US2939835A - Treatment of mineral oils to produce light and middle oils - Google Patents

Description

TREATMENT OFMINERAL OILS TO PRODUCE LIGHT AND MIDDLE OILS Jozsef Varga and Gyula Rab, Budapest, Andras Zalai,

Varpalota, and Pa! Steingaszner, Budapest, Hungary,

assignors to Nagynyomasu, Kiserleti Intezet, Budapest, Hungary, :1 Hungarian corporate body Drawing. Filed Dec 30, 1954, S81; No. 478,912 Claims priority, application Hungary Dec. 31, 1953 7 Claims. (Cl. 208--108) This invention is concerned with improvements in or relating to the treatment of mineral oils to produce light and middle oils. The invention is more particularly concerned with the hydrogenation of asphalt-containing raw mineral oils and similar hydrocarbon liquids rich in asphalt and/or poor in hydrogen which, upon hydrogenation yield light and middle oils, and which for convenience are hereinafter termed hydrocarbon oils of the type described.

It is known that hydrocarbon oils of the type described, in particular brown coal tar, can be hydrogenated in the presence of fixed catalysts and in the liquid phase at temperatures up to about 420 and under pressures of about 200-300 atmospheres, the asphalts of the' starting material being reduced, and oils obtained which can be further' processed into gasolines and lubricants. In con tinuojis operation, however, the asphalt content of the raw material cannot conveniently exceed .a certain limit and is advantageously not greater than 4-5% In such processes the starting material is diluted with an organic diluent consisting preferably of cyclic hydrocarbons. According ,to literature .(cf WL Kronig: Die katalytische Drukhydrierung von Kohlen, Teeren und Mineralolen,

Berlin, Springer Verlag, 1951, pp. 82-85), however, under pressures of 200-300 atmospheres and at temperatures required for the effective decomposition of asphalts, in most cases coke is produced with resultant risk of choking the reactor. 'Therefore, according to- Kriinig, loc. cit.,- mineral oils rich in asphalt and heavy residues can be split up smoothly and economically and avoiding detrimental coke deposits in the known installations only by using high pressures of 700 atin. In this way, for instance, a heavy residue with a content of 7% hard asphalts, can be converted'bymeans of 5.5% by weight of hydrogen, into light oils (17% by weight) and middle oils "(about 63% .by-weight). It isknown however, that costly'high pressure installations are required for carrying out such a process and, inconsequencethereof, said process is. economical in exceptional cases only.

Attempts have been made to hydrogenate hydrocarbon oils of the type described under pressures lower than usual in liquid phase hydrogenation, i.e. at 70 atmospheres. It has been found, however (see Kronig, loc, cit, p. 87), that at 70 atmospheres and otherwise with the usual conditions of the technology of destructive hydrogenation, asphalt decomposition as far reaching as attained by a high pressure process cannot be effected.

It has now been found that the asphalt content of asphalt-rich mineral oils, of heavyhydroca'rbon residues and other similar hydrocarbon materials rich in asphalts and/or poor in hydrogen, for instance of coal tars, can 'be decomposed in high yield (generally of 80-90% or 'more) and with generally only slight coke production by carrying out the hydrogenation under conditions at which the 'material is present in the reaction space substantially in the gas or vapour phase. For this purpose, the starting material is mixed with sufiicient light oil and/or middle oil distillates (or witha' mixture contain- 2,939,835 Patented June 7, 1960 ing the same) that in the resulting mixture the constituents boiling below 350 C. amount to 20-95%, preferably 30-80%, whereafter this mixture is reacted with hydrogen or gas mixtures rich in hydrogen in presence of a moving catalyst, at temperatures above 420 C. and under pressures upto 110 atmospheres, preferably at 10-70 atmospheres.

It has been found that under hydrogenation conditions according to this invention a decomposition of the asphalts is efiected and a substantial amount (for example by weight) of distillates boiling up to 350 C. is produced while coke, as said above, is formed in only a slight amount (e.g. about 3-5%). The coke is generally of very fine grain, has much less tendency to adhere to the pipe-still walls and is continuously discharged by the efiluent material itself.

In consequence of the relatively low pressure, the plant required for carrying out the process may be more simple and substantially more economical as those required for high pressure hydrogenation processes The distillate of low boiling point range which in the process of this invention is added to the asphalt-containing raw material (and which for convenience is called in the following description low boiling diluent) should be so selected as to be present under the given reaction conditions substantially in the vapour phase. Suitable admixtures are light and/or middle oils. Mixtures of hydrocarbon materials consisting substantially of light and middle oils but containing some higher boiling constituents too are equally suitable.

The amount of the low boiling diluent to be used depends on the asphalt or hydrogen content of the starting material and further on the extent to which the decomposition of the asphalts is to be carried.

The process according to the invention can be eflected in the temperature range between 420 and 550, preferably between 430 and 480 C. l

By suitably selecting a suitable temperature and pressure within the above limits herein specified, the reaction can be conducted so that the reaction components are present substantially in the gas or vapour phase. V

The oxygen, sulphur and nitrogen compounds present in the starting material are in general substantially eliminated in the course of the reaction. Thus, for example, the sulphur may be eliminated to the extent of from 40-70%. r

As catalysts any convenient hydrogenation catalyst is suitable, such as hydrogenation catalysts selected from themetals of groups 5, 6, 7 and 8 of the periodic system, their compounds, alone or in mixtures with each other, whether dispersed on a carrier substance or not. Further elfective catalysts-are: artificial silicates, aluminum oxide, mixtures of these substances with each other or with the hydrogenationcatalysts previously mentioned. Particularly effective catalysts are active coke and carbon powder and catalysts comprising iron oxide dispersed on coke or carbon powder. The catalyst must be fed continuously into the reaction space with the feed and be discharged with the efiluentmaterial togetherrwith which the fine coke produced from the asphalts is also discharged too. The catalyst may also be kept floating dues thereof can also be converted into lubricants or gasolines in good yield.

It has been found that in the process according to the invention the hydrogen. consumption calculated with respect to the starting material does not, in general, amount to more than about 1 to 2.5% and is consequently smaller than that of the known high pressure hydrogenations. A further advantage of the present process consists in the possibility of using gas mixtures with a lower hydrogen content in place of pure hydrogen; such mixtures are for instance industrial gases with a content of 40-70% H e.g. synthesis gas and coke oven gas.

For the better understanding of the invention the following general description of a preferred method of operation is given by way of example only.

The asphalt-containing material, the light and middle oil content of which has been preliminarily ascertained, is mixed with the low boiling diluent (mineral oil distillate, a gas oil containing light and middle oils or the like) of known composition and fed with a calculated amount of a hydrogen containing gas (0.2-4 cub. m. preferably 0.5-2 cub. m./kg. starting material) and with the cata- 'lyst under a pressure of 1-100 atmospheres, preferably 10-70 atmospheres into an oven. In order to provide for a thorough mixing of the solid, liquid and gaseous reactants and further for the more effective elimination V of the small amount of coke produced, it is convenient H In most cases the asphalts are decomposed withinthe pipe-still already.

For the treatment of a starting material particularly poor in hydrogen or containing asphalts particularly resista'nt to decomposition, the efliuent stock can be passed through one or more reactors connected in series behind the pipe-still. The efiluent stock is then passed to any convenient fractionators, thecatalyst and the heavy residue, as usual, and if desired recycled and the stock recovered in the usual way.

The process according to the invention can be efiected in a reactor containing a fluidised catalyst, similar to the method usual in fluid catalyst cracking processes.

The following examples are given by way of illustration only; the reactants and their proportions are presented as being typical and should not be construed as limiting the invention. Knowing the features of the particular asphalt-containing material to be treated, the preferred admixture and the preferred reaction conditions within the scope of the invention can be preliminarily ascertained by those skilled in the art.

Example 1 100 kg. raw mineral oil of specific gravity 0.924 (at 60 C.) with acontent of:

' Percent by weight Fractions boilingup to 350 C. 20.5 Sulphur -3.6 Hard asphalts 14.4

is mixed with 100 kg. petroleum distillate of specific gravity 0.815 (at 25 C.) and having a boiling point range of 167295 C. The resulting mixture of 200 kg. has the following characteristics:

Specific gravity (25 C.) L. 0.880 Fractions boiling up to325 C ..percent by weight 61 Sulphur do 1.8 Hard asphalts do 7.2

o '4 I ing i en ob ns f om t 0 ts Starting mater al 90 kg. hydrocarbon oils consisting of:

Fractions boiling up to 350 C About 70 kg.

100 11g. starting material according-to Example I are 7 mixed with 100 kg. heavy gasoline of specific gravity 0.783 (25 C.) and of a boiling range between 128-200 C. The resulting mixture of specific gravity 0.864 contains Percent by weight Fractions boiling up to 325 C. 61 Sulphur 1.8 Hard asphalts 7.2

The mixture is introduced under conditions set forth in Example 1 into an installation consisting of a pipe-still and a reactor connected thereto. After recovery of the admixture, 100 kg. asphalt-rich starting material yield kg. hydrocarbonaceous oils of the following composition:

Fractions boiling within the range of 200- 350 C. t. 66.2 kg. Heavy oils (boiling about 350 C.) 23.8 kg.

Total 90.0 Asphalt decompositionefiect, about 90%. Desulphurizing effect, about 55%.

Example 3 7 kg. raw asphalt-containing material according to Example 1' are mixed with an equal amount of th'elow boiling diluent used in that example. The mixture is hydrogenated at 445 C. under a pressure of 15 atmospheres but otherwise under the conditions set forth in Example 1.

After recovery of the 100' kg. of low boiling diluent,

the treated starting material yields 90.0 kg. hydrocarbon oils consisting of Fractions boiling within the range up to 350 C. V p 45.9 kg. Heavy oils boiling above 350 44.1 'kg.

Total 96.0 kg.

Hard asphalt decomposition effect 90%. Desulphurizing effect 46%.

Example 4 Fractions boiling in the range up to 350 C. 45.9 kg

Heavy oils boiling above 350 C. 46.1

Total liquid constituents Hard asphalt decomposition effect Desulphurizing effect 48%.,

specific gravity 0.904 comprises aasasss 8 Example 100 kg. bituminous residuumof petroleum vacuum dlstillation with the following characteristics:

Specific gravity 0.993 Softening point C 54 Hard asphalt content ..percent by weight 11.2 Sulphur content do 0.6

are rnixedwith 100 kg petroleum. distillate used as low boillng diluent in Example 1. The resulting mixture of Percent by weight Fractions distillable up to 325 C 50 Sulphur. 0.3 Hard asphalts 5.6

The 200 kg. mixture is treated at 430-440 C. under a pressure of 70 atmospheres but otherwise substantially under the conditions and in the installations set forth in Example 1.

After recovery of the admixture, the 100 kg. bitumen yield 92.0 kg. hydrocarbonaceous oils, consisting of Fractions boiling in the range up to 350 C 31.2 kg.

Heavy oils, boiling range above 350 C 60.8 kg. Total liquid 92.0 kg.

Hard asphalt decomposition effect 60%.

Desulphurizing effect 22%.

Coke deposits in the pipe-still and the reactor: practically none.

Example 6 Kg. Starting material 100 Low boiling diluent 100 both identical with those set forth in Example 1. After addition of 2% by weight of iron oxide activated active carbon powder catalyst, the mixture is preheated and conducted into a pipe-still (without the use of a connected reactor) together with a gas mixture containing 70% H under a pressure of 70 atmospheres and treated at 475 C. Volume-space-velocityz 6 kg./litres of pipestill volume/hours.

After recovery of the low boiling diluent from the cooled efliuent product, one obtains from the 100 kg. starting material 94 kg. hydrocarbon oils, consisting of Fractions in the boiling range up to 350. C 60 kg.

Heavy oils of boiling range above 350 C 34 kg. Total liquid 94 kg. Hard asphalt decomposition effect 70%. Desulphurizing effect 50%.

Example 7 100 kg. brown coal tar of specific gravity 0.971 with a content of 35.5% by weight of fractions distilling in the range up to 325 C., sulphur content 2.67% by weight and containing 6.8% by weight hard asphalts are -mixed with an equal amount of the distillate used as low boiling diluent in Example 1. One obtains 200 kg. mixture of the following characteristics:

Specific gravity 0.895 Fractions boiling in the range up to 325 C.

' percent by weight 67.8 Sulphur content do 1.34 Hard asphalt'content do 3.4

The mixture is treated according to Example 1. After recovery of the low boiling diluent one obtains 90 kg. product consisting of:

Fractions boiling in the range up to 350 c 59% by weight. Heavy oils boiling above 350 C--- 31% by weight.

Total liquid 90.0%. Hard asphalt decomposition effect" 68%. Desulphurizing effect 45%.

Example 8 Starting asphalt-containing" material: 100 kg. asphalt and sulphur containing raw'mineral oil set forth in Example'l. Low boiling diluent: 100 kg. heavy gas oil of the. following characteristics:

Specific gravity' 25 o. 0.856

Boiling point range; C 180-440 Fractions distillable up to 325 C.

. 1 percent by weight r40 The resulting 200'kg. mixture of specific gravity (25 C.) '0.900 contains Percent by weight Fractions distillable up to 325 C 30 Sulphur Hard asphalr This mixture :is conducted into a pipe-still with two re-. actorsconnected in series thereto, whereby in the first reactor the temperature is maintained at 430 and in the second at 445 C. Under 'a pressure of 70 atmospheres 2 cub; m./kg. feed of a gas mixture witha content of 70% H is fed into the system; volume-spacevelocity: 06 kg./litre/hour. As catalyst, 2% by weight of iron oxide-active carbon powder are used.

After recovery of the admixture, the 100 kg. starting mineral oil yield 92.0 kg. hydrocarbonaceous oils of the following composition:

Fractions boiling in the range up to 350 C 58.4 kg. Heavy oils boiling in the range above 350 C 33.6 kg.

Total liquid 92.0 kg. Hard asphalt decomposition efiect 95%. Desulphurizing effect 50%.

Example 9 Fractions boiling up to 350 C About 58 kg.

Heavy oils boiling above 350 C About 32 kg.

Total liquid About 90 kg.

Asphalt decomposition effect About 90%.

Desulphurizing effect About 50%.

Example 10 100 kg. of the starting material and 100 kg. of the low boiling diluent set forth in Example 1 are treated according to the same example, but mixed with 2% by weight of a catalyst consisting of activated silica in powder form. After recovery of the 100 kg. low boiling diluent, one obtains from the 100 kg. starting material 90 kg. liquid consisting of Fractions boiling up to 350 C About 70 kg. Heavy oils boiling above 350 C About 15 kg. Total liquid About kg. Hard asphalt decomposition eifect About Desulphurizing effect About 60%.

Example 11 Starting asphalt containing material: kg. asphalt and sulphur containing raw mineral oil set forth in Example l. Low boiling diluent: 100 kg. petroleum distillate as set forth in the same example. Catalyst: 4 kg. silica-alumina catalyst. The mixture is treated as set forth in Example 1. After recovery of the 100 kg. low

7 boiling diluent, one obtain's li'rom the 100 kg. starting m te ial 0: 5.2. liq i consi t ng of Total liquid g As h swm esi n fi t A o t 9.9%- De ul h n ect Ab 0% 'We claim: I 3 v I 1. In aproc'ess for hydrogenating asphalt-containing raw mineral oils and similar-hydrocarbon oils'having an asphalt content in the range of 6.814.4% layweight, in order to form products selected from the group consistmg of light and'iniddle oils, and mixtures thereof, theimovement which eensists, in 'admixingthe oils to be hy- 'dr'ogenat'ed with an aliphatic diluent selected from the group consisting of mineral oil distillat'es, gas oil containing light and middle oils, heavy gas oil, and heavy gasoline, to form. amixture containing from 20% to r 95% by weight of fractions boiling up to 350 C.. and hy- 3. A process as claimed in claim 1, in which hydrogenation is carried out at a pressure in the range oi 10-70 atmospheres.

4. A process as claimed'in claim 1, in which hydro- V genationis carried out at a temperature in the range of 420-4s0 c. s s V e 5. A process as claimed in claim in which the hydrogenating catalyst is selected from the group consisting of active coke, active carbon powder and carbon powder activated with iron OXideJ V 6. A' process as claimed in claim 1, in which hydrogenation is carried out with a hydrogen-containing gas mixture containing at least 40% of hydrogen.-

7. A process, as claimed in claim 1, in which hydrogenation is carried out at a pressure 'in'the range of 10-110 atmospheres. 1

References Citedin the file of this patent UNITED STATES PATENTS

Claims (1)

1. IN A PROCESS FOR HYDROGENATING ASPHALT-CONTAINING RAW MINERAL OILS AND SIMILIAR HYDROCARBON OILS HAVING AN ASPHALT CONTENT IN THE RANGE OF 6.8-14.4% BY WEIGHT, IN ORDER TO FORM PRODUCTS SELECTED FROM THE GROUP CONSISTING OF LIGHT AND MIDDLE OILS, AND MIXTURES THEREOF, THE IMPROVEMENT WHICH CONSISTS IN ADMIXING THE OILS TO BE HYDROGENATED WITH AN ALIPHATIC DILUENT SELECTED FROM THE GROUP CONSISTING OF MINERAL OIL DISTILLATES, GAS OIL CONTAINING LIGHT AND MIDDLE OILS, HEAVY GAS OIL, AND HEAVY GASOLINE, TO FORM A MIXTURE CONTAINING FROM 20% TO 95% BY WEIGHT OF FRACTIONS BOILING UP TO 350* C. AND HYDROGENATING THIS MIXTURE SUBSTANTIALLY IN THE VAPOR PHASE AT A PRESSURE IN THE RANGE OF 1 TO 110 ATMOSPHERES AND AT A TEMPERATURE OF 420-550* C., IN THE PRESENCE OF A MOVING HYDROGENATION CATALYST OF MILD ACTIVITY.