US3155607A - Process for the production of heavy heating oils having low sulfur contents - Google Patents

Description

United States Patent 3,155,607 PRQCESS FCR THE PRQDUCTEQN Gil HEAVY HEATING 013125 HAVING LQW SULFUR CQNTENTS Herbert Friess, Gladheclr-Brauch, Germany, assignor to Gelsenherg Benyin Alrtiengesellschaft, Geisenlsirchen- Horst, Germany, a German corporation No Drawing. Filled Mar. 20, 1%2, Ser. No. 181,153 Claims priority, application Germany, Mar. 2S, 1961,

15 Claims. (a. 2ss 2iz This invention relates to a process for producing heavy heating oils having low sulfur contents. More particularly, the invention relates to a practical and economical process for the removal of sulfur from crude oils serving as starting materials in the production of heavy heating oils.

Practically all heavy heating oils are commercially traded with a content of 24 Weight percent sulfur and preferably of 3-3.5%. A sulfur content of 2-4 weight percent is high, particularly when one considers that substantially all of the sulfur is discharged into the atmosphere in the form of S0 An estimate based on the year 1957 discloses, for example, that in Los Angeles alone, 550 tons of S0 daily are permitted to escape into the air. Heating oil represents a substantial source of such 80;. With the rising energy requirements an increase in heating oil consumption must also be taken into account. S0 has a deleterious and injurious effect on the organs of respiration of humans and also on the assimilation of plants. Therefore, a decrease in the sulfur content in heating oil which is in actual use constitutes an activity of highest priority.

Heavy heating oils are obtained by processing of crude oils as atmospheric residues such as top oil residues, as vacuum residues, as thermal cracking residues, in viscosity breaking, etc. It is possible to employ mixtures of the various types of residues, assuming that they are otherwise compatible, as heating oils. In addition, there are conventionally used as heavy heating oils brown coal tars, coal tars, oil shale tars and generator tars.

Heavy heating oils have, for example, been designated in DIN (German Industrial Standards) 51,693 (1969) by the terms S=heavy oil or viscous oil, in contrast to the lighter products which are in the main derived from distillation procedures, M=middle oil, L=light oil and EL=extra light oil. The exact definition as set out in DIN 51,603 (1960) reads as follows:

Heating oils are liquid fuels derived from petroleum, oil shale, coal tars or brown coal tars and are especially suitable as fuel for furnaces and for combustion purposes. The heating oils are subdivided into the types EL (extra light oil), L (light oil), M (middle oil) and S (heavy oil). The properties and characteristic values of the residual products of petroleum processes which are more viscous than heating oil S, may, on account of the variety of the crude oils and the manner of their processing, not be standardized and they must in each case be expressly determined.

A definition corresponding to that above set forth is also given by Handbook of Oil Burning, editors Frank H. Faust and S. Theodore Kaufman, published by Oil Heat Institute of America, 1951, page 37.

It is of course possible to prepare heating oils having low sulfur contents by utilizing as starting materials crude oils low in sulfur. Such possibilities are fairly limited, as can be appreciated, because of the raw material situation. As a result, numerous processes have been proposed, in order to lower the sulfur content of heating oils, as for example utilizing chemical reactions.

Thus there has been proposed a desulfurization using Fatented Nov. 3, 1964 "ice metallic sodium. This process is not technically satisfactory, due to the fact that sodium is too expensive and furthermore the resulting sodium sulfide cannot be disposed of to economical advantage.

It has also been suggested to desulfurize top-oil residues catalytically, utilizing therefor iixedly arranged catalyst in the presence of hydrogen. Several processes in this connection have been described, which attempt, similarly as in the processing of vacuum distillate, to manage with pressures below atmospheres. As catalyst there is generally used cobalt molybdate on aluminum oxide. These processes have the disadvantage that the catalyst is very rapidly deactivated, i.e., the desulfurization reaction falls off very quickly. Under such circumstances, the frequent regeneration of the catalyst bed required to obtain satisfactory desulfurization has mitigated against the introduction of these catalytic processes into general practice.

As a result, it has been proposed to eifect the desulfurization of top-oil residue over fixedly arranged catalyst using therefor higher pressures. Using pressures above 200 atmospheres, there may be obtained substantially better life spans of the catalyst than at lower pressures, and therefore the desulfurization may be carried out with fewer interruptions for regeneration of the catalyst. However, the disadvantage of deposition of ash of the charged oil product on the catalyst still remains and is per se a serious liability. Experience has shown that the deposits cannot be removed in the regeneration.

In order to avoid this ditficulty of deposit removal according to another proposal a preliminary step is carried out prior to the actual desulfurization, in which the starting oil product is treated with large surface area materials in the presence of small amounts of hydrogen, in an attempt to at least remove a part of the ash of the charged product from the catalyst.

The primary object of the invention is to provide a process for producing desulfurized heavy heating oils whereby economy of operation is obtained.

Another object of the invention is to provide a process for the production of heavy heating oil of low sulfur content, meeting the commercial requirements of storage and heat stability.

Still another object of the invention is to provide a process for the production of heavy heating oil of low sulfur content which is readily miscible with other oils having a lower C/H ratio.

Other and further objects and advantages will become more apparent from a consideration of the following description:

The present invention consists in a process for preparing heavy heating oil having a low sulfur content which comprises the steps of:

(1) Subjecting the starting oil product as for example top-oil residue (A) to a decomposition treatment as for example a cracking or vacuum distillation treatment wherein there are formed a minor amount of an asphalt and, ash rich phase (C) and a major amount of an asphalt and ash poor phase (B) which latter phase (B) is to be desulfurized,

(2) Thereafter subjecting the asphalt and ash poor phase (B) to a desulfurization treatment as for example a hydrogenation treatment to obtain a desulfurized heavy oil phase (E), and

(3) Admixing the asphalt and ash rich phase (C) with the desulfurized heavy oil phase (E) so as to obtain a heavy heating oil (F) of low sulfur content and of desired quality and properties.

In accordance with the invention, it is possible to substitute for phase (C) in the third step other residual oils.

In contrast to the known and conventionally carried out direct hydrogenation desulfurization of top-oil residue by passing the same over and in contact with fixed catalyst beds, the process of the invention has the advantage that only slight, technically non-disturbing quantities of ash are deposited on the catalyst, and as a result the life period of the catalyst is prolonged considerably, and furthermore a lower hydrogen consumption is required for the hydrogenating desulfurization.

The first step of the process in accordance with the invention advantageously is carried out, as for example, as de-asphaltizing, or as a vacuum-distillation. The starting heavy oils, as for example top-oil residue, can, as is known, be deasphaltized by treatment thereof with propane or other hydrocarbon having a lower C/I-I ratio. Such treatment results in a rafiinate (B which contains but little asphalt and little ash, and also an extract (C which contains substantially all of the asphalt and the ash. It is possible by suitable regulation of the treatment conditions to obtain an entirely ash-free raffinate (B The extract (C which is obtained is depending on the starting product (A), a more or less viscous mass. In carrying out the process in accordance with the invention as defined in the first step, it is not so important to ensure the concentration of all of the ash and the asphalt in the extract (C but rather to obtain as much as possible of a rafiinate (B so that this raffinate (B which is to be subjected to the desulfurization produces a correspondingly large amount of desulfurized heavy oil (E). That is, in the first step it is desirable that only a small quantity of extract (C be produced. In order to carry out step 1 so that this in fact occurs, the starting top-oil residue can for example be subjected to a de-asphaltizing treatment wherein through suitable selection of the pressure and temperature conditions and the proportions of, for example, propane to oil, the quantity of extract (C is decreased to about 330% of the initial charge, and most preferably to l20% of the top-oil-residue charged. Under these conditions, the extract (C as obtained is in a brittle and dry form and may be comparatively easily broken up or pulverized. However, it is also possible to vary the resulting ratio of raffinate (B to extract (C by selecting the charge product (A) according to its asphalt content and also its boiling point.

The art has for the desulfurization of residual oil products (A) utilized various chemical procedures as, for example, treatment thereof with sodium, sulfuric acid or iodic acid as a desulfurization agent. In the method of the invention, the preferred form of carrying out the second step of the process is a hydrogenating desulfurization.

The phase (B), characterized in that it is poor in asphalt and in ash, and which is obtained by the decomposition treatment of the first step, is desulfurized in the second step under hydrogenation conditions selected so that the sulfur content of the resulting hydrogenation residue (E meets the requirements desired in each case. However, the choice of the desulfurization conditions depends not only on these requirements, but also on the boiling point of the product (B) to be desulfurized. To the extent to which this phase is composed of constituents boiling above 490 (3., sharper hydrogenation conditions must be selected. This applies equally to the conditions of pressure as well as of temperature. Desulfurization may be readily ellected at about 40 atmospheres with entirely satisfactory results. Under certain circumstances, however, it may be necessary to utilize pressures of 500 atmospheres. As the pressure above all determines the degree of coking of the catalyst, the temperature (in general between 300 and 450 C.) is essentially responsible for the degree of desulfurization. In products having a high proportion of high-boiling constituents, cracking or splitting of some of the hydrocarbons cannot be avoided, especially if the desulfurization is to be carried to a very high degree, as for example to 0.1%.

By adjusting the conditions of the hydrogenation to the boiling point of the product (B) charged to the desulfurization, the desulfurization is carried out without any difficulties, as this charge product (B) is substantially free from ash to begin with as well as from any difiicultly hydrogenizable highly aromatic compounds, such as asphalts, oil-resins, etc. In contrast to the processing of the top-oil-residue (A) by passage thereof in contact with fixedly positioned catalyst, the catalyst may be steadily subjected to throughputs of charge (B) with satisfactory operable running times for the catalyst of up to several months. Since the ash content of the charged product (B) is only slighty, hardly any ash remains or is de posited onto the catalyst requiring that the catalyst be frequently regenerated. A further advantage of the process of the invention over direct hydrogenation of top-oil residue by passage of the charge over a fixedly positioned catalyst consists in the decrease of the hydrogen required to efiiciently effect the hydrogenating desulfurization.

Heating oil represents, by its physical properties, a colloid system of asphalts in oil. An asphaltic nucleus adsorbs high-molecular aromatic hydrocarbons, which have a somewhat lower C/H ratio than the asphalts themselves. Onto this addition product, highly aromatic hydrocarbons are adsorbed, whose C/H ratio is somewhat lower than that preceding the deposition of highly aromatic hydrocarbons taking place, until the C/H ratio of the most external layer substantially corresponds to that of the dispersion phase, thus the oil. A system of such layerings around an asphalt nucleus is defined as a micelle. It is obvious that a particular micelle is destroyed if the C/H ratio of the surrounding medium is disturbed by hydrocarbons having a lower C/H ratio. Said in another Way, a heating oil is more stable, the more insensitive it is against changes of the C/H ratio on diluents therefor.

It is therefore most surprising, and entirely unexpected, that the asphalts, after they have been precipitated by adsorption thereon of a hydrocarbon having a low C/H ratio, as, for example, propane, subsequently may, in accordance with the invention, again be recolloidized by the third step of the process, namely by admixture with an oil, whose C/H ratio has been lessened through bydrogenation, that is, that without any difficulties the extract (C asphalt rich and ash rich) can absorb the desulfurized residue (E derived from the asphalt and ash poor ratfinate (B It is furthermore most surprising that heating oils of other derivation may be admixed with the heating oil (F) without any impairment of its stability.

The same situation results if the decomposition of step 1 is carried out by means of a vacuum-distillation and followed by steps 2 and 3 as above described.

A heating oil is regarded as stable if, on storage as well as on being subjected to heat, no dry carbon-rich sludge, or only small amounts of such sludge are formed. In no event should the sludge formed amount to more than 1%, and most advantageously to not more than 0.2% (M. M. Marshall, Schweizer Archiv fuer angewandte Wissenschaft und Technik, 23, 273 ff./ 1957). In order to determine the stability of heating oils, certain tests have been developed, the aim of which it is, to bring about the separation, through artificially induced aging or through alteration of the C/ H ratio of the oil phase, a dry carbonrich sludge, the exact quantity of which serves as a measure of the stability of the heating oil. Included in these tests are the Hot-Filtration test and the Butlin test.

The Hot-Filtration test is carried out according to the mehod described by W. I. van Kerkvoort, M. B. E. and A. I. I. Nieuwstad in Journal of the Institute of Petroleum 37, pages 596 if. (1951), and comprises the following: 10 g. oil are filtered at C. in vacuum through an A2 Gooch crucible the frit of which is covered with a paper filter (Schleicher & Schiill, No. 575). The amount of filtered-off sludge is gravimetrically determined. In order to evaluate the influence of aging, a sample of the same oil is kept for 24 hours at a temperature of 100 C. and then the quantity of sludge formed,

again determined. According to the solvent power of the mixture one may observe an increase or decrease of the sludge which has been formed (see, for example, Table I, No. 8 and No. 9). In other cases absolutely no change is to be ascertained (see Table I, No. 13).

The Butlin test determines the flocculation of sludge produced by a change of the C/H ratio of the oil phase, which may be brought about in that the heating oil is mixed with a thinner oil, i.e., with an oil which possesses a lower C/H ratio than the heating oil itself. For the determination there is used a mixture of xylene with isooctane. Iso-octane acts to precipitate the sludge, xylene to dissolve it again. The quantity of oil mixture which is required serves as a measure of the quantity of sludge which was separated. The test is carried out according to the procedure set forth by B. G. Butlin, Journal of the Institute of Petroleum 36, 43 (1950) and Willy Parpan, Dissertation, Promotion, No. 2252, Zurich, 1954. In the determination there are used 2 g. oil and cm. of the testing solution of xylene and iso-octane. The solvent mixtures, which are used, are graduated in amounts of 5%, and the solvent-ratio at which flocculation fails to occur is determined. If, for example, flocculation does not occur with a solvent-mixture containing xylene, then it is taken to mean that the sludge may be held in solution by a solvent mixture containing 20% xylene. The stability of the heating oil is indicated in xylene units (XE), Butlin differentiates five stability stages and defines as stable products having 11-30 XE (xylene units).

In accordance with the invention, the production of heating oils (F) is accomplished in that in the third step the phase (C), rich in asphalt and in ash, is admixed with the desulfurized heavy oil (E). It is, however, also possible to use only a portion of the phase (C), rich in asphalt and in ash, derived from the first step, and to use the remaining part in another wa as for example as starting material or mixing component for bitumina (Example 7) or as raw material for the production of synthetic gas, etc. (Example 8). As can be seen from Examples 1-4, there may be obtained, under certain circumstances, heating oils (P), which do not contain more than 1% sulfur, if one absorbs the entire extract (C into the desulfurized hydrogenation residue (E If a sulfur content of more than 1% is possible, then there may be added a component having a greater sulfur content as top-oil residue (A). It is also possible to replace the phase (C), rich in asphalt and in ash, in the third stage with residual oils (A). In this connection the starting product (A) for the decomposition has proved particularly suitable (see Example 6). If, as regards the degree of desulfurization of the heating oil, it is required that the sulfur contents be limited to 0.10.2%, then there may be utilized in step 3 the desulfurized heavy oil (E) obtained in the second step, in which case the phase (C), rich in asphalt and in ash, obtained in the first step, is utilized for an entirely different use.

The range of variations possible in the process of the invention for the production of heating oils having low sulfur contents is, therefore, very great. By the possibility presented of varying the ratio of the desulfurized heavy oil (E) to the phase (C), rich in asphalt and in ash, in the mixture, or of replacing the phase (C), rich in asphalt and in ash, partially or completely by residual oils and perhaps through the starting product (A) or through a mixture of the two, an extremely great latitude of operations are made possible. It is further provided by the possibility of carrying out the desulfurization to a more or lesser degree of the phase (B low in asphalt and in ash, perhaps to use this product (E) per se as heating oil without the necessity for admixture thereof with other components. Further, the process is broadened through the possibility presented to utilize the phase (C), rich in asphalt and in ash, for other intended uses.

Among the advantages of the process in accordance with the invention, is not to be overlooked the possibility afforded to process residues of all kinds, as, for example, top-oil-residues, vacuum residues, thermal cracking residues, coal tars or brown coal tars, etc., into heating oils having low sulfur contents so that it is possible to advantageously dispose of in the heating oil (F) itself, of the phase (C), rich in asphalt and in ash, from the first step of the process. This phase has to be considered significant, even if it is obtained only in small quantities percentagewise, where large quantities of heating oil are being produced.

It has already been pointed out that the commercial heating oils are of different types and are classified not only according to the raw material source, but also with respect to the manner of their production. The classification is based on the analyses of various commercial products, which has been set out in Table 1 as Numbers 59. The sulfur and asphalt values as well as those for the boiling point curves and the solidifying point are different in each instance as are the values which are typical for new sludge formation.

If the sulfur content of the conventional commercial products is compared with the values determined for the heating oils produced in accordance with the invention, No. 3 and N0. 4 of Table 1, their low sulfur contents are immediately apparent, the same all falling below 1%. The stability of the heating oils produced in accordance with the invention lies within the limits prescribed for the commercial heating oils. The same applies as well for the miscibility with oils which have a lower C/H ratio. These properties fall within the permissible range also if the heating oils produced in accordance with the invention are admixed with heavy commercial product, as in Numbers 10-14 of the table.

TABLE 1 Hot filtration test Butlin- Percent Percent Sol1di fyt t X Products S asp P A (xylene 0. Before After units) aging aging (1) Hydrogenation residue 340 0. from O3 rafllnate with cobaltmolybdate-catalyst, (Ex. 3) 0.15 0. 045 +30 0. 003 0.006 +0. 003 (2) Hydrogenation residue 340 C. from C3 ratfinate with cobaltmolybdate-catalyst, (Ex. 4.)---" 0.11 0.063 +25 0.003 0.004 +0. 001 100) (3) Hydrogenation residue 340 0. according to Ex. 4+20% extract 1.01 1.58 +19 0.009 0.008 +0001 '25 (4) Hydrogenation residue 340 0. according to Ex. 3+19% exa 0.81 1. 01 +24 0.015 0. 013 -0. 002 20 (5) Commercial product III, 8.13., 1 301 0.; vol. percent, 400 C.=13.0; vol. percent, :4051.-- 2.77 1.51 +23 0.012 0.014 +0. 002 15 (6) Commercial product IV, S.B.,

O.=365: vol. percent, 400 C.= 28.0; vol. percent, 490 C.=6l.0 3.70 2.95 +15 0.008 0.008 3:0 30

See footnote at end of table.

TABLE 1Continued Hot filtration test Butlin- Percent Percent Solidifytest XE Products S asphalt ing point, A (xylene C. Bciore Alter units) aging aging (7) Commercial product V, 5.13., C.: 268, vol. percent, 400 C.=

14.0; :01. percent, 490 C. =42.0 2. S2 2. 04 +11 0.007 0. 000 +0. 002 25 (8) Commercial product VI, 5.13., C.: 250, vol. percent, 400 O.=

25.5; vol. percent, 490 C.=17.0 2. 95 1.81 0.050 0. 020 0. 02 (9) Commercial product VII. S.B., (3.: 328, vol. percent, 400 0.:

11.5; v01. percent, 490 C.=4S.0 2.36 0.95 +25 0.007 0.009 +0. 002 20 (10) Mixed product from hydrogeuation residue 340 C. ac-

cording to Ex. 1 and VII, 1:1..." 1.20 0.40 +27 0.007 0. 008 +0. 001 (11) Mixed product from 3 and III,

1:1 -7 1. 80 1.55 +22 0. 010 0. 014 +0. 004 20 (12) Mixed product from 3 and IV,

1:1 2.34 2.30 +22 0. 006 0.007 +0. 001 25 (13) Mixed product from 3 and V,

1: 1.92 2. 23 +16 0. 000 0. 000 3:0 25 (14) Mixed product from 3 and VI,

The Butlin tests or the hydrogenation residues are not specific, since the products are light (bright and clear).

By way of example only and not by Way of limitation, 25 Example 3 the following examples illustrate appropriate compositions, flows and operating conditions which may be present and encountered in the practice of this invention:

Example 1 In a de-asphaltizing-installation top-oil-residue (A) is extracted at 120 C. and atmospheres with a fivefold quantity of isobutane (vol./vol.) utilizing a countercurrent flow of materials. There is thereby obtained 84% of a ratfiniate (B and 16% of an extract (C 0 The C rafiinate contains 1.81% sulfur and the C extract 3.3% sulfur. The extract is brittle and may very easily be pulverized.

The rafiinate (B is subjected to a hydrogenating desulfurization in the presence of a cobalt-molybdate catalyst at a through-put rate of 1 l g./l. catalyst/hr., a pressure of 500 atmospheres and with 2 Nm. l-l /kg. at 440 C. There is obtained 49.3 weight percent of a residue 340 C. and 50.7 weight percent lighter products.

The extract (C is taken up in the hydrogenation residue (E of the raflinate under intensive stirring at 70-80 C.

In this manner 57.8 weight percent of the top-oil-residue (A) charged are converted into heating oil (F) 340 C. having a 0.96% sulfur content. In the aging procedure 0.001 weight percent dry sludge are newly formed.

In Table 2 the analyses of the starting product, of the intermediate products and of the heating oil mixture are set forth.

Example 2 The same C ratfinate (B as in Example 1 is subjected to a hydrogenating desulfurization using a cobalt-molybdate-catalyst (the catalyst is prepared in pellet form, the pellets having a 3 mm. diameter) at a through-put rate of 1 kg./l. catalyst/hr, but with a pressure of 300 atmospheres, 2 Nm. H /kg. and at a temperature of 445 C. There are obtained 49.9 weight percent of residue (E 340 C. and 50.1 weightperccnt of lighter products. After 239 days the experiment or run is discontinued; the catalyst throughout has retained its desulfurizing activity. About 7% coke has deposited on the catalyst; after the burningoff of the coke the run is continued.

The C extract is combined with the hydrogenation residue (C of the C ratrinate (E under intensive stirring. 58.7 weight percent of the top-oil-residue (A) charged are converted into heating oil (F) 340 C. with 0.92 weight percent sulfur (Table 3). In the aging no dry sludge is newly formed.

Top-oil residue (A) is deasphaltized with propane at 63 C. and 40 atmospheres. The ratio of propane to top-oil-residue used in the deasphaltizing amounts to about 2:1 kg./kg. As a result the top-oil-residue is distributed in a ratio of 5.25:1. The C railinite (B contains 1.88 Weight percent of sulfur and the C residue (C 3.73 weight percent of sulfur.

The C ratfinate (B is subjected to hydrogenation desulfurization using therefor a cobalt-molybdate catalyst, a throughput of 1 kg/l. of catalyst/hr., a pressure of 200 atmospheres, 1.4 Nm. H /kg. and a temperature of 400 C. 18.5 weight percent of the C rafiinate (B charged are in this run converted into fission products 340 C. The hydrogenation residue (E of the C raftinate is mixed with the C extract (C 84.5 weight percent oi the top-oil-residue (A) charged are converted into heating oil (F) 340 C. having an 0.81 weight percent of sulfur (Table 4). In the aging 0.002 weight percent dry sludge are peptized.

Example 4 In the manner set out in Example 3, a top-oil residue (A) is deasphaltized with propane. The top-oil-residue having a C/H ratio of 6.3:1 is decomposed into of a C rafiinate (B and 20% of a C extract (C The C raffinite (B contains 1.91 Weight percent of sulfur and the C extract (C 4.61 Weight percent of sulfur. The raftinate (B has a C/H ratio of 6.2:1, the extract (C 2. C/H ratio of 8:1.

The C rafiinate (B is treated in a hydrogenation desulfurization using the same catalyst as employed in Example 3, a throughput of 1 kg./l. of catalyst/hr. but in this instance a pressure of 300 atmospheres, and 1.5 Nm. H /kg. at 410 C. 79 weight percent of the C rafiinate (B remains as hydrogenation residue (E characterized by its loW sulfur content. The residue has a C/H ratio of 5.9:1 and is admixed with the C extract (C 78.8 Weight percent of the top-oil-residue (A) which had been charged are obtained as heating oil (F) having a sulfur content of 1.01 weight percent (Table 5). In the aging test 0.001 Weight percent dry sludge are peptized.

Example 5 A top-oil-residue (A) is distilled in vacuo until 50 weight percent are removed by distillation. The vacuum distillate (B which is obtained is treated at 40 atmospheres, 380 C., a 1.5 Nm. H /kg. and a throughput of 1 kg./l. catalyst/hr. using a cobaltmolybdate cata- 9 lyst. In the hydrogenation desulfurization 80 weight percent 340 C. are obtained.

The hydrogenation residue (E is admixed with the vacuum residue (C in proportions whereby the mixture point of +23 C. and a dropping point of 29 C. is mixed together with an extract (C recovered from the butane deasphaltizing of top-oil-residue (A) having an ash content of 0.11 weight percent, a softening point Weight percent sum. test Weight percent asphalt Weight percent S Vise. units/50 O Vise. units/100 C solidification point. C Dropping point, C Soitening point, C Hot filtration test before/ contains 1 weight percent of sulfur. This is accom- 5 of +88 C. and a dropping point of +133 C. using the plished by admixing the hydrogenation residue (E with mixing ratio of 1:2. 33 weight percent of the vacuum residue (C Thus, The resulting mixture has a penetration of 68, a sot-tenonly 40 Weight percent of the vacuum residue (C which ing point of 49 C. and a refraction point of -8 C. has been processed is to be taken up into the heating oil The mixture accordingly corresponds to the DIN (Ger- (F) (Table 6). In the aging test 0.0002 weight percent 1 man Industrial Standards) Standard 1955 (Ausgabe, of dry sludge are formed anew. February 1960) B 65.

Example 6 Example 8 The hydrogenation residue (E) Which results fromthe C raffinate (B treated as set out in Example 4, is treat- A 3 fixt'l'act 1) is injected at about Under ed for the production of heating oil (F), using in the pp y of Water vapor and technically p yg into t t t i place f th c extract (c thg t i1- a cracking reactor. The cracking pressure utilized id (A) d i th deasphaltizing I order to bamounts to 25 atmospheres and the reaction temperature tain a heating oil mixture (F) having a 1 weight percent t0 flbOut 1509" content of sulfur, it is necessary to add 34.5 Weight per- For each eXtl'act 1) about 750 of Oxygen and cent of top-oil-residue (A). 1 00 kg. top-oil-residue (A) 0.75 of Water vapor are charged- A cracking gas is yields 97.7 kg. of heating oil (F) (Table 7). In the formed, which consists of about 49 volume percent of aging test no dry sludge is newly formed. CO and about 45 volume percent H In addition to the Example 7 CO and H about 0.4 vol. percent CH CO and H 5 and about g. of soot are formed in the cracking. For A vacuum residue (A) having a boiling range begineach kg. of charged product about 2850 liters gas are ning at 390 C., 0.04 Weight percent ash, a solidification recovered.

TABLE 2 Hydrogena- Heating oil Top-oil- G4 raf- Cicxtion residue mixture with residue finate tract of c raflinate 20% C4 340 C. extract Density/50 C Weight percent ash after aging 0. 004/0. 005 0. 037/0. 038 Butlin test xylene units. 10 20 Start of boiling, C 303 356 356 Volume percent, 400 0 19. 0 26. 0 25. 0 Volume percentl C 48. 0/490 00. 5/400 61. 5/490 TABLE 3 Hydrogena- Heating oil Top-oil- C4 raf- 04 extion residue mixture with residue finate tract of O4 raffinate 27% C 340 C. extract Density/50 G 0. 918 Weight percent ash 0. 023 Weight percent conr. test 6. 99 Weight percent asphalt. 0. 97 Weight percent S 2. 03 Vise. units/50 C 37. 4 Vise. units/100 O 4. 48 solidification point, C +19 Dropping point, C +20. 5 Softening point, G. Hot filtration test before/ 0. 004/0. 005 0 031/0. 031

after aging.

Butlin test xylene units 10 25 100) 15 Start of b0i1ing, C 303 280 360 356 Volume percent 400 C 19.0 19. 0 30.0 25. 0 Volume percentl C 48.0/490 63.0/490 80. 5/490 61. 5/490 TABLE 4 Hydrogena- Heating oil Top-oil- C raf- C extion residue mixture with residue finate tract of C raffinate 19% C 340 C. extract Density/50 C 0.923 0. 872 0.902 Weight percent ash..- 0.030 0.011 0. 035 Weight percent conr. t s 7. 14 1.16 3. 58 Weight percent asphalt 0. 78 0.045 1.01 Weight percent S 2. 22 0. 0. 81 Vise. units/50 0.. 36.9 8. 64 31.0 Vise. units/100 O 4.32 1.090 3.92 solidification point, 0 +11 +30 +24 Dropping point, 0.-.- +325 Softening point, C. Hot filtration test before/ after egin 0. 003/0. 006 0. 015/0. 013 Butlin test xylene units 100) Start of boiling. C 300 353 Volume percent. 400 17. 21. 13. 0 11. 0 Volume percentl C 47. 0/490 54. 0/490 58. 0/400 47. 0/490 TABLE 5 Hydrogena- Heating oil Top-0i1- C rai C extion residue mixture with residue finate tract of C raffinate 20% C 3-10 O. extract Density/50 O. 0. 927 0.907 0.870 0.808 \Veight percent ash 0. 0283 0. 011 0. 108 0. 008 0. 0'20 Weight percent c0111. test 7. 97 3. 40 27. 27 0. 83 5. 94 Weight percent asphalt 1. 30 0.15 0. 01 0.063 1. 58 Weight percent S 1. 4. 01 1.0 Vise. units/50 G 15. 2 Vise. units/100 O z. solidification point. C--." Dropping Point, C Softening Point C Hot filtration test before] after aging 0. 003/0. 004 0. 009/0. 008 Butlin test xylene units. 100) 25 Start of boiling, C 375 352 Volume percent. 400 11.0 12.0 Volume pereentl O 50. 0/490 48. 0/490 TABLE 6 Hydrogenation Heating oil Tep-oil- Vacuum Vacuum residue mixture with residue distillate residue of 33% vacuum vacuum residue distillate 340 C.

Density/50 C 0. 922 0. 881 0.963 0.867 0. 807 Weight percent ash 0. 0328 0.0100 0. 0366 0.0029 0. 0178 Weight percent eonr. test. 6.86 0.316 15.11 0. 029 4.60 Weight percent aspl1alt 0.99 0. 011 1. 84 0. 005 0. 39 W'eight percent S 2.12 1.79 2. 56 0.22 1.01 Vise. units/50 C 2170.7 3.34 15. 67 Vise. units/100 C 58. 7 1. 460 2. 43 solidification point, 0. +36 +34 +24 Dropping point, C +44. 5 +29. 8 Hot filtration test before] after aging 0. 0015/0. 0017 Butlin test wlene units- 100) 10 Start of boiling, C 448 360 345 Volume percent, 400 0.. 18. 5 34.0 30. 0 20.0 Volume percentl C 47. 0/490 86. 0/490 4 0/490 02. 0/400 00. 5/490 TABLE 7 Hydr0gene- Heating oil Top oi1- C; raf- C ertion residue mixture with residue finete tract of C raiiinate 34. 5% top- 340 O. oil-residue Density/50 C 0.927 0.907 0.870 0. 880 Weight percent ash 0. 028 0. 011 0. 103 0. 008 0. 011 Weight percent eonr. test 7.97 3. 27. 17 0.83 3. 20 Weight percent usnh'ilt 1. 30 0.15 0. 61 0.063 0.18 Weight percent S 2. 63 1. 91 4. 01 0. 11 1. 00 Vise. units/ C. 44.0 15.34 8.30 13. 40 Vise. units/100 O 4.91 2. 1.06 2.46 solidification point, C---" +18 +25 +23 Dropping point, C +235 .1 +107 +17. 5 Softening point, C 1. +72 Hot filtration test before/ after aging 0.083] 0. 003/0. 004 0 003/0003 Butlin test xylene units 15 Start of boiling. C. 375 337 Volume percent, 400 0.. 11.0 15. 0 Volume percent/ C 56. 0/490 54. 5/490 What is claimed is:

1. A process for preparing heavy heating oils having low sulfur contents comprising the steps of (1) subjecting an oil residue derived from a member selected from the group consisting of petroleum, oil shale, coal tar, brown coal tar, generator tar, and mixtures thereof (A) to a separation treatment in which said residue (A) is separated into an asphalt and ash rich phase (C) and an asphalt and ash poor heavy oil phase (B);

(2) subjecting the asphalt and ash poor heavy oil phase (B) to a desulfurization treatment to obtain a desulfurized heavy oil phase (E); and

(3) thereafter admixing the asphalt and ash rich phase (C) with the desulfurized heavy oil phase (E) in such quantity relative to said desulfurized heavy oil phase (E) that a heavy heating oil having a low sulfur content not exceeding about 2% is formed.

2. A process according to claim 1 wherein said residue (A) is separated by vacuum distillation.

3. A process according to claim 1 wherein said residue (A) is separated by a de-asphaltizing treatment.

4. A process according to claim 1 wherein said residue (A) is separated by a deasphaltizing treatment carried out in the presence of a hydrocarbon having a low C/H ratio.

5. A process according to claim 4 wherein said separation is carried out in the presence of a hydrocarbon having a low C/H ratio selected from the group consisting of propane, N-butane, isobutane, pentane and mixtures thereof.

6. A process according to claim 1 wherein said asphalt and ash poor phase (B) is desulfurized by being subjected to a hydrogenating treatment.

7. A process according to claim 6 wherein said hydrogenating treatment is carried out in the presence of a hydrogenation catalyst.

8. A process according to claim 1 wherein said oil residue (A) is a top-oil residue.

9. A process according to claim 1 wherein said asphalt and ash poor phase (B) is desulfurized by being subjected to a hydrogenating treatment at a pressure of about 40 atmospheres.

10. A process according to claim 1 wherein said asphalt and ash poor phase (B) is desulfurized by being subjected to a hydrogenating treatment at a pressure of from about 40 to 500 atmospheres.

11. A process according to claim 1 wherein said asphalt and ash poor phase (B) is desulfurized by being subjected to a hydrogenating treatment at a temperature of from about 300 to 450 C.

12. A process according to claim 1 wherein in step 3 the admixing is effected so that a heavy heating oil hav ing a low sulfur content not exceeding about 1% is formed.

13. A process according to claim 1 wherein in said third step the desulfurized heavy oil phase (E) is additionally admixed with a further quantity of the starting oil residue (A) employed as starting material in step 1.

14. A process according to claim 1 wherein in said third step the desulfurized heavy oil phase (B) is admixed with a different member of the group of oil residues than used as starting oil residue (A).

15. A process for preparing heavy heating oils having low sulfur contents comprising the steps of (1) subjecting an oil residue derived from a member selected from the group consisting of petroleum, oil shale, coal tar, brown coal tar, generator tar, and mixtures thereof (A) to :a separation treatment in which said residue (A) is separated into an asphalt and ash rich phase (C) and an asphalt and ash poor heavy oil phase (B) and (2) subjecting the asphalt and ash poor heavy oil phase (B) to a desulfurization treatment to obtain a desulfurized heavy oil phase (E).

References titted in the file of this patent UNITED STATES PATENTS McKittrik Apr. 16, 1938 UNITED STATES PATENT. OFFICE CERTIFICATE OF CORRECTION Patent No. 3,155,607 November 3', 1964 I Herbert Friess I I. I

It is hereby certified that error appears the aboire numbered pet--' ent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 2 and 12, and in the heading to the printed specification, line '6, for "Gelsenberg Beny'in Aktiengesellschaft", each occurrence, read Gelsenberg Benzin Aktiengesellschaft column 4, line 10, for

"slighty" read slight, line 70, after "crucible" insert a comma; columns 9 and 10, TABLE 2, in the heading to the fifth column, for "C raffinate" read. C raffinate Same table, column 5, line 5 thereof, for "O. 129" read 0.029 column 14, line 40, for "Apr, 16, 1938" read Apr. 19, 1938 v Signed and sealed this 20th day of April 1965,

(SEAL) Attest:

ERNEST w. SWIDER EDWARD J. ,BRE-NNER Attesting Officer Commissioner of Patents

Claims (1)

1. A PROCESS FOR PREPARING HEAVY HEATING OILS HAVING LOW SULFUR CONTENTS COMPRISING THE STEPS OF (1) SUBJECTING AN OIL RESIDUE DERIVED FROM A MEMBER SELECTED FROM THE GROUP CONSISTING OF PETROLEUM, OIL SHALE, COAL TAR, BROWN COAL TAR, GENERATOR TAR, AND MIXTURES THEREOF (A) TO A SEPARATION TREATMENT IN WHICH SAID RESIDUE (A) IS SEPARATED INTO AN ASPHALT AND ASH RICH PHASE (C) AND AN ASPHALT AND ASH POOR HEAVY OIL PHASE (B); (2) SUBJECTING THE ASPHALT AND ASH POOR HEAVY OIL PHASE (B) TO A DESULFURIZATION TREATMENT TO OBTAIN A DESULFURIZED HEAVY OIL PHASE (E); AND (3) THEREAFTER ADMIXING THE ASPHALT AND ASH RICH PHASE (C) WITH THE DESULFURIZED HEAVY OIL PHASE (E) IN SUCH QUANTITY RELATIVE TO SAID DESULFURIZED HEAVY OIL PHASE (E) THAT A HEAVY HEATING OIL HAVING A LOW SULFUR CONTENT NOT EXCEEDING ABOUT 2% IS FORMED.