CN101709473A - High-temperature water-soluble corrosion inhibitor - Google Patents

Abstract

The invention relates to a high-temperature water-soluble corrosion inhibitor which belongs to the field of metal corrosion and protection. The corrosion inhibitor comprises acid, alkali, water, organic amine and aromatic azole and is prepared by the following steps of: stirring and heating the organic amine, and then mixing with the acid; and then adding the alkali and a part of water; and finally adding the aromatic zaole and the rest of water. The corrosion inhibitor solves the corrosion problem of primary reverse osmosis demineralized water and vapor condensed water in the using process at high temperature, replaces carcinogens of sodium nitrite and rare molybdate, reaches the requirement of the GB50050-2007 standard that the water side corrosion speed of a heat transfer surface of carbon steel equipment shall be lower than 0.075mm/a; in addition, the corrosion inhibitor has good corrosion inhibition effect, no pollution and low cost.

Description

High-temperature water-soluble corrosion inhibitor

Technical field:

The present invention relates to a kind of metal inhibitor, particularly a kind of first-stage reverse osmosis de-mineralized water and the steam condensate metal inhibitor in high temperature uses belongs to the metal corrosion and protection technical field.

Background technology:

Metal is used widely in every profession and trade as main equipment and materials, and the research of Corrosion of Metallic Materials and protection is extensive day by day, and solving one of effective way of metallic material corrosion is exactly to use inhibiter to come metal is protected.

At present, first-stage reverse osmosis de-mineralized water and steam condensate are applied aspect water saving because its calcium, magnesium and basicity are low less scaling, still, because its corrodibility causes enough attention by force and not, even cause heavy losses; Moreover, causing metallic corrosion speed sharply to increase along with the diffusion of the dissolved oxygen in the rising water of temperature is accelerated, corrosion speed is 48 times of present national standard up to 3.6mm/a in the time of 80 ℃.Corrosion has limited first-stage reverse osmosis de-mineralized water and the widespread use of steam condensate aspect water saving.For solve the problem that first-stage reverse osmosis de-mineralized water and steam condensate occur in high temperature uses, there is the people in water, to add a large amount of carcinogens Sodium Nitrites and rare molybdate, protect hardware, avoid corrosion.Though the Sodium Nitrite corrosion mitigating effect is fine, because the pollution problem that its toxicity and discharging cause is restricted its application; Molybdenum is non-renewable strategic goods and materials, and country strengthens management to rare metal production and outlet, causes the molybdenum valency to rise suddenly and sharply, and its application also is restricted.

Summary of the invention

The purpose of this invention is to provide a kind of high-temperature water-soluble corrosion inhibitor, this kind inhibiter can solve first-stage reverse osmosis de-mineralized water and steam condensate etching problem in high temperature uses.

The technical scheme that the present invention takes is:

A kind of high-temperature water-soluble corrosion inhibitor, form by the material of following weight part ratio:

(1) acid: 10～40 parts;

(2) alkali: 10～40 parts;

(3) water: 20～60 parts;

(4) organic amine: 10～40 parts;

(5) aromatic series azole: 1～10 part.

Described acid be in 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDPA), phosphoric acid, the thionamic acid any one or multiple;

Described alkali is potassium hydroxide or sodium hydroxide;

Described water comprises natural water, deionized water, distilled water;

Described organic amine be in cetylamine, morpholine, triethylene diamine, the trolamine any one or multiple;

Described aromatic series azole be in mercaptobenzothiazole, benzotriazole, the Methylbenzotriazole any one or multiple.

The preparation method of above-mentioned a kind of high-temperature water-soluble corrosion inhibitor comprises the steps:

(1) accurately takes by weighing acid, alkali, water, organic amine, aromatic series azole in proportion;

(2) with sour stirring heating and and organic amine mixing;

(3) add alkali and portion water (Total Water 50%) to said mixture, stir;

(4) dropping into the aromatic series azole in the mixture that step (3) obtains stirs;

(5) add remainder water (Total Water 50%), filter finished product packing.

Product relative density 1.17,1% solution PHs 8～9.

The invention has the beneficial effects as follows:

This kind high-temperature water-soluble corrosion inhibitor can solve first-stage reverse osmosis de-mineralized water and steam condensate etching problem in high temperature uses, substitute carcinogens Sodium Nitrite and rare molybdate, the carbon steel equipment heat-transfer surface water side corrosion speed that reaches " GB50050-2007 " standard code should be less than the level of 0.075mm/a, corrosion mitigating effect is good, pollution-free, cost is low.

Embodiment

Embodiment 1

A kind of high-temperature water-soluble corrosion inhibitor, form by the material of following weight part ratio:

(1) acid: 40 parts of 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid;

(2) alkali: 40 parts in potassium hydroxide;

(3) water: 60 parts of deionized waters;

(4) organic amine: 30 parts of cetylamines;

(5) aromatic series azole: 8 parts of mercaptobenzothiazoles.

The preparation method of above-mentioned a kind of high-temperature water-soluble corrosion inhibitor comprises the steps:

(1) accurately takes by weighing acid, alkali, water, organic amine, aromatic series azole in proportion;

(2) with sour stirring heating and and organic amine mixing;

(3) add alkali and portion water (Total Water 50%) to said mixture, stir;

(4) dropping into the aromatic series azole in the mixture that step (3) obtains stirs;

(5) add remainder water (Total Water 50%), filter finished product packing.

Embodiment 2

A kind of high-temperature water-soluble corrosion inhibitor, form by the material of following weight part ratio:

(1) acid: 0 part of phosphatase 11,10 parts of thionamic acids;

(2) alkali: 20 parts in sodium hydroxide;

(3) water: 40 parts of natural waters;

(4) organic amine: 10 parts of morpholines, 20 parts of triethylene diamines;

(5) aromatic series azole: 1 part of benzotriazole.

The preparation method of above-mentioned a kind of high-temperature water-soluble corrosion inhibitor is with embodiment 1.

Embodiment 3

A kind of high-temperature water-soluble corrosion inhibitor, form by the material of following weight part ratio:

(1) acid: 0 part of phosphatase 11;

(2) alkali: 10 parts in sodium hydroxide;

(3) water: 20 parts of distilled water;

(4) organic amine: 10 parts of trolamines;

(5) aromatic series azole: 2 parts of benzotriazoles, 2 parts of Methylbenzotriazoles.

The preparation method of above-mentioned a kind of high-temperature water-soluble corrosion inhibitor is with embodiment 1.

Embodiment 4

The present invention's corrosion mitigating effect test in high temperature uses at first-stage reverse osmosis de-mineralized water and steam condensate:

Because processing requirement, a certain unit operation in the chemical engineering process must guarantee homo(io)thermism, for example the unit operation of two producers in Shandong and Shanghai is respectively to carry out under 80 ℃ and 90 ℃ of steady temperatures, the way of its assurance utilizes the constant water temperature to reach processing requirement exactly, with being easy to fouling under surface water or the subsurface temperature, influence ordinary production, therefore two producers solve scale problems with first-stage reverse osmosis de-mineralized water and steam condensate respectively.But first-stage reverse osmosis de-mineralized water and steam condensate are because its calcium, magnesium and basicity are low, and the diffusion of the dissolved oxygen in the water is accelerated, and causes metallic corrosion speed sharply to increase, and corrosion speed is 48 times of present national standard up to 3.6mm/a in the time of 80 ℃.Below two tests be inhibiter to add concentration be 500ppm, hang corrosion coupon in the system, detect the corrosion mitigating effect of this inhibiter.

Test 1: the application of inhibiter of the present invention in Shandong factory first-stage reverse osmosis de-mineralized water see Table 1,2,3.

Table 1: system parameter

Operating parameter	Unit	Numerical value
			Quantity of circulating water	??m 3/h	??4000
Possess the water yield	??m 3	??1500
			Evaporated water	??m 3/h	??48.35
Water amount of blowdown	??m 3/h	??1.37
			Amount of makeup water	??m 3/h	??53.72

Table 2: water quality analysis

Analysis project	Unit	De-mineralized water
			??PH		??6.98
Specific conductivity	??us/cm	??42.0
			Calcium ion	??mg/L
Magnesium ion	??mg/L
			Total hardness (CaCO 3)	??mg/L	??7.50
Total alkalinity (CaCO 3)	??mg/L	??4.63

Analysis project	Unit	De-mineralized water
			Chlorion	??mg/L	??16.0

Table 3: result of use

Lacing film	Lacing film number	Hang the angle of incidence	Quality before hanging	Take-off time	Hang the back quality	Corrosion speed
							Carbon steel 1#	??1301	??2008.05.08	??21.1035g	??2008.05.23	??21.0755g	??0.03072mm/a
Carbon steel 2#	??1302	??2008.05.08	??21.1346g	??2008.05.23	??21.1033g	??0.03434mm/a
							Carbon steel 3#	??1303	??2008.05.08	??20.7293g	??2008.05.23	??20.7145g	??0.01624mm/a

Remarks: lacing film material A ₃, area 28.00cm ²Average corrosion rate 0.02710mm/a, index is better than national standard.

Test 2: the application of the present invention in certain Shanghai factory steam condensate see Table 4,5,6,7.

Table 4: system parameter

Operating parameter	Unit	Numerical value
			Quantity of circulating water	??m 3/h	??1270
Possess the water yield	??m 3	??1200
			Evaporated water	??m 3/h	??22.86
Water amount of blowdown	??m 3/h	??3
			Amount of makeup water	??m 3/h	??27.15

Table 5: water quality analysis

Analysis project	Unit	Steam condensate
			??PH		??8.12
Calcium ion	??mg/L	??1.56

Analysis project	Unit	Steam condensate
			Magnesium ion	??mg/L	??0.83
Iron ion		??0.18
			Total hardness (CaCO 3)	??mg/L	??7.52
Total alkalinity (CaCO 3)	??mg/L	??100.6
			Chlorion	??mg/L	??14.06

Table 6: result of use

Lacing film	Lacing film number	Hang the angle of incidence	Quality before hanging	Take-off time	Hang the back quality	Corrosion speed
							Carbon steel 1#	??1324	??2008.06.17	??20.9613g	??2008.06.29	??20.9531g	??0.01125mm/a
Carbon steel 2#	??1325	??2008.06.17	??21.0652g	??2008.06.29	??21.0411g	??0.03305mm/a
							Carbon steel 3#	??1326	??2008.06.17	??20.7293g	??2008.06.29	??20.7145g	??0.02030mm/a

Remarks: lacing film material A ₃, area 28.00cm ²Average corrosion rate 0.02153mm/a, index is better than national standard.

Table 7: result of use

Lacing film	Lacing film number	Hang the angle of incidence	Quality before hanging	Take-off time	Hang the back quality	Corrosion speed
							Carbon steel 1#	??1366	??2008.06.29	??21.4477g	??2008.07.11	??21.4294g	??0.02510mm/a
Carbon steel 2#	??1367	??2008.06.29	??19.4721g	??2008.07.11	??19.4632g	??0.01221mm/a
							Carbon steel 3#	??1368	??2008.06.29	??21.1568g	??2008.07.11	??21.1488g	??0.01097mm/a

Remarks: lacing film material A ₃, area 28.00cm ²Average corrosion rate 0.01609mm/a, index is better than national standard.

Attached: corrosion speed is calculated

$B=\frac{\mathrm{KG}}{\mathrm{ATD}}$

B---corrosion speed mm/

K——3.65×10 ³

G---quality, g are reduced in lacing film corrosion back

T---lacing film time, d

A---lacing film area, cm ²(carbon steel 28)

D---density metal, g/cm ³(carbon steel 7.92)

Claims (6)

1. a high-temperature water-soluble corrosion inhibitor is characterized in that, it is made up of the material of following weight part ratio:

(1) acid: 10～40 parts;

(2) alkali: 10～40 parts;

(3) water: 20～60 parts;

(4) organic amine: 10～40 parts;

(5) aromatic series azole: 1～10 part.

2. according to the described a kind of high-temperature water-soluble corrosion inhibitor of claim 1, it is characterized in that, described acid be in 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid, phosphoric acid, the thionamic acid any one or multiple.

3. according to the described a kind of high-temperature water-soluble corrosion inhibitor of claim 1, it is characterized in that described alkali is potassium hydroxide or sodium hydroxide.

4. according to the described a kind of high-temperature water-soluble corrosion inhibitor of claim 1, it is characterized in that, described organic amine be in cetylamine, morpholine, triethylene diamine, the trolamine any one or multiple.

5. according to the described a kind of high-temperature water-soluble corrosion inhibitor of claim 1, it is characterized in that, described aromatic series azole be in mercaptobenzothiazole, benzotriazole, the Methylbenzotriazole any one or multiple.

6. according to the preparation method of the described a kind of high-temperature water-soluble corrosion inhibitor of claim 1, it is characterized in that comprising the steps:

(1) accurately takes by weighing acid, alkali, water, organic amine, aromatic series azole in proportion;

(2) with sour stirring heating and and organic amine mixing;

(3) add alkali and the water of half to said mixture, stir;

(4) dropping into the aromatic series azole in the mixture that step (3) obtains stirs;

(5) add remainder water, filter finished product packing.