US1967173A - Treatment of hydrocarbon oils - Google Patents

Description

Patented July 17, 1934 UNITED STATES PATENT OFFICE TREATMENT or HYDROCARBON OILS No Drawing. Application December 3, 1931,

, Serial No. 578,750

7 Claims.

This invention relates to the treatment of hydrocarbon oils and refers more particularly to the refining of relatively low boiling hydrocarbon distillates at elevated temperatures, especially those resulting from the conversion of relatively high boiling hydrocarbons at elevated temperatures. More particularly the invention is directed towards the removal of sulphur from such hydrocarbons.

More specifically the invention comprises subjecting hydrocarbon oil vapors to treatment with aqueous solutions of oxygenated halogen acids containingsalts of metals, treatments being conducted in contact with finely divided metals. oxygenated halogen acids include such acids as hypochlorous acid, chloric acid, bromlc acid,

iodio acid either alone or in various admixtures and the salts in solution with these acids may be those of such metals as aluminum, zinc, tin, iron,

' copper, lead, mercury, cobalt, nickel, chromium,

, and the results desired. The metallic salts are' preferably those of other acids than the particular oxyhalogen acid which furnishes the excess acid constituent of the treating ,solution, such salts as chlorides, sulfates, phosphates, etc. being used as their solubilities permit. The treating solutions may contain a single salt or combinations of salts, and the metals employed as solid contact materials may be any of the metals whose salts are employed in solution alone or in combination, the particular aggregation of materials utilized in any case depending upon the nature of the vapor treated and the treating efiects desired.

In some cases it may be found preferable to space the particles of metals by supporting them on or mixing them with relatively inert materials of a non-metallic nature such as fullers earth,

clays, bentonite, bauxite, crushed firebrick,

pumice stone, etc., this expedient serving to expose more surface and prevent the agglomeration of the oxides into masses too large for effective action. The function of the oxide mixtures employed may be of a true chemical nature or they may function merely as catalysts.

It is recognized that materials like fullers earth may have an independent refining effect, quite diflerent, however, from the action of the oxygenated halogen acids in that fullers earth and similar materials while having a marked polymerizing influence have substantially no eifect in respect to reduction in sulphur content. Materials like crushed firebrick serve the principal purpose of providing large contacting surface and a spreading or spacing effect on the active reagents. The vapor undergoing treatment may be mixed with oxygen-containing gases and steam, the former assisting in the chemical reactions produced by the solution of oxygenated halogen 55 acids and metal salts and the latter serving to maintain proper concentrations of the solutions by preventing excessive evaporation of solvent. As examples of oxygen-containing gases air, oxygen, ozone alone or in combination may be mentioned, ozonized air having been found to be particularly efficacious in some instances.

The invention is more particularly directed to the treatment of vapors of lower boiling cracked distillates though straight run distillates may also be treated within the scope of the invention, and is also particularly directed towards the dean]- furization of hydrocarbons and especially cracked hydrocarbons.

The'oxygenated halogen acids, the use of which so is comprised in the present invention, have analogous properties to a considerable extent in that they all exert an oxidizing and some polymerizing action upon cracked hydrocarbon vapors whether dissolved alone in water or dissolved along with other salts and alkalies which may have been produced incidentally to the production of the desired acid. It is, recognized, however, that they differ in degree and to some extent in the nature of the reactions produced.

In applying the process of the invention to practice any suitable equipment may be, employed which will permit the contacting of the hydro- I carbon vapors and the treating reagents employed with the solid contacting or polymerizing materials; for example, a suitable tower or chamber packed with a selected mixture of contact materials may be employed following the fractionator of a cracking system, the reagents being introduced at a suitable point or points along the line of flow of the ascending or descending vapors thus permitting contact of the mixture of hydrocarbon oil vapors, oxygen-containing gases and steam with the solution of oxyhalogen acid and metallic salt and the solid contact materials. Similarly any device which permits the emci'ent contacting of the hydrocarbon vapors undergoing treatment with gases, liquids and solids may be employed, The solid contacting materials may sometimes be employed in successive strata of varying composition.

particular It has been found desirable to neutralize the vapors before or after condensation and to this end the vapors may be treated with ammonia, gas or pass counterflow to solutions of alkalis in auxiliary neutralizing equipment or the condensed vapors may be treated with liquid alkalis such as solutions of caustic soda, ammonia or the like, the traces of reagents and reaction products re.- maining being washed out with water when found necessary. In cases involving the use of solutions containing only a small excess of the oxygenated acid the excess of acid may be completely consumed so that subsequent neutralization is'not necessary.

Reactions involved in treatments comprised within the scope the invention are of a complicated nature from a chemical standpoint but the net results are in the direction of reduced gum and sulphur content the treated product. The nature and extent of the reactions with any particular type of imdrocarbon vapors will vary with the amount and nature of the particular oxyhalogen acid and metailic salt solution employed, and

also with the amount and type of oxidizing gas mixture and the amount of steam used. It has already been mentioned that the reactivity and treating action of the solutions of oxyhalogen acids and metallic salts which may be used ve y in degree and that while they produce similar effects that they are not precise equivalents. Temperatures and pressures employed intreating operations may vary over a wide range,'and it may be advisable in certain instances to use the less reactive acid than the more reactive to control the extent of polymerization desired. Frequently the element of cost enters into consideration as well. By the use of varyingfmixtures of the oxyhalogen acids and dissolved metallic salts and different oxygen-containing gases, and steam. it has been found possible to, produce a wide range cftreating effects, all tending toward the selective elimination of unsaturated compounds and reduction in sulphur content. The

reactions involved when solutions of oxyhalogen acids containing metallic salts in solution act upon hydrocarbon vapors are apparently of an oxidizing and polymerizing nature, particularlyin the presence of oxygen-containing gases and metals both of which also assist the reactions. Whatever fixation of halogen occurs seems to be taken care of by the fact that the addition compounds are higher boiling than the original hydrocarbons from which they were formed and assuch are left behind as heavy refiuxes during the subsequent fractionation of the treated vapors.

The amounts of reagent used in conducting treatments comprised within the scope of the invention will vary over a wide range depending on the chemical nature of the particular vapors in question, the extent of refining action desired and "the emciency of the particular reagent mixture chosen from the standpoint of economy and availability.

The use of hypochlorous acid has been shown to be of definite commercial value and experimental results thus far obtained indicate that beneficial results are also obtainable by the use of the more highly oxygenated chlorine acids and corresponding acids of bromine andiodine.

Treating solutions of varying degrees of effectiveness may be produced by varying the amount and type of metall' wed in solution with. any

" llegen acids.

'Colo'r lemon yellow Various temperatures of treatment may be employed, for example, from 250-600 F., more or less and the pressures may be subatmospheric, atmospheric, or superatmospheric. While the results may vary with the conditions employed, the pressures and temperatures are chosen so that the hydrocarbons are treated substantialy in the vapor phase.

As a. specific example of a method of treatment comprised within the scope of the invention and the results obtainable therefrom the case of a. treatment conducted upon vapors of approximate gasoline boiling point range produced from California crude may be mentioned. Such vapors may be passed upwardly through a contact mass composed of approximately nine parts of crushed firebri'ck and one part of a mixture of finely divided iron and copper in the molecular proportions of one to one respectively, countercurrent to a descending solution containing approximate-' 1y 6% free hypochlorous acid. The vapors may be mixed with a small amount of air to assist in oxidizing reactions and steam to the extent of approximately 5 lbs. per bbl. of condensed gasoline. The gasoline produced from the vapors without chemical treatment of any kind may have the following properties:

Gravity A. P. I. 54.6

Gums by copper dish method 457 mgs.

Sulphur 0.38%

After treatment with reagents in the amounts and the manner described the condensed gasoline may be found to havethe following properties:

Gravity A. P. I. "54.8 Color 30 Color after 4 hrs. exposure to sunlight 26 Gums ..15 mgs. sulphur 0.08%

Gravity A. P. r 54.0 Cblor light yellow Gums by copper dish method 490 ms. Sulphur 0.45%

When the vapors are subjected to'treatment as described prior to their final fractionations, a finished gasoline of the following properties may be The foregoing specification containing descrip-. tive material and examples of the results obtainable by the use of the process of the invention have been given for illustrative purposes and while they clearly-define the invention and indicate its commercial value, it isto be understood that the 1 invention is not limited thereto as a considerable number of other. operations are possiblewithout departing from its scope.

- We claim as jour'invention:

In the vapor phase-"refining of hydrocarbon 15 oils, the'step which comprises treating the vapors with an aqueous solution of an oxygenated halogen acid containing a salt of a nonalkalinous metal, said salt being soluble in\the solution and said acid" being selected from the group consisting of hyochlorous acid, chloric acid, bromic acid, and iodic acid.

2. In the vapor phase refining of lwdrccarbon oils, the step which comprises treating the vapors in the presence of a metallic contact agent with an aqueous solution of an oxygenated halogen acid containing a salt of a non-alkalinous metal, said salt being soluble in the solution arid said acid being selectedfrom the group consisting of hypochlorous acid, chloric acid, bromic acid, and iodic acid.

3. In the vapor phase refining of hydrocarbon oils, the step which comprises treating the vapors with an aqueous solution of hypochlorous acid to which has been added a nonalkalinous metal salt of an acid other than hypochlorous acid, said salt being soluble in the solution.

4. In the vapor phase refining of hydrocarbon oils, the step whichcomprises treating the vapors in the presence of a metallic contact agent with an aqueous solution of hypochlorous acid to which has been added a nonalkalinous metal salt of an acid other than hypochlorous acid, said salt being soluble in the solution.

. 5. The step as defined in claim 4 further characterized in that said contact agent comprises the metal of said salt.

6. In the vapor phase refining 01' hydrocarbon oils, the step which comprises treating the vapors with an aqueous solution of hypochlorous acid to which has been added a copper salt which is soluble in the solution.

'7. In the vapor phase refining of hydrocarbon oils, the step which comprises treating the vapors in the presence of metallic copper with an aqueous solution of hypochlorous acid to which has been added a copper salt which is soluble in the solution.

JACQUE C. MORREIL. GUSTAV EGLOFF.