US1827537A - Desulphurization and purification of hydrocarbon oil - Google Patents

Description

I Oct.'l3, 1931. Q MORRELL 1,827,537

DESULPHURIZATION AND PURIFICATION OF HYDROCARBON OIL Original Filed June 28, 1926 Patented 0a. 13,1931- UNITED STATES PATENT OFFICE JAC Q'UB C. IOBBELL, OF CHICAGO, ILLINOIS, ASSIGNOB TO UNIVERSAL OIL PBDDUC'IS OOIPANY, OII' CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA DESU'IiPHUBIZATION AND PURHICATION OF HYDROCABBON OIL Application filed 1m 28, 1926 Serial 1T0. 119.074.

' ThlS invention relates to 1m rovements 1n In the specific embodiment of the present invention, it is directed particularly to the purification and desulphurization of the dis- I tillates produced in the treatment of hydrocarbon oil under cracking heat and superatmospheric pressure. Up to the present time it has been required that distillates and gaso e-like products be refined to a water white sweet odor stage. This has necessitated expensive refining treatments for the purpose of removing color and odor forming compounds. This condition is now beginning to change, and it is becoming unnecessaryto treat a distillate so rigidly. In other words, a gasoline having a distinctive color other than water white and an unobjectionable odor other than a sweet odor will sell as readily as the product which was formerly refined to a water white sweet odor stage.

Therefore, in view of the fact that it is becoming unnecessary as pointed out, to rigidly treat the oil, I have discovered that the vaporous overhead product taken from the dephlegmator of an oil cracking system may be fractionated in such a manner that roducts may be removed which can be sufliclently refined for market purposes, by very simple and inexpensive treatment, while the heavier portions containing the more objectionable substances, may be separately removed for more drastic treatment, if-desrred.

Among the advantages of the present invention, may be listed the elimination of a redistillinghstep for the lighter products subjected to t s simple treatment, economy. in-

amount of refinin agents used, decrease in amountof waste as to refining, and other incidental advantages. As*"anadded. result of fractionating the product removed from the dephlegmator where the fractions contain ob'ectionable amounts of sulphur, it has been ound that they can be more easily desulphurized in separated fractions than where mixed in a mass.

Other objects and advantages of the present invention, will hereinafter more fully appear.

In the drawing,'the single figure is a diagrammatic side elevational view of an apparatus illustrating one manner in which the invention may be carried out.

Referring more in detail to the drawing, 1 designates a raw oil inlet line in which is interposed the pump 2 and the valve 3. This raw oil charging stock line may introduce the oil to the heating coil 4 mounted in the furnace 5, which may be heated by means of the burner 6. The oil passes through the heating coil 4 and may be heated to a temperature at which substantial conversion will take place, and it may or may not be maintained under a superatmospheric pressure. The heated oil after passing through the heating coil 4, may be discharged through the transfer line 7 controlled by the valve 8 into the interior of an enlarged expansion drum 9, which is preferably insulated, and may or may not be externally heated. This chamber may be provided with the usual manholes 10 and liquid residue drawofi' lines 11 controlled by the valves 12.

Substantial separation of the vapors will take place in this expansion chamber 9, the vapors passin out through the vapor outlet 13 controlled y the valve '14, and discharging into the lower end of a dephlegmator 15 provided with suitable bafiies 16.

Proper temperature conditions are maintained on the dephle ator 15 to condense the proper amount 0 heavy ends and only permit those vapors havin the required. characteristics to discharge rom the top of the de hlegmator through the vapor line 17 'controll ed by the valve 18. The reflux condensate collecting in the dephlegmator 15 m y be returned through the line 19 controlled by the valve 20 to the heating coil 4 in an obvious manner or desired amounts of reflux may be diverted entirely from the system.

Describing now some of the features of the present invention, the vapors passing through the line 17 are caused to discharge into a fractionating introducing regulat tower 21. Assume for the first illustration that the vapors introduced to the tower 21 db not contain an objectionable amount of sulphur. By pro rly controlling the temperature conditions maintained on the fractionating tower 21 in a well known manner such for instance, as

ed amounts of cooling medium to the pipe 22 and spray 23, it is possible to withdraw from the top of said tower those vapors which only require a simple refining treatment for the pu ose of sta ilization. These vapors are wit drawn through the line 24 controlled by the valve 25, conden'sed in condenser coil 26 and collected in the receiver 27. The liquid collected in the receiver'27- is then subjected to the simple refinin treatment necessary, for instance, a simp e alkaline wash followed if desired, y an adsorbent earth. The condensed fraction may withdrawn from tower 21 and cooled in the cooling coil 28, this cooled fraction being separately collected. The condensed. fraction from the tower 21 may then be separately subjected to whatever refining treatment is n which of course, Wlll be or fractions may be made in the fractionatin'g tower, and that the fractions or cuts'may be taken off separately at varying heights in the fractionating tower, and subjected to ,only that amount of refining action which will :produce the most eflicient results. Changes in the apparatus'to permit-such operationswill be obvlous, and come within the broad scope of the invention. 4

Assume forthe purpose of another illustration, that the vapors discharging into the bottom of the fractionating tower 21 contain an ob'ectionable amount of sulphur. I have foun that these objectionable amounts of sulphur compounds can be more readily removed from the distillate if the distillate is. divided into fractions. The reason for this is that the separated fractions permit of more intimate contact between the oil and the desulphurizing agent. While the reactive types of sulphur compounds may be of the same general series in the several fractions, the separation of these fractions permits more selective action between the desulphurizing agent and the reactive sulphur compounds. PK

The proper temperature conditions are creasing redlstillation, etc. 1

mama? maintained throughout the height of the tower 21 to accuratel regulate the characteristics of the indivi ual fractions taken 05, and these individual fractions are then subjected to that degree of refining and desulphurizing action, as has been predetermined a redistillation preferably in the ,presenceof steam.

Barium peroxide used with sulphuric acid has been found to be a good desulphurizing agent, although other peroxides of metal may be used as well as other acids. The amount of peroxide of metal used is not proportional to the amount of sulphur present in' the various fractions. more drastic than the refining treatment to After the various fractions have b i d pendently subjected tqthe n combined, and the recombined product is ready for use as a motor fuel.

From the foregoing, it will be apparent that the use of the present invention results in a saving in amount of refining and de-' sulphurizing agents used,

I claim as my invent1on 1. Amethod for treating hydrocarbon oil comprising subjecting the oil to cracking con- .ditions of temperature and pressure to produce gasoline, subjecting vapors evolved from the oil to dephlegmation to separate therefrom fractions heavier than gasoline,

fractionatingthe dephl ated vapors to "form heavy and lighter hquidoil fractions,

subjecting the lighter liquid oil fraction to the refining action of only an alkali wash followed by treatment with an adsorbent earth, subjecting the heavier liquid oil fraction to refimng and desulphurizing treatment, they are economy in dethe refining action of sulphuric acid, caustic soda, and 'plumbite followed by filtration through an adsorbent earth, thereafter recombinin said light and heavy form the al product of the process.

2. The method of treating a mixture of cracked vapors formed in the cracking of hy drocarbon oils to produce gasoline which comprises separating from the vaporous mixture by dephlegmatidn thereof fractions heavier than gasoline,fractionally condensing the remaining-uncondensed' vapors into a relatively heavy gasoline cut and a. relatively lighter gasoline cut, subjecting said lighter cut to a relatively mild refimng treatment 'onsto 5 consisting of an alkali wash and said heavy cut to a more drastic refining treatment with sulfuric acid followed by neutralization, and then commingling the thus refined cuts.

- 3. The method of purifying cracked gasoline which comprises separating the same into a relatively heavy gasoline cut and a relatively lighter gasoline cut, subjecting said lighter cut to a relatively mild refining treatment consisting of an alkali wash and said heavy cut to a more drastic refiningtreatment with sulfuric acid followed by neutralization, and then commingling' the thus refined cuts.

4. The method of treating a cracked vaporous gasoline mixture which comprises frac-' tionally condensing the mixture into a relatively heavy gasoline cut and a relatively lighter gasoline cut, subjecting said lighter cut to a relatively mild refining treatment consisting of an alkali wash and said heavy- I cut to a more drastic refining treatment with sulfuric acid followed by neutralization, and then commingling the thus refined cuts.

5.. The process of preparing marketable products from a mixture of hydrocarbons consisting chiefly of compounds of the gasoline range, which comprises subjecting the mixture in vapor form to partial condensation to produce a first condensate requiring relatively drastic chemical treatment and a second vapor which requires no such drastic chemical treatment and has a lower'end point than said first condensate, separating the 4 second vapor into liquid products substantially free of normal gaseous hydrocarbons and into a gas, drastically chemically treating the first condensate and mildly chemically treating said liquid products, and blending the treated condensate with the treated liquid products separated from the second vapor.

JACQUE C. MORRELL.

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