US2073147A

US2073147A - Method of treating petroleum distillates

Info

Publication number: US2073147A
Application number: US49287A
Authority: US
Inventors: Gardner Frank
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-11-11
Filing date: 1935-11-11
Publication date: 1937-03-09
Anticipated expiration: 1954-03-09

Description

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE Frank Gardner, Dallas, Tex.

No Drawing.

Application November 11, 1935,

Serial No. 49,287

4 Claims.

This invention relates to the treating of petroleum distillates and it has particular reference to a method for treating gasolene and kerosene for the removal of objectionable sulfur compounds 5 therefrom.

The principal object of the invention is to provide a method for treatment of distillates whereby mercaptans are converted to disulfides and whereby the sulfur content of the finished prod:

not is considerably less than when conventional methods are employed.

Another object of the invention is to provide a method for treatment of distillates whereby the conversion to disulfides may be effected at little cost and whereby the refined distillate from a given grade of crude oil will have a uniform quality.

With the foregoing objects as paramount, the invention has particular reference to the salient steps in the method which will become manifest as the description proceeds;

In the manufacture of gasolene and kerosene, the conventional method of removing hydrogen sulfide is by washing with water or a solution 5 of sodium hydroxide, while mercaptans are changed to the less objectionable disulfides by the use of sodium plumbite, known as doctor solution, and sulfur according to the following equations:

Let R represent a hydrocarbon group such as ethyl (Cal-I5).

NagPbog (Mercaptans) (Sodium plumbite) (RS)2Pb 2NaOH (Lead mercaptide) (Sodium hydroxide) (RShPb s 2RS PbS (Lead mercaptide) (Sulfur) (Disulfido) (Lead sulfide) It will be understood that, although theoretically the latter reaction will go to completion as shown, in actual refinery practice an excess of sulfur is often used, either through inadvertence or in order to drive the reaction to completion. An excess of sulfur in the distillate is most undesirable due to the resultant corrosive action on the 45 metal of internal combustion engines.

The present invention relates. to a method of converting mercaptans to disulfides which does not require the addition of sulfur, thereby precluding the possibility of an off corrosion prod 50 uct due to this cause. The treating compounds by which this may be accomplished are the alkaline plumbates, either sodium or potassium metaplumbate (NazPbOa) or the corresponding orthoplumbate, such as Na4PbO4.

The reactions with meta-plumbate may be represented:

2RSH NazPbOs (Mercaptans) (Sodium meta-plumbate) 2RS Na,Pb0, 11,0 (Disulfides) (Sodium plumbite) (Water) The action of sodium ortho-plumbate and mercaptans may be represented:

2RSH Na Pbo (llfercaptans) (Sodium orthoumbate) ans Na Pbo 2NaOH (Disulfides) (Sodium plumbite) (Sodium hydroxide) The chief advantages of the ortho-plumbate over the meta-plumbate are that the reaction time is much less and that the ortho compound may be regenerated electrolytically at less expense due to the formation of less molecular oxygen. It will be understood that when orthoplumbate is used as the principal treating reagent, the solution will in general contain an appreciable percentage of the meta-plumbate as well.

Manifestly, the method described is capable of considerable modification and such modification as may fall within the scope of the appended claims is considered within the spirit and intent of the invention.

What is claimed is:

1. A method for converting mercaptans to disulfides in petroleum distillates without the addition of sulfur thereto, which comprises subjecting said distillates to the action of an aqueous solution of an alkali metal plumbate.

2. A method for removing mercaptans from petroleum distillates without the addition of sulfur thereto, which comprises subjecting said distillates to the action of an aqueous solution of an alkali metal meta-plumbate.

3. A method for treating petroleum distillates for the removal of objectionable sulfur compounds therefrom which comprises subjecting said distillates to the action of an aqueous solution of an alkali metal ortho-plumbate without the addition of sulfur to said distillates.

4. A method for insuring against excessive corrosive properties in petroleum distillates which, comprises subjecting said distillates to the action of an aqueous solution of sodium plumbate without the addition of sulfur to said distillates.

FRANK GARDNER.