US2381828A - Conversion of hydrocarbons - Google Patents

Description

Aug. 7, 1945. y C. B, NN Em 2,381,828

CONVERSION OF HYDROCARBONS v Filed Nov. 25,y 1942 Patented Aug. 7, 1945 CONVERSION oF mnocAnBoNs Carl B. Linn and Vladimir N. Ipatiefl, Riverside,

lll., assignors to Universal Oil Products Company, Chicago, Ill., a. corporation of Delaware Application November 25, 1942,v Serial No. 466,925

19 Claims. (Cl. 196-9) This invention relates to the conversion of hydrocarbon oils and particularly of hydrocarbon fractions produced by the distillation of petroleum oils, c oal, and other hydrocarbonaceous materials. tion is concerned with a modiication of hydrocarbon oil conversion processes involving the use of particular and speciiic types of catalysts which function to promote the formation of a relatively l high yield of high quality gasoline from hydrocarbon oils such as crude oil, topped crude, gas oil, naphtha; kerosene;v lowYY antiknfxzky gasoline, and also oils from sources other than petroleum.

The cracking of relatively heavy hydrocarbon oils to produce primarily gasoline or gas has been carried out by many methods and it is recognized that large numbers of the basic principles of hydrocarbon decomposition are known and that particular commercial processes have been developed which embody these principles. However, the application of catalysts to-cracking of hydrocarbon oilsis still largely empirical and it is not possible to predict just what catalysts should be employed to produce maximum yields.of desired product when cracking different fractions of diierent petroleums or other different hydrocarbon oils. A large number of solid catalysts In a more specific sense, the invenone iiuorine compound selected from the group consisting of hydrogen fluoride, boron fluoride, and carbonyl uoride.

According to the present invention, a hydrocarbon oil or a fraction thereof is treated'at a temperature of from about 300 to about 700 C. in the presence of a small amount of phosgene and of at least one compound selected from the y group consisting of hydrogen uoride, boron fluoride and carbonyl uoride. Generally not more than about 5% by weight of any one of the above mentioned `halogen compoundsl is commingled with the hydrocarbon oil or its vapors prior to being subjected to the heat treatment. While the process of this invention may be carried out under substantially atmospheric pressure, it is preferable to employ a superatmospheric pres'- sure which is generally less than about 60 atmoshave been developed for catalytic cracking which' comprise various raw and acid treated clays, synthetically prepared composites comprising silica and at least one member oi the group consisting of alumina, magnesia, and zirconia. Other proc- .esses are known according to which a-hydrocarbon oil is subjected to a cracking temperature in the presence of an alkyl halide, particularly an alkyl chloride or bromide, these halogenated parains being sometimes employed simultaneously withsynthetically prepared or clay-type cracking catalysts.

The present invention is concerned with the cracking of hydrocarbon oils in the presence of at least one of a-group of ilumine-containing compounds which are substantially gaseous. at 25 C. and under a pressure of 1 atmosphere. These volatile catalysts are characterized by selectivity in accelerating gasoline-forming reactions rather than gas-forming reactions, by their property 'ofbeing readily mixed with the hydrocarbons subjected to treatment, and by otherv factors. Y

One specific embodiment of the present invention relates to a process for converting hydrocarbon oils into substantial yields of gasoline which comprises heating said oil under cracking conditions in the presence of phosgen'e and of at least` pheres in order to increase the capacity of the treating equipment to produce a good yield and high quality gasoline. Thus, a hydrocarbon oil may be treated in the presence of about 5% by weight of phosgene and ab'out 5% of hydrogen iiuoride or in the presence of about 5% by weight feach of phosgene, hydrogen fluoride, boron uoride and carbonyl uoride to produce a substantial yield of lower boiling hydrocarbons with high antiknock value suitable as gasoline.

' It is sometimes advantageous to mix a butane fraction, and particularly isobutane, with a naphtha or other hydrocarbon oil prior to treatment with phosgene, hydrogen fluoride, and/or boron fluoride and /or carbonyl fluoride in order to effect interaction between said butane fraction and the decomposition products of the oil.

The process may be carried out as a batch type of operation in which the oil'is heated in contact with the catalyst for a time suilicient to eiect substantial decomposition into relatively lower boiling products of gasoline boiling range, said products being separated by suitable fractional distillation of the reaction mixture recovered from the batch type operation.

It is preferable, however, to carry out the, process in a continuous manner by simultaneously charging the hydrocarbon oil and the catalyst to a reaction zone maintained at the desired operating temperature and through which passes a mixture of hydrocarbons and catalyst. The resultant reaction mixture is then separated into hydrocarbons of gasoline, boiling ra'nge, hydrocarbons boiling higher than gasoline, and gaseous products containing fiuorine compounds at least part of which maybe recycled to further contact with fresh and recycled oil to assist in its conversion. The recovered hydrocarbons boiling higher than gasoline are recycled to commingle with the fresh charge of hydrocarbons and catalyst which are introduced continuously to the reaction zone.

The process of the present invention is also applicable to the conversion of low antiknock value gasolines and naphtha, into gasolines of higher I octane number by methods commonly referred to asreforming.

For the purpose of illustrating the present process, the accompanying drawing is given which illustrates dagrammatically one specific apparatus utilizable for producing gasoline of high antiknock.value from a hydrocarbon oil in the presence of phosgene and of at least one of the iiuorine compounds selected from the group consisting of hydrogen fluoride, boron fluoride, and carbonyl nuoride.

Referring to the diagrammatic drawing, fresh charging stock, preferably gas oil, naphtha or kerosene, is directed through line I and valve 2 to pump 3 which discharges through line 4 and valve 5 into coil 6 which receives heat from heater 1 to increase the temperature of said oil to the desired reaction temperature. From coil 6,- the heated oil passes through line 8, valve 9, and line I to the top of reactor H. If thecharging stock should not be substantially completely vaporized under the chosen reaction conditions, valve 9 is closed and the heated oil is passed from line 8 through line I2 containing valve I3 to flash VVchamber VI4 in wlii'ch'the'vaporsV are separated from higher boiling residual material, the latter being withdrawn from the system through Iine I5 and valve I6 to storage or other use not illustrated in the drawing. From ash chamber I4 the vapors are directed through line I1, valve I8, and lines 8 and I0 to reactor II already mentioned.

The mixture of phosgene and at least one of the i'luorine-containing compounds mentioned above, which mixture is preferably dissolved in oil or commingled with oil, is simultaneously directed through line I9 and valve 20 to pump 2| which discharges through line 22 and valve 23 into line ID already mentioned which contains valves 24 and 25 and through which the oil containing halogen compounds may be introduced in the proper proportion into either the stream of oil being treated or the stream of heated vapors of said oil. The halogen compounds may also be introduced simultaneously through both valve 24 and valve 25. Thus, with valve 25 closed, the mixture of phosgene and fluorine-containing compound or compounds may be added through line I IJ and valve 24 to the stream of oil being charged through line 4 to heating coil 6, or with valve 24 closed said mixture may be passed through line I0 and valve 25 and admixed with the oil vapors just prior to introduction into reactor II. It is preferable to use the latter method, particularly when charging heavy oil which makes it necessary to use flash chamber I4.

'I'he vaporized mixture of hydrocarbons, phosgene, and nuorine-containing compounds is passed downwardly through reactor II and the components of said mixture are intimately contacted in said reactor under the operating conditions hereinabove set forth whereby the oil is cracked to produce a high 'yield of a gasoline fraction of vhigh octane number. From reactor I I the reaction products are withdrawn through line 26 and valve 21 and passed through cooler 28 and line 29 containing valve 30 into separator 3I of suitable design for collecting heavy tarry material formed during the reaction. Said heavy tarry material is withdrawn from the bottom of separator 3I through line 32 and valve 33 while the vapors are directed through line 34 and valve 35 to fractionator36 of adequate design suitable for separating light gases and gasoline from highr boiling hydrocarbons.

Fractionator 36 is operated so as to produce an overhead fraction containing substantially no material boiling higher than gasoline and a distillation residue consisting of hydrocarbons boiling above the gasoline range. The overhead vapors from fractionator 36 are directed through line 31 and valve 38 to condenser 39 and thence through run down line 40 and valve 4I to receiver 42 equipped with conventional gas release line 43 containing valve 44 and with liquid drawofl" line 45 containing valve 46. Uncondensed gases which are released through line 43 and valve 44 contain not only hydrogen and light hydrocarbons but also hydrogen fluoride and other fluorine-containing compounds, some of which are suitable for recycling to the heating coil or reactor by means not illustrated in the drawing.

The gasoline fraction is directed from receiver 42 through liquid drawoff line 45 and valve 46 to pump 41 which discharges through line 48 and valve 49 into line 50 containing valves 5I and 52. A major-proportion of said gasoline is withdrawn from line 50 through valve 5I to storage or other use while a portion of the gasoline is directed from line 50 through valve 52 to the top of fractionator 36 to serve as reux liquid and thus assist in controlling the temperatures with fractionator 36.

From the bottom of fractionator 36, the hydrocarbonrmaterial boiling higher than gasoline is withdrawn through line 53 and valve 54 by pump 55 which discharges through line 56 and valve 51 into line 4 in which it is mixed with fresh charging stock and is thence directed to heating coil 6. A portion of the oil being recycled through line 56 may be Withdrawn therefrom through line 58 and valve 59 to storage or other use not illustrated in the diagrammatic drawing.

Because the heavy oil which is recycled through line 56 has been subjected to the cracking treatment, it contains a greater proportion of more refractory hydrocarbons than does the original oil and consequently it gives lower yields of gasoline than does the fresh charging stock. Accordingly, in order to substantially avoid fluctuations in the operation of the process of this invention, we prefer to vary the amount of phosgene and duerme-containing compound introduced to the reaction zone to compensate for variations in the amount and refractoriness of the recycle stock` more of the halogen-containing compounds being introduced as the amount of recycle stock and its refractoriness increase.

It will be apparent to one skilled in the art that other types of apparatus may be used for carrying out the process of this invention, and that many features not shown or described herein would normally be included in hydrocarbon cracking equipment, such as heat exchangers, controls, etc. Also a plurality of reactors could be provided and arranged for either series or parallel operation.

The following examples are given to indicate results expected in the operation of the process, although the examples should not be misconstrued to limit the broad scope of the invention.

Example I A gas oil fraction and each-of ,phosgene .and hydrogen iluoride' based upon the weight o! formed.

Eample II A naphtha boiling between 150 and 250 C. is

- mixed with about an equal molecular proportion of a butane fraction consisting largely of isobutane. The resultant hydrocarbon mixture is .then heated to a temperature of 500 C. under a pressure of about 2 atmospheres and commingled with 5% by weight of phosgene, 5% of hydrogen fluoride, and 1% of boron fluoride. The whole reaction mixture is then maintained at 500 C. for a time suiicient to effect reaction of said isobutane and naphtha to give an 80% yield f of a' product boiling mainly in the gasoline range and having an octane number of 77.

The character of the present invention is evident from the preceding specifica-tion and examples, although neither section is intended to limit unduly its generally broad scope.

We claim as our invention:

1. A process forconverting a hydrocarbon oil which comprises heating said oil in the presence of both phosgene and at least one of the normally Ygaseous compounds of fiuorine selected from the group consisting of hydrogen fluoride, boron uoride, and carbonyl fluoride.

an amount not more than about 5% by weight of said hydrocarbon oil.

6. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction under cracking. conditions in the presence of both phosgene and at least. one of the normally gaseous compounds of iluorine selected from the group consisting of hydrogen fluoride, boron uoride,

'and carbonyl iiuoride.

7. A process for converting a hydrocarbon oil into a substantial yield of gasoline which com- 4a temperature of from about 300 to about 700 2. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil under cracking conditions in the presence of both phosgene and at least one ot 'the normally gaseous compounds of fluorine selected from the group consisting of hydrogen -iluoride, boron iluoride, and carbonyl fluoride.

' 3. A process for converting la hydrocarbon oil 'into a substantial yiem of gasoline whichA comprises heating said oil to atemperature of from about 300"lto about [700 C. in the presence :of both phosgene and at least one of the normally gaseous compounds of fluorine selected from the Agroup consisting of hydrogen fluoride, boron fluoride, and carbonyl fluoride.

prises heating said oil and a butane fraction to a temperature of from about 300 to about 700 C. in the presence of both phosgene and 4at least one of the normally gaseous compounds of ilu-v orine selected from the group consisting of hydrogen fluoride, boron iluoride, and carbonyl fluoride.A g

8. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction to C. under a; pressureof from about 1 to about 60 atmospheres in the presence of both phosgene and at least one of the normally gaseous compounds of iiuorine selected from the group consisting of hydrogen uoride, boron fluoride, and carbonyl iiuoride I 9. A process for converting a hydrocarbon loil into a substantial yield of gasoline which comprises heating said oil and a butanefraction to a temperature of from about 300 to about 700 C. in the presence of both phosgene and at least one of the normally vgaseous compounds of uorine selected from the group consisting of hydrogen fluoride, boron fluoride, and carbonyl fluoride, each of the halogen compounds so employed being present -ln an amount not more than about 5% by weight of said hydrocarbon oil.

10. A process for converting a hydrocarbon comprises heating said oil andra butane fraction to a temperature of from about 300 to about l4. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil to a' temperature' of from about 300 to about 700 C. under a pressure of from about 1 to about 60 atmospheres in the presenceof both phosgene and at least one' of the normally gaseous compounds of fiuorine selected from the group consisting 'ofhydrogen fluoride, boron fluoride, and carbonyl fluoride.

5. A process for converting a. hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil to a temperature of from about 300 to about 700 C. in the presence of both'pho'sgene and at least one `of the normally gaseous compounds of iluorine selected fromdihe group consisting of hydrogen iiuoride, boron Iluoride, and carbonyl fluoride, each of the halogen compounds so employed being present in 700 C.. under a pressure of from about 1 to about 60 atmospheres in the presence of both phosgene and at least one of the normally gaseous compounds of fluorine selected from the group consisting of hydrogen -fiuoride, boron.

iiuoride, and carbonyl fluoride, each of the halogen compounds so employed being present in an amount .not more than about 5% by weight of said hydrocarbon oil.

11. A process` for converting a. hydrocarbon oil intoA a substantial yield of gasoline of high antiknock value which comprises heating said oil to a temperature of from about 300 to about 700 C. under a pressure of from about 1 to about 60 atmospheres in the presence of phosgene, hy drogen fluoride, and boron fluoride.

12. A process for converting a hydrocarbon oil into `a substantial yield of gasoline of high antiknock value which comprises heating said oil to a temperature of from about 300 to about 700 C. under a pressure of from about lto about .60 atmospheres in the presence of phosgene and hydrogen uoride.

13. A process for converting a hydrocarbon oil into a,v substantial yield of gasoline of high antiknock value which comprises heating said 4oatmospheres in the presence of phosgene and boron fluoride.

14. A process for converting a hydocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction to a temperature of from about 300 to about 700 C. in the presence of phosgene, hydrogen fluoride, and boron fluoride.

l5. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction to a temperature of from about 300 to about 700 C. in the presence of fluoride.

16. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction to a temperature of from about 300 to about 700 C. in the presence of phosgene and boron fluoride.'

17. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comphosgene and hydrogen.

prises heating said oil and a butane fraction to a. temperature of from about 300 to about 700 C. under a pressure of from about 1 to about 60 atmospheres in the presence of phosgene and carbonyl fluoride.

18. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating Said oil and a butane fraction to a temperature of from about 300 to about 700 C. under a pressure of from about 1 to about 60 atmospheres in the presence of phosgene and hydrogen iluoride.

19. A process for converting a hydrocarbon oil into a substantial yield of gasoline which comprises heating said oil and a butane fraction to a temperature of from about 300 to about '700 C. under a pressure of from about 1 to about 60 atmospheres in the presence of phosgene and boron lluoride.

CARL B. LINN. VLADIMIR, N. IPATIEFF.

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