US1826141A - Process of refining hydrocarbon oils with mercury salts - Google Patents

Description

A. LACHMAN Oct. 6, 1931.

PROCESS OF REFINING HYDROGARBON OILS WITH MERCURY SALTS Original Filed May 8. 1929 4 H w a INVENTOR m? THU/E 4.40014 '14 ATT GRN EY Piaenasd Oct. e, 1931 UNITED srArEs PATENT orrlcs ARTHUR LAGHMAN, 0F BERKELEY, CALIFORNIA, ASSIGNOR TO RICHFIELD OIL COM- PANY OF'CALHORNIA, 0F LOS ANGELES, CALIFORNIA, A CORPORATION OF DELA- WARE PROCESS OF REFINING- HYDROCARIBON OILS WITH MERCURY SALTS Original application filed May 8, 1929, Serial No. 361,513. Divided and this application filed May 8,

1929. Serial No. 361,516.

This invention relates to a process of purifying and refining hydrocarbon oils obtained by distillation or cracking of mineral oils, such as lubricating oils, lamp oils, gasoline stocks or distillates derived from oil shale. This application is a division of my application for process of refining hydrocarbon oils, executed April 20, 1929, Serial No. 361,513 filed May 8, 1929, which consists of a similar method or process for purifying and refining mineral oil products with soluble metal salts.

The process of refining hydrocarbon oils, as described-in this application, is applicable to all mineral oil products derived by distillation or cracking operation, such as lubr1- eating oils, lamp oil stocks, gasoline stocks, distillates derived from oil shale, etc., and is particularly adaptable to gasoline stocks obtained'by cracking higher boiling hydrocarbon oils. For the purpose of simplifying the description, reference will be-made to gasoline only.

, Crude gasoline stocks obtained by distilling or cracking petroleum oils consist of a mixture of saturated and unsaturated hydrocarbons together with sulphur compounds, nitrogenbases and other substances of an unde These latter substances are and are usually responsible for thechange of color which takes place when refined gasoline is stored. These oxidizable substances are removed with difliculty when gasoline stocks are treated by the methods known in com- 'mon use.

i In order to show the nature of my invention, it is desirable todescribe the method now in common use in oil refineries, and particularly that step of refining gasoline stocks which consists in deodorizing and stabilizing the same. Crude gasoline stocks obtained by distillation of crude petroleum oil or by cracking a higher boiling petrdleum oil, are customarily treated with approximately from 1 per cent to as hi h as 8 per cent by weight sulphuric acid, t e quantity of sulphuric acid depending upon the nature of the gasoline stock to be treated and the product desired. This acid treatment usually. consists in commingling the gasoline stoc:

with the required amount of sulphuric acid necessary to obtain the'desired extraction, either by the well-known batch or continuous treatment, after which the products of the acid reaction are permitted to settle and then withdraw from thetreated gasoline stock.

usually employed to render the gasoline sweet to the doctor test.

The general objections to a treatment of this character are as follows:

(1) Gasoline purified by this method fre= quentlv becomes discolored whenstored for a period of time;

(2) considerable quantities of sulphuric acid arerequired, which are diificult to recover; J

(3) as high as 10 per cent of the valuable stable unsaturated hydrocarbons contained inthe gasoline stock may be lost;'-'and (4) the treatment must frequently be followed by a deodorizing or sweetening process, such as that heretofore described.

Now, I have discovered'that the sulphuric acid normally used to treat crude gasoline stocks maybe reduced to a high extent, and in many cases may be entirely eliminated by the employment of a water solution of cer tain metallic salts, or mixtures of the same, A

which may be zinc, copper, cadmium, mercury, iron, chromium, maganese, aluminum, nickel or cobalt water soluble salts, such as the chloride, bromide, iodide, sulphate, nitrate, and also any of the water soluble salts of the above named metals of organic acids,

such as the sulphonic acids of benzol, toluol and 'xylol, or the .sulphonic acids derived from the treatment of petroleum' oils with sulphuric acid.

1 The process-described briefly consists in passing the hydrocarbon oil product such as gasoline stock while in a vapor state, through 2 p eeann or in contact with a hot concentrated water solution of any of the aforesaid metallic salts or mixtures thereof. The gasoline stock so treated is usually'pure enough for immediate use, although it sometimes may contain small amounts of hydrogen sulphide, which may be removed by washing with an alkaline solution of sodium or calcium hydroxide, or the carbonates of sodium or potassium.

The hydrocarbon oil stock to be treated by my invention may or may not have had a preliminary treatment with sulphuric acid, or other agents to partly purify the same, or may be first partly purified by my invention and the purifications completed by methods known in the art, such as treatment with caustic alkali, sulphuric acid, etc. Tn case of gasoline stocks produced by cracking high sulphur bearing crude petroleum oils or residuums, it may be advantageous to treat such gasoline stocks with small amounts of sulphuric acid before the treatment with a concentrated water solution of any. of the afore-statedmetallic salts, which may also be followed by treatment with an alkaline water solution of sodium, potassium or caleium hydroxide, or the carbonates of sodium or potassium.

Although a solution of less concentration may be employed which may range from 50 or less to approximately 85 per cent, the

strength of the water solution of the metallic salt or mixture of salts employed is preferablya substantially concentrated solutlon,

and the temperature employed for the treatment is approximately 300 to 4:00 degrees E, which normally fluctuates, depending upon the vaporizing temperature of the oil under treatment.

With the foregoing preliminary explanation, the preferred embodiment of my invention will now be more fully explained by reference to the accompanying drawing which is a diagrammatic view of one form of apparatus which may be employed for carrying out the objects of the present invention.

Referring to the drawing, 2 indicates a pipe leading to a source of crude gasoline vapors not shown, such as a fractionating tower employed to separate lower boiling oils from higher boiling oils. B indicates a tower of suitable height and diameter filled with resistant or contact material, such as fire brick, spiral tile or the like, indicated at 3, which forms numerous tortuous passages through the tower, although it is to be understood that the well-known bubble cap contact tower may be employed. Disposed above the tower or adjacent to the same, is a tank12 containing a substantially concentrated water solution of a metallic salt or mixtures of the same, as heretofore enumerated, having a concentration of from 50 per cent or less to as high as approximately per cent. This tank is connected to the top of the tower by means of a pipe 4 having a regulating valve 5. This pipe terminates over a spreader plate 6 and this plate evenly distributes the water solution of the metallic salt or salts whenthe valve 5 is opened, over the brick work or contact material. The water solution of the metallic salt or salts flows downward through this contact material and may finally be discharged through the bottom by a pipe 7, after which it is treated for recovery. The tower B is also provided with a. steam or water inlet pipe 8, which intermittently or continuously supplies a predetermined amount of water or steam to the tower. The hot gasoline vapors from the pipe 2 enter the lower end of the tower B at a point 9. The oil vapors pass up through the numerous contact passages in the brick work and thereby come into intimate contact with the said water solution of metallic salt or salts flowing over the same. Although other temperatures may be employed, both the water solution of metallic salt or salts and oil vapors are generally maintained at a temperature of approximately 300 to QLOO degrees F, and the oil vapors are discharged at the upper end of the tower through a pipe 10 which is connected with a condenser 11 of suitable construction. The gasoline vapors passing through the contact tower B at the temperature specitied, vaporize a certain amount of water from the water solution of metallic salts and the purpose of the steam or waterinlet pipe 8 is that of continuously maintaining the solution at a certain water content so as to maintain the necessary fluidity which is essential for good contact between the rising gasoline vapor and the down-flowing water solution of metallic salt or salts. Preferably the concentration of the water solution of metallic salt or salts is maintained at its predetermined limits of concentration by a continuous introduction of water or water vapor. Otherwise solid metallic salt or salts and solid sludge impurities may plug the passages through which the gasoline vapors are being conducted.

While not always necessary, it is beneficial that the water solution of metallic salt or salts contain hydroxides or oxides of any of the metals or mixtures thereof, heretofore enumerated, before being introduced into the system. This may be accomplished by agitating the water solution of the metallic salt or salts with any of the hydroxides or oxides of any of the enumerated metals. The optimum amount of the metal oxide or hydroxide ranges from about of l per cent to 3 per cent by weight of the water solution of mei tallic salt or salts. Tn explanation, when the oxides or hydroxides of any of the aforementioned metals or mixtures thereof are soluble in substantial amounts in the salt or salts soluble at the temperatures and pressures emliZO ployed, it is no doubt that the beneficial action will be enhanced, but even if no substantial solubility exists, useful effects can be obtained if the oxides and hydroxides are suspended in the salt or salts solution.

The reaction tower B is kept full of the Water solution of the metallic salt or salts containing metallic hydroxides or oxides such solution of metallic salt or salts varies within wide limits, depending upon the concentration of the solution employed, the temperature at which the operation is carried out and the nature and amount of inert gases which may accompany the gasoline vapor being treated. By this treatment the major portion of the impurities contained by the gasoline stock is removed and carriedout with the water solution of metallic salt or salts as a sludge and the purified gasoline vapors, when condensed, are suitable for use as a refined gasoline stock of high purity. i

While the process herein described is well adapted for carrying out the objects of the present invention, it is to be understood that various modifications and changes may be made without departing from the invention, such for example as the use of centrifugal or other mechanical mixers or the employment of any of the well-known contact towers wherein a water solution of a metallic salt or mixtures of metallic salts, either organic or inorganic, heretofore enumerated, may be commingled with or" brought into contact with a petroleum oil vapor at the reacting temperatures and the invention includes all such modifications and changes as come within the scope of the appended claims.

7 M What I claim is:

.. ized mineral oil with a substantially concentrated water solution of a mercury salt maintained in solution, and then condensing purified .oil vapor separated from products of reaction and treating agent. I

3. A processof refining mineral oils, comprising,vaporizin'g a mineral oil, contacting the vaporized mineral oil with a water solution of amixture of mercury salts maintained in solution and'then condensing purified oil vapor separated from products of reaction and treating agent.

4. A process of refining mineral oils, comprising, vaporizing a mineral oil by the application of heat, contacting the heated vaporized mineral oil with a water solution of a mercury salt maintained in solution, and then condensing purified oil vapor separated from products of reaction and treating agent.

5. A process of refining mineral oils, comprising, vaporizing a mineral oil by the application of heat, contacting the heated vaporized mineral oil with a heated Water solution of a mercury salt maintained in solution and heated to a temperature of not less than the vaporizing temperature of the vaporized mineral oil under treatment, and then condensing the vapor separated from products of reaction and treating agent.

6. A process of refining mineral oils, comprising, heating a mineral oil to form a vapor at a temperature of approximately 300 to 400 degrees F., contacting the heated vapor with a water solution of a mercury salt maintained in solution at a substantially similar temperature, and then condensing purified oil vapor separated from products of reaction and treating agent.

7. A .process of refining mineraloils, comprising, heating a mineral oil to form a vapor at temperatures of approximately 300 to 400 degrees F, passing the lieatedyapors through or in contact with a concentrated water solution of mercury salts, maintained in solution, at a substantially similar temperature, and then condensing purified oil vapor separated from products of reaction and treating agent.

8. A process of refining mineral oils, comprising, heating a mineral oil to form a vapor, contacting the heated. vapor with a water solution of mercury salts maintained in solution and containing mercury oxide, and then condensing purified oil vapor separated from products of reaction and treating agent.

9. A process of refining mineral oils, comprising, heating a mineral. oil to form a vapor, passing the heated vapor through and in contact with a concentrated water solution of mercury salts, maintaining the solution in a fluid condition by the addition of water during contact of the vapor with the treating solution and-condensing the vapor after passing through the solution.

10. A process of refining mineral oils, comprising, commingling the vapor of a mineral oil with a water solution of a mercury salt maintained in a fiuid condition during con- .ery

in contact with a Water solution of a mercury salt containing mercury oxide, maintaining the solution in a fluid condition by th addition of water during contact of the vapor with the treating solution and condensing the vapor after passing through the solution.

12. A process of refining mineral oils, comprising, heating a mineral oil to form a vapor, passing the heated vapor through and in contact with a water solution of mercury salts containing from of 1 per cent to 3 per cent by weight of a metallic oxide, maintaining the solution in a fluid condition by the addition of water during contact of the water with the treating solution and condensing the vapor after passing through the solution.

13. A process of refining mineral oils, comprising, heating a mineral oil to form a vapor, passing the heated vapor through and in contact with a water solution of mercury salts, maintaining the concentration of the solution Within predetermined limits lay the addition of water during contact of the vapor with the treating solution and condensing the vapor after passing-through the solution.

14. A process of refining mineral oils, con;- prising, heating a mineral oil to form a vapor at temperatures of approximately 300 to 400 degrees F, passing the heated vapor through and in contact with a concentrated water solution of a mercury salt maintained at a similar temperature, maintaining the concentration of the solution as specified by continuous addition of water during contact of the vapor with the treating solution, and then condensing the vapor after passing through the solution.

15. A process of refining mineral oils, comprising, vaporizing amineral oil, contacting the vaporized Oll with a water solution of a mercury salt, intermittently introducing wa-- ter into the solution of mercury salt to maintain the aqueous solution and continuously condensing vapors of the purified mineral oil separated from the products of reaction and solution of mercury salt.

16. A process of refining mineral oil's, comprising, heating a mineral oil to form a vapor, passing the vapor through and in contact with a water solution of mercury salts containing mercury oxide, intermittently introducing water into the solution of mercury salts to maintain the aqueous solution containing mercury oxide and continuously condensing the vapors of the purified mineral oil separated from products of reaction and solution of mercury salts containing mercury oxide. A

17. A process of refining mineral oils, comprising, heating a mineral oil to form a vapor, passing the vapor through-and in contact with a water solution of a mercury salt containing mercury oxide, intermittently in- ARTHUR LACHMAN.

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