US2232909A - Hydrogenation process - Google Patents

Description

' Feb. 25, 1941;" E. J. GoHR HYDROGENATION PROCESS Filed June 20, .1939

w* l f MNHN. ww vww y Patented Feb. .25, 1941 ,UNITED STATES PATENT oFElcE nrnaoGENA'rToN raocrzss` Edwin J. Gohr, Summit, N. J., assignor to Standard-I. G. Company Application `.nine 29, 1939, smal No. 280,916

12 claims. (ci 19H3) This/invention relates to the treatment oi vaporized carbonaceous materials with4 hydrogenof such catalysts in the hydrogenation of carbonaceous materlalsis described in U. S. Patents 1,890,434 and 2,115,336 to Kranen and Pier and 15 2,123,623 to Cecil L. Brown.

`It. has 'also been proposed to activate such catalysts and to regulate their activity during use by introducing sulfur into the hydrogenation zone during operation. Elemental sulfur is preferred `for this use on account lof its cheapnessfease of handling and safety. However, it has been observed that in the treatment oi carbonaceous materials in the vapor phase, such as the treatment of distillate oil fractions under conditions at which they are substantially completely vaporized, considerable diiliculty has been experienced due to the plugging up of heat exchanger and preheater tubes and in the building up oi pressure drop across the reaction zones in continuous operation.

An improved process has now been devised whereby these objections` to the use of elemental sulfur are avoided'. A heavy liquid carbonaceous y material, which is vaporized to only a slight extent, if at all, in the preheaters and the hydrogenation reaction zone, is supplied ina minor proportion of the total charge of carbonaceous material. 'Ihe heavy oil is preferably such that at least the major portion of it is unvaporized in 40 the preheatersand the inlet portion of the re- 1 action zone, and it may beso involatile andrefractory that at least a substantial portion oiit remains in liquid phase even to the exit from the reactionzone. It is oilered in explanationpthat this heavier, relatively involatile liquid fraction maintains a small amount of a continuous liquid phase which serves as a solvent for elemental sulfurbeing supplied to the reaction zone and thereby prevents 'its deposition and also aids in 5o its uniform distribution over the catalyst.

` The drawing is a ditic illustration in partial sectional elevation oi an apparahis suitable- Ior carrying out one embodiment ofthis invention, and indicates the ow of materials.V

, 575 Areadily vaporizable oil'fraction. preferably a petroleuml distillate oil boiling within the range of about 200 to 500"- F. is supplied as the major. portion of the charge stock by pump l. A heavier oil fraction, preferably boiling substantially completely above 500 F., is supplied by pump 2. A 5 portion of either or both of these oils is passed through line 3 into vessel 4 which is lled with lumps of sulfur and which is provided with suitable-heating means, such as the steam coils 5. The heated oil solution of sulfur is then passed 10 by line 6 through filter 1 and by line 8 into heat exchanger 9, being mixed either in this exchanger or just prior to entry thereinto with the remainder of the oil charge and with hydrogenating gases supplied by line I0. Lines 6 and 8 and 15 iilter I are suitably heated or lagged in order to avoid precipitation of sulfur from the hot oil solution.

The mixture of charge stocks and hydrogen.

passes from the heat exchanger 9 through a heat- 20 ing coil l0, preferably a direct red coil, in which they are heated to a. temperature approximating or somewhat below the desired reaction temperature. The heated charge materials are then passed by line Il into a reaction chamber l2 25 which is preferably designed to provide an elongated substantially` vertical reaction zone into f which the charge materials are supplied at or near the top, the reaction vessel being suitably heated or lagged to prevent loss of heat should $0 this 'be desired, and being constructed to with' stand the pressure and corrosive effects of the reagents and catalytic materials used. .Vessel I2 also` contains the catalyst, which is preferably provided in the form of pills, tablets or lumps 35 which are either packed directly intoA the reaction vessel or are disposed therein upon suitable trays or bailles. The treated materials leave the re-V action vessel by line il, pass'through -heat exchanger l and cooler I5 into arhigh pressure j separator I6, from which the liquid fraction is Y withdrawn to low pressure separator I'i and liquid products are then passed by line Il to suitable storage or distillation equipment. 'I'he gases leaving separator I6 may be passed through trap y heavy liquid fraction withdrawn as bottoms in o5 feed.

line may be returned with or without cooling in cooler 26 to the feed pump 2 by line 21. This recycling of the heavy oil fractionis preferred as in many types of hydrogenation operations the heavy recycle oil becomes saturated and does not thereafter require as much hydrogen as the fresh Numerous modifications in the above illustrated process will be readily apparent. The

amount of sulfur supplied with the charge stock v ably conducted in'a continuous manner, and indeed the reaction chamber I2 is usually operated continuously, it is'not necessary to supply either the sulfur or the heavy oil continuously in such a process. Sulfur may' be supplied as desired in order to regulate the activity of the catalyst I3. The heavy oil is supplied throughout the time that sulfur is being supplied and the heavy oil charge is preferably continued for a suilicient time after the completion of the period of sulfur supply in order to prevent any deposition of sulfur in -the preheaters. The sulfur used in this invention may be wholly or partly replaced with elemental selenium or tellurium, or Witha mixture of these materials.

While the materials charged 'are preferably passed downwardly over the catalyst in \the reaction zone in order to prevent accumulation of,

liquid therein, the materials may be passed horizontally and even upwardly through the catalyst bed in the event that such accumulating liquid is not objectionable, as in the relatively low temperature hydroning treatments in which oils are treated with hydrogen at temperatures at which no substantial cracking occurs.

The process of this inventiomis applicable to the treatment of volatile and even normally gaseous carbonaceous materials in the presence of catalysts whose activity is enhanced orprolonged by the'presence of sulfur or hydrogen sulde with hydrogenating gases over a wide range of temperatures'and pressures. Such catalysts include the compounds of metals of group 6 of the periodic system, particularly the oxides and sulfldes. The expression treatment with hydrogenating gases is intended to comprise processes conducted with 'either a net consumption or a net production of hydrogen. These processes include livdrogenation treatments involving partial or complete saturation of unsaturated carbonaceous materials with hydrogen, for example, the conversion of aromatic hydrocarbons into hydroaromatic hydrocarbons. Such processes also include the destructive livdrogenation of carbonaceous materials with hydrogenating gases under high pressures, preferably above about 20 atmospheres, for conversion into relatively lower `nols'or cresols'into the corresponding aromatic hydrocarbons. Such processes also include iso-- merization and-dehydrogenation treatments such as the catalytic reforming treatments, and the hydrocyclization treatments of naphthas. Such catalytic reforming treatments comprise the conversion of hydrocarbons boiling in or slightly above the motor fuel range into hydrocarbons of higher octane number, suitable for motor fuel, conducted at temperatures between about 850 and 1000 F. and under moderate pressures, for example about 100 to 500 pounds per square inch, in the presence of catalysts of the type described above, particularly the oxides and suldes,of metals of group 6 of the periodic system which may also be used in admixture with natural clays of the -Attapulgus type or activated clays such as Super-uitrol or other materials containing substantial proportions of alumina and silica. In operation `under these conditions the catalyst usually becomes coated with contaminants, chiefly carbonaceous deposits which gradually destroy the activity of the catalyst for reforming purposes after relatively short periods of operation. The activity of the catalyst is regenerated by burning olf the carbonaceous deposits by means of inert gases containing relatively small amounts of inert gases containing relatively small amounts of oxygen, usually not more than a few percent. The catalytic reforming process as carried out commercially therefore coni sists of alternate periods of reforming and regeneration. Advantages ofthe present process are that gasoline of higher octane number is obtained with reforming periods of equal length, and that gasoline of equal octane number is obtained during longer reforming periods, as compared to operation without the addition of sulfur. An example of suitable conditions of catalytic reforming in the presence of hydrogen according to the present invention is as follows:

A heavy naphtha, admixed with about 10% of a relatively heavier petroleum oil boiling above about 600 F. having elemental sulfur dissolved therein in a proportion of about l/2% of the total charge, is introduced into a reaction vessel at a temperature of about 950 F. under a pressure of about 200 to 400 pounds per square inch at a rate of about 1 to 2 volumes of naphtha per' the reactor so that the quantity of hydrogen is about mol percent. Asthe reaction proceeds, the gases evolved in the process, which contain substantial quantities of hydrogen, are continuously recycled at a rate of about 2000 to 3000 cubic feet per barrel of naphtha. 'I'he reaction vessel is packed withlumps of a sulfactive catalytic material such as a mixture ofA aluminum oxide and chromium oxide. At the beginning of the process there is a net production of hydrogen of about to 400' cubic feet per barrel of naphtha. As the reaction proceeds, the net production of hydrogen decreasesv gradually until iinally after 16 to 24 hours or more, the

net production of hydrogen approaches zero and if the process is continued further, there will be a net consumption of hydrogen. If the reforming cycle is continued, it would be necessary to add fresh hydrogen to make up for this consumption. It is preferable, however, to discontinue the reforming cycle at this point and to -regenerate the catalyst even though its activity may not have been substantially destroyed. I'he regeneration may be accomplished by passing inert gases or' steam containing 4 to 10% of oxygen through the catalyst mass at a rate oli4 several thousand volumes pervolume of reaction space per hour. After the regeneration, another `cording to the process of this invention also insoi cludes isomerization and dehydrogenation treatments conducted in the presence of hydrogen, and various combinations of the treatments described above. v

The process of this invention is particularly suitable for the conversion of relatively low boiling petroleum distillation fractions into motor fuels high in naphthenlc constituents and oi" high knock rating. Suitable conditions for carrying out this modification of the present invention are described in the following example:

The characteristics of a suitable light petro-4 leum oilcharging stock and of a heavy petroleum oil suitable for use therewith in accordance with this process are presented in the following table:I

Light oil Heavy oil A. P. I 49.3 37.1 Color +8 Anlline point, F. 120. 3 192 Lamp sulfur, percent 0. 036 0, 10 Gum:

Copper bowl milligrama 2 Glass bowl 1 I. B. P., 244 580 7 oif at, F. 258 600 10% of: at, aso co5 wg@ of! at, F.. 264 610 30 a oil at, F 268 615 407 oil at, F. 271 618 we? 0s at, F- 214 cao snai on at, 271 c25 7W oi! at, F.. 281 632 ao/ ou at, ass 64o ou at, 294- 650 95 D oil at, "F 304 "F 338 700+ The hydrocyclization of this light oil is preferably `conducted by passing the oil with .about 2,00il'to 15,000 cubic feet of hydrogen per barrel of charge through a reaction zone` maintained at a temperature between about 600 an'd 950 F. and preferably between about 650 and 850 F. and at a pressure of about to 300 atmospheres,

, or at even higher pressures. 1 The reaction chamber is packed with lumps of a hydrogenation catalyst, such as the oxygen and sulfur compounds of metals of group 6 of the periodic table, which require the presence of sulfur in order to maintain optimum activity, particularly the polysuldes (disulildes and trisuldes) of tungsten and of molybdenum, such as the catalysts described in U. S. Patent 2,123,623. With such catalysts the oil feed rate may be from one to three Yvolumes of oil charge lper volume of catalyst-filled reaction space per hour. The concentration of heavy oil may be in the range of i0 to 50% on the basis of the total charge of oil to the hydrogenation unit in this process, and is preferably below about The quantity of sulfur added to the total feed is adjusted in relation to the extent of use and the activity of the catalyst. The addition of about 0.5 to 2% or more of elemental sulfur by solution in the feed stock will generally be foundsufcient. This sulfur is preferably dissolved in the heavy oil, because of the greater solubility of sulfur in such oils than in the lighter oils used as a major portion of the charge stock.

Under such conditions of operation about 40 to 10% of the light charge stock is converted per pass to products boiling in the motor fuel cation of the Acontent of unsaturated and aromatic hydrocarbons and has a high valuefor a gasoline rich in these types of hydrocarbons and a low value for a gasoline relatively free1 from such types of hydrocarbons.

This invention is not to be limited to any examples or explanations presented herein, all such being intended solely for purpose of illustration, as it is intended to claim all novelty in'this invention as broadly as the prior art permits'.

1. In a process for the treatment of vaporizable carbonaceous materials with vhydrogenating gases, in which said carbonaceous material is passed in vapor phase with hydrogen through a reaction zone packed with a solid sulfactive catalyst, an improved method of operation to regulate the activity of saidv catalyst comprising preparing a solution of elemental sulfur in a relatively small amount of an oil which is not substantially vaporized in said reaction zone and passing said sulfur. solution into said reaction zone.

2. In a process for the treatment of distillate 4oil fractions with hydrogenating gases in which `said oil fraction is passed with hydrogen through ,3. Process according to claim 2 in which said sulfur solution is passed through said preheating zone and into said reaction zone.

4. Process according to claim 2 in which said .sulfur solution is'mixed with said distillate oil fraction and the resulting mixture is passed with hydrogen through said preheating zone and into said reaction zone.

5. In a process for the treatment of distillate oil fractions with hydrogenating gases in which said oil fraction is passed with hydrogen through a preheating zone in which it is substantially completely vaporized, and the mixture of vapor and hydrogen is then passed through a reaction zone packed with solid sulfactive catalyst, an

Yimproved method of operation to regulate the 'containing dissolved sulfur with hydrogen through said preheating zone and into said reaction zone.

6. Process according to'claim 5' lnjwhichsaid u heavier oil is from V10,to 25% of the total oil charge. y

7. Process according to claim 5 in which the amount of elemental sulfur dissolved is above about 0.5% by weight of the total charge.

8. Process according to claim 5 in which the amount of elemental sulfur dissolved is from about 0.5 to about 2% by weight of the total oil charge.

9.. Process according to claim 5 in which said catalyst contains a compound of a metal of group 6 of the periodic table and sulfur.

l0. Process according to claim 5 in which said catalyst contains a polysulde of molybdenum.

11. In a process for the ltreatment of a distillate oil fraction boiling within the range of 200 to 500 F. with hydrogenating gases in which said oil fraction is passed with hydrogen through a preheating zone in which it is substantially completely vaporized and into a reaction zone maintained at a temperature of about 600 to 950 F., said zone being packed with a solid hydrogenation catalyst containing a sulfur compound of a metal of group 6 of the periodic table,4

whereby said distillate oil fraction is converted into a motor fuel of high knock rating and low acid heat, an improved method of operation to regulate the activity of said catalyst comprising preparing a solution of about 0.5 to about 2% (based en the mm1 en charged) of elemental sulfur in about 10 to about 25% (based on the total oil charged) of a heavier oil which is not substantially vaporized in said preheating zone and in the inlet portion of said reaction zone and which boils substantially `completely within the range ofv 500 to about 850 F., mixing the resulting sulfur solution with said distillate oil fraction and passing the resulting mixed oils with hydrogen through said preheating zone 'and into said reaction zone.

12. In a process for hydrogenating vaporlzable carbonaceous materials in the'vapor Vphase and in the presence of a solid sulfactive catalyst, the activity of which is increased by the addition of elemental sulfur to the carbonaceous material to be hydrogenated, the method of preventing the deposition of added elemental sulfur in the preheating apparatus and inlet lines to the reaction zonein which the vapor phase hydrogenation is carried out, whichA comprises introducing into the vaporizable material prior to its passage through the preheating and inlet lines to the reaction zone a relatively small quantity o! a higher boiling hydrocarbon oil which remains substantially unvaporized under the conditions prevailing in the preheating and reaction ZOneS.

EDWIN J. Goma.

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