JPH05501578A - Improving oil storage stability - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] ° of The present invention is a method for improving the storage stability of oil, especially diesel fuel, and implements the method. Relating to a device for

Oil is widely used industrially as a fuel and lubricant. Oil, especially heavy oil fuel ( For example, diesel fuel, light oil, and gas turbine fuel), the problem is However, even when a car is not used for a long period of time, sediment can form due to storage. . This kind of sediment can clog fuel pipes, filters, etc., or cause fouling of engine parts. Can cause a ring.

One important mechanism for forming sediments is the reaction between trace compounds present in the oil. It is believed that a reaction occurs resulting in the formation of a solid or gummy product.

Therefore, even if the oil is repeatedly passed through, the problem of sediment formation cannot be solved. el″67 (August 1988) 1124-1130 and idan (Janu Ary (1989) 27-31 describes the main factors involved in sediment formation in diesel oil. One of the most important reactions is the reaction with indole produced by the oxidation of phenalene (III). , whereby the following formula (IV) (wherein R is alkyl and n is 1-3 , or an integer greater than that) is produced. is presented.

Phenalene, phenalanone, phenalenone and indole are extracted from catalytically cracked oil. In addition, it is believed that they are introduced into the oil during oil upgrading. like this The phenomenon is increasingly being seen in diesel and gas turbine fuels.

The 1989 literature describes synthetic phenalenone or synthetic phenalenone and infusion under acidic conditions. There are 0 products that state that indolylphenalene salt is produced by reacting with dol. Co-pending application PCT/AU90100467 by the applicant is phenarene, phenare Explains how to test diesel fuel for non-, phenaranone and indole are doing. This test method involves adding an acid and an oxidizing agent to the fuel to create a foreground of the compound. The resulting forefield is extracted into a solvent that is immiscible with the fuel, and the color of the solvent phase is observed. Consists of things. Whether such compounds are detected in the oil or the presence of these compounds is If there is a concern that these compounds may be present in the oil, it is necessary to remove these compounds from the oil to improve storage stability. It is highly desirable that provide methods and equipment for carrying out this work; This is the object of the present invention.

As used herein, the term "oil" refers to all types of oil, regardless of the source of the oil. including natural oils (e.g. petroleum or heavy fuel oil), either completely or partially. heating synthetic oil (e.g. oil made from natural gas, coal, or keratite) or oil produced by any other method). The term specifically refers to distillate fuels (e.g. vetolium spirit (gasoline), naphtha, paraffin (kerosene)), and heavy oil (e.g. tractor fuel, diesel fuel) , light oil, gas turbine fuel, lubricating oil, cutting oil, hydraulic oil, etc.).

for the at least partial removal from oil of potentially sediment-forming compounds. The method of the invention comprises a solution of an oxidizing agent and an acid in an at least partially organic solvent. and the oil (the oxidizing agent, acid and solvent are not or substantially immiscible with the oil); It then consists of separating the oil phase and the solvent phase.

Although this method is not limited to any particular scientific theory, it oxidizes phenalene. to produce phenalenone or phenalanone, and then phenalenone and phenalanone. react with indole, if indole is present in the oil, and then with acid. It is thought that the reaction consists of producing indolylphenalene salt. these salts are completely or only slightly soluble in oils such as diesel fuel, but in organic solvents. is soluble in organic solvents and therefore extracted into organic solvents. These salts are also bright blue in color.

Any oxidizing agent known to oxidize phenalene to produce phenalenone can be used. Inorganic oxidizing agents, especially Ce IV, Mn VII (e.g. oxidation state transitions such as permanganate) or CrVI (e.g. dichromate) Metals are preferred, and the reaction rate is faster in Mn VII and CrV. other suitable As a suitable oxidizing agent, I2. IO,-, Br0s- and Cl0-.

H202 may also be used, but the reaction rate will be slower.

Preferred acids are indolylphenalenone or the condensation product of indolylphenalenone. Acids known to form salts with substances such as mineral acids (e.g. hydrochloric acid, sulfuric acid) (acid or perchloric acid) 3 may also be used, in which case the reaction rate will be faster.

Preferred acids are alkylsulfonic acids or especially arylsulfonic acids (e.g. ρ-tolu organic sulfonic acids such as alkylphenyl sulfonic acids (such as en-sulfonic acids) It is. Carboxylic acids (e.g. acetic acid) which can be aliphatic or aromatic may also be used. However, the reaction rate will be slower.

Acids such as perchloric acid and nitric acid can also be oxidizing agents. Therefore, in some cases, this An acid having an oxidizing effect such as It may be used with one or both of the acids. Perchloric acid and nitric acid e.g. may be used as a oxidizing agent or with oxidizing agents such as dichromates .

A solvent that is as immiscible as possible with the oil, i.e. a water-miscible organic solvent or an organic solvent and water. It is preferable to select a mixture of It is desired that the density of the solvent is different from the density of the oil so that the density of the solvent is different from that of the oil. The density of the solvent is the same as that of the oil. It may be higher or lower than the density. Therefore, the preferred solvent is denser than diesel fuel. Less polar solvents (e.g. alcohols, especially lower alcohols (i.e. up to C9) alcohol), especially methanol or ethanol) or these polar solvents. It is a mixture with water. If alcohol is used, the use of nitric acid is not recommended. , because alcohol and nitric acid can react violently.

The solvent is a mixture of an organic solvent and water (e.g. methanol or a mixture of ethanol and water). (products), the ratio of organic solvent to water in the solvent can be important. too much If water is present, the solvent may be difficult to separate from the oil or may not separate at all. Ru. If too much organic solvent is present, the preferred transition metal ions will be exposed to the oxidizing agent. It can be difficult to dissolve in solvents when used as a solvent.

The concentration of oxidizing agent and acid in the solution may vary over a wide range.

Usually a transition metal oxidizing agent (e.g. potassium permanganate or potassium dichromate) ), a solution concentration of 2-3% by weight is suitable. This concentration is convenient of these in a methanol/water mixture containing 70-80% methanol by volume. The solubility limit of the oxidizing agent is 0. Normally, the acid concentration must be below 10% by weight. .

This method progresses quickly at room temperature (20-30°C), and the process accelerates with slight heating. It can be done. The relative volume ratio of oil/solution is particularly important for phenalenone in oil, phenalenone , the amount of phenalene and indole and the procedure of the method as described below. More different.

The main chemical reactions involved in the method of the invention are represented by the following formula: (where A- is the acid to anion ). Obviously, to quickly terminate the reaction , using oxidizing agents and acids in excess of the sediment-forming compounds likely to be present in the oil. It is desirable to use Typical diesel fuel contains 1 of these compounds, e.g. ~2 ppm may be contained. The permissible upper limit for sediment formed during long periods of non-use is According to British Ministry of Defense standards, 2mg of sediment per 100g of diesel fuel; That is, it is 20 ppm. These numbers and the stoichiometry of the above reaction are calculated using the minimum required acid. may be used as a rough guide to the amounts of curing agent and acid.

The method of the present invention can be broadly distinguished as a batch (or static) method or a continuous method. It can be implemented in many ways. On an industrial scale, it is necessary to provide equipment for carrying out the method. It is convenient to have two.

Accordingly, another feature of the invention is that at least one of the potentially precipitate-forming compounds is Also provides a device for removing portions from oil. This outfit! So, let's talk about the oil mentioned above. The oil phase and the solvent phase can then be separated.

In a specific example of a batch process, a large amount of solution is added to a container of oil (e.g. a storage tank) and mixed. Simply leave the compound alone. the interfacial area, preferably by breaking up the solution into small droplets. the oil and the solution, especially immediately after adding the solution, to increase the contact between the solution and the oil. It is preferable to periodically stir the mixture.

Upon standing for a suitable period of time, the oil phase and solvent phase separate. If the solution and oil have different densities, For example, phase separation occurs spontaneously and the solution forms an upper or lower layer. This layer is simply a solution It can be removed by discharging.

Apparatus suitable for carrying out such batch processes are known to those skilled in the art, e.g. , the device in its simplest form simply stirs the oil and solution, optionally with stirring means. It may consist of a container of suitable capacity having inlet and outlet means for introduction and removal. Ru.

In a specific example of a continuous process, oil and solvent are brought into contact as a free flow in moving contact for a suitable period of time. Let me touch it. Stream by creating turbulence and fragmenting the stream into droplets Preferably, the streams are contacted in such a way as to increase the interfacial area of the .

Turbulence may optionally be increased by stirring means. In this method, oil and solution separation can be achieved in known manner, e.g. if the oil and solution have different densities, this They can also be separated by density differences.

The oil and solution may, for example, move from an area of turbulent contact to an area of relatively quiescent conditions; Natural phase separation occurs in this quiescent zone and each phase can be discharged separately.

Apparatus suitable for carrying out such continuous methods are known to those skilled in the art. The device is an example For example, it may be provided with inlet means for the oil and the solution and configured to allow contact between the oil and the solution. It may have a mixing chamber. The mixing chamber is connected to one or more separation chambers, where the oil and soluble 0 Separation chambers for oils and solutions where physical mixtures with liquids can separate as a result of density differences Separate means of egress is provided.

Whether the method is applied in a batch or continuous manner, the treated oil It is desirable to test for the presence of potentially precipitate-forming compounds. example This test was performed using the test method described in e.g. PCT/AU90100467. You may.

Alternatively, since the indoylefercin salt produced by the method of the present invention is bright blue, the precipitate Observe the color of the solution phase that separates from the oil to determine whether the product compounds have been completely removed. It may also be monitored. This work involves melting in the wavelength range of 600 to 850 nm. This can be carried out using a colorimeter that measures the absorbance of the liquid phase. The electrical output of this colorimeter is It may be electronically coupled to the device's control system.

After the oil has been treated with the method of the invention, it is further purified to remove traces of solvents, acids, oxidizing agents, etc. may need to be removed. Generally, a lot of filtration is sufficient for such purification. It's a minute.

Reference is made to FIG. 1, which schematically shows an apparatus for carrying out the method of the invention in a continuous manner. The present invention will be described by way of example only. A 10% methanol solution containing sulfonic acid was prepared. 50ml acid solution was mixed with 15 ml of dichromate solution.

Add this mixed solution to 500 ml of straight-run diesel oil (known to be completely stable). added to. This diesel oil contains 10% by volume (known to be unstable to sedimentation). catalytic cracking oil) was pre-mixed in a separatory funnel. a mixture of solution and oil; Stirring produced an unstable emulsion and then standing for 5-10 minutes. the The methanol solution then separated as a blue upper layer. Drain the lower oil layer and remove the PCT Tested according to the method described in Ta. Both tests are free of precipitate-forming compounds according to UK MoD standards. It was shown that

Potassium permanganate, hydrogen peroxide and perchloric acid as alternative oxidizing agents, The above experiments were carried out using hydrochloric acid, sulfuric acid, acetic acid and perchloric acid at concentrations close to the above. repeated.

Perchloric acid can be used alone as an oxidizing acid in place of an oxidizing agent and an acid. I can do it. The process proceeds slowly if hydrogen peroxide or perchloric acid is used. became.

Husband and father-in-law 450 ml of catalytically cracked North Sea gas oil was treated as follows.

a) 25 ml of a solution of 5% p-)luenesulfonic acid dissolved in methanol; °≦Add 24 ml of aqueous potassium dichromate solution in methanol to the fuel. The mixture was stirred vigorously for 1 minute and then allowed to stand for approximately 30-40 minutes. fuel part was removed and washed with methanol (4xlOOml) to remove excess reacted material.

The fuel layer was then removed, washed with water, and left to stand. Centrifuge this portion to remove excess After removing the water and then storing in the dark for 6 months under room temperature conditions, no insoluble matter and no adhesive Insoluble matter was quantified.

b) Add the same amount of fuel as a) to the acid and oxidizer used in this example (2 5ml). The mixture is stirred as described above and the separated fuel portion is then Wash with methanol (5 x 50 ml) to remove reaction material and then use the method described above. was used to oxidize again. However, a 2% acid solution was used.

The fuel part was finally washed twice with 50 ml of methanol and stored as described in a). Ta.

C) 500 ml of untreated fuel was stored under the same conditions as a control for a) and b). Ta.

Show the measurement results of insoluble matter to the table worker.

Total filterable sediment Adhesive gum sediment Amount g/l mg/l wag/e Control 26.29 41.71 68.00a) Single oxidation 55.05 54 ．． 59 109.64b) 2x oxidation 24.46 17.03 41.49X "l fake" (death Uses two fuel blends consisting of 5% and 10% light cycle oil in straight run fraction The method of the present invention was then carried out in a continuous manner. These concentrations are found in commercial blends This is the normal concentration of decomposed material. The blend was processed as follows.

a) Methanol solution containing 1% P-1 luenesulfonic acid, fuel and e1: Mix the fuel and potassium dichromate saturated aqueous solution at an acid/fuel ratio of 1:20. Added at an oxidizer:fuel ratio of 200. The mixture was stirred vigorously and left in contact for approximately 30 minutes. , and then passed through separate vessels to allow the phases to separate. The fuel phase was 1.1O methanol, Pump into another methanol extraction vessel at the fuel ratio and separate, then the fuel phase Treated with methanol solution containing 1% potassium hydroxide at a 1:4o alkaline cofuel ratio did. The treated fuel phase was finally washed with methanol.

b) 5% blend was processed according to a) above and 1o? 6 blends are alkaline washed All other treatments were performed in the same manner except that no cleaning was performed. ASTM D4 626 (stored at 43°C for 12 weeks) to determine the stability of each blend. Physical insoluble matter and adherent insoluble matter were quantified. Untreated aliquots of each blend were also controlled. It was subjected to ASTM D4626 test. The measurement results of insoluble matter are shown in Table II. .

Soni Transient Sediment Adherence Gum Sediment Total Color ^STM D15005%LCO Blend 5.1 1.1 B, 2 3.5 unpaid 11M! 5.9 0.9 6.8 3. 5 processing implementation 1.0 2.1 3.1 2.00.9 2.3 3.2 2.0 10% LCO blend 2.3 4.3 6.6 3.5 Untreated 2.9 4. 9 7.8 3.5 Process implementation 0.3 1.4 1.7 2.00.1 2.7 2.8 2.0 Each reading is shown as two separate measurements of the same treatment.

In general, the ASTM D4625 test indicates that storage for 12 weeks at 43°C will last for 1 year at room temperature. It is generally accepted that this corresponds to the storage of Therefore, storage for one week at 43°C corresponds to 1 month of storage at room temperature. Precipitation and color of insoluble matter as a guide to storage stability It has been found using the method of the invention that the storage performance is considerably improved. sufficient It should be noted from Table 1 that the fuel can become even more unstable if it is not oxidized to be.

Therefore, the application of the test method of PCT co-pending application PCT/AU9010O467 is , which is useful in determining the appropriate amount of oxidizing agent required before actually carrying out the method. be.

Further washing with methanol to remove all soluble reaction products from the treated fuel However, the alkaline cleaning illustrated in the example is unnecessary. Of course, the cost of methanol used in the process is kept low and the problem of waste is reduced. It is most conveniently recycled.

λ1 The apparatus for carrying out this method in a continuous manner is shown in FIG. 1 and a still room 2.

The mixing chamber 1 is cylindrical and vertically mounted with an axially oriented vertical shaft passing through it. 3 and an end wall through an oil tight seal. On this axis 3 there is a radial direction A blade 4 is attached, and a baffle plate 5 facing inward in the radial direction is arranged on the inner wall of the mixing chamber. has been done.

The mixing chamber 1 includes an inlet pipe 6 and an outlet pipe 7 communicating with the stationary chamber 2 via a control valve 8. It is growing. The inlet pipe 6 is connected to an oil inlet pipe 10 and a solution supply pipe 11 via a control valve 9. has been done.

The control valve 9 controls the oil flowing along the inlet pipe 10 and the solution flowing along the supply pipe 11. They are of the type that cannot mix until they both enter the inlet tube 6.

The stationary chamber 2 is also cylindrical, is mounted vertically, and has an oil outlet 12 communicating with the control valve 13. It is provided near the bottom of the stationary chamber 2.

The solution outlet 14 near the top of the quiet chamber 2 communicates with a control valve 15, and the control valve 15 It communicates with the vent 16 and the solution recirculation tube 17. The recirculation pipe 17 is a solution supply pipe. 11 and solution inlet pipe 19 . The control valve 18 connects the solution to the pipe 17 for recirculating the solution. to the supply pipe 11 and/or from the inlet pipe 19 to the supply pipe 11 only. belongs to. The stationary chamber 2 has a drain valve 20 and a drain outlet 21 at the lower end of the stationary chamber. do.

In use, diesel oil flows into the inlet pipe 10, for example in the laboratory implementation described above. A solution consisting of an oxidizing agent and an acid having a composition as used in the example flows into the inlet pipe 19 and the valve 18 into the supply pipe 11. Oil and solution via valve 9 and inlet pipe 6 The oil flowing into mixing chamber 1? 'f! The ratio with liquid is measured by valve 9, and the result is The fruit mixing chamber 1 is filled with oil and solution.

The shaft is rotated by a motor (not shown). into the mixing chamber 1 in cooperation with the baffle plate 5. When turbulence occurs, the large droplets 22 of the solution break up into pieces, with the oil as a matrix. , an unstable emulsion 23 of small droplets with a wide interfacial area is created in the mixing chamber 1. child is discharged from the mixing chamber 1 via the outlet pipe 7 and the valve 8, and the emulsion is discharged from the mixing chamber 1 via the outlet pipe 7 and the valve 8. 0 enters the standing chamber 2 in an open state and is supplied until it is substantially full.

When the emulsion 23 is supplied to the stationary chamber 2 until it is full, the solution density becomes lower. Therefore, it is separated into an upper solution phase 24 and an oil phase 25 that does not contain a solution. Refined oil 25 can be recovered via outlet pipe 12 and valve 13. Solution 24 is supplied to outlet 14, valve 15 and and can be collected via vent 16. Alternatively, the ability to remove sediment-forming compounds If power remains in the solution 24, this solution 24 can be routed to outlet 14, valve 15 and for recirculation. A second round of fresh oil is recirculated by returning it to the supply pipe 11 via pipe 17. It may be used for subsequent processing.

The flow rate of oil and solution in the device, the degree of agitation in mixing chamber 1, and the difference between mixing chamber 1 and stationary chamber 2. The relative dimensions are such that the degree of contact between the solution and the oil will tolerate sediment-forming compounds. The flow in the standing chamber 2 is sufficient to remove the upper solution phase 24 and the lower oil phase. The speed can be determined to be low enough to separate and agglomerate 25. Valve 8,9 ．． 13, 15.18 and oil solution supply pump (not shown) are electronically controlled. The flow rate may be further controlled.

The device further allows, among other things, to evaluate whether the solution phase 24 can be recycled. includes a colorimeter 26 for monitoring the color of the solution phase 24. The entire device is electronic, e.g. For example, it can be controlled by a microprocessor.

Occasionally it may be necessary to empty the device for cleaning or the like.

This operation can be carried out via valve 20, outlet 21, valve 9 and discharge outlet 27.

International search report. , TLCOOn/n170c international search report ρCr/6b’SQ/Cl176 S^　41889

Claims (35)

[Claims] 1. 1. A method for removing potential sediment-forming compounds from oil, comprising: a. A solution of an oxidizing agent and an acid dissolved in an at least partially organic solvent is brought into contact with the oil. (the oxidizing agent, acid and solvent are completely or substantially immiscible with the oil); b. A method consisting of separating an oil phase and a solvent phase. 2. 1. A method for removing potential sediment-forming compounds from oil, comprising: a. A solution of an oxidizing agent and an acid dissolved in an at least partially organic solvent is brought into contact with the oil. (the oxidizing agent, acid and solvent are completely or substantially immiscible with the oil); b. separating the oil phase and the solvent phase; c. washing the oil phase of step b with a solvent that is not or substantially immiscible with the oil; d. A process consisting of separating the oil phase and the solvent phase produced in step c. 3. 1. A method for removing potential sediment-forming compounds from oil, comprising: a. A solution of an oxidizing agent and an acid dissolved in an at least partially organic solvent is brought into contact with the oil. (the oxidizing agent, acid and solvent are completely or substantially immiscible with the oil); b. separating a liquid phase and a solvent phase; c. washing the oil phase of step b with a solvent that is not or substantially mild to the oil; d. separating the oil and solvent phases produced in step c; e. Acid concentration and/or acid in solution Repeat step a unless the oxidizing agent concentration is lower than the concentration used in step a. and f. separating the oil and solvent phases produced in step e; g. The oil phase of step f is mixed with oil washing with a clean or substantially immiscible solvent; h. A process consisting of separating the oil phase and the solvent phase produced in step g. 4. 4. The method according to claim 1, wherein the oxidizing agent used is an inorganic oxidizing agent. The method described in any one of the above. 5. 5. The method according to claim 4, wherein the oxidizing agent comprises a transition metal in an oxidized valence state. How to put it on. 6. Compounds in which the oxidizing agent contains Ce(VI), Mn(VII) and/or Cr(VI) 6. A method according to claim 5, characterized in that the method comprises: 7. Oxidizing agent is hydrogen peroxide, iodine, iodate ion, bromate ion or chlorine 5. A method according to claim 4, characterized in that it consists of an acid salt ion. 8. The acid reacts with the condensation product of indolylzenalone or indolylphenalanone. Any of claims 1 to 3, characterized in that it contains an anion capable of forming a salt accordingly. The method described in paragraph (1). 9. 9. A method according to claim 8, characterized in that the acid consists of a mineral acid. 10. Claims characterized in that the acid consists of nitric acid, hydrochloric acid, chloric acid and/or sulfuric acid The method according to item 9. 11. 9. A method according to claim 8, characterized in that the acid consists of an organic acid. 12. 12. The method according to claim 11, wherein the acid is a sulfonic acid or a carboxylic acid. How to put it on. 13. Claim 12, characterized in that the acid consists of an alkylphenyl sulfonic acid. Method described. 14. 14. Claim 13, characterized in that the acid consists of para-toluenesulfonic acid. the method of. 15. Claims 1 to 3, characterized in that the oxidizing agent component and the acid component are the same. The method described in any one of the above. 16. Characterized by the oxidizing agent component and acid component consisting of nitric acid and/or perchloric acid. 16. The method according to claim 15. 17. Specify that the oxidizing agent concentration is the oxidizing agent solubility limit concentration in the solvent used. 5. The method according to claim 4, wherein: 18. The method according to claim 5, characterized in that the oxidizing agent concentration is 2-3% by weight. . 19. It means that the solvent consists of an organic solvent that is miscible with water or a mixture of an organic solvent and water. 4. A method according to any one of claims 1 to 3, characterized in that: 20. Claim 19, characterized in that the solvent consists of an alcohol that is immiscible with the oil. Method described. 21. A claim characterized in that the solvent consists of an alcohol containing 1 to 5 carbon atoms. The method according to claim 20. 22. Any one of claims 1 to 3, characterized in that the density of the solvent is different from the density of the oil. The method described in paragraph (1). 23. Is the solvent a mixture of methanol and water containing 70-80% methanol by volume? 20. The method according to claim 19, characterized in that: 24. Any one of claims 1 to 3, characterized in that the acid concentration is 10% by weight or less. The method described in paragraph (1). 25. Claim 1 characterized in that the contacting and washing steps are carried out at 20-30°C. 3. The method according to any one of Item 3. 26. Any one of claims 1 to 3, characterized in that the removal is performed by a batch processing method. The method described in paragraph 1. 27. According to any one of claims 1 to 3, the removal is performed continuously. the method of. 28. The contact and/or The method according to any one of claims 1 to 3, characterized in that a washing step is carried out. Law. 29. The contact and/or 4. The method according to claim 1, wherein the washing step is repeated. Method. 30.2 Stirring the coffin and using means to promote mixing, contact and/or The method according to any one of claims 1 to 3, characterized in that a washing step is carried out. Law. 31. 4. A method according to any one of claims 1 to 3 substantially as herein described. Method. 32. Substantially herein with respect to Examples 1-3 and the description of the apparatus of FIG. A method according to any one of claims 1 to 3, such as. 33. Apparatus for removing potential sediment-forming compounds from oil, the apparatus comprising: has an oil supply inlet and at least a portion containing the oxidizing agent and acid as solutes. organic solvent solution (oxidant, acid and solvent are not or substantially immiscible with the oil) a feed inlet, a stirring device located inside the container or acting on it, and a settling device. A device characterized in that it consists of a container with an outlet from the container communicating with it. 34. 34. The apparatus of claim 33 substantially as herein described with respect to FIG. . 35. Claim characterized in that the final separation of oil and solvent is followed by a filtration step. 35. The method or apparatus according to any one of paragraphs 1 to 34.