RU2791778C1 - Alkaline preparation for removing scaling and cleaning internal surfaces of heat power and process equipment - Google Patents

Abstract

FIELD: petrochemical industry.

SUBSTANCE: removal of acidic contaminants from oil refinery waste. The alkaline preparation contains the following components, in % by weight: sodium hydroxide - 5.5-15.5; surfactants: amine oxide and alkyl polyglucoside - 1.5-2.5 and 1-2, respectively; ethylene diamine tetraacetic acid (EDTA) - 0.5-1; phenolphthalein - 0.01; water - the rest.

EFFECT: reduction in the redox-potential and increase in the reducing ability of the system.

1 cl, 1 ex

Description

Technical field

The drug (commercial name "BIODESOL-TURBO A" (BIODESOL-TURBO A) refers to alkaline detergents and can be used at enterprises where acidic deposits of oil products are formed during operation on equipment. These include both chemical and petrochemical industries, and and fuel industry.

State of the art

A detergent is known (RU No. 2186098, publ. 27.07.2002) for cleaning a metal surface, containing the following ratio of components, g / l: sodium hydroxide 0.9-3.3; sodium tripolyphosphate 0.72-2.64; sodium carbonate 2.82-10.34; sodium metasilicate 0.6-2.2; ethoxylated monononylphenol based on propylene trimers, containing 12 mol of ethylene oxide in the molecule 0.024-0.088; ethoxylated monononylphenol based on propylene trimers containing 6 moles of ethylene oxide in the molecule 0.036-0.132; trisodium phosphate 0.84-3.08; polyethylene glycol ethers of synthetic primary higher fatty alcohols of the C ₁₆ -C ₂₀ fraction 0.06-0.22; water the rest up to 1 liter.

Having a satisfactory washing ability, the composition has disadvantages: high foaming, which makes it impossible to use it in high-speed metal processing units and leads to increased material consumption, sodium metasilicate, which is part of the composition in large quantities, forms a passive film on the metal surface, which leads to a deterioration in quality properties coatings applied to metal.

Known detergent (RU No. 2359013, publ. 20.06.2009), containing the following ratio of components, in g/l: sodium hydroxide 1,16-6,38; sodium silicate 0.01-0.70; trisubstituted sodium phosphate 0.016-0.09; complexone (disodium salt of ethylenediaminetetraacetic acid, aqueous or trisodium salt of hydroxyethylidene diphosphonic acid, aqueous) 0.0095-0.05; detergent surface-active agent  Berol DGR 81 (optimized mixture of   non-ionic surfactants of alcohol ethoxylates and alkyl glucosides) 0.078-0.428; water the rest up to 1 liter.

This detergent product cleans rolled metal well with the chemical degreasing method, but does not give sufficiently good cleaning results with the electrochemical method. The silicates included in the composition form a passive film on the metal surface, which leads to a deterioration in the quality properties of the zinc or aluminum-zinc coatings applied to the metal.

Known detergent (RU No. 2245359, publ. 27.01.2005), containing the following ratio of components, g/l: sodium hydroxide 6.05-12.05; sodium carbonate 5.25-10.75; sodium silicate 0.27-0.47; sodium tripolyphosphate 1.20-2.70; ethoxylated monoalkylphenol based on propylene trimers, containing 12 moles of ethylene oxide in the molecule 0.073-0.158; ethoxylated monoalkylphenol based on propylene trimers containing 6 moles of ethylene oxide in the molecule 0.054-0.106; antifoam agent PK-3 0.011-0.023; water the rest up to 1 liter.

This tool has low foaming, but it cannot provide a good degree of cleaning of rolled metal in rolls, because. the surfactants included in its composition are ineffective in removing lubricants and carbonaceous contaminants during high-speed (25-30 sec) processing, moreover, they are not completely biodegradable substances. The disadvantage of the tool is also that the complex phosphates included in the composition in an amount of more than 15-20% are undesirable from the point of view of ecology, because. are the main cause of esterification of surface waters.

It is known to use in industry for cleaning metal surfaces from contamination of an alkaline detergent composition containing soda ash, (RU No. 2083648, publ. 10.07.1997), containing a nonionic surfactant (surfactant), such as a block copolymer of ethylene oxide and propylene oxide at a ratio of 0.6:1 with a molecular weight of 5500 and ethoxylated organic acid C18-C20 with 6 moles of ethylene oxide and sodium silicate of the liquid glass type, sodium polyphosphate and water.

The disadvantage of the described composition is the need to heat up to a temperature above 40°C, the need to protect workers from getting hot alkaline solution during surface treatment, as well as the need for subsequent washing of the degreased surface with water and regeneration of the alkaline solution.

Also known detergent composition for cleaning metal surfaces (RU No. 2010844, publ. 15.04.1994), having the following composition, wt.%: nonionic surfactant 2-5; sodium metasilicate 39-42; sodium trisodium phosphate 14-16; sodium hydroxide 12-14; alkylammonium or alkylpyridinium halide 0.2-0.8; water up to 100.

Known detergent composition (RU No. 2179998, publ. 27.02.2002), containing, wt.%: neonol 2.5-8.0; trisodium phosphate 5-10; sodium metasilicate 5-30; sodium hydroxide 10-40; sodium chloride 1-2.5; sodium sulfate 5-10; carbamide 0.5-1.0; water up to 100.

A common disadvantage of these detergents is the high content of sodium metasilicate, since when its content is more than 20%, SiO2 is released on the surface being cleaned, which prevents cleaning, i.e. reduces cleaning power. In addition, detergents have a relatively low content of surfactants, which affects the quality of cleaning from contaminants.

Known water-soluble detergent for cleaning the surface of organic contaminants (RU No. 2132367, publ. 27.06.1999), which has the following composition, wt.%: non-ionic surfactant 0.2-14.0; polyelectrolyte 2.2-5.5; active additive the rest up to 100. As a polyelectrolyte, sodium salt of polyacrylic acid or sodium salt of carboxymethylcellulose is used, as a nonionic surfactant - neonol with the number of oxide groups from 9 to 12. The active additive has three options, and the ratio of its components is as follows, wt.%: a) soda ash 81-83.4 and carbamide 16.6-19.0; b) soda ash 40-46 and metasilicate 54-60; c) soda ash 39.5-44 and urea 0.8-1.5.

The disadvantage of detergent compositions containing a large amount of metasilicates (loss of purification due to the release of SiO2 on the surface to be cleaned) has already been noted above. In addition, the detergent containing the active additive according to option a) is not suitable for cleaning metal surfaces, because. it has pronounced corrosive properties due to the presence of urea and a large amount of carbonate ions in it. The amount of non-ionic surfactant with corrosion inhibitor properties is obviously small enough to reduce this effect. In addition, the disadvantages of this detergent include its high consumption (15 g/l) with a relatively low washing power of 90-94%.

Known detergent for cleaning metal surfaces from organic contaminants (RU No. 2169175, publ. 20.06.2001), which has the following composition, wt.%: a mixture of nonionic and anionic surfactants 4-20; polyelectrolyte 2-12; salts of benzoic acid 0.01-0.02; the active component is up to 100, and the mass ratio of non-ionic to ionic surfactant is 2-8: As a non-ionic surfactant, neonols and/or sintanol are used. As an anionic surfactant, anionic surfactants are used, for example, salts of alkylbenzenesulfonic acids, alkylbenzenesulfonatamine and cationic surfactants - amine-containing compounds, for example, triethanolamine or ammonium bases with alkyl chains of an aliphatic structure, for example, quaternary salts of alkylamines - tetrasodium sulfoaminosulfonate. Soda ash, tripolyphosphate or trisodium phosphate and metasilicate or liquid glass are used as the active component. As a polyelectrolyte, for example, sodium polyacrylate is used, which provides flocculation of contaminants, which makes it possible to use the detergent repeatedly.

Although the detergent is characterized by good detergent, coagulating properties, but at the same time it has a number of disadvantages: a high content of sodium metasilicate, which provokes the release of SiO2 on the cleaning surface, which prevents cleaning, i.e. reduces the washing ability of the product; the presence of a large number of phosphate-containing compounds, the entry of which into wastewater harms water bodies and the environment; high content of soda ash, which causes corrosion of equipment; relatively high consumption of cleaning agent, which subsequently affects the cost of cleaning; the high cost of the detergent as a whole due to the content of an expensive non-ionic surfactant (syntanol) in it in large quantities

Closest to the invention in terms of technical essence and the achieved effect is a detergent (RU No. 2422499, publ. 06/27/2011) for cleaning a metal surface, containing the following ratio of components, in wt.%: sodium hydroxide 15-25; potassium hydroxide 10-15; sodium metasilicate (liquid glass) 1-3; nonionic surfactant (alkyl polyglycoside C ₈ -C ₁₀ ) 3-7; nonionic surfactant (alkyldimethylamine oxide) 1-5; potassium carbonate 1-3; sodium gluconate 0.1-3; sodium tripolyphosphate 0.1-1; ethylene glycol 1-3; water the rest.

Using this detergent at a temperature of 65-80°C and a degreasing time of 25-30 seconds, a good degree of cleaning of the metal surface can be obtained. But the drug has significant drawbacks - high foaming, which makes it impossible to use it in high-speed metal processing units, as well as high material consumption. A fairly strong heating of the working solution is required.

Disclosure of invention

The technical result of the invention is the elimination of these disadvantages and the creation of a cleaning agent with high detergency in relation to a wide range of contaminants in a situation where the scale contains oil products, reduced corrosion activity and low consumption rates of the cleaning agent.

The specified technical result is achieved by the fact that the preparation for descaling and cleaning the internal surfaces of heat power and process equipment from scale deposits contains: sodium hydroxide, ethylenediaminetetraacetic acid (EDTA), which prevents corrosion of equipment during its cleaning and has a protective effect of scale formation, surfactants: amine oxide and alkyl polyglycoside, which increase the ability of the drug to dissolve scale and wash surfaces from oil products, a dye-indicator of the pH level (phenolphthalein), which discolors when the pH level shifts to the neutral zone, in the following ratio of components, wt.%: sodium hydroxide - 5.5- 15.5; amine oxide - 1.5-2.5; alkylpolyglucoside - 1-2; ethylenediaminetetraacetic acid (EDTA) - 0.5-1; phenolphthalein - 0.01; water is the rest.

Implementation of the invention

The invention relates to a mineral detergent. The drug was developed for washing heat and power and process equipment at the enterprises of the oil refining complex. Such equipment, in addition to scale, is also contaminated with various oil products. Often oil products and scale deposits are sintered together and are not subject to decomposition by standard detergents. In addition, the preparation also contains additives that prevent corrosion of equipment during its cleaning and have a protective effect of scale formation. Cleaning can be carried out without dismantling the equipment: during cleaning, the solution circulates in a closed circuit and does not damage the seal and rubber materials. Additionally, it also introduced a dye-indicator of the pH level, which discolors when shifted to the neutral zone. In this case, we can conclude that the possibilities of the drug for cleaning equipment have been exhausted and the spent drug can be disposed of without special measures by draining into the sewer

The tool can be obtained by mixing the components.

The basis for the preparation of the drug "BIODESOL-TURBO A" (BIODESOL-TURBO A) is alkali in dry form. Together with surface-active substances (surfactants), its ability to dissolve scale increases significantly.

For the preparation of "BIODESOL-TURBO A" (BIODESOL-TURBO A) at all stages, it is necessary to completely dissolve the components. If crystals or viscous lumps of surfactant remain, over time they will NOT DISSOLVE on their own and are a marriage.

Preparation of the drug should be carried out in strict sequence. Failure to follow this sequence may result in the rejection of the entire batch!

Based on the volume of the batch produced, we add half the volume of distilled water to the reactor. With the stirrer on (30-60 rpm), sodium hydroxide (NaOH) is introduced. Stirring for 5 min. We visually assess the absence of mechanical inclusions of undissolved solids, after which ethylenediaminetetraacetic acid (EDTA) can be added and stirred until completely dissolved. We bring the volume of distilled water to 85% of the size of the produced batch. We heat up to a temperature of 25-30 ° C. Separately, we prepare surfactants: amine oxide and alkyl polyglucoside are added to a total container with a volume of 15-20 liters. We add (10% of the total volume of the produced batch) distilled water. Mix until smooth. Drain into the reactor. We mix the surfactants in the reactor until homogeneous (there should be no lumps in the mixture), if it does not dissolve, we increase the heating to 40 ° C and mix until completely dissolved.

Entering an indicator. We add the required volume of the methyl red indicator to the container. Add distilled water. Stir until completely dissolved. We introduce the indicator solution into the reactor. Mix until smooth.

Implementation example

Tests of "BIODESOL-TURBO A" (BIODESOL-TURBO A) were carried out in Perm at the working site of NIPT LLC on a heat exchanger issued from the Lukoil-Permnefteorgsintez plant. In the tests carried out on 07/30/2021, a heat exchanger with two circuits was used. To clean its internal circuit, a heated solution of "Biodesol-Turbo A" was pumped into it.

During the cleaning procedure, the process was accompanied by the release of foam. She occupied a significant amount. Excess pressure was bled through a valve from above. The solution performed well when flushing the heat exchanger, but flushing was carried out with a concentrate, and in the future it is rational to flush not with a concentrate, but with a solution diluted with water.

After the cleaning procedure, a layer of rust pieces approximately 10-15 cm thick formed on the bottom of the cube. Thus, a chemical reaction took place not only with carbonate deposits, but also with iron.

Thus, the claimed drug has a high detergency against a wide range of contaminants, including when the scale contains oil products, and also has reduced corrosiveness and low consumption rates.

A comparative analysis of the claimed drug shows that the totality of its essential features is unknown from the prior art, and therefore corresponds to the condition of patentability "Novelty".

In the prior art, no features were identified that coincide with the distinctive features of the claimed drug and affect the achievement of the claimed technical result, therefore the claimed invention meets the condition of patentability "Inventive step".

The above information confirms the possibility of using the claimed preparation as a detergent that can be used on equipment where acidic deposits of oil products are formed during operation, and therefore meets the patentability condition "Industrial applicability".

Claims (2)

Alkaline preparation for descaling and cleaning the internal surfaces of thermal power and technological equipment, containing sodium hydroxide, ethylenediaminetetraacetic acid (EDTA), surfactants (surfactants): amine oxide and alkylpolyglycoside, pH indicator dye - phenolphthalein and water, in the following ratio of components , wt.%: Sodium hydroxide (NaOH) 5.5-15.5 Aminoxide 1.5-2.5 Alkylpolyglucoside 1-2 Ethylenediaminetetraacetic acid (EDTA) 0.5-1 Phenolphthalein 0.01 Water rest