Compositions and Methods for Improving the Quality of Brine in Desalination Equipment

Abstract

Method for improving the quality of the effluent brine, the method comprising (i) providing a slurry washing solvent comprising a hydrocarbon having a specific gravity less than the specific gravity of the desalination unit brine to be treated; and (ii) adding the slurry washing solvent to the slurry wash stream of the desalination unit system to provide a treated effluent brine.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 62 / 887,036, filed on August 15, 2019, the entire content of which is incorporated herein by reference. Technical Field

[0003] The disclosed technology generally provides a mud washing solvent, and more specifically, provides a mud washing solvent and method for improving the quality of the effluent brine of desalination equipment. Background Art

[0004] Refinery desalination equipment systems are designed to primarily remove inorganic salts from crude oil that can cause corrosion and fouling in downstream units prior to refining. The desalination step is provided by adding and mixing several volume percentages of fresh water with the crude oil to contact the brine and salts present in the crude oil. The salts are extracted by shearing the crude oil with water and treating the resulting oil-water emulsion with the aid of electrical, thermal, and / or chemical energy. The resulting oil-water emulsion needs to be separated for further processing of the crude oil.

[0005] Over time, separated solids (such as, but not limited to, sand, silt, clay, carbonates, corrosion by-products, asphalt, and / or aggregated asphaltenes) within the separated crude oil from the crude oil accumulate in the bottom of the desalination equipment vessel. Therefore, the desalination equipment must be periodically washed to remove this accumulation. The solids (usually in the form of a heavy complex emulsion of water, solids, asphaltenes, asphalt, and / or other hydrocarbons) are removed by "mud washing": a portion of the brine or wash water is circulated through nozzles in the bottom of the mud washing vessel to create turbulence to remove the solids from the desalination equipment effluent brine. These solids are then sent to the wastewater system.

[0006] Many desalination equipment systems are equipped with mud washing pipes, which are designed to periodically agitate the water on the bottom of the desalination equipment and remove the accumulation of oily solids. Water is pumped into the mud washing manifold and exits the nozzles as turbulent jets directed at the bottom of the vessel. Due to the turbulence generated in the desalination equipment during mud washing, some oil and emulsion are typically entrained from the intermediate phase into the desalination equipment brine. This is especially true when solids have accumulated in the bottom of the desalination equipment, reducing the available water volume and creating uneven water distribution. In addition, the mud itself may contain a large amount of oil attached to the solids, which makes the treatment of the mud more expensive and time-consuming.

[0007] With the emergence of new opportunity crude oils and crude oil blends, desalting equipment faces the challenge of extracting not only inorganic salts, but also excessive amounts of other components (such as amines, metals from naphthenic acid metal salts, and fine solid particles), while increasing the flexibility of crude oil blend processing to include crudes containing heavy asphalt or incompatible crude oil blends. This increased operating range of crude oil blends can put pressure on the quality of the desalted equipment effluent brine, thus increasing the risk of compliance with wastewater discharge specifications and volatile component regulations.

[0008] Accordingly, there is a need in the art for compositions and methods for improving the quality of the mud wash effluent brine of refinery desalting equipment systems. SUMMARY OF THE INVENTION

[0009] The disclosed technology generally provides a mud wash solvent, and more particularly, provides a mud wash solvent and method for improving the quality of desalted equipment effluent brine.

[0010] In one aspect of the disclosed technology, a method for improving the quality of effluent brine is provided. The method includes (i) providing a mud wash solvent comprising a hydrocarbon having a specific gravity less than the specific gravity of the desalted equipment brine to be treated; and (ii) adding the mud wash solvent to the mud wash stream of the desalted equipment system to provide a treated effluent brine.

[0011] In some embodiments, the specific gravity of the hydrocarbon is less than about 1. In some embodiments, the specific gravity of the hydrocarbon is less than about 0.7. In some embodiments, the hydrocarbon comprises (i) kerosene, (ii) naphtha, (iii) diesel, (iv) aromatic naphtha, and / or (v) heavy aromatic naphtha.

[0012] In some embodiments, the mud wash solvent is added to the mud wash stream at about 0.1 - 100% solvent / gallon / minute of the mud wash stream. In some embodiments, the mud wash solvent is added to the mud wash stream at about 0.1 - 10% solvent / gallon / minute of the mud wash stream. In some embodiments, the mud wash solvent is added to the mud wash stream at about 0.5 - 5% solvent / gallon / minute of the mud wash stream.

[0013] In some embodiments, the mud wash stream comprises up to 10,000 ppm of oil and grease content. In some embodiments, the mud wash stream comprises 10,000 ppm or more of oil and grease content. In some embodiments, the mud wash stream comprises about 1,000 - 10,000 ppm of oil and grease content.

[0014] In some embodiments, the slurry wash solvent is directly injected into the slurry wash stream. In some embodiments, the slurry wash solvent is injected into the slurry wash stream at a rate of about 0.1 - 10% solvent / gallon / minute of the slurry wash recycle stream.

[0015] In some embodiments, the desalination equipment system includes (i) a single-stage desalination equipment method, (ii) a two-stage desalination equipment method, or (iii) a desalination equipment method with more than two stages. In some embodiments, the desalination equipment system includes a slurry wash pump. In some embodiments, the slurry wash solvent is added to the slurry wash stream before the slurry wash pump.

[0016] In some embodiments, the treated effluent brine contains less than about 1000 ppm of oil and grease content. In some embodiments, the treated effluent brine contains less than about 500 ppm of oil and grease content. In some embodiments, the treated effluent brine contains less than about 125 ppm of oil and grease content. In some embodiments, the slurry wash solvent further includes a demulsifier composition. In some embodiments, the demulsifier composition includes polyacrylamide, polyol, resin ester, sulfonate, succinate, tannin, polyamine, alkylphenol resin ethoxylate, non-alkoxylated phenolic resin, hydroxy acid, polyisobutyl succinimide derivative, succinate derivative, or a combination thereof. In some embodiments, less than about 50 ppm of the demulsifier composition is added to the slurry wash solvent.

[0017] In some embodiments, the demulsifier composition includes a non-alkoxylated phenolic resin, a polyisobutyl succinimide derivative, and / or a succinate derivative. In some embodiments, more than about 50 ppm of the demulsifier composition is added to the slurry wash solvent.

[0018] In yet another aspect of the disclosed technology, a method for improving the quality of the effluent brine is provided. The method includes (i) providing a slurry wash solvent that includes a hydrocarbon having a specific gravity less than about 1; and (ii) adding the slurry wash solvent to a slurry wash stream of a desalination equipment system, wherein the slurry wash stream includes desalination equipment brine having an oil and grease content of at least 1,000 ppm, to provide a treated effluent brine having a content of less than about 500 ppm of oil and grease.

[0019] In some embodiments, the slurry wash stream contains up to 10,000 ppm of oil and grease content. In some embodiments, the slurry wash stream contains 10,000 ppm or more of oil and grease content. In some embodiments, the slurry wash stream contains from about 1,000 - 10,000 ppm of oil and grease content.

[0020] In yet another aspect of the disclosed technology, a slurry wash solvent composition is provided. The composition contains a hydrocarbon compound having a specific gravity of less than about 1.0. In some embodiments, the specific gravity of the hydrocarbon is less than about 0.8. In some embodiments, the specific gravity of the hydrocarbon is less than about 0.7.

[0021] In some embodiments, the hydrocarbon compound comprises (i) kerosene, (ii) naphtha, (iii) diesel oil, (iv) aromatic naphtha, (v) heavy aromatic naphtha, and / or (vi) combinations thereof. In some embodiments, the hydrocarbon compound is a kerosene distillate. In some embodiments, the solvent composition further comprises other distillates or naphtha. In some embodiments, the solvent composition further comprises a demulsifier composition. In some embodiments, the demulsifier composition comprises polyacrylamide, polyols, resin esters, sulfonates, succinates, tannins, polyamines, alkylphenol resin ethoxylates, non-ethoxylated phenolic resins, hydroxy acids, polyisalkyl succinimide derivatives, succinate derivatives, or combinations thereof. In some embodiments, less than about 50 ppm of the demulsifier composition is added to the slurry wash solvent.

[0022] In some embodiments, the demulsifier composition comprises non-ethoxylated phenolic resins, polyisalkyl succinimide derivatives, and / or succinate derivatives. In some embodiments, greater than about 50 ppm of the demulsifier composition is added to the slurry wash solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and other features and advantages of the disclosed technology will be specifically illustrated in the embodiments now to be described by way of example with reference to the drawings, wherein:

[0024] Figure 1 is a diagram of a slurry wash system of an illustrative embodiment of the disclosed technology; and

[0025] Figure 2 provides the results of an illustrative embodiment of the disclosed technology. DETAILED DESCRIPTION

[0026] The disclosed technology generally provides a mud washing solvent, and more specifically, provides a mud washing solvent composition and method for improving the quality of the effluent brine from desalination equipment. Using this technology, the use of the disclosed mud washing solvent composition and method in desalination equipment applications helps to reduce the concentration of oil and grease (O&G) in the desalination equipment effluent brine (i.e., produce a low oil and grease desalination equipment effluent brine), thereby improving the quality of the mud washing effluent brine in the refinery desalination equipment system. In addition, this technology can contribute to the treatment and extraction of solid-laden emulsions.

[0027] The disclosed technology provides a method for improving the quality of the effluent brine. The method includes (i) providing a mud washing solvent; and (ii) adding the mud washing solvent to the mud washing stream of the desalination equipment system to provide a treated effluent brine. By treating the effluent brine, harmful contaminants and other debris are removed, and their removal is crucial for avoiding expensive corrosion and fouling of downstream equipment. In addition, by removing complex emulsions and organic matter in the desalination equipment effluent brine, the risk of non-compliance with downstream regulations in the wastewater treatment plant is reduced, including emission specifications and volatile emissions. It also minimizes (i) the cost of separating emulsions in the wastewater treatment plant, (ii) the energy for reheating the recovered oil, and (iii) the opportunity cost of reprocessing with the recovered oil instead of crude oil.

[0028] As shown in Figure 1 a mud washing system 100 of a desalination equipment system is provided. The mud washing system 100 includes a desalination equipment container 102 having a mud washing header 104. The raw crude oil is provided to a mixing valve 106 before being introduced into the desalination equipment container 102. In some embodiments, the raw crude oil includes oil sand crude oil, heavy crude oil, crude oil blends, and / or combinations thereof.

[0029] The washing water is introduced into the mud washing header 104 by a washing water pump 108 located upstream of the mud washing pump 110. In some embodiments, the desalination equipment system includes a single-stage desalination equipment method or a two-stage desalination equipment method. In some embodiments, the mud washing system is a single-pass system, while in other embodiments, the mud washing system is a recirculation system.

[0030] The mud washing solvent of this technology dissolves / solubilizes and / or dilutes the oil and grease components in the oily (i.e., problematic) brine, thus reducing the density of these pollutants. By reducing the density, the blend of the solvent with the oil and grease components (lighter than water) that are combined / dissolved / solubilized (i.e., lighter) will rise (or separate) into the oil phase faster within the desalination equipment. Therefore, the mud washing solvent produces cleaner brine (i.e., improved brine quality), which has a significantly reduced oil and grease content, as well as a reduction in the emulsion layer within the desalination equipment container, and results in lower treatment costs.

[0031] In some embodiments, the mud washing solvent is an organic solvent. The mud washing solvent of the present technology comprises a hydrocarbon having a specific gravity less than that of the desalination equipment brine to be treated. In some embodiments, the mud washing solvent comprises a hydrocarbon having a specific gravity less than about 1.0. In other embodiments, the specific gravity of the hydrocarbon is less than about 0.8, and in other embodiments, the specific gravity of the hydrocarbon is less than about 0.7. In some embodiments, the hydrocarbon comprises (i) kerosene, (ii) naphtha, (iii) diesel, (iv) aromatic naphtha, (v) heavy aromatic naphtha, and / or combinations thereof.

[0032] In some embodiments, the mud washing solvent further comprises a demulsifier composition. It should be understood that the presence of the demulsifier composition in the mud washing system as described herein can contribute to improving the effluent brine quality, the treatment of the solid-laden emulsion, and compliance with downstream regulations. The combination of the organic mud washing solvent with blends of different demulsifier compositions provides a synergistic effect to complicate the emulsion treatment of the oily effluent brine during mud washing.

[0033] In some embodiments, less than about 50 ppm of the demulsifier composition is added to the mud washing solvent. In some embodiments, greater than about 50 ppm of the demulsifier composition is added to the mud washing solvent. In some embodiments, the demulsifier composition includes, but is not limited to, polyacrylamide (usually cationic), polyols, resin esters, sulfonates and / or succinates, tannins, polyamines, alkylphenol resin ethoxylates, non-alkoxylated phenolic resins, hydroxy acids, amines, or chemicals derived from polyisobutyl succinimide and / or succinates.

[0034] The mud washing solvent of the present technology is added directly to the mud washing stream. Refer to Figure 1 , the mud washing solvent is added directly to the mud washing stream at location A before entering the mud washing pump 110. It should be understood that the mud washing solvent can be added at any point in the desalination equipment mud washing stream or the mud washing recycle stream.

[0035] In some embodiments, the mud washing solvent is added by connecting the solvent to the suction inlet of the injection and / or recycle system of the bottom water and / or mud washing header of the desalination equipment. In other embodiments, the mud washing solvent is connected to the discharge outlet of the recycle feed pump to return to the mud washing header.

[0036] In some embodiments, the slurry wash stream of the present technology contains up to 10,000 ppm of a high oil and grease (O&G) content. In other embodiments, the slurry wash stream contains an oil and grease (O&G) content of 10,000 ppm or higher. In some embodiments, the slurry wash stream of the present technology contains an oil and grease (O&G) content of about 1,000 - 10,000 ppm.

[0037] The oil and grease content as described herein is a measure or presence of oil and grease contaminants such as, but not limited to, asphalt, fine solids, and / or clay, oil, crude oil, and / or asphaltenes. By adding the disclosed slurry wash solvent directly to the slurry wash stream, a treated or improved effluent brine is provided, wherein the treated or improved effluent brine contains a reduced oil and grease content. It is advantageous to improve (i.e., reduce) the oil and grease content of the effluent brine in refineries with short desalination unit residence times and thus difficulty in producing low oil and grease brine.

[0038] In some embodiments, the oil and grease content of the effluent brine is reduced by at least about 99%. In other embodiments, the oil and grease content is reduced by at least 50% - 99%.

[0039] In some embodiments, the slurry wash solvent is added to the slurry wash stream at about 0.1 - 100% solvent / gallon per minute (GPM) of the slurry wash stream. In other embodiments, the slurry wash solvent is added to the slurry wash stream at about 0.1 - 50% solvent / gallon per minute (GPM) of the slurry wash stream, in other embodiments, the slurry wash solvent is added to the slurry wash stream at about 0.1 - 10% solvent / gallon per minute (GPM) of the slurry wash stream, and in other embodiments, the slurry wash solvent is added to the slurry wash stream at about 0.5 - 5% solvent / gallon per minute (GPM) of the slurry wash stream.

[0040] In some embodiments, the slurry wash solvent is injected directly into the slurry wash stream. In other embodiments, the slurry wash solvent is injected directly into the desalination unit vessel. In some embodiments, the slurry wash solvent is injected into the slurry wash stream at about 0.5 - 5% / gallon per minute (GPM) of the slurry wash recycle stream. It should be understood that if the oil and grease concentration in the desalination unit effluent brine increases, the slurry wash solvent requirement will increase.

[0041] In some embodiments, when the mud washing solvent comprises a demulsifier composition, the demulsifier composition is provided continuously or intermittently to the mud washing circuit. For example, the combination of the mud washing solvent and the demulsifier composition dispersed into the mud washing header enhances sludge separation and treatment. Solvent droplets solubilize organic matter into the rising solvent oil droplets to enhance the removal of organic matter from the brine and accelerate their transport to the bulk hydrocarbon phase (i.e., a liquid-liquid solvent extraction process using a mud washing header to deliver a solvent solution). In some embodiments, the demulsifier composition comprises from about 20% to about 100% active material in the mud washing solvent.

[0042] In other embodiments, the demulsifier composition is provided in the desalination equipment vessel in an amount less than about 50 ppm water. By providing a dilution of the demulsifier composition to the mud washing solvent that is less than 50 ppm (compared to other ppm dosages (e.g., 50 - 20,000 ppm) in other typical applications), a separate solvent injection system can be had, or an atypical chemical dilution can be produced to eliminate excess chemicals, to have a sufficient number of solvent droplets for absorbing and transporting organic matter from the bottom of the desalination equipment vessel.

[0043] In some embodiments, the treated effluent brine contains less than about 1000 ppm oil and grease content. In other embodiments, the treated effluent brine contains less than about 500 ppm oil and grease content. In other embodiments, the treated effluent brine contains less than about 250 ppm oil and grease content, and in other embodiments, the treated effluent brine contains less than about 125 ppm oil and grease content.

[0044] In a specific embodiment, a method for improving the quality of the effluent brine is provided. The method includes (i) providing a mud washing solvent that comprises a hydrocarbon having a specific gravity less than about 1; and (ii) adding the mud washing solvent to the mud washing stream of a desalination equipment system, wherein the mud washing stream comprises desalination equipment brine having an oil and grease content of at least 1,000 ppm, to provide a treated effluent brine having less than about 500 ppm oil and grease content. Examples

[0045] The present invention will be further described in the following examples, which should be considered illustrative and should not be construed as narrowing the scope of the disclosed technology or limiting the scope to any particular embodiment.

[0046] Figure 2 Results of adding a mud washing solvent composition to a mud washing stream according to the disclosed technology are provided.

[0047] Compared with the effluent brine in other conventional systems (see Figure 2 , from January 2018 to September 2018), by adding a mud washing solvent as disclosed herein, the oil and grease content is reduced to an average of less than 500 ppm (see Figure 2 , from September 2018 to December 2018).

[0048] In the foregoing specification, the invention has been described with reference to specific embodiments of the invention. It is contemplated that the mud washing solvent of the method can be used in other hydrocarbon processing operations other than those specifically mentioned. Although embodiments of the disclosed technology have been described, it should be understood that the disclosure is not limited thereto and can be modified without departing from the disclosed technology. The scope of the disclosed technology is defined by the appended claims, and all apparatuses, processes, and methods within the meaning of the claims, whether literally or by equivalents, are intended to be included therein.

Claims

1. A method for improving the quality of effluent brine by reducing oil and grease contaminants in a mud washing system, the mud washing system including a desalting equipment vessel for processing raw crude oil, wherein the desalting equipment vessel includes a mud washing header located at the bottom of the desalting equipment vessel, the method comprising: (i) directing wash water to the mud washing header through a wash water pump located upstream of the mud washing pump that directs mud wash water to the mud washing header, wherein the wash water turbulently contacts solids separated from the raw crude oil at the bottom of the desalting equipment vessel and removes at least a portion of the solids from the desalting equipment vessel, thereby generating a mud wash stream to direct the solids to a wastewater system or recycle them back to the desalting equipment vessel through the mud washing header, wherein the mud wash stream contains water, oil, and grease; and (ii) directly adding a mud wash solvent to the mud wash stream before the mud wash stream enters the mud washing pump within the desalting equipment system to provide a treated effluent brine, wherein the mud wash solvent contains a hydrocarbon having a specific gravity less than the specific gravity of the mud wash liquid to be treated, wherein the mud wash solvent is added to the mud wash stream at a rate of 0.1 - 100% solvent / gallon / minute of the mud wash stream, and wherein the mud wash stream contains an oil and grease content of up to 10,000 ppm.

2. The method of claim 1, wherein the mud wash solvent is directly injected into the mud wash stream, and wherein the mud wash solvent is injected into the mud wash stream at a rate of 0.1 - 10% solvent / gallon / minute.

3. The method of claim 1, wherein the desalting equipment system comprises (i) a single - stage desalting equipment method, (ii) a two - stage desalting equipment method, or (iii) a desalting equipment method with more than two stages.

4. The method of claim 1, wherein the treated effluent brine contains (i) an oil and grease content of less than 1000 ppm.

5. The method of claim 1, wherein the mud wash solvent further comprises a demulsifier composition, wherein the demulsifier composition comprises polyacrylamide, polyol, resin ester, sulfonate, succinate, tannin, polyamine, alkylphenol resin ethoxylate, non - alkoxylated phenolic resin, hydroxy acid, polyisalkyl succinimide derivative, succinate derivative, or a combination thereof.

6. The method of claim 5, wherein less than 50 ppm of the demulsifier composition is added to the mud wash solvent.

7. The method of claim 1, wherein the mud wash stream contains an oil and grease content of 1,000 - 10,000 ppm.

8. The method of claim 1, wherein the treated effluent brine contains an oil and grease content of less than 500 ppm.

9. The method of claim 1, wherein the treated effluent brine contains an oil and grease content of less than 125 ppm.

10. A method for improving the quality of the effluent brine in a mud washing system, the mud washing system including a desalting equipment vessel for treating raw crude oil, wherein the desalting equipment vessel includes a mud washing header located at the bottom of the desalting equipment vessel, the method comprising: (i) directing wash water to the mud washing header through a wash water pump located upstream of the mud washing water pump that directs the mud washing water to the mud washing header, wherein the wash water turbulently contacts solids separated from the raw crude oil at the bottom of the desalting equipment vessel and removes at least a portion of the solids from the desalting equipment vessel, thereby generating a mud washing stream to direct the solids to a wastewater system or recycle them back to the desalting equipment vessel through the mud washing header, wherein the mud washing stream contains water, oil, and grease; and (ii) directly adding a mud washing solvent to the mud washing stream prior to the mud washing stream entering a mud washing pump within the desalting equipment system to provide a treated effluent, wherein the mud washing solvent contains a hydrocarbon having a specific gravity less than the specific gravity of the mud washing liquid to be treated, wherein the mud washing stream contains desalting equipment brine having an oil and grease content of at least 1,000 ppm to provide a treated effluent brine having an oil and grease content of less than 500 ppm.

11. The method of claim 10, wherein the hydrocarbon compound comprises (i) kerosene, (ii) naphtha, and / or (iii) diesel.

12. The method of claim 10, wherein the hydrocarbon comprises aromatic naphtha or heavy aromatic naphtha.

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