US1654581A - Process of desulphurizing and purifying petroleum oil - Google Patents

Description

Jan. 3, 1928. I 1,654,581

R. CROSS PROCESS OF DESULPHURIZING AND PURIFYING PETROLEUM OIL Filed NOV. 21. 1923 6 THEFT/Ala 7'0 14/595 3 It 8 5 2 g R R k 6 IN VEN TOR. 4'

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latented Jan. 3, 1923.

usrrao s'ra'ras ROY CRQSS, O15 KANSAS CITY, MISSQUBI.

PROCESS OF DESULPHUBIZING AND PURIFYING PETROLEUM OIL.

Application filed l 'ovember 21, 1923. Serial No. 676,028.

This invention relates to improvement. in a process and apparatus for desulphurlzlng and purifying petroleum 011, and refers more particularly to a process in which oils aredesulphurized, decolorized,-puritied, deodorized and sweetened by treatment with a solution of metal salts at temperatures and pressures bestadapted to etfcct the most complete and eificient refining of the product treated.

Amongthe objects of the invention are to provide a process in which petroleum hydrocarbons, and particularly cracked distillates or oils containing objectionable amounts of 1 sulphur compound, may be-treated whereby the sulphur is removed and the oil sweetened and decolorized to produce a water-white product; to provide a process whereby the oil may be marketed directly after treatment, or when treating certain oils especially difiicult to refine, an additional bleaching material may be used subsequent to the purifyin treatment. Tn the drawings: 2 The single figure is a diagrammatic side 1 elevational view of the-apparatus with parts shown in section.

"While the apparatus, shown in the drawin'gs, discloses a construction adaptable for the purpose described, it is understood that petroleum hydrocarbons may be treated by this process in other types of apparatus withoutdeparting from the spirit of the invention.

Referring briefly to the drawings, at 1 is shown a heating coil mounted in a furnace 2, preferably heated by means of gas burner 3. The discharge end of the heating coil communicates with a chamber 4, which has connection through a transfer line 5 to the treating tower 6. The treating tower in turn communicates through a line 7 with a bleaching tower or stage 8; this latter zone being connected by line 9 to a cooling coil 10. A receiving tank 11 is equipped with a liquid drawofi line 12, controlled by a valve 13.

Rgoferring now to the method in which the oil is" treated, the distillate or petroleum hydrocarbon which is to be treated is introduced to the system for purifying, desulphurizing, deodorizing and deeolorizing.

The hydrocarbon is supplied from any convenient source, not shown, through the pipe 1. This supply or charge is preferably con-- tinuously directed through the inlet line 14 and charged, by means of the pump 15,v

through t e line 16 and thence through the heating oil 1 where it is heated to the desired treating temperature. The most efficient temperatures utilized will vary with the type of oil treated, but temperatures ranging from 200 to 500 F. will include a range which, normally, is suflicient to properly treat-the oils by this process. At this temperature, there are sufficient volatile prod ucts evolved to generate a self-imposed pressure which is maintained upon the oil collecting in the chamber 4:. Ifthe vapors, evolved at the temperatures used, are insufiicient to generate the desired pressur,--an extraneous gas may be supplied through the pipe 17 controlled by a valve 18 or the pres sure built up by the pump 15. The chamber is equipped with a pressure gau e 19Ifor ascertaining pressure maintame in the chamber.

A heated oil, under pressure, is discharged from the chamber through the line 5, controlled by a valve 20, and is conducted to the treating tower 6. A bypass line 21, controlled b a valve 22, is connected between the chain er and the line 5 beyond the valve The tower 6 consists preferably of a heavily insulated cylindrical chamber whichhaspositioned therein a plurality of bafile. n 1emhers 23 which serve to cause the oil to follow a circuitous route in its travel from the bottom to the top of the tower. Between these bafiie members is positioned a plurality of screens or metal lath, diagrammatically shown at 24, broken stone or other relatively inert material which has the ability of increasing the surface over which the oi is -passed in order that a more complete treatintimately combined in order that the treating material-introduced to the top shall be ,brought in contact with as much of the oil as is possible in its travel. The treating solution consists of certain metal salt such as lead, copper, antimony, zinc, manganese, or

other metals which have the ability of combining with the sulphur, and other impurities, to remove it from the oil. These metal salts are dissolved in such solvents as water, alcohols, glycerin, ethylene-glycol, or other solvent materials which do notreadily dissolve in the oil nor have the characteristicsof dissolving any substantial amount of. hydrocarbon material. The treating solutions which havebcen used with the most got satisfactory results are sodium-plumbite solution known in the art as a doctor solution, and copper solution preferably in a neutral or weak acid condition.

It is well known thatsodium plumbite solution has been used heretofore as a cold solution in treating oils' toiremove a part of heir sulphur content, but it has-never been satisfactorily demonstrated that such a solution can extract effectively sulphur from oils which have anything more, than a very small amount of sulphur therein. This solution, when used underheat and pressure conditions such as those described, may be eflectively utilized to treat the most odoriferous sulphur containing hydrocarbon products such as natural gasoline or cracked gasoline recovered from Luling crude, which is notoriously high inits' sul hur content. The product resulting from t is treatment was a water-white, clean, sweet distillate which could readily pass both a doctor and copper corrosion test. The oil, after treatment in t'hctower-G, passes over through the line 7 and may be withdrawn through the line 27 controlled by a valve or if oil of a character which necessitates subsequent bleaching, the valve 28 may be closed and the valve 29 opened, whereupon the oil is introduced to a" bleaching stage which consists of a tower 30 filled, between the 'uppcr and lowerscreens,

- with fullers earth, b'ntonite, or other bleach ing material. This latter container is preferably"steam-jacketed, as shown at 32, for

maintaining the p roper heat during the bleaching treatment. The oil, on rising to the top of the container 8, flows off through the line 9, controlled bya valve 33, to a cool ing.,.coil 34'and is collected as refined distillate in the receiving "tank 11 from which it may be dfwn ed as desired.

drawn off through the line 35 regulated In place of the bleaching stage, the ull withdrawn from the line 27, if not suf ficiently bleached, may: be subsequently subjected to a dilute' acid and caustic treatment in continuous agitators not shown but in ra-ctice well known in the-"art;

' he treating substance, which is of heavier gravity than the oil, will find its way to the bottom of a treating tower'6 and may Ihe. a valve 36. This material may be settled out" and regenerated for reuse or,'if such drawn oil as waste.

practice, is ineffective to thesatiefac tory ref covery of the material, it may simply be' As described, temperature range of from 200 to 500 F. results in the most satis-F factory treatment;."and pressures ranging.

from 25 to 150 pounds have proven to be satisfactory. -The function of the pressure lies not only in the maintaining of the treat ing material or solution. in the liquid phase, but also in the fact that it tends to. combine more effectually and intimately the treating and treated material. The increase of temperature increases velocity of reaction amounting to doubling of the effectiveness for each 20 F. rise in temperature.

Normally, the hydrocarbons introduced I from the chamber into'the treating tower, is in a. fluid state- A portion of the volatile hydrocarbons being in a vaporous condition, while a substantial portion of the oil being in a liquid state.

In the event that a regeneration of the treating material is not practical, it may be desirable to distill off thesolvent material after such liquids as alcohol. orglycerin is, used. This recovered solvent may subse-.

quently recombined with'a fresh supply of metal salts for reuse. Considerable reviving of the treated material may be efiectedby mechanical filtration to remove the objection able impurities.

This treatment may also be used in' crackmg still towers for vapors under pressure or while the oil is in the vapor phase. I

When treating be'nzine dis'tillates where as subsequent distillation is necessary to recover a satisfactory inarketable,gasolinedike I the liquid materials.

2. A process for purifying and decolorizing hydrocarbon oils, comprising the steps of. bringing the oil in intimate contact by counterflowing' it with a sodium plumbite' solution, the solvent being substantially immiscible in the oil, separating the oil and. treating materials and subjecting the formal to the bleaching action of an adsorptivc agent and maintaining the oil at temperatures above 200 F. andunder pressure sufficient to prevent substantial vaporiaation during operation.

7 nor cross.

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