Scale inhibitor composition as well as preparation and application thereof

Abstract

The invention discloses a scale inhibitor composition as well as preparation and application thereof, and the scale inhibitor composition comprises an organic phosphonic acid substance, polyaspartic acid and amino trimethylene phosphonic acid, the mass ratio of the organic phosphonic acid substance to the polyaspartic acid to the amino trimethylene phosphonic acid is 1: (0.1-0.6): (0.1-0.7). According to the invention, a plurality of scale inhibitor monomers are compounded, so that scaling of a plurality of metal ions can be inhibited at the same time, a better anti-scaling effect is achieved, and the scale inhibition rate can reach more than 95%.

Description

Technical Field

[0001] The present invention relates to a scale inhibitor composition, its preparation and application. Background Art

[0002] With the gradual intensification of the shortage of fossil energy supply, people pay more and more attention to the utilization of geothermal energy. Geothermal resources belong to clean energy. According to the evaluation of the formation geology, the geothermal energy contained in areas where the geothermal resources are buried less than 2000 meters is equivalent to 2500 trillion tons of standard coal, and 50 billion tons of which can be utilized by humans. When the hot fluid transfers from the heat reservoir to the ground or during the pipeline transportation process, due to the decrease in pressure and temperature, some components will reach the saturation state, resulting in the precipitation of solid substances and the formation of a scaling layer on the wellbore or pipeline. The scaling problem of geothermal wells is one of the most important problems faced in the process of geothermal development and utilization, and it is also an important factor affecting the normal operation of the geothermal utilization system. Many geothermal projects at home and abroad have encountered scaling problems.

[0003] At present, the main method adopted at home and abroad to prevent scaling of geothermal wells is the chemical agent method. However, the existing monomer scale inhibitors have some limitations in terms of economy, technical stability, operability and treatment effect. Summary of the Invention

[0004] In order to improve the scale inhibition effect, an embodiment of the present invention provides a scale inhibitor composition, which can simultaneously inhibit the scaling of multiple metal ions.

[0005] As a first aspect of the present invention, it relates to a scale inhibitor composition, and the scale inhibitor composition includes:

[0006] Organic phosphonic acid substances, polyaspartic acid and amino trimethylene phosphonic acid; the mass ratio of the organic phosphonic acid substances, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.6: 0.1 - 0.7.

[0007] In one or some alternative embodiments, the organic phosphonic acid substances are diethylenetriamine pentamethylene phosphonic acid or 2-phosphono-1,2,4-tricarboxylic acid butane.

[0008] In one or some alternative embodiments, when the organic phosphonic acid substance is diethylenetriamine pentamethylene phosphonic acid, the mass ratio of the diethylenetriamine pentamethylene phosphonic acid, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.6: 0.1 - 0.6;

[0009] When the organic phosphonic acid substance is 2-phosphono-1,2,4-tricarboxylic acid butane, the mass ratio of the 2-phosphono-1,2,4-tricarboxylic acid butane, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.4: 0.1 - 0.7.

[0010] As a second aspect of the present invention, it relates to a method for preparing the above scale inhibitor composition, characterized in that the method includes:

[0011] Mixing and stirring an organic phosphonic acid substance, polyaspartic acid and amino trimethylene phosphonic acid evenly according to their mass parts.

[0012] As a third aspect of the present invention, it relates to the application of the above scale inhibitor composition in removing scale from the water quality of geothermal wells, characterized in that the scale inhibitor composition is put into the geothermal well water for scale removal.

[0013] In one or some alternative embodiments, the geothermal well water contains Ca 2+ , HCO3 - , SO4 2- or Mg 2+ .

[0014] In one or some alternative embodiments, the application specifically includes:

[0015] When the pH of the geothermal well water is 6.21 - 6.39, mixing diethylenetriamine pentamethylenephosphonic acid, polyaspartic acid and amino trimethylene phosphonic acid evenly according to their mass parts, and then putting them into the geothermal well water for scale removal;

[0016] Or,

[0017] When the pH of the water body is 8.5 - 9.3, mixing 2-phosphono-1,2,4-tricarboxybutane, polyaspartic acid and amino trimethylene phosphonic acid evenly, and then putting them into the geothermal well water for scale removal.

[0018] In one or some alternative embodiments, the dosing concentration of the scale inhibitor composition is 75 - 150 ppm.

[0019] In one or some alternative embodiments, the dosing concentration of the scale inhibitor composition is 100 - 150 ppm.

[0020] In one or some alternative embodiments, the salinity of the geothermal well water is 1874 - 7940 g / L.

[0021] The scale inhibitor composition provided by the present invention is a compound of a variety of scale inhibitor monomers. Among them, diethylenetriamine pentamethylenephosphonic acid (i.e., DTPMPA) has a strong chelating ability for metal ions; 2-phosphono-1,2,4-tricarboxybutane (i.e., PBTCA) has good performance in inhibiting calcium carbonate and calcium phosphate scale, and can stably exist and have high scale inhibition performance in an alkaline environment; polyaspartic acid (i.e., PASP) has good corrosion and scale inhibition performance and can inhibit the formation of CaCO3, CaSO4 and BaSO4 scale. Therefore, for water samples with a relatively high SO4 2- content, the scale inhibition effect is better; while amino trimethylene phosphonic acid (i.e., ATMP) can dissociate into six positive ions and six negative ions in water, and then can form polycyclic chelates with metal ions such as Ca 2+ , Mg 2+ and disperse in water in a loose form, disrupting the normal crystallization of calcium and magnesium scale. Therefore, for water samples with a relatively high Mg 2+ content, the scale inhibition effect is better. By compounding the above scale inhibitor monomers, the present invention can simultaneously inhibit the scaling of multiple metal ions, achieving a better scale prevention effect, and the scale inhibition rate can reach more than 95%.

[0022] In addition, compounding a variety of scale inhibitor monomers in the present invention also reduces the usage amount of a single scale inhibitor and reduces the impact on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the scale inhibition rate of scale inhibitor compositions with different concentrations under water sample A;

[0024] Figure 2 is the scale inhibition rate of scale inhibitor compositions with different concentrations under water sample B;

[0025] Figure 3 is the scale inhibition rate of scale inhibitor compositions with different concentrations under water sample C;

[0026] Figure 4 is the scale inhibition rate of scale inhibitor compositions with different concentrations under water sample D;

[0027] Figure 5 is the scale inhibition rate of scale inhibitor compositions with different concentrations under water sample E. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters not specified in the following embodiments are usually in accordance with conventional conditions.

[0029] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0030] It should be noted that in the embodiments of the present invention, PASP refers to polyaspartic acid, ATMP refers to aminotrimethylenephosphonic acid, DTPMPA refers to diethylenetriamine pentamethylenephosphonic acid, and PBTCA refers to 2-phosphono-1,2,4-tricarboxylic acid butane.

[0031] The sources of the raw materials used in the embodiments of the present invention are as follows:

[0032] HEDP (Shanghai Aladdin Biochemical Technology Co., Ltd.), DTPMPA (Shandong Kerry Chemical Co., Ltd.), PBTCA (Shandong Kerry Chemical Co., Ltd.), PESA (Shandong Kerry Chemical Co., Ltd.), PASP (Shandong Yuanlian Chemical Industry Co., Ltd.), GLDA (Guangzhou Zhichun Chemical Co., Ltd.), ATMP (Shandong Kerry Chemical Co., Ltd.)

[0033] In the following examples, unless otherwise specified, the parts are all parts by weight.

[0034] Examples 1-19

[0035] At 25°C, DTPMPA, PBTCA, PASP, and ATMP were fully mixed in a stirring kettle according to the weight parts shown in Table 1 to obtain a scale inhibitor composition.

[0036] Table 1 Weight parts of each component of the scale inhibitor composition / part

[0037] Example DTPMPA PBTCA PASP ATMP 1 1 0 0.3 0.3 2 1 0 0.1 0.1 3 1 0 0.2 0.2 4 1 0 0.4 0.4 5 1 0 0.5 0.5 6 1 0 0.6 0.6 7 1 0 0.2 0.1 8 1 0 0.1 0.2 9 0 1 0.2 0.1 10 0 1 0.1 0.1 11 0 1 0.2 0.2 12 0 1 0.1 0.2 13 0 1 0.3 0.3 14 0 1 0.4 0.4 15 0 1 0.1 0.6 16 0 1 0.1 0.3 17 0 1 0.1 0.4 18 0 1 0.1 0.5 19 0 1 0.1 0.7

[0038] Test Example 1

[0039] The scale inhibition rates of commercially available scale inhibitor monomers were measured:

[0040] The scale inhibitors HEDP, DTPMPA, PBTCA, PESA, PASP, GLDA, and ATMP were respectively added to CaCO3 water samples with pH values of 7, 8, 9, and 10, and heated in a water bath for 16 h. When the scale inhibitor concentration was 100 mg / L, the scale inhibition rate was measured, and the measurement results are shown in Table 2.

[0041] Table 2 Scale inhibition rates of each scale inhibitor under different pH conditions (%)

[0042] pH value HEDP DTPMPA PBTCA PESA PASP GLDA ATMP 7 57.5 87.6 83.6 60.5 75.4 30.9 67.6 8 59.9 78.2 86.4 52.3 77.6 48.5 74.2 9 60.5 73.4 87.2 54.2 75.1 55.2 64.5 10 62.5 70.5 87.0 53.1 70.5 51.5 60.2

[0043] Analysis of Table 2 shows that: under the condition that the water sample is neutral (pH value is 7), the scale inhibition rates of organic phosphonic acid scale inhibitors DTPMPA, PBTCA and polymeric scale inhibitor PASP are relatively high, and they have good scale inhibition effect on CaCO3. Among them, DTPMPA has the highest scale inhibition rate. When the dosage is 100 mg / L, the scale inhibition rate can reach 87.6%, indicating that DTPMPA has a strong chelating ability for metal ions; the scale inhibition rate of PBTCA is also relatively high. When the dosage is 100 mg / L, the scale inhibition rate can reach 83.6%. Under the condition that the water sample is alkaline (pH value is 8 - 10), PBTCA has a better scale inhibition rate, while the scale inhibition rate of DTPMPA decreases, indicating that DTPMPA has a lower tolerance for calcium and is not suitable for application in alkaline water samples, while PBTCA is more alkali-resistant and is more suitable for scale inhibition in alkaline water samples.

[0044] Test Example 2

[0045] The scale inhibitors prepared in Examples 1 - 6 were put into Water Sample A, and the scale inhibition rates of the scale inhibitors at different concentrations were tested at 80°C. The test results are shown in Table 3 and Figure 1 as follows.

[0046] In this test example, the pH value of Water Sample A is 6.39, which belongs to a neutral water sample. The main scale formation is Na2SO4, and its salinity is 1874.3 g / L. The concentrations (mg / L) of various ions in the water sample are respectively: 417.8Ca 2+ 、30.9K + 、162.7Mg 2+ 、298Na + 、152Cl - 、215SO4 2- 、372.4HCO3 - 、214.1CO3 2- . In this water sample, the proportions of Ca 2+ 、HCO3 - 、SO4 2- and Mg 2+ are relatively high, and its salinity is not high.

[0047] Table 3 Scale Inhibition Rates of Scale Inhibitor Combinations at Different Concentrations in Water Sample A

[0048]

[0049] Analysis of Table 3 and Figure 1It can be seen that when the dosing concentration of the scale inhibitor composition reaches about 100 ppm, the scale inhibition effects of all scale inhibitor compositions are relatively good. Among them, the scale inhibitor composition with a mass ratio of DTPMPA, PASP and ATMP of 1:0.3:0.3 (i.e., Example 1) has the highest scale inhibition rate, reaching 95.1%.

[0050] Test Example 3

[0051] The scale inhibitor compositions prepared in Examples 1 to 4 and Examples 7 to 8 were put into Water Sample B, and the scale inhibition rates of the scale inhibitor compositions at different concentrations were tested at 80°C. The test results are shown in Table 4 and Figure 2 as follows.

[0052] In this test example, the pH value of Water Sample B is 6.21, which belongs to a slightly neutral water sample. The scaling in it is mainly CaCl2, and its salinity is 9313.4 g / L. The concentrations of various ions in the water sample (mg / L) are respectively: 697Ca 2+ , 120K + , 195Mg 2+ , 2492.1Na + , 4626.2Cl - , 172.25SO4 2- , 64HCO3 - . In this water sample, the proportions of Ca 2+ , SO4 2- and Mg 2+ are relatively high, and its salinity is relatively high.

[0053] Table 4 Scale inhibition rates of scale inhibitor compositions at different concentrations in Water Sample B

[0054] Analyzing Table 4 and Figure 2 it can be seen that when the dosing concentration of the scale inhibitor composition reaches about 100 ppm, the scale inhibition effects of all scale inhibitor compositions are relatively good. Among them, the scale inhibitor composition with a mass ratio of DTPMPA, PASP and ATMP of 1:0.1:0.1 (i.e., Example 2) has the highest scale inhibition rate, which can reach 96.4%.

[0055] Test Example 4

[0056] The scale inhibitor compositions prepared in Examples 9 to 14 were put into Water Sample C, and the scale inhibition rates of the scale inhibitor compositions at different concentrations were tested at 80°C. The test results are shown in Table 5 and Figure 3 as follows.

[0057] In this test example, the scaling in Water Sample C is mainly NaHCO3, its pH value is 8.6, and its salinity is 3630 g / L. This water sample belongs to an alkaline water sample. The concentrations of various ions in the water sample (mg / L) are respectively: 382.2Ca2+ , 42.05K + , 131.52Mg 2+ , 753.2Na + , 689Cl - , 204SO4 2- , 1035.3HCO3 - , 379.2CO3 2- , the salinity of this water sample is relatively high, and the contents of HCO3 - and SO4 2- in the water sample are also relatively high.

[0058] Table 5 Scale inhibition rates of scale inhibitor compositions at different concentrations under Water Sample C

[0059]

[0060]

[0061] Analysis of Table 5 and Figure 3 shows that when the dosage concentration of the scale inhibitor reaches about 100 ppm, the scale inhibition effects of each scale inhibitor composition are relatively good. Among them, the scale inhibitor composition with the mass ratio of PBTCA, PASP and ATMP being 1:0.2:0.1 (i.e., Example 9) has the highest scale inhibition rate, reaching 95.9%.

[0062] Test Example 5

[0063] The scale inhibitor compositions prepared in Examples 9 to 14 were put into Water Sample D, and the scale inhibition rates of the scale inhibitor compositions at different concentrations were tested. The test results are shown in Table 6 and Figure 4 as follows.

[0064] In this test example, the scale formation in Water Sample D is mainly NaHCO3, with a pH value of 8.5 and a salinity of 5621 g / L. This water sample belongs to an alkaline water sample, and the concentrations of various ions in the water sample (mg / L) are respectively: 381.87Ca 2+ , 79.85K + , 135.86Mg 2+ , 3190.2Na + , 677Cl - , 70SO4 2- , 890.7HCO3 - , 177.6CO3 2- , the salinity of this water sample is relatively high, and the content of HCO3 - in the water sample is relatively high, but the content of SO4 2- is relatively low.

[0065] Table 6 Scale inhibition rates of scale inhibitor compositions at different concentrations under Water Sample D

[0066]

[0067]

[0068] Analysis of Table 6 and Figure 4 It can be seen that when the dosing concentration of the scale inhibitor reaches about 100 ppm, the scale inhibition effects of each scale inhibitor composition are all good. Among them, the scale inhibitor composition with the mass ratio of PBTCA, PASP and ATMP being 1:0.1:0.2 (i.e., Example 12) has the highest scale inhibition rate, reaching 95.5%.

[0069] Test Example 6

[0070] The scale inhibitor compositions prepared in Examples 15 to 19 and Example 12 were put into Water Sample E, and the scale inhibition rates of the scale inhibitor compositions at different concentrations were tested at 80 °C. The test results are shown in Table 7 and Figure 5 as follows.

[0071] In this test example, the scale formation in Water Sample E is mainly NaHCO3, with a pH value of 9.3 and a salinity of 7490 g / L. This water sample belongs to an alkaline water sample. The concentrations (mg / L) of various ions in the water sample are respectively: 276.79Ca 2+ 、790.19K + 、1343.1Mg 2+ 、1285Na + 、248.77Cl - 、0.76SO4 2- 、3011.2HCO3 - 、420.5CO3 2- , and the salinity of this water sample is relatively high, and the contents of HCO3 - and Mg 2+ are also relatively high.

[0072] Table 7 Scale inhibition rates of scale inhibitor compositions at different concentrations in Water Sample E

[0073]

[0074] Analysis of Table 7 and Figure 5 It can be seen that when the dosing concentration of the scale inhibitor reaches about 100 ppm, the scale inhibition effects of each scale inhibitor composition are all good. Among them, the scale inhibitor composition with the mass ratio of PBTCA, PASP and ATMP being 1:0.1:0.6 (i.e., Example 15) has the highest scale inhibition rate, reaching 96.3%.

[0075] Although the specific embodiments of the present invention have been described in detail, those skilled in the art will understand that, based on all the teachings that have been disclosed, various modifications and substitutions can be made to those details, and such changes are within the scope of protection of the present invention. The full scope of the present invention is given by the appended claims and any equivalents thereof.

Claims

1. A scale inhibitor composition, characterized in that, The scale inhibitor composition includes: Organic phosphonic acid substances, polyaspartic acid and amino trimethylene phosphonic acid; the mass ratio of the organic phosphonic acid substances, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.6: 0.1 - 0.

7.

2. The scale inhibitor composition according to claim 1, wherein, The organic phosphonic acid substances are diethylenetriamine pentamethylene phosphonic acid or 2 - phosphono - 1,2,4 - tricarboxylic acid butane.

3. The scale inhibitor composition according to claim 2, characterized in that, When the organic phosphonic acid substance is diethylenetriamine pentamethylene phosphonic acid, the mass ratio of the diethylenetriamine pentamethylene phosphonic acid, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.6: 0.1 - 0.6; When the organic phosphonic acid substance is 2 - phosphono - 1,2,4 - tricarboxylic acid butane, the mass ratio of the 2 - phosphono - 1,2,4 - tricarboxylic acid butane, polyaspartic acid and amino trimethylene phosphonic acid is 1: 0.1 - 0.4: 0.1 - 0.

7.

4. A method for preparing the scale inhibitor composition according to any one of claims 1 to 3, characterized in that, The method includes: Mixing and stirring evenly the organic phosphonic acid substances, polyaspartic acid and amino trimethylene phosphonic acid according to their mass parts.

5. Use of the scale inhibitor composition according to any one of claims 1 to 3 in removing scale from the water quality of geothermal wells, characterized in that, Putting the scale inhibitor composition into geothermal well water for scale removal.

6. The application according to claim 5, wherein The geothermal well water contains Ca 2+ , HCO3 - , SO4 2- or Mg 2+ .

7. The application according to claim 5, wherein The application specifically includes: When the pH of the geothermal well water is 6.21 - 6.39, mixing and stirring evenly diethylenetriamine pentamethylene phosphonic acid, polyaspartic acid and amino trimethylene phosphonic acid according to their mass parts, and then putting them into the geothermal well water for scale removal; Or, When the pH of the water body is 8.5 - 9.3, mixing evenly 2 - phosphono - 1,2,4 - tricarboxylic acid butane, polyaspartic acid and amino trimethylene phosphonic acid according to their mass parts, and then putting them into the geothermal well water for scale removal.

8. The application according to claim 5, wherein The dosing concentration of the scale inhibitor composition is 75 - 150 ppm.

9. The application according to claim 5, characterized in that The dosing concentration of the scale inhibitor composition is 100 - 150 ppm.

10. The application according to claim 5, wherein The salinity of the geothermal well water is 1874 - 7940 g / L.

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