US1934037A - Process for destructive hydrogenation of hydrocarbon oil to form improved lubricants - Google Patents

Description

E..M. CLARK 1 ,934,037 TIVE HYDH N OF HYDROGARBON GANTS oGENATIo LUBR; 1930 PROCESS FOR DESTRUC OIL TO FORM Filed IMPROVED Jan. 25

PATENT OFFICE PROCESS FOR DESTRUCTIVE HYDROGENA- TION OF HYDROCARBON OIL TO FORM IMPROVED LUBRICANTS Edgar M. Clark, Greenwich, Conn., assignor to Standard-I.

Application January .25,

16 Claims.

The present invention relates to a process for the production of valuable refined hydrocarbon products from heavy unrenned hydrocarbons, such as petroleum or heavy petroleum cuts, tar

cils and the like, through the action of hydrogen at elevated temperature and pressure. My invention will be fully understood from the following description. I

In the process of destructive hydrogenation disclosed in Serial No. 379,086, filed July 18, 1929, by the present inventor, high grade lubricating oils may be made from low grade raw' materials, such as crude oils, high sulphur, tarry or otherwise undesirable residue as Well as distillates, coal tar and the like, by subjecting such materials to a restricted destructive hydrogenation. By the term restricted destructive hydrogenation is meant a process in which the initial materials are subjected to the action of hydrogen under pressure in excess of atmospheres at temperatures between the approximate limits of 700 and 850 F. and preferably in the presence of a sulfur-insensitive catalyst, limiting the duration of the treatment so that the formation of low boiling hydrocarbons is at least 5% but not more than about 20% of the initial material. It has been found that the valuable improvements are accompanied by decomposition which results in the formation of products o f lower molecular weight, lower boiling point and viscosity. In other words, the process is not merely addition of hydrogen but appears to be a decomposition or rearrangement of the hydrocarbon structure as well. By the term high grade lubrication oils as used herein, is meant lubricating oils of high quality, particularly with respect to temperatureviscosity characteristics.

I have found that the yield of light low boiling nonviscous oils, which have no value as lubricants, such as the naphtha, kerosene and gas oil cuts, depends on the improvement made in the lubricating oil fractions. For example, lubricating oils may be classed according to the relation between .`viscosities at 100 F. and 210 F.

0n such a classification the Pennsylvania or other Appalachian crudes are the best and the others grade downwards as the ratio of vis. 100 to vis. 210 F. increases. The following table shows some of the well known crudes classined as above:

It must be understood that the numerical value of G. Company l 1930. Serial No. 423,555

the ratio given is only signiiicant where oils of the. same viscosity at 210 are compared but as Will beunderstood the cuts from some particular crude can be compared with cuts of equal viscosity, say at 210 F. and 100 F. or any other two temperatures and the particular oil falls into its proper class.

As has been stated, high grade lubricants can be made from lower grade oils by the process disclosed in the above notedapplication and it is possible to take a cut from Texas Coastal oil and by such treatment produce an oil having the characteristics of a Colombia, Mid-Continent or even Pennsylvania type. 1n such treatment the yield of the improved oil depends on the improvement made, that is the yield of equivalent Pennsylvania oil made from Mid-Continent feed stock will be greater than the yield of such equivalent Pennsylvania made from say Colombia or Texas Coastal oil.

The method of carrying outthe process of the present invention will be fully understood from the following description, reference being had to the accompanying 'drawing which is a semi-diagrammatic View in sectional elevation of a suitable type of apparatus.

Referring to the drawing, numeral 1 designates av storage supply tank containing the crude lubricating oil. This oil is drawn through line 2 by pump 3 and forced through line 4 into a rectncation tower 5. The lighter fractions of the crude oil are removed from rectification tower5 through line 6; The heaviest fractions of the crude oil are removed from tower 5 through line 7. The fraction of the crude oil which is to be subjected to a restricted destructive hydrogenation treatment is removed from the tower through line 8 and is collected in supply tank 9.- Pump 10 withdraws oil from tank 9 through line 11 and forces it through line 12 into and through heating coil 13 which is mounted in a suitable furnace setting 14 adapted to theflring by gas, oil, or other suitable means. The heated oil flows from coil 13 through line 15 and discharges into the bottom of reaction drum 16 through a suitable series of openings 17. Reaction drum 16 is adapted to withstand high temperatures and pressures and is also resistant to attack by hydrogen and the reacting materials. It is preferably provided with an insulating coating 18 and is packed with a suitable catalytic material 19. l

The hydrogen is drawn from any suitable source (not shown) through line 20 and is compressed by compressor 21 and then forced through line 22 which connects with line 12, carrying' oil into the heating coil. In, this way the mixture of oil andv hydrogen is caused to ow through the heating coil. All of the hydrogen necessary for the reaction may be introduced into the oil prior to the passage through the heating coil 13 or a part thereof may be mixed with the oil at this point and the remainder introduced' directly into the bottom of the reaction drum 16 through line 23. 1

The' reaction products leave drum 16 through line 24, flow through cooler 25 and thence discharge through line 26 into the separating drum 27, wherein the liquid and vaporous products are separated. The vapors pass out of drum 27 through line 28 and may be forwarded to a suitable recovery-purification system (not shown) The liquid products are withdrawn from drum 27 through line 29, flow past a pressure reduction valve 29a and thence are discharged into a rectification tower 30, wherein the desired lubricatingfraction is separated .from the lower boiling hydrocarbons such as gasoline' and heavy naphtha. The lower boiling fractions are removed from tower 30 through line 31, pass through cooler 32 and are collected in drum 33, wherefrom they may be withdrawn and passed to a suitable storage drum (not shown) The lubricating fraction is withdrawn from tower 30 through line 34 and is collected in drum, 35, wherefrom it may be withdrawn by line 36 and forwarded to equip-- ment for further treatment (not shown) In the operation of my process the unrened oil is first fractionated or rectied to -produce a narrow boiling range cut, which is subsequently subjected to destructive hydrogenation. The fractionation may be done by repeated fractional distillation or by rectification preferably under vacuum. The cut should of course be heavier than the oil product desired and the viscosity, for heavy oils say of viscosities above 300 sec. Saybolt at 100 F., should be not more than 30 seconds Saybolt at 210 heavier than the viscosity of the desired product. If the feed -is very low grade oil and the improvement desired is great, say for example, if it is desired to make equivalent Pennsylvania oil from Texas Coastal oils, the viscosity difference between feed vand desired product should be greater than if the feed were Mid-Continent oil. It is desirable to use a cut not more than 20'sec. Saybolt 210 heavier than the desired product whe'n the improvement required is less and the difference may be less than 10 or even 5 sec'. Saybolt at 210 F. when the desired improvement is correspondingly smaller.

It is also desirable to use narrow cut oil, in general the narrower the cut the greater will be the yield of athe desired product for any given improvement in grade. Narrowness may be expressed in viscosity range which is the difference between the viscosities at 210 F. of the first 10% and last 10% fractions obtained by simple distillation of the cut under high vacuum, say 30 mm. of mercury. Narrowness'may also be expressed in terms of the boiling range as the difference between the 10 and 90% points when distilled under 30 mm. absolute pressure. Viscosity range should be below 150 seconds Saybolt at 210 F. but it is preferably below 100 sec., 75 sec. or even 50 sec. at ,210 F. The boiling range as defined above should be below 250 F., but it is preferable that it should be below 200 F. or 150 F. or even 50 F. It should be understood that the narrower the cut, the better the `results obtained.

For oils of viscosity below 300 Saybolt 100 F. where it is not generally the practice to take viscosities at 210 F., the oil fraction should not have a viscosity more than 500 seconds Saybolt at 100 F. above the viscosity of the desired product and as indicated above,` this may be advantageously lower, say 300 or 100 where the improvement desired is correspondingly not so great.

The viscosity range for lighter oil, that is the difference between the Saybolt viscosities 100 F. of the first 10 and last 10% when distilled at 30 mm. of mercury absolute pressure, should be less than 750 sec. and may be less than 500 or 300 or even 100 sec. with advantage.

'Ihe destructive hydrogenation may be accomplished in any suitable form of apparatus, for example, in a heavy steel retort heated internally with electric coils and thoroughly'agitated or the heating may be done in a red coil through which hydrogen is also passed. 'Ihe temperature is in general between the limits of 700 and 850 F. and pressure should be in excess of about 20 atmospheres although higher pressures, say above 100 or 200 atmospheres are more satisfactory. Suitable catalytic material,y such as metallic oxides or sulphides of chromium, molybdenum, tungsten and the like may be used either alone or in `combination or mixture with each other or other oxides, such as those of the alkaline earth, alkali, rare earth metals, zinc oxide, alumina and the like. Such material may be finely ground and suspended in the oil or packed into the hydrogenation drum in coarse lump form. The reaction preferably proceeds in the liquid phase and a large excess of hydrogen is forced into the reaction zone with the oil. The refined product may be removed in the liquid state or as a vapor.

The products of my'process may be finished in any suitable manner either with acid or other--l wise but it is desirable to iirst eliminate the hydrogen sulphide which is dissolved in the oil. The oil is preferably given an alkali wash and rerun with steam or under vacuum to give the desired cuts.

My invention is not to be limited to any theory of the chemical reactions involved nor to any illustrative details which may have been given but only by the following claims in which I wish to claim all novelty inherent in my invention.

I claim:

1. An improved process for producing valuable lubricating oil of pre-determined viscosity and v improved quality particularly with respect to temperature-viscosity characteristics from heavier lower grade hydrocarbon oil which comprises separating from the lower grade oil a fraction Ahaving a Saybolt viscosity at 210 F-. not more than 30 seconds greater than the viscosity of the desired product, subjecting this fraction to the action of hydrogen at temperature between 700-850 F. and under pressure in excess of 20 atmospheres for a time such that at least 5% but not more than about 20% of the fraction is converted into low boiling hydrocarbons and recovering from the' product of this treatment a lubricating fraction of the desired viscosity.

2. Process according to claim 1 in which a fraction having a Saybolt viscosity at 210 F. not more than 20 seconds greater than the viscosity of the desired product is nrstseparated from the lower grade hydrocarbon oil and thiszfraction is subjected to the destructive hydrogenation treatment.

3. Process according to claim 1, in which the Saybolt viscosities at 210 F. of the first 10% and last 10% cuts obtained'by distillation ofthe fraction to be hydrogenated at absolute pressure of 30 mm. o! mercury do not differ by more than 150 seconds.

, 4. Process according to claim ,1 in which the Saybolt viscosities at 210 F. of the first and lat 10% cuts obtained by distillation of the fraction to be hydrogenated at absolute pressure of 30 mm. of mercury of the fraction to be hydrogenated do not diier by more than 100 sec.

5. Process according to claim 1 in which the Saybolt viscosities at 210 F. of the first and last 10% cuts obtained by distillation at yabsolute pressure of 30 mm. of mercury of the fraction to be hydrogenated do not diier by more than 6. An improved process for producing valuable lubricating oils of higher grade particularly with respect to temperature-viscosity characteristics from lower grade heavier petroleum oils, which comprises fractionating the lower grade oil whereby a fraction is produced which is heavier than the desired oil and which if distilled at an absolute pressure of 30 mm. of mercury gives rst and last 10% cuts differing no more than 150 sec. in the Saybolt viscosities 210 F., subjecting such fraction to the action of hydrogen at a temperature between 70D-850 F. under pressure in excess of 20 atmospheres and in the presence of a sulphur-insensitive catalyst for a time such that the formation of the low boiling hydrocarbons is at least 5% but not more than 20% of the initial material and recovering the fraction of the desired viscosity from the product of this treatment.

'7. Process according to claim 6, in which the ilrst and last 10% cuts of the fraction to be hydrogenated do not differ in viscosity by more than 100 sec. Saybolt at 210 F.

8. An improved process for obtaining lubricating oil of high grade particularly with respect to temperature-viscosity characteristics from than about 20% -of the initial material is` con- Verted into low boiling hydrocarbons, and recovering from the product of this treatment a lubricating fraction of. the desired viscosity.

9. Process according tofclaim 8, in which the fraction to be hydrogenated shows 10 and 0M- distillation temperatures diifering not more than 150 F. when the fraction is distilled under absolute pressure of 30 mm. of mercury.

10. Process for producing valuable lubricants "of high grade, particularly with respect to teminsensitive catalyst 'for a time such that at least 5% but not more than 20% o! the initial material is converted into low boiling hydrocarbons and recovering the lubricating fraction of the desired viscosity from the product of this treatment.

11. Process according to claim 10 in which the viscosity of the fraction to be hydrogenated has a viscosity at 100 F. not more'than 300 sec. above the viscosity of the desired product.

12. Process according to claim 10, in which the viscosity of the fraction to be hydrogenated has a viscosity 100 F. not more than 100 sec. above the viscosity of the desired product.

13. Process according to claim A10, in which the fraction to be hydrogenated if distilled under 30 mm. of mercury absolute pressure shows 10 and distillation l temperature diilering by not more than 250 F.

14. Process according to claim 10, in which the fraction to be hydrogenated if distilled at absolute pressure of 30 mm. of mercury shows 10 and 90% distillation temperatures differing by not more than 150 F.

15. Process according to claim 10, in which the Saybolt viscosities at 100 F. of the first and last 10% cuts of the fraction to be hydrogenated if distilled under absolute pressure of 30 mm. of mercury, diter by not more than 500 sec.

16. Process according to claim 10, in which the fraction to be hydrogenated is of such narrow range that if such fraction be distilled under vacuum of 30 mm. of mercury and the iirst and last 10% fractions be collected, their Saybolt viscosities at'100 F. will not differ by more than 300 sec.

EDGAR M. CLARK.

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