.

6. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the mass ratio of the component 1 to the component 2 is 2-3: 1.

7. the salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the dosage of the 2, 2-dibromo-3-nitrilopropionamide is 1/4-1/2 of polyethylene glycol silicate.

8. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the long-chain alkyl benzene sulfonate is selected from one or more of long-chain alkyl benzene sulfonates with 8-20 carbon atoms.

9. The salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in claim 1, wherein:

the polyethylene glycol silicate is one or more selected from polyethylene glycol silicate with molecular weight of 400-4000.

10. The use method of the salt inhibitor for the salt-containing wastewater back-spray quenching tower process as claimed in any one of claims 1-9, wherein the salt inhibitor comprises the following steps:

when the content of sulfate and silicon dioxide in the wastewater accounts for less than 10 percent (not containing) of the total salt content,

adding 50-80ppm of medicine per 1% of salt content;

when the content of sulfate and silicon dioxide in the wastewater accounts for 10 percent (including) to 30 percent (not including) of the total salt content, the addition amount is 80 to 150ppm per 1 percent of the salt content;

the addition amount is 150-300ppm per 1 percent of salt content.