US1870792A

US1870792A - Method and apparatus for hydrogenation and distillation of low-sulfur petroleum oils

Info

Publication number: US1870792A
Application number: US249585A
Authority: US
Inventors: Edgar M Clark
Original assignee: Standard IG Co
Current assignee: Standard IG Co
Priority date: 1928-01-26
Filing date: 1928-01-26
Publication date: 1932-08-09
Anticipated expiration: 1949-08-09

Description

g- 9 1932- E. M. CLAR 1,870,792

S FOR HYDROGE METHOD AND APPARATU ION AND D ISTILLATION OF LOW SULPHUR PETROLEUM OILS Filed Jan. '26, 1928 EDGAR V\. CLARK 5mm 7 hm Qbtozmeq Pawnee Ange, 1932 UNITED, STATES PATENT OFFICE I YEDGAR M. CLARK, OF NEW YORK, N. Y., ASSIGNOR TO STANDARD I. G. COMPANY METHOD AND APPARATUS FOR HYDROGENA'I'ION AND DISTILLATION OF LOW-SULFUR 'PETROLEUM OILS Application filed January 26, 1928. seriallq'o. 249,585.

This invention relates to the art of hydrogenating hydrocarbon oils. More particularly, it comprises the combination of a bat tery of stills with hydrogenating equipment,

the hydrogenated product being distilled in 'the battery. In my application, Serial No. 249,584, filed of even date herewith, this general combination is broadly claimed and is exemplified by equipment specifically difi'ercut from that described and claimed herein. The present invention will be fully understood fromthe following description, read in connection with the accompanying drawing, in which the figureis a diagrammatic vertical section of equipment suitable for practicing the improved method.

Referring to the drawing, 1, 2, 3, 4', and 5 denote a battery of series-connected stills.

These may be of the usual shell type having bell-cap plate towers 6, 7, 8, 9, and 10. It

will be understood that the number of stills may be varied. A refluxing coil 11 is installed in the upper part of each tower and receives a suitable cooling medium, preferably the oil to be treated, through pipe 12 and branch pipes 13. The coils 11 discharge through lines-14 into the hot oil line 15. The inlets and outlets to the coils 11 are valve controlled so that the amount of oil. passing through the coils may be regulated to secure the desiredcooling efiect.

Vapors are taken off from each still through lines 16, the stills being maintained at progressively higher temperatures in the usual .manner. Steam may be injected into the bottom of, each still through a spray pipe 17. Liquid oil is transferred from one still to the next in series through

lines

18, 19, 20 and 21. Pumps may be provided in these lines but it is preferred to utilize a steam lift effect as by injecting steam through a pipe 22. I v

Branch lines23 and 24 lead fromline's 18 and 19 and discharge into a header 25, which also receives liquid oil from the last still 5 the cold feed line 12 are connected by a line 27. This conveys the oil= to the tower 6 of still 1. i

pipe 28 into the heatexchanger 29 and' therice containing hydrogen in effective amounts, is

through a line 26. The hot oil line 15 and by a pipe 30, in which a pump 31- is installed, to a heating coil 32, mounted in a suitable furnace setting 33. The coil discharges through line 34 and branch lines 35 into one or more reaction chambers or reactors 36. These'are constructed to withstand the action of hydrogen at very high pressures and temperatures. They are heat insulated and may contain electric heaters or other suitable internal means (not shown). A stirrer 37 may also be installed in each reactor, or the injection of oil and hydrogen may be depended upon for agitation.

Line 38a receives hydrogen from the condensate drum 39 "(subsequently described) through line '40. Line 38a conveys the hydrogen to the lower part of a purifying tank 41, into the upper part of which a purifying solution, such as" sodium hydroxide or sodium carbonate solution, is introduced through spray head 42. The purifying solution is drawn of]? through line 43iandmay be revivitied a for further use. The hydrogen then passes through line 44 into the lower part of a second purifying tank 45, into the upper part of which a solvent for hydrocarbons is sprayed at 46. The solvent is withdrawn through line 47 and the dissolved hydrocarbons are removed by distillation in the well known manner. 1

The purified hydrogen leaves the tank 45 through line 48'and is forced by pump 49 throughlines 48a and 50 into thereactors 36. Additional high pressure hydrogen, or a gas supplied through line 38 to line 48a. The oil lines 35 and the hydrogen lines 50 preferably discharge neareach other at thebottom of the reactors, A line 48b conveys hydrogen from line 48a to amixing device 30a in the oil line 30; The mixing device may be porous or perforated plates," a baflie tower, or other means for bringing liquid and gas into intimate contact.

Lines. 51 are provided, for withdrawal of material from the lower part of the reactors,

and'gases and vapors are: takenofif through lines 52, which discharge into a manifold 53. The hot'oil from header 25 flows through Preferably lines 51 connect with line 30, so that'chargemay be c0nt in,uous1y circulated m0 through the reactors 36 and coil 32. Gases and vapors pass to the heat exchanger 29 and then to thecondensing coil 54. This discharges into the drum 39. A pressure control valve 55 is installed between the coil'54. and the drum 39.

Hydrogenated condensate preferably flows from this drum through line 56 to line 56a,

branch lines 23a and 24a, and thence into toware 7 and 8 of

stills

2 and 3, respectively. Line 56 is also connected with line 27 and through this with tower 6 of still 1. A valve 27a is vided they do not contain suificient sulfur in the low-boiling fractions to render them commercially undesirable. The flow of hydrogen is indicated by feathered arrows and the flow of other fluids by plain arrows. The preheated oil is forwarded through line 27 to 'tower 6 of still 1. The topped crude and other residual. oils are taken off, for example, from stills 2 and 5, and flowed through header 25 to heat exchanger '29. The oil fiows from this heat exchanger through line 30 to the coil 32, in which it is heated to a temperature of about 7 50-950 F., and passes at this temperature'to the reactors 36. The pressure in the battery of stills is preferably substantially atmospheric and the pump 31 raisesthe oil to the required pressure.

The hydrogen or hydrogen-containing gas is raised to the proper pressure by pump 49 and is injected through lines50 into the reactors,'wherein it .is intimately mixed with the oil. The hydrogen in lines 50 may be passed in heat exchange relationship to the productsfrom the reactors in lines 52. The

temperature inthe reactors is maintained at about 750 to 9502 F. and at a pressure of 50 to 200. atmospheres or .more, preferably about 200 atmospheres. Gases and vapors from the reactors are cooled by heat exchange with the oil passing through heat exchanger 29 and the normally liquid products are condensed in cooler 54. These products'are preferably forwarded through

lines

56, 56a, 23a and/or.

24a .to the stills 2 and/ or 3. If-desired, some or all of the hydrogenated product may be forwardedthrough line 27 to tower 6. The

' stills are usually held at temperatures progressively increasing from about 350 F. to 700 F., taking off successively light naphtha, heavy naphtha, kerosene, gas oil, and lubricating oils. Superatmospheric pressure or subatmospheric pressure may be maintained on oneor more ofthe stills, in accordance well-known practice.

.is removed by washing with alkali solution in tank 41. Methane and other light hydrocarbons carried along with the hydrogen are absorbed by the oil in tank 45.

It will be noted that the entire feed oil does not pass through the hydrogenation equipment. Lighter fractions are distilled off in stills 1 and 2, only'unvaporized oil from one or both these stills passing to line 25. This method of operation is especially advantageous for those oils the low-boiling fractions of which contain only small amounts of sulfur. High-sulfur 'naphthas and the like should be passed through the hydrogenation equipment for. the reduction of the sulfur content, as described in the copending application above mentioned.

Catalysts are ordinarily provided in the reactors for promoting the reaction between the oil and hydrogen. When charge is recirculated through

lines

51 and 30, the catalyst accompanies the oil through coil 32. Hydrogen may also bepassed through line 48b for admixture with the oil passing through the coil. Finely pulverized metal oxids, especially a mixture of 90% chromium and 10% molybdenum oxid are recommended. Such catalysts are maintained in suspension by the agitation provided in the reactors. The amount of catalyst may be varied greatly. When using the mixed oxid catalyst described, about one-third by volume of the oil in the reactors at any one time, is generally satisfactory. The amount of hydrogen supplied may also be widely varied. By way of example, it may be said that about 10,000

' to 15,000 cubic feet of hydrogen is required for the satisfactory treatment of each 50 gallon barrel of oil passing to the reactors.

One or more secondary reactors containing catalytic bodies may be provided to receive the gases and vapors from reactors 36. The secondary reactors are supplied with an additional quantity of high temperature hydrogen, in the manner described in the copending application referred to above. A pressure control valve may be provided in the line between the primary and secondary reactors and the latter may be run at the same pressure, or at a higher or lower pressure. Electric heaters or the like may be installed in the secondary reactors.

Itwill be understood that the foregoing description is merely illustrative of preferred forms of the invention and that various changes and alternative arrangements and procedures may be adopted within the scope of the appended claims inwhich it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

I claim: I

1. Process for obtaining valuable products from hydrocarbon oil which comprises distilling from the oil the lowest boiling fraction, subjecting the residual oil to the action of hydrogen under a pressure in excess of 50 atmospheres and at temperature above 7 50 F. but below 950 F., removing vapors evolved in the hydrogenation, cooling the same, passing the hydrogenated condensate to the distilling operation and distilling same with fresh unhydrogenated oil.

2. Process for obtaining a plurality of Valuable fractions from a crudepetroleum oil having a low sulfur content, which comprises distilling ofi' the lowest boiling fraction of the oil in the first of a seriesof distillation zones, continuously passing aportion of the undistilled residue successively through the other distillation zones of the series, continuously subjecting another portion of the undistilled residue from the first distillation zone to the action of hydrogen under pressure in excess of 50 atmospheres and at temperature above 750 F. but below 950 F., removing vapors evolved in the hydrogenation, cooling the same, passing the hydrogenated condensate to the first of the series of distillation zones, and continuously removing from each of the zones a vapor comprising a mixture of hydrogenated and unhydrogenated oil.

3. Process according to claim 2 in which the undistilled residue from the last of the series of distillation zones is subjected to the hydrogenation,

4. Process for obtaining a plurality of valuable products from a crude petroleum oil having a low sulfur content, which comprises continuously passing the oil through a series of stills, continuously withdrawing a portion of the undistilled residue from one or more of the stills, subjecting the with drawn oil to the action of hydrogen under pressure in excess of 50 atmospheres and at temperature above 750 F, but below 950 F., condensing vapors evolved in the hydrogenation, passing hydrogenated condensate to one or more stillsof the series, and continuously removing from each still a vapor of the series, separate means for taking oii another portion of the residual oil from said still, a heater, means for passing said residual oil through said heater, a'reactor, means for supplying hydrogen at high pressure thereto, means for passing the oil from said heater to said reactor for intimate commingling with the hydrogen therein, means for separating normally liquid products from the gases and vapors fromsaid reactor, and means for returning said normally liquid products to the series of stills.

6. Apparatus according to claim 5, in which means are provided for taking off residual oil from a still other than the first in series, and for passing residual oil from such other still to the reactor.

7. Continuous hydrogenation equipment, comprising a series of stills, means for passing a portion of the residual oil from the first still successively through the other stills of the series, separate means for removing residual oil from the first and last stills of said series, a heater, means for passing the residual oil through said heater, a series of reactors, means for passing oil from said heater to said series of reactors, means for supplying a gas rich in free hydrogenand at high pressure thereto, means for separating normally liquid products from the vapors from said reactors, and means forreturning said normally liquid roducts to an intermediate still of the sald series of stills. I EDGAR M. CLARK.

comprising a mixture of hydrogenated and unhydrogenated'products.

'5. Continuous hydrogenation equipment, comprising a series of stills, means for passing preheated oil into a preliminary still of said series, means for passing a portion of the residual oil through the remaining stills