US1598973A - Art of treating oils - Google Patents

Description

Patented Sept. 7, 1926.

UNITED STATES GEORGE KOLSKY, OF JERSEY CITY, NEW JERSEY.

ART OF TREATING OILS.

No Drawing.

The present invention relates to the art of treating oils.

More particularly the invention relates to the treatment of hydro-carbon oils for the purpose of converting relatively high boiling point oils to lower boiling point saturated oils of high quality.

Various processes have been proposed for the conversion of relatively high boilingpoint h dro-carbon oils to lower boiling point oi s, which are subject to various disadvantages from a commercial viewpoint. One of the well-known prior processes is that known as cracking, in which the hydrocarbon oils to be treated are subjected to the application of heat and pressure usually at temperatures within the limits of about 750 to 860 degrees Fahrenheit. In such processes only about 20 to per cent of an average raw stock can be converted into gasoline, and considerable quantities of low grade residues, coke and permanent gases are formed, the cheapest raw materials, such as heavy crudes and residues from heavy California, Gulf and Mexican oils cannot be used commercially for the production of gasoline in these processes because of the excessive deposition of carbon and low yield of gasoline obtained. Gasoline produced by the cracking processes comprises to a large extent unsaturated hydrocarbons, or hydrocarbons which do not contain enough hydrogen to satisfy all of the chemical combining power of the carbon contained therein. As is well known unsaturated hydrocarbons are undesirable and etroleum roducts containing them are of ower gra e and value than those which are composed substantially of.

saturated hydrocarbons.

\ It has been found impossible to attain complete conversion of high boiling point hydrocarbons to low boiling point hydrocarbons by cracking or any of the other prior processes. Commercial gasoline contains on an average of 84 to 85 per cent of carbon, and 15 to 16 per cent of hydrogen while the composition of the raw materials varies according to locality from which it is secured. .A parafline base Pennsylvania crude oil has 86 per cent carbon and 14 per cent hydrogen; a Mexican crude has 84 per cent carbon and only 10 per cent hydrogen and there is a greater variation than this in the composition of the various refiner residues and intermediates. It is accordingly evident that for a complete conversion, the dissociation Application filed November 27,*1925. Serial No. 71,805.

catalyzers must be renewed frequently, and

their catalytic activity is rapidly paralyzed by the impurities such as sulphides of carbon or hydrogen or other sulphur compounds contained in the raw material and continuously present during the treatment. 2

Other well known processes for the production of lower boiling point hydrocarbons or gasoline from the higher boiling point hydrocarbons are those in which the oils to be treated are heated in the presence .of a catalytic substance such, for example, as anhydrous aluminum chloride at temperatures below 600 degrees Fahrenheit. Saturated low boiling point hydrocarbons of high quality are produced but these processes are subject to the difliculty that the aluminum chloride or other catalytic agents utilized are expensive, their catalytic activity disappears after about thirty or forty hours of operation, and they become converted into coky mass and are regenerated or recovered only with great difiiculty. A further disadvantage of these processes is that in order to provide the necessary hydrogen to produce saturated hydrocarbons, a certain portion of the hydrocarbon is robbed of its hydrogen content. As high as 15 per cent of the raw stuff treated may be reduced to coke due to the robbing of the hydrogen content and to the decomposition which proceeds during the process.

,It has also been proposed to efiect hydrogenation in combination with the dissociation of the hydrocarbons in the presence of catalyzers, and at temperatures below the usual cracking temperatures, by utilizing hy drogen generated by reacting hydrochloric acid with metal. This process is inoperative for the reason that reaction of the hydrochloric acid with the metal forms molecular hydrogen which does not readily combine with the unsaturated hydrocarbons. The presence of free hydrochloric acid in the usual treating processes and metallic apparatus is moreo er h ghly undesirable for the reason that reaction vessels are attacked and corroded by the free acid.

Efforts have been made to hydrogenate hydrocarbon oils with hydrogen made from steam and metals or carbon at very high temperatures and pressures. Thishas been unsuccessful commercially for the reason that the required temperatures and pressures are so great that the cracking reactions are uncontrollable and cannot be coordinated with the formation of the hydrogen, and the extreme temperatures destroy the products. In other processes using free hydrogen pressures as high as 100 atmospheres or more are required; the plants that are constructed to operate at these high pressures are very expensive in first costand in maintenance, the addition of the hydrogen is too expensive and difiicult by this method and has been entirely impractical from a commercial view point.

I have discovered that it is possible to synchronize the dissociation of the higher boiling point hydrocarbons and the formation of nascent hydrogen at temperatures and pressures within the limits at present utilized in the well known cracking processes; and also within the temperaturelimits at which the present well known catalytic reactions in the presence of aluminum chloride and like compounds is carried out. In this way the hydrogen necessary to saturate the hydrocarbons is supplied in nascent or atomic form at the temperature and pressures at which dissociation or the formation of hydrocarbon remnants occurs and an immediate combination of the nascent hydrogen with the dissociated compounds or hydrocarbon remnants is effected before a substantial proportion of the hydrocarbons can break up into free gases and carbons. A considerably improved yield and quality of lower boiling point oils is in this wa attained and I have found that the cheaper grades of raw materials which at present are commercially unavailable gfor cracking may be profitably converted into gasoline by means of my improved process. Heavy crudes and residues from heavy California, Gulf and Mexican oils may be treated successfully in accordance with my invention, and high yield high grade low boiling point saturated hydrocarbons of saturated nature, free from undesirable olefines are produced.

Accordingly objects of my invention are to provide novel improved, and more economical processes for bons; to provide novel processes for increasing the yield of lower boiling point hydrocarbons from higher boiling point hydrocarbone; and to provide novel processes of by drogenating, and dissociating hydrocarbon materials. v

Further objects of the invention are such treating hydrocaras may be attained by a utilization of the various novel combinations, subcombinations, steps and principles hereinafter set forth for the various uses and in the various relation to which they are applicable by those skilled in the art, and as defined by the terms of the appended claims.

In accordance with my invention, the dissociation of the higher boiling point hydrocarbons such as is effected in the various well known cracking processes, may be carried out simultaneously with the formation or generation of hydrogen in a nascent state and in such manner that the hydrogen acts on the hydrocarbon molecule at the point of cracking, combining with and saturating the lower boiling point unsaturated hydrocarbons before a further dissociation or decomposition with a resulting deposition of carbon and formation of fixed gases can occur. This is preferably effected by carrying out the reactions for the formation of nascent hydrogen in a manner to cause the simultaneous formation of substances which aid the dissociation of the hydrocarbons, and simultaneous hydrogenation of'the components thereof by catalytic action. In this way the cracking, catalysis, hydrogenation and generation of nascent hydrogen are synchronized, resulting in decreased formation of free carbon and fixed gases, and an increased yield in saturated low boiling point hydrocarbons. \Vhile it is preferred to utilize the cracking reactions, it will be understood that this is not essential and that the formation of nascent hydrogen and a catalyzing substance together with hydrogenation may be carried out below the cracking temperatures and pressures with decidedly improved results over those attained in the aluminum chloride and like prior catalytic processes.

In the preferred methods of carrying out my invention I react ammonium salts of the haloid group such as chloride with finely divided iron, Zinc, copper, aluminum or similar metals, or finely divided metallic alloys or mixtures of metals to produce metallic salts or chlorides, free ammonia as, and nascent hydrogen, in the presence of the hydrocarbons to be treated. The metallic chlorides act as catalytic agents in well known manner. The ammonia gas which is evolved is inert to the hydrocarbons at the temperatures utilized. When finely divided iron is used with the ammonium chloride, their reaction starts below 300 degrees F.; is slow up to about 400 degrees F is active above about 400 degrees F.; and is completed between about 650 and 750 degrees If. in accordance with the pressure in the apparatus. At very high pressures it may not be completed until a temperature of 800 degrees F. or more is reached. When finely divided z nc 9 alum i ut li ed ith ammoni- .lar variable factors.

um chloride the, temperatures at which the reactions occur are slightly lower, 'while when finely divided copper is utilized lthe temperatures are slightly higher than when iron is utilized. Although ammonium chlo- -ride-is preferably utilized, in general anyammonium 'salt of the haloid group such for example asbromides, and the like may be used effectively with finely divided metals to generate the nascent hydrogen in my im proved processes. I

While the range of temperatures at which; the reactions have been observedto occur in casewhen finely divided iron is used have been given, it will be understood that the reactions with other metals are not limited to these temperature ranges. The best condition for any particular oil to be treated may be determined experimentally and will be dependent upon the composition of the raw product, the time of treatment, the metal used, the pressure utilized and simi- For example, using ammonium chloride and the proper metals, a Pennsylvania crude oil may be hydrogenated and completely treated at the temperatures just above its boiling point. Relatively heavy oils such as heavy California and Mexican crudes require higher temperatures and pressures and a longer time of treatment for complete hydrogenation and dissociation in a commercially satisfactory manner. The reactions are carried out in a manner dependent upon the desired degree of conversion or result and the raw material treated, and the temperatures, pressures, and duration of treatment are varied accordingly. i Certain other of the ammonium salts or compounds such as sulphates, carbonates, sulphites and the like may also be utilized in carrying out my improved processes, providing that such 'metals are reacted therewith as will eliminate the influence of water, or will react with water as rapidly asit is formed to generate nascent hydrogen. For example neither aluminum nor iron may be utilized with such ammonium compounds,

' as the temperatures at which they will re act with water to form nascent hydrogen are entirely too'high for the purposes of my invention. Zinc dust, however, maybe utilized with such compounds, and a mixture of ammonium sulphate or carbonate with zinc dust will produce the desired result, The substances must be so chosen that they will liberate nascent hydrogen within the desired temperature limits and at the same time will not cause undersirable reactions such as the formation of free acids to take place simultaneously. I As the reactions do not proceed, at ordi nary temperatures, nor in the presence of water, it is assumed that the metal having a high afiinity for the radical or group com- In the preferred manner bined with the chemical group NH within the temperature limits set forth, combines with the radicalor group leaving the chemi-- cal group NH which immediately splits up into NH, and atomic or nascent hydrogen. The' processes are accordingly carried out in the presence of free excess ammonium vapors which are evolved continuously, and in cracking operations the cracking occurs in an atmosphere of ammonia under pressure.- Under these conditions when the process is properly carried out, the existence of free vacid is prevented.

of practicing the invention, ammonium chloride and finally divided iron are utilized. Under ordinary conditions of heating, ammonium chloride dissociates intoammonia and hydrochloric acid vapor. In my improved process the formation of hydrochloric acid vapors is prevented by the combination of the'chlorine with the finely divided metal, and the pres-v ence of free acid is entirely avoided. This permits the carrying out o my invention in apparatus made of steel'or suitable steel alloy without undue corrosion.

When the reactions are carried out at cracking temperatures and pressures in the presence of hydrocarbons to be treated, the evolved ammonia gases may be regulatedto control the pressure in the treating apparatus, and the benefit of the reactions may be attained over a wide range of temperatures. By permitting higher pressures to develop in the apparatus, the reactions may be caused to proceed at higher temperatures, and the speed of reaction between the ammonium compound and the metal or metallic alloy or mixture may be controlled by varying the pressure in the vessel In this way the generation of the nascent hydrogen, and the dissociation of the hydrocarbons for different grades of oil to be treated may be controlled to give the maximum efficiency of operation.

In the preferred embodiment of the invention the substances entering into the reaction for the formation of the nascent hydrogen and the catalytic substances are preferably regenerated or recovered for use in succeeding operations. The regeneration is preferably carried out so that a complete cycle of operations is maintained.

By way of a specific example of carrying out the invention, the reactions will be given for the case in which ammonium chloride and finely divided iron are utilized and in which regeneration ofthe substances is carried out in a cycle. The ammonium chloride andfinely divided iron react at the temperatures utilized to produce iron chloride, free ammonia, and nascent hydrogen as set forth in the following equation:

1 2NH.o1+F e=Feo1 N ,+2H. The raw oil to be treated is mixed with a suitable quantity of dry ammonium chloride and finely divided iron or other metal and the mixture is heated and treated preferably as is done in the usual cracking or catalytic processes and in any usual type of apparatus. The quantities necessary for complete treatment of a given product may be readily determined from equation (1), and from the amount of hydrogen necessary to effect hydrogenation and saturation of the particular grade of hydrocarbon to be.

treated. For example if the'raw material to be, treated requires two parts of hydrogen per 100 parts of raw oil to conform to the hydrogen content of gasoline, the quantities for complete hydrogenation should be at least one molecule, or 55 parts of iron, and

'2 molecules or 106 parts of ammonium chlo- (2) 2NH,Cl|-Fe-(-unsaturated.

V, hydrocarbon: FeCh-I-QNI-L-I-saturated hydrocarbon.

For example, if the raw material has been broken down through cracking and dissociating reactions to amylen-e the reactions will be as follows:

The gasoline vapor and other low boiling point hydrocarbon vapors together with the ammonia vapors formed during the reactions are released from the still or the reaction vessel preferably as fast as they are formed and preferably in continuous manner. 7 The release of the evolved vapors may be controlled to maintain predetermined pressures in the reaction Vessel and to control the reaction temperatures in cracking operations'if desired. The gasoline vapors are condensed in any suitable manner and separated from the ammonia vapors. The ammonia vapors are then preferably brought in contact in the presence of water with the iron chloride formed in the reaction vessel and ammonium chloride is recovered for use in va following operation. hydroxide formed in the regeneration of the ammonium chloride is preferably reduced to metallic ,iron and also used over in a suc- .ceeding operation. The reduction of the iron hydroxide maybe effected with reducing gases available at a refinery such as still gases, or with hydrogen, or with industrial gas such. as water gas. In the preferred instead of one. of ammonium chloride with finely divided The iron method of regeneration, iron chloride from the reaction vessel is preferably separated from the adhering oil by heating the same, and the vapors from the adhering residual oil-are utilized for the reduction of the iron hydroxide from a previous operation.

The regeneration reactions may be expressed in the following equations:

(4) FeCl +2NH +2H Q= I Fe (OH) +2NH,C1. (5) Fe(OH) +R-educing gases:

H O+CO+Fe The treatment of the hydrocarbons and regeneration of the reacting substances may in this manner be carried out in a cycle of operations, and in economical manner. Finely divided metal from any source may be used, but it is preferable to utilize the metal which has been recovered from a regeneration of the metallic salts formed in the treatment of the hydrocarbons as the restood that the process is not limited to these quantities. Improved results and yields as compared to ordinary methods of treating high boiling point oils to produce low boiling point oils may be obtained even though much smaller quantities are used than will be necessary to effect complete hydrogenation of the ro'duct.

It w1ll be found that desirable results may be attained by a mixture of ammonium compounds of the character mentioned with a finely divided mixture of two or more metals In certain cases a mixture iron and a small quantity of metallic aluminum gives excellent results due to the additional catalytic action of the aluminum chloride formed. The quantity of iron and ammonium chloride may be calculated and used inan amount to give the desired hydrogenation while the quantity of aluminum used, preferably in catalytically active form may be so small as to be negligible for purposes of regeneration.

If a mixture of anhydrous ammonium chloride and finely divided aluminum is used in place 'of the aluminum chloride in the well known catalytic processes, and the treatment of the oils is then carried out in the manner commonly used in such processes, all of the desirable results of these aluminum chloride processes will be assured, and in addition a much better yield of saturated prod.

uct will be obtained, for the reason that the hydrocarbon remnants are hydrogenated and saturated and the decomposition and formation of coke with all its disadvantages is reduced to a minimum or entirely avoided. It will also be found that in a cyclic operation the ammonium chloride and the metallic aluminum can be more easily and more ecowill react to evolve hydrogen and free ammonia.

2. In a process of treating hydrocarbon oils, the step of heating the same in the presence of an ammonium salt of the intermediate members of the halogen group and finely divided metal.

3. In a process of treating hydrocarbon oils, the step of heating the same in the resence of ammonium chloride and finely ivi'ded iron.

4. The process of treating hydrocarbon 011s which comprises reacting the oils with a monia at temperatures substantially at or a above the, boiling point of said oils to efiect simultaneously the cracking of the highboiling point hydrocarbons and the hydrogenation of the unsaturated products formed during said cracking.

5. The process for treating oils which comprises reacting the same with ammonium chloride and a metal at temperatures substantially at or above the boiling point of said oils to simultaneously produce a catalytic metallic salt, crack the oils and hydrogenate the unsaturated hydrocarbon products.

6. The process of treating hydrocarbon oils which comprises reacting the hydrocarbons with an ammonium salt in the presence of finely divided. metal that will react to evolve hydrogen and free ammonia at a temperature between 300 and 800 drawing the low boiling point hydrocarbons thus formed, and controlling the pressure of the evolved vapors to controlthe activity of reaction.

In testimony whereof I afiix my signature.

GEORGE 'KoLsKY.

F., withr j