SOLUTION FOR REMOVING VARIOUS TYPES OF DEPOSITS FROM A SURFACE

Abstract

The invention relates to the field of removing various types of deposits from a surface, specifically to means for cleaning metallic and ceramic surfaces of industrial equipment, and can be used for removing deposits, such as oxides of metals (iron, chromium, nickel, etc.), carbonate and salt deposits, asphaltene-resin-paraffin deposits and deposits of a petroleum nature, and deposits of an organic and biological deposits. The proposed solution for removing various types of deposits contains hydrogen peroxide, complexone, an anti-foaming agent, water-soluble calixarene and water in the following ratio: hydrogen peroxide, a catalyst for decomposing peroxide compounds, an antifoaming agent, complexone, water-soluble calixarene and water in the following quantitative ratio: 2-35% by mass of hydrogen peroxide; 2-20% by mass of a catalyst for decomposing peroxide compounds; 3-10% by mass of complexone; 0.1-5% by mass of surface-active agent; 0.01%-1.0% by mass of anti-foaming agent; 0.01-1% by mass of water-soluble calixarene, with the remainder being water. The technical result is an increase in the effectiveness of action of a solution (degree of cleaning) for cleaning surfaces soiled with deposits having a high content of organic substances, while simultaneously extending the field of use of said solution.

Claims

1: A solution for removing various types of deposits from a surface, including deposits with a high organic content, comprising hydrogen peroxide, a chelating agent, an anti-foaming agent, water-soluble calixarene and water at the following quantitative ratio, % wt.: TABLE-US-00003 hydrogen peroxide 2-35 catalyst for decomposing peroxide compounds 2-20 chelating agent 3-10 surfactant 0.1-5 anti-foaming agent 0.01-1.0 water-soluble calixarene 0.01-1 water remaining part

2: The solution according to claim 1, wherein an alkali metal hydroxide, a transition metal compound or their mixtures is used as the catalyst for decomposing peroxide compounds.

3: The solution according to claim 1, further comprising a peroxide compound stabiliser in the amount of 1-5% wt.

4: The solution according to claim 1, further comprising a corrosion inhibitor in the amount of 0.5-2.5% wt.

5: The solution according to claim 1, wherein the chelating agent is chosen from polyatomic salts of organic acids and phosphonic acid derivatives.

6: The solution according to claim 3, wherein the peroxide compound stabiliser is chosen from the following group: sodium hexametaphosphate, potassium phosphate, sodium tripolyphosphate.

7: The solution according to claim 1, wherein surfactant is chosen from the following group: alkylbenzene sulfonate, nonoxynol, ethoxylated fat alcohol, laureth sulfate or a mixture thereof.

8: The solution according to claim 1, wherein the anti-foaming agent is chosen from the following group: water-oil emulsion of polymethylsiloxanes and other silicon organic compounds, ethylene oxide-based block copolymers or propylene oxide-based block copolymers.

9: A high-concentration component for preparation of the solution for removing various types of deposits according to claim 1, comprising, at least, a chelating agent, water-soluble calixarene, a catalyst for decomposing peroxide compounds and water at the following quantitative ratio, % wt.: TABLE-US-00004 chelating agent 30-50 water-soluble calixarene 0.1-10 catalyst for decomposing peroxide compounds 2-20 water remaining part

10: The high-concentration component according to claim 9, further comprising a corrosion inhibitor in the amount of 5-25% wt.

11: The high-concentration component according to claim 9, further comprising a peroxide compound stabiliser in the amount of 5-20% wt.

12: The high-concentration component according to claim 9, further comprising a surfactant in the amount of 3-30% wt.

13: The high-concentration component according to claim 9, wherein the chelating agent is chosen from polyatomic salts of organic acids or phosphonic acid derivatives.

14-19. (canceled)

20: A method for cleaning a surface from deposits of various nature, comprising applying on the deposits a solution produced by mixing a high-concentration component and hydrogen peroxide with further dilution with water to provide over-gassing on deposits' surface and inside pores of the deposits with formation of bubbles with radius from 1.6*10.sup.5 m to 2*10.sup.3 m, while maintaining temperature up to 250 C. and pressure from 0.1 to 16 MPa in area around the deposits, wherein the high-concentration component comprises, at least, a chelating agent, a water-soluble calixarene, a catalyst for decomposing peroxide compounds and water at the following ratio, % wt.: TABLE-US-00005 chelating agent 30-50 water-soluble calixarene 0.1-10 catalyst for decomposing peroxide compounds 2-20 water remaining part

21. (canceled)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0028] As it was already mentioned above, the background of the claimed cleaning technology is to combine the mechanical, chemical and physical-chemical effect on the deposits, as well as combine complexing and surface-active properties in a molecule of the active component.

[0029] The peroxide compound decomposition is associated with excessive gas formation with energy release. The volume of the gas released is proportional to the hydrogen peroxide concentration. The exothermic effect of decomposition provides for solution heating that leads to sped-up effect occurrence and chemical reaction rate directly in the pores of deposits.

[0030] The cleaning composition (solution) comprises hydrogen peroxide, catalyst for decomposing peroxide compounds, SAA, chelating agent, water-soluble calixarene, anti-foaming agent and water.

[0031] The hydrogen peroxide 2-35% wt. (depending on the initial solution concentration) provides for gas formation processing by exothermic decomposition that, in its turn, has the destructive effect on deposits. Using the composition with the percentage of less than 2% wt. does not provide for necessary effect (incomplete cleaning), using the composition with the percentage of more than 35% wt. is not recommended as in this case the intense decomposition effect can have destructive effect on the equipment. The hydrogen peroxide concentration affects the gas volume and temperature in the pores of deposits. By changing the peroxide component concentration, the specified gas formation intensity is achieved.

[0032] The catalyst for decomposing peroxide compounds in the amount of 2.0-20.0% wt. (depending on the initial solution concentration), in case of use of alkali metals as hydroxides, provides for necessary pH of the solution, has the destructive effect on organic deposits and passivates metal surfaces. For extra complex deposits, the cleaning composition can further comprise the catalyst for decomposing peroxide compounds in the form of transition metal compounds, for example, copper, iron, chrome, nickel, manganese ions, etc.

[0033] Besides, the transition metal compounds can be used as the catalyst for decomposing peroxide compounds beyond the combination with alkali metal hydroxides, with the cleaning efficiency preserved. Also, the use is possible, for example, in cases, when the use of the solutions with alkali components is hindered by the nature of the equipment material. Thus, for example, aluminium alloys are subject to severe destruction, that is why to use the composition for the equipment made of this material, the transition metal catalysts are used. And maintaining the efficiency of cleaning is achieved by maintaining the catalytic decomposition of peroxide compounds in the pores of deposits.

[0034] The water-oil emulsion of polydimethylsiloxanes and other silicon organic compounds, ethylene oxide and propylene oxide-based block copolymers are used as the anti-foaming agents in the amount of 0.01-1.0% wt. Using the anti-foaming agents in the amount of 0.01% wt. does not provide for foam and foam formation decrease, and of more than 1% wt. does not affect the anti-foaming rate. Presence of such component as the anti-foaming agent in the claimed solution makes it possible, as opposed to the prototype, to use the solution for the facilities with large volumes (from 1 m.sup.3) of solutions because of possible violation of the facility safety conditions.

[0035] The claimed solution comprises the SAA in the amount of 0.1-5% wt. to ensure better wetting quality of the equipment surface, provide for deeper penetration of the solution into the pores of deposits and emulsification of organic deposits in the solution.

[0036] The non-ionic surfactantsalkoxylates, alkyl glycosides, anionic surfactantscarboxyethoxylates, phosphates and polyphosphates, sulphosuccinates, alkyl sulfates, alkyl ester sulfates. The use of surfactants (SAA) provides for further increase in cleaning efficiency of the solution due to the decreased surface tension at the interface of the fluid and solid matter phases (cleaning solutiondeposits). This effect is due to the SAA molecule sorption on the surface of deposits and due to the similarity of chemical nature of the deposits molecules and SAA molecules. The decreased surface tension provides for better wetting quality of deposits by the cleaning composition that entails the increased contact area of the solution with deposits. Besides, the above effect makes the solution penetrate into the pores of deposits that leads to possible delivery of peroxide compounds to the pores of deposits with further decomposition. The selection of the surface-active agent is the important task to be solved individually depending on the nature of deposits. The use of the SAA in the concentrations of less than 0.1% does not provide for wetting effect, and of more than 5% does not influence the further increased cleaning efficiency.

[0037] The chelating agent is used in the amount of 3-10% wt. The water-soluble chelating agents, for example, sodium salts of overbased organic acids or overbased organic acid themselves, such as complexone 2, as well as phosphonic acid derivatives,

such as ATM, etidronic acid, can be used as the chelating agent. The use of the chelating agent in the concentration of less than 3% wt. does not provide for necessary complexing effect, and in the concentration of more than 10% wt, the composition cost increase is not compensated by the increased detergency effect (the composition is deteriorated by the efficiency-cost criterion).

[0038] The water-soluble calixarene of general formula is used in the amount of 0.01-1.0% wt. The compound of general formula is preferably used

##STR00001##

The use of the water-soluble calixarenes of the structure specified provides for efficient binding of heavy ions, including radioactive ones, thus forming stable complexes. Any structures of the content specified can be used. For heavy metal binding, the compounds with the number of monomer units of 6-8 are preferred, as in this case, the internal cavity of the molecule matches the heavy metal radius. The use of the water-soluble calixarenes in the concentrations less than 0.01% wt. does not provide for complexing effect, and with the increased concentration (more than 1.0% wt.), no improvement in cleaning properties is observed.

[0039] The use of the water-soluble calixarenes that combine both complexing and surface-active properties provides for considerable increase in the cleaning efficiency. In particular, in case of metal surfaces, metal ion binding and transition to mycelial phase occur (it was not claimed earlier).

[0040] As the universal complexing agent, the use of tetracarboxylic based compounds, for example, EDTA and its salts is the most optimal. These examples of specific acids are given for illustration of embodiment of the group of inventions and do not restrict the scope. These examples of acids should not be considered as restricting the scope of the claimed group of inventions that is determined by the claims.

[0041] The peroxide compound stabiliser can be further added in the amount of 1-5% wt. Sodium hexametaphosphate or similar salts of phoshoric and polyphoshoric acids, such as sodium tripolyphosphate, are used as such stabiliser. With the use of the stabiliser in the concentration of less than 1% wt., the decomposition occurs incrementally and is not controllable, and of more than 5% wt., no proper gas formation is provided. The gas release rate during the peroxide compound decomposition is primarily dependent on the concentration ratio of stabiliser and catalyst for decomposing peroxide compounds.

[0042] To neutralize the destructive effect of the cleaning composition, the relevant inhibitor in the amount of 0.5-2.5% wt. are further applied directly on the equipment surface. These substances form the non-soluble solid layer on the surface to protect it from exposure of the solution active components. The use of inhibitor in the concentrations of less than 0.5% wt. does not provide for proper inhibiting effect, and with the concentration of more than 2.5% wt., leads to the unjustified composition cost increase. Captax (2-mercaptobenzothiazole), benzotriazole, tolyltriazole (4-methyl-benzotriazole and 5-methyl-benzotriazole mixture), pyridinic and pyridinic based compound can be used as corrosion inhibitors.

[0043] The detergency effect is achieved by the cleaning composition pumping through the equipment contours or by placing the parts into the bath with circulation.

[0044] To justify the assay content of reagents in the aqueous solution, for cleaning the metal and non-metal surfaces from deposits, the illustrative samples (see Table 1) that had passed the cleaning efficiency testing were prepared.

TABLE-US-00001 TABLE 1 Examples (samples) of cleaning solutions. Content, Examples % wt. 1 2 3 4 5 6 7 8 9 10 Hydrogen 1 25 30 5 15 30 5 15 30 30 peroxide Sodium 0 0 5 5 10 10 15 15 30 40 hydroxide (catalyst for de- composing peroxide com- pounds) EDTA 4 4 6 15 4 6 20 30 5 10 Anti- 0.05 0.01 0.05 0.01 0.1 0.1 1 0.5 1 0.5 foaming agent SAA 0 0.1 0.1 1 1.5 2 2 3 5 7 Water- 5 2 0.01 5 0.1 0.1 3 0.1 0.1 0.1 soluble calixarene Water re- re- re- re- re- re- re- re- re- re- main. main. main. main. main. main. main. main. main. main.

[0045] To produce the solution (sample) according to example 1, the high-concentration component comprising the chelating agent (EDTA), sodium hydroxide and water-soluble calixarene (6 monomer units), was mixed with 36% hydrogen peroxide solution and diluted with water. The produced cleaning solution comprised the following components: hydrogen peroxide, sodium hydroxide, EDTA, water-soluble calixarene, SAA, anti-foaming agent (water-oil emulsion of polydimethylsiloxanes) and water. The produced solution was pumped through the heat exchanging equipment contaminated with oil residues (thermal decomposition products of heavy hydrocarbon fractions). Purity test was conducted by the visual method and pressure difference method upstream and downstream heat exchanger. The cleaning efficiency test results are given in Table 2.

TABLE-US-00002 TABLE 2 Cleaning efficiency test results for solution samples. Indicators of cleaning Examples, No. of compositions of the equipment with according to present invention organic deposits 1 2 3 4 5 6 7 8 9 10 Presence of Present 5 0 0 0 0 0 0 0 0 0 deposits invention after Prototype 10 20 30 10 10 20 15 10 20 30 cleaning, % to area Cleaning Present 6 6 6 6 6 6 6 6 6 6 time, h invention Prototype 8 8 8 8 8 8 8 8 8 8 Aggressive Present no no no no no no no no no no action of the invention solution on Prototype Partial no no no no no Partial no no no the metal

[0046] In the first example, the presence of residual deposits made 5%, as in such solution, the peroxide compound content is not sufficient to complete the reaction (in this example, the content is 1%, and in the remaining ones, it is more).

[0047] Solutions according to examples 1-10 were obtained similarly to example 1. With the only difference that: [0048] as the chelating agent, according to example 2, the ATM was used; according to example 3, the EDTA; according to example 4, the EDTA; according to example 5the ATM; according to example 6, the etidronic acid; according to example 7, the EDTA, according to example 8, the EDTA; according to example 9, the etidronic acid; according to example 10, the ATM; [0049] as the catalyst for decomposing peroxide compounds, the sodium hydroxide was used in examples 3-10; [0050] as the SAA, in example 4, alkylbenzene sulfonate was used; in example 5alkylphenol polyethoxylate surfactants (APnEO, n=7-9), in example 6laureth sulfate, in example 7APnEO (n=10-12), in example 8alkylbenzene sulfonate and laureth sulfate mixture 1:1, in example 9alkylbenzene sulfonate, in example 10alkylbenzene sulfonate and APnEO (n=10-12) mixture. [0051] as the anti-foaming agent, in examples 1-5 the water-oil emulsion of polymethylsiloxane was used, in examples 6-10the ethylene oxide-based block copolymers

[0052] The solutions obtained according to examples 2-10 were tested and assessed in a similar way according to example 1. The conducted tests are confirmed by the increased efficiency of the claimed solution for cleaning from deposits of organic nature which feature is inactivity in relation to chemical agents with simultaneously increasing scope.

[0053] Although this group of invention has been described in detail in the examples of embodiments that appear to be preferred, it should be remembered that these examples of embodiment are given only for illustrative purposes. This description should not be considered as restricting the scope of invention, as the described solution, its high-concentration component, method of preparation and cleaning method can be modified by those skilled in the art of chemistry, etc., in order to adopt them to specific solution contents or situations and not to be beyond the appended claims of group of inventions. Those skilled in the art are aware that variations and modifications, including equivalent solutions, defined by the claims are possible within the scope of the invention.