US2985582A - Pressure hydrogenation of crude oils, tars or their residues - Google Patents

Description

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United States Patent 9 PRESSURE HYDROGENATION F CRUDE OILS, TARS 0R THEIR RESIDUES Willi Oettinger, Ludwigshafen (Rhine), Germany, assiguor to Bathsche & Soda Fabrik Aktiengesellschaft, Ludwigshafen (Rhine), Germany N0 Drawing. Filed Mar. 18, 1958, Ser. No. 722,123

Claims priority, application Germany Mar. 21, 1957 7 Claims. (Cl. 208-85) This invention relates to the removal of ash from crude oils, tars and their residues.

It is already known to lead the initial materials, in the desulfurization of crude oils or their residues by refining pressure hydrogenation, over large-surfaced substances prior to the refining treatment proper. In this pretreatment, the inorganic constituents contained in the crude oil or residue are retained in the preliminary stage so that the activity of the catalyst in the following refining stage is not impaired by the deposition of ash In carrying out this method of working in practice, however, it has been found that in prolonged operational periods there often takes place a coking of the large-surfaced substance or that small amounts of ash constituents pass into the following refining stage and reduce the activity of the catalyst therein.

I have now found that the said disadvantage can be avoided by preheating the initial materials, prior to the pressure hydrogenation proper, in a preliminary stage in the presence of large-surfaced substances in such a way that the initial material is led into the preliminary stage at a temperature above 250 C., preferably above 300 C., but below 400 C., and a rise in temperature of the reaction material is effected in the same stage by at least about 30 C. and advantageously 50, 60, 75 C. or more.

The process according to this invention is suitable for all kinds of pressure hydrogenation, for example for refining, destruction and/or aromatizing pressure hydrogenation, in which the high-boiling initial material, such as crude oils, tars, especially bituminous or brown coal tars, shale oils or their residues boiling above 300 C., for example distillation, extraction or cracking residues, are Worked up. The process according to this invention is further particularly suitable for refining the initial materials mentioned above and for enlarging the quantity of lower boiling products as diesel oils, gas oils and fuel oils.

The said initial materials are heated preferably in the presence of hydrogen to at least 250 C., advantageously to at least 300 C., for example to a temperature lying between 310 and 350 C., and then led into a reaction chamber provided with large-surfaced substances. This reaction chamber may consist of one chamber or of a plurality of successive chambers. In this reaction chamber the temperature is allowed to rise, for example to 370 C., 400 C. or more. When using two vessels, the temperature distribution may be as follows: in the first vessel a rising temperature within the range of from about 280 C. to about 360 C. is chosen and in the second vessel a rising temperature between about 360 C. and the reaction temperature. By working in this way there is achieved a reliable removable of the ash without depositions of coke occurring. It is also possible to work, however, by allowing the temperature to rise only in the second vessel, whereas a constant or even slightly falling temperature is maintained in the first vessel.

It is advantageous to withdraw 0.1 to 2% by weight, with reference to the initial material, of an ash-containing high-boiling oil from behind the first reaction vessel or, when a plurality of successive vessels is used, preferably behind the second or last reaction vessel.

In general the heat evolved by the hydrogenation reaction at this temperature is suificient for the achievement of the rise in temperature. It is also possible, however, to supply to the reaction material additional heat, for example by intermediate heating up or by the addition of hot gases at one or more places or by the addition of gases, as for example carbon monoxide or oxygen, which under the reaction conditions react with the hydrogen with the production of heat.

In general the same pressure is chosen for the pretreatment as is used in the subsequent pressure hydrogenation. As hydrogenating gas there may be used pure hydrogen or gases containing hydrogen, such as illuminating gas, town gas, watergas, cracking gas, coke-oven gas or low temperature carbonization gas. As large-surfaced substances there are suitable porous substances or non-porous substances, especially open hollow bodies, as for example rings, hemispheres or angular structures, such as cubes, cones, truncated cones, boxes or pyramids which are open on at least one side and which if desired contain in the hollow space deflecting plates; for example there may be mentioned metallic materials, for example metals of the 8th group or alloy steels, or ceramic materials, such as porcelain, clay, cement, pumice, bleaching earths, aluminas or synthetically prepared silicates, graphite and plastics. In many cases it has proved to be preferable to add to these largesurfaced substances a small amount of a catalyticallyacting substance, such as molybdenum, tungsten, chromium, vanadium, nickel, cobalt, platinum, ruthenium, gold, manganese, titanium or compounds of these or mixtures of the said elements or their compounds.

The reaction chamber is arranged with large-surfaced substances, so that the free space is about 40 to especially 50 to 70%, the free space in the reaction chamber being regarded as the intermediate spaces and between the large-surfaced substances and the hollow spaces within the large-surfaced substances. This is achieved, for example, as already described, by using the said substances in the form of suitable rings or other surface-forming voluminous open or partly closed structures.

The chamber for the large-surfaced materials is in general smaller than the reaction vessel proper which is provided with the hydrogenation catalyst and in which occurs the refining, destruction or/ and aromatizing pressure hydrogenation, advantageously in a plurality of stages, at pressures of 5 to 700 atmospheres, especially 20 to 300 atmospheres, and at temperatures of 350 to 550 C., preferably at rising temperature. The amounts of hydrogen to be used amount to 100, 200, 300, 500, 1,000'or 3,000 litres per kilogram of initial material and it is advantageous to choose a throughput of 0.3 to 10 kg. of initial material for each part by volume of catalyst per hour. In general the throughput through the vessel containing the large-surfaced material is larger than the throughput through the reaction vessel provided with the hydrogenation catalyst. Mostly it is larger, at least about 1 kg.

The circulating gas containing hydrogen can be washed with an extraneous oil or an oil originating from the process, for example with a heavy gasoline or a gas oil. To remove ammonia, the gas may be treated with water or an acid solution, if desired in conjunction with an oil washing. To remove H S the circulating gas or part of it can be washed with solvents known in the art. The

washing may take place in cocurrent or countercurrent, preferably under the reaction pressure.

As catalysts for the treatment there come into question those which have hydrogenating, rafiinating, cracking, dehydrogena-tin'g, isomerizing and/ or cyclizing properties, for example oxides, sulfides, selenides, tellurides, sulfates, borates, nitrates, carbonates, halides, phosphorous compounds or also silicates of vanadium, molybdenum, tungsten, chromium, uranium, rhenium, iron, nickel or cobalt, as well as gold, silver, copper, tin, titanium, lead, zinc, magnesium, cadmium, Zirconium, antimony, bismuth and manganese as well as the metals of the platinum, palladium and iron groups and the heavy metals of the 1st group or mixtures of the same. Thus there may be used for example the said compounds of molybdenum, tungsten, chromium or vanadium in admixture or in chemical combination, for example as molybdates, tungstates, chromates, chromites, vanadates or titanates, with compounds of nickel, cobalt, titanium, tin or lead or/ and with the metals of the platinum and palladium groups or/and heavy metals of the 1st group as well as their compounds, the added substances preferably being used in smaller amounts than molybdenum, tungsten, chromium or vanadium. For example molybdenum or tungsten with cobalt, nickel and/or titanium and if desired tugnsten or molybdenum are especially suitable. Some elements have proved to be promoters for the more usual catalysts of the 5th to 8th groups of the periodic system, for example gold, silver, mercury, titanium, copper, zinc, tin or uranium and lead or their compounds. Mixtures consisting of the compounds of the said metals of the 4th group of the periodic system, for example of titanium, with the compounds of iron, nickel, cobalt or manganese, as well as of copper, silver, gold, platinum, palladium, ruthenium or their compounds .or in chemical combination as titanates, are also suitable. The compounds of the metals of the iron group in admixture with platinum, palladium, ruthenium, copper, silver, gold or their compounds also come into question. These mixtures may also be used in the form of chemical compounds. The activity of the catalysts can be adjusted with compounds of the alkali and alkaline earth metals because these influence the activity. The said catalysts may be applied in a moist or calcined state to carriers in an amount of 0.1 to 30% by weight. As carriers there may be used acid-treated montmorillonite, active silicic acid, silica gel, preferably together with the oxides of titanium, thorium, zirconium and magnesium, titania gel or titanium oxide, if desired together with 0.1 to 30% by weight of SiO as silicates, bleaching earths, fullers earth, synthetic silicates, for example aluminum and/or magnesium silicates, as well as the abovementioned silicates, active aluminas, preferably with a surface of more than 300 square meters per gram, aluminum hydroxide or peptized aluminas which are treated with an amount of acid insuflicient for complete solution, bauxite, if desired with 1.1 to 25% by weight of SiO;,,, titanium oxide, zirconium oxide, cerium oxide, zinc oxide and/ or magnesium oxide. When using synthetically pre pared carriers, such as silicic acid, silicates, aluminas or titanium oxide, the catalytically active components may be added already during the preparation by adding for example a soluble compound of the catalytically active 'metal to a Waterglass solution, silica sol, titanium salt solution, aluminum salt solution or/ and aluminate solution and then precipitating the solution and/ or by adding the metal or the metal compound during the precipitation. It is advantageous, also to treat the carrier with gases, such as ammonia, hydrogen, sulfur dioxide, halogen or rare gases,..and the gas may remain in the pores. The carrier may also be pretreated with hydrogen halide or an inorganic or low-molecular weight organic mono basic or dibasic acid, among which may be mentioned for; example lhydrochloric acid,hydrogen fluoride, chlorsulfonic acid, formic acid or oxalic acid. The carrier crease in the pressure difference takes place.

may absorb halogen in an amount of 0. 1 to 10% by weight. The catalyst may also be shaped with carbon and the carbon then wholly or substantially removed by burning off.

When working under pressures up to about 150 atmospheres, the catalyst is generally regenerated from time to time with oxygen or an oxygen-containing gas at temperatures of 450 to 600 C. The catalyst or the catalyst carrier may also be exposed for a long time to a temperature above 300 C., for example 400 to 600 0., prior to its use.

The catalysts may be rigidly arranged in known manner in the reaction chamber or they may be present in the reaction chamber in a moving condition. The initial material may be led with hydrogen in cocurrent or countercurrent over the catalyst;

The following examples will further illustrate this invention but the invention is not restricted to these examples.

Example 1 The constituents boiling up to 365 C. are separated by distillation from a Near East crude oil. The residue boiling above 365 C. is heated up to 330 C. under a pressure of 100 atmospheres together with hydrogen and led into a preliminary vessel I which is filled with Raschig rings of aluminawhich have been impregnated with 4% by weight of M00 of the interior of the vessel is free space. The throughput, with reference to this first vessel, amounts to 1:8 kilograms of residue per litre of Raschig rings per hour. The temperature at the exit from the first vessel amounts to 360 C. The gas and oil mixture is heated up to 408 C. and led into a preliminary vessel II which is filled with Raschig rings of the same composition. The throughput, with reference to the second preliminary vessel, amounts to 1.0 kilograms of residue per litre of Raschig rings per hour. The temperature at the outlet of the second preliminary vessel is 435 C. The gas and oil mixture then passes at this temperature into a third vessel (the reaction chamber proper) which is filled with a rigidly arranged catalyst. The catalyst consists of active alumina with 5% of silicic acid which has been provided with cobalt and molybdenum oxide in such a way that the finished catalyst contains 3% by weight of Co and 10% by weightyof molybdenum (calculated as metal). The throughput, with reference to this reaction chamber, amounts to 0.5 kilogram per. litre of catalyst per hour. The ratio of hydrogen to oil amounts to 0.8 cubic metre of gas per kilogram of oil. The reaction temperature is 430 C. p

A stripping product is obtained with 70% by weight of components boiling up to 480 C. anda sulfur content of 116% by weight, whereas the distillation residue introduced contained only 34% by weight of components boiling up to 480 C; and 4% by weight of sulfur.

After an operational period of two months, an in- The system is then shut off and the catalyst present in the hydrogenation vessel regenerated with nitrogen and air.

Treatment of the alumina Raschig rings in the preliminary vessels I and II is not necessary. These vessels are reconnected, after the end of the regeneration of the catalyst, with the reaction chamber properand used again for the refining treatment of distillation residue 'as above described. In order to avoid shutting off the system, it is also possible to switch in a second reaction chamber containing fresh catalyst.

The solid ash contained in the residue and also the ash constituents newly formed by decomposition of the organo-metallic compounds separate in the preliminary vessels. After an operational periodof four months, the vessels I and II are emptied. The Raschig rings are separated from the ash constituents and returned to the vessels.

Example 2 A German crude oil from Emslaud is heated up to 320 C. under a pressure of 240 atmospheres together with 2 cubic metres of gas containing hydrogen per kilogram of crude oil, and led into a preliminary vessel which is filled with Raschig rings of magnesia cement which have been impregnated with 5% by weight of M A free space of 70% by volume is present in this vessel filled with Raschig rings. The throughput with reference to this preliminary vessel amounts to 1.9 kilograms of oil per litre of Raschig rings per hour. The temperature is allowed to rise in this preliminary vessel so that at the outlet a temperature of 425 C. prevails. A small part of gas containing hydrogen is heated up to 400 C. and introduced into the second part of the vessel that an exit temperature of 425 C. is reached. From the lower part of the preliminary vessel 0.8% by weight of oil with reference to the amount of crude oil introduced is continuously withdrawn.

The oil vapors are heated together with the gas up to 430 C. and then pass into the reaction chamber proper which is filled with rigidly arranged catalyst. The catalyst consists of a synthetic aluminum silicate which contains 5% by weight of molybdic acid. The throughput in the hydrogenation chamber amounts to 0.6 kilogram of oil per litre of catalyst per hour.

Behind the reaction chamber there is withdrawn a stripping product with 77% by weight of constituents boiling up to 480 C., whereas the initial oil contained only 31% by weight of these constituents.

After an operational period of 2,250 hours the system is shut off and opened. The ash contained in the crude oil and the ash newly formed by decomposition of the organo-metallic compounds has collected in the preliminary vessel in and between the Raschig rings and can readily be separated from the Raschig rings. There is practically no coke formation in the reaction chamber proper or in the preliminary vessel.

I claim:

1. In a process for the pressure hydrogenation of an initial material selected from the class consisting of crude oils, shale oils, tars and their residues at temperatures between 350 C. and 550 C. wherein said initial material is preheated in a preliminary stage while being contacted with large-surfaced substances for removal of ash and then introduced into a succeeding stage for said pressure hydrogenation, the improvement which comprises heating said initial material while passing it through said preliminary stage from an initial temperature above 250 C. but below 400 C. to a temperature of at least 30 C. higher than said initial temperature, said preliminary stage being formed by at least one reaction chamber containing said large-surfaced substances and having a free space of at least 40% up to about 2. The improved process of claim 1 wherein said largesurfaced substances provide a free space in said preliminary stage of at least 50% 3. The improved process of claim 2 wherein the initial temperature in said preliminary stage is at least 300 C.

4. The improved process of claim 2 wherein the preliminary stage is carried out in more than one reaction chamber, and the temperature of the initial material being treated rises in at least one of said chambers.

.5. The improved process of claim 4 wherein intermediate heating is applied between the reaction chambers.

6. In a process for the pressure hydrogenation of an initial material selected from the class consisting of crude oils, shale oils, tars and their residues at temperatures between 350 C. and 550 C. wherein said initial material is preheated in a preliminary stage while being contacted with large-surfaced substances for removal of ash and then introduced into a succeeding stage for said pressure hydrogenation, the improvement which comprises heating said initial material while passing it through said preliminary stage from an initial temperature above 300 C. but below about 350 C. to a temperature of at least about 50 C. higher than said initial temperature, said preliminary stage being formed by at least one reaction chamber containing said large-surfaced substances providing a free space of about 50% to about 80%, and withdrawing from said preliminary stage about 0.1 to 2% by weight, with reference to the initial material, of an ash-containing high-boiling oil.

7. The improved process of claim 6 wherein the throughput in the succeeding pressure hydrogenation stage is about 0.3 to 10 kilograms of initial material for each part by volume of catalyst per hour, and the throughput of initial material in the preliminary stage is larger than the throughput of the succeeding pressure hydrogenation stage.

References Cited in the file of this patent UNITED STATES PATENTS 1,932,174 Guas et a1 Oct. 24, 1933 1,974,057 Steffen et a1. Sept. 18, 19.34 2,848,376 Oettinger et a1 Aug. 19, 1958 I 1 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,985,5532' May 23 1961 Willi Oettinger It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 41, strike out- "and"; column 4, line 37, for "1.0 kilograms" read 1,9 kilograms Si ned and sealed this 5th day of December 19610 (SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents USCOMM-DC

Claims (1)

1. IN A PROCESS FOR THE PRESSURE HYDROGENATION OF AN INITIAL MATERIAL SELECTED FORM THE CLASS CONSISTING OF CRUDE OILS, SHALE OILS, TARS AND THEIR RESIDUES AT TEMPERATURES BETWEEN 350*C. AND 550*C. WHEREIN SAID INITIAL MATERIAL IS PREHEATED IN A PRELIMINARY STAGE WHILE BEING CONTACTED WITH LARGE-SURFACED SUBSTANCES FOR REMOVAL OF ASH AND THEN INTRODUCED INTO A SUCCEEDING STAGE FOR SAID PRESSURE HYDROGENATION, THE IMPROVEMENT WHICH COMPRISES HEATING SAID INITIAL MATERIAL WHILE PASSING IT THROUGH SAID PRELIMINARY STAGE FROM AN INITIAL TEMPERATURE ABOVE 250*C. BUT BELOW 400*C. TO A TEMPERATURE OF AT LEAST 30*C. HIGHER THAN SAID INITIAL TEMPERATURE, SAID PRELIMINARY STAGE BEING FORMED BY AT LEAST ONE REACTION CHAMBER CONTAINING SAID LARGE-SURFACED SUBSTANCES AND HAVING A FREE SPACE OF AT LEAST 40% UP TO ABOUT 80%.