US2405997A - Averaging with pentane - Google Patents

Description

Patented Aug. 20, 1946 UNITED STATES PATENT OFFICE AVERAGING WITH PENTANE Robert E. Burk, Novelty, Ohio, assignor to The Standard Oil Company, Cleveland, Ghio, a corporation of Ohio No Drawing. Application August 9, 1944,

- Serial No. 548,807

Claims. 1

drocarbons of intermediate molecular weight, a

process termed averaging.

A preferred and important embodiment of the invention comprises the use of a normal pentane containing fraction as the lighter hydrocarbon, and a liquid hydrocarbon boiling above the gasoline range as the heavier hydrocarbons, to produce gasoline of desirable properties.

It is one of the objects of the invention to utilize normal pentane as one of the raw materials in making more valuable hydrocarbon products.

A further object of the invention is to utilize heavier hydrocarbon fractions, such as kerosene or naphthas, in the formation of hydrocarbons of lower molecular weight, such as gasoline, without the production of large amounts of unsaturated hydrocarbons or fixed gases, and also without the destructive influences and losses incident to conventional methods of cracking.

An additional object of the invention is to utilize both a pentane containing hydrocarbon fraction and a heavier hydrocarbon fraction simultaneously in a single reaction to produce valuable products intermediate said fractions resulting from a net consumption of both of them at the same time.

An additional object of the invention is to provide a process in which a mixture of butanes and pentanes may be used as the lighter fraction in an averaging process resulting in a net con- .sumption of normal pentane to form more valuable hydrocarbons.

Still a further object of the invention is the provision of a process in which a butane and pentane containing lighter fraction may be used as the lighter hydrocarbon in an averaging reaction and the proportions adjusted so as to result in .a net consumption of the butanes along with the pentanes.

A further object is to provide a process in which the normal pentane in the lighter fraction is used in the manufacture of higher hydro 2 carbons as well as converted to isobutane which may be fractionated and used in other processes such as alkylation.

Still another object of the invention is to carry out the averaging reaction in the presence of an amount of the lighter hydrocarbon fraction in excess of that entering into the reaction, and in which the excess of the lighter hydrocarbon fraction may be recycled to the averaging re-- action in a continuous or semi-continuous process.

A further object of the invention is to carry out the above process, utilizing a pentane frac-.

tion containing normal pentane in excess of that entering into the reaction, fractionating the excess to remove all or a portion of isobutane or isopentane which is formed during the averaging reaction if desired and recycling the balance of the lighter fraction to the reaction zone.

Still a further object of the invention is to carry out the above reactions in the liquid .phase in the presence of a liquid catalyst comprising primarily hydrogen fluoride and promoted by a minor proportion of boron trifluoride, and if desired, also promoted by the presence of an unsaturated hydrocarbon.

Another object is the provision of a process in which fluorides containing the impurities present in commercial grades may be used.

An additional object of the invention is to carry out the pentane averaging process under conditions of temperature and pressure not lower nor higher than can be obtained conveniently in ordinary plant operations.

The invention has as a further object the provision of a process of the character described in which the activity of the catalyst, in addition to being controlled by variations in temperature, pressure and other factors ordinarily employed in catalytic operations, also can be controlled readily by means of the partial pressure of the boron trifluoride constituent of the catalyst.

Still a further object is the provision of a process of averaging as described in which the catalyst can be readily recovered and reused.

Other objects of the invention will appear from the following description.

In carrying out the process of the invention, a lighter hydrocarbon fraction comprising normal pentane is mixed with the heavier boiling fraction, such as a normally liquid hydrocarbon. These are caused to react preferably in a liquid state, in the presence of a liquid catalyst and under conditions of temperature and pressure as will be pointed out more particularly hereinafter, to produce products heavier than the light hydrocarbon and lighter than the heavier hydrocarbon starting materials. At the conclusion of the treatment the hydrocarbons are separated as one phase and may be fractionated, and the catalyst is separated as another phase. The catalyst phase may be reused as such or may be regenerated and reused.

The light hydrocarbon may be normal pentane or a mixture of normal and isopentane. It may also be a mixture of normal (or normal and iso-) pentane with normal butane or a mixture of normal and isobutane. Normal pentane is readily reacted in accordance with the invention and since it is not of great value in itself as a motor fuel, the invention assumes particular importance with reference to its use as the lighter reacting component.

The lighter hydrocarbon fraction may be obtained from any refinery operation; it is immaterial if it contains small amountsof other constituents, and for this reason it need not be highly purified. It is also immaterial, and in fact it is an advantage as pointed out later, if it contains a small amount of unsaturated hydrocarbons. For this reason it is not necessary to fractionate the unsaturated hydrocarbons and other ingredients from the lighter fraction. Generally the normal pentane is found mixed with some isopentane and no harm is done if the latter is present. Under some conditions the reaction may be facilitated by the presence of isopentane. However, since isopentane is more useful in itself as a motor fuel, the ability to use normal pentane as a rawmaterial in the averaging process is of great importance. If the lighter fraction contains butanes, as it may especially in a continuous process, the presence of the latter does not interfere with the net consumption of the normal pentane.

In a continuous operation in which an excess of the lighter fraction is used, a part of the normal pentane may be isomerized to isopentane and a part converted to isobutane. When the excess of the lighter fraction is recycled the amounts of the isopentane and/orisobutane in the recycled fraction may be varied and this becomes a controllable variable.

The heavier fraction, in general, should be a heptane or heavier hydrocarbon. While the heavier fraction may be a pure hydrocarbon, generally it will be a mixture, such as naphthas (250-400" F), kerosenes (350-550 F), light gas oils MOO-625 F), heavy gas oils (SOD-710 F), mixtures of light and heavy gas oils lOO-l'lO F), deasphaltized and dearomatized residues (above 700 F), the portion of crude boiling to 550 F., the portion of crude boiling to 700 F., the portion of crude oil boiling between 250-710 F., mixtures of naphthas with kerosenes, and

fractions boiling higher than 825 F. In these stocks the presence of hydrocarbons lower than heptanes is no disadvantage. Other stocks that may be used are Fischer-Tropsch (Hz-l-COY tain normal hydrocarbons, isomers, napthanes or small amounts of hydrocarbons other than normal or unsaturated hydrocarbons. The latter may be beneficial as mentioned heretofore.

In some instances both the light and the heavier fractions to be reacted in the process may be in the form of a single fraction. For example, a stock boiling from 70 to above 400 F., or crude oil or reduced crude as such, may be used in the averaging reaction.

The presence of aromatics in the feed stocks, particularly in the heavier fraction where they are more apt to be present, is undesirable because these aromatics tend to form a complex with the catalyst and decrease its activity. For this reason it is desirable that the feed stock should contain a minimum of aromatics. While it is not essential that the stock be free from aromatics if other conditions are adjusted suitably, it will be generally preferable at least to reduce the aromatic content of the stock somewhat by a dearomatization process if the stock is high in aromatics. This may be done by any means conventional in the art, such as solvent extraction, or the fluorides may be used for dearomatizing in accordance with the process described in my Patent No. 2,343,744, granted March 7, 1944. p

The ratio of the light to the heavier fraction may vary over a relatively wide range. Generally it is preferred to have at least i mol of the lighter fraction per mol of the heavier fraction. Two to 6 mols of the light fraction per mol of the heavier fraction is the preferred range. There is no object in having present more of the lighter fraction than will reflect an improvement, since there is no point in recycling a larger excess of this fraction than can accomplish a corresponding improvement in the reaction.

The catalyst used in the process comprises hydrogen fluoride promoted with a minor proportion of boron trifluoride therein, and in some instances with an olefin. It is used preferably in the liquid phase.

Hydrogen fluoride boils at about 67 F. and is therefore a liquid at temperatures just under room temperature and may be kept liquid at higher temperatures by moderate pressures. The temperatures and pressures used in the process of the invention are conveniently those that maintain the hydrogen fluoride liquid. Boron trifluoride boils at -l50 F. and is a gas at the temperatures and pressures conveniently employed in hydrocarbon treating processes. However, boron trifluoride dissolves in liquid hydrogen fluoride to agiven extent and the amount which dissolves at any given temperature depends on the partial pressure of boron trifluoride. At higher partial pressures, a larger amount of boron trifluoride is dissolved.

The boron trifluoride in the hydrogen fluoride in the liquid phase possibly may react at least to some extent, but an understanding of the chemistry involved is not necessary to practice my invention, and I do not intend to be bound by any theory. At any event the amount of the boron trifluoride in the hydrogen fluoride, which controls the activity of the catalyst, is a function of the partial pressure of the boron trifluoride.

The amount of boron trifluoride dissolved in the hydrogen fluoride, at any given temperature, may be expressed conveniently in terms of the partial pressure of boron trifluoride. This may vary, in accordance with the invention, from 5 to 1000 Pounds per square inch; generally about 50 to 300 pounds .per square inch will be used. However, the partial pressure should under no circumstances be such that the amount of boron trifiuoride exceeds 50 mol per cent of the'fluorides' With the partial pressures usually used the amount does not exceed mol per cent. The words dissolved and solution are used as generic to both a physical admixture and a reaction product.

One of the advantages of the process of the invention is the ability to control the reaction by adjusting the activity of the catalyst through control of its composition. This may be accomplished by varying the partial pressure of the boron trifluoride, because a change in this partial pressure results in a change in the amount of boron trifiuoride dissolved. If the partial pressure of the boron trifluoride is increased, by admitting boron trifluoricle to the reaction zone from a high pressure source of supply, the activity of the catalyst is greater under conditions otherwise the same. If this partial pressure is decreased, by bleeding boron trifluoride, the ac tivity of the catalyst is reduced.

If an olefin is added, or is present in the reaction zone in an amount less than that which acts as a poison, the olefin appears to act as a promoter. The available evidence indicates that the olefin acts as ;a hydrogen acceptor and that the hydrogen fluoride-boron trifluoride solution or the reaction product may form a new compound or chemical complex with the olefin. Since olefins may be formed in the process, especially when heavier stocks are used, the addition of an olefin as a separate addcd'ingredient to the stocks may not reflect a separate improvement.

The catalyst to be used in practicing the invention, therefore, may be viewed as hydrogen fluoride promoted by a minor proportion of boron trifluoride; or it may be viewed as hydrogen fluoride promoted by both boron trifiuoride and an olefin; or a combination of both fluorides promoted by the olefin. The presence of an olefin generally gives somewhat better results.

The hydrogen fluoride and boron trifluoride may be the available commercial grades. It is not necessary to have chemically :pure fluorides. The impurities in the commercial grades, including water, which are generally present in an amount of about A; to 5 per cent, do not interfere materially with the operation of the catalyst. In view of the economic advantage of using the commercial grade, .it is preferred, and was used in the following examples. Reference to the fluorides hereinafter is intended to include such commercial grades and their normal impurities or their equivalent in composition.

The conditions under which the process is carried out are selected within convenient ranges so as to produce maximum yields. In general the temperature may vary from to 400 F., preferably from about 20 to 212 F. Averaging with kerosene as the heavier stock shows that the process can be carried out conveniently at a temperature within a range of about 32 to 150 F. It is an advantage of the process that extreme temperatures in either direction are not necessary. A single temperature may be used throughout the reaction, or it may be varied during the reaction. If the catalyst is reused a somewhat higher temperature may be desirable than is the case when the catalyst is fresher. It may be desirable, for this reason, to operate with ascending temperatures in the direction of flow.

duce a given amount of product.

This may enable a reduction in the amount of catalyst per unit of the product formed, and may also have a beneficial effectin causing some of the hydrocarbons to shift from the catalyst phase of the reaction to the hydrocarbon phase. The amount of the catalyst employed must be considered with reference to both of the fluoride ingredients comprising :it. The amount of the hydrogen fluoride may be 5 to 1300 volume per cent based on the hydrocarbons to be treated when in liquid form, preferably-the amount should be about 15 to 1.00 volume per cent. Amounts as low as 1 volume per cent may be used in a multistage treatment in which the total would be at least 5%. The use ,of larger amounts increases the rate of conversion and the yield ina given time under conditions otherwise the same. The amount used may depend. to a large extent upon the economics involved and the maximum conversion desired per pass .of the material. The total amount necessary may also be less if it is supplied in increments'during the reaction. If desired the used catalyst may be removed before the next increment is supplied. -No more-is used than is necessary to efiect the desired reaction in the desired time since to use more would only add to the amount to be recovered or regenerated. I

The amount of the boron fluoride used, as expressed in termso-f partial pressure, has been indicated heretofore in describing the composition of the catalyst.

When an olefin is added separately as an ingredient it may vary from extremely small amounts to or more mol per cent based on the amount of the boron trifluoride dissolved in the hydrogen fluoride. Expressed in practical terms, the amount of the olefin may be to based on the hydrocarbons being treated.

The total pressure .should be .sufficient to keep the hydrogen fluoride in the liquid phase, and preferably also to keep all the hydrocarbons in the liquid phase. It must, of course, exceed the partial pressure of the boron trifluoride. The total pressure may vary up to 1000 pounds per square inch, such as might be obtained by the presence of an inert gas, but generally no advantage is gained (un'less hydrogen is used as .de-

scribed later) by -having a total pressure greater than the sum .of the partial pressure of the boron trifluoride and the partial pressures of the hydrogen fluoride and the hydrocarbons at the temperature utilized.

The time of contact between the pentane and other hydrocarbons and the catalyst may vary with the temperature, thoroughness of contact or mixing between the hydrocarbon and the catalyst, and other factors. Depending upon such other factors, the time should be selected to give optimum yields. This may be from 5 minutes to 3 hours, although in the higher temperature ranges and with very thorough mixing, as

might be accomplished with the best commercial mixing apparatus available, the time might be reduced to the order of a minute. In a commercial operation, it is desirable, of course, to keep the reaction time as short as possible since this decreases the size of the reactor necessary to pro- Observations indicate .that the reaction proceeds quite quickly, and readily reaches :a condition where more time does not materially alter the distribution of the products to such an extent that it .is of economic advantage to continue the reaction longer.

The .agitation may be accomplished with any an orifice under high pressure.

The temperature, composition of the catalyst,

time of contact, and other factors mentioned heretofore are more or less interdependent. The

ranges described heretofore are not intended to mean that any temperature may be used with any length of time or any composition of catalyst to obtain the identical result. For example, if a lower temperature is used, a somewhat larger amount of catalyst may be present or a somewhat higher partial pressure of boron trifluoride may be used, or the treating time may be longer, or mixing better, or any or all of them, to obtain about the same result that would be obtained with a higher temperature and with a lesser amount of catalyst, or a lower partial pressure of boron trifluoride, or with a, shorter treating time. Thus, for example, any temperature within the range may be employed and the other variables may be adjusted within their ranges so as to obtain averagingiwith pentane.

It is a particularly important part of the process that in addition to varying the time of contact, the amount of catalyst, and the temperature, which are the variables with which the prior art has had to work, it is possible, in accordance with the process to vary the composition of the catalyst by varying the partial pressure of the boron fluoride. Thus, for any given temperature, time of contact, etc., at which it is desirable to operate because of plant equipment or economic reasons, the activity of the catalyst and the rate of the pentane averaging reaction can be varied into the reaction in an amount to provide a partial pressure of hydrogen of 100 to 1000 pounds per square inch. This tends to minimize the amount of hydrocarbons entering the lower layer.

The process is adapted either for batch operation or for continuous operation. In either type of operation the feed stocks may be dried, if desired, by suitable driers. In a batch operation the pentane-containing fraction and the higher hydrocarbons are brought together with the fluorides in the desired amounts in a closed container or autoclave where they are preferably subjected to agitation and maintained under the desired temperature and pressure for the required length of time. In a continuous process the fluorides and the hydrocarbons to be treated are fed into a continuous type mixer, for example, a three-stage mixer, and maintained at the desired temperature and under the appropriate pressure. The flow through the mixer may be intermittent or continuous and may be adjusted so that the hydrocarbons are in contact with the catalyst for the desired length of time.

In either the batch of continuous operation, if an olefin is to be added as a promoter, this may be contained in either of the pentane or other 'raw materials or may be introduced separately or absorbed in the fluorides. If hydrogen is to be used, thismay' be introduced from a separate high pressure source of the supply.

The order of mixing the components is not critical. The pentane-containing fraction and heavier hydrocarbons may be fed separately or .mixed and introduced into the fluorides or vice versa. Alternatively the pentane-containing component may be mixed with the fluorides and this mixture fed gradually to the heavier hydrocarbons or vice versa in one or more stages. In

I either a batch or continuous process, the fluorides may be introduced in increments at different intervals during the total reaction period. When using a continuous mixer having a plurality of stages, the fluorides may be introduced at each stage. The operation may be countercurrent or concurrent.

In a multiple treatment process the first treatment with the catalyst may be largely or in part one of dearomatizing, and subsequent treatments may be responsible for the major portion of the pentane averaging reaction. Although the catalyst may be reduced in activity during the averaging reaction so as to render it ineffective for further reacting pentane, it may still be used to dearomatize and the. dearomatization of the heavier fraction feed stock with the used catalyst from the pentane averaging reaction is an important aspect of the invention. This could be accomplished, for example, in a two-stage countercurrent treatment. The catalyst containing the aromatics may then be subjected to a regenerating action in accordance with any of the processes indicated heretofore, and the fluorides returned to the averaging zone.

The following examples are given merely as illustrative of the results that may be accomplished when the invention is practiced on a laboratory scale. This may be transferred to a commercial basis with the incident improvements as described heretofore.

Example 1 An Illinois kerosene, containing 16% aromatics was used as the heavier stock for averaging with a pentane fraction. Five per cent of the kerosene boiled below 360 F. and 50% below 425 F.; the end point was 551 F. The process was carried out in a two stage treatment. In the first stage the kerosene was treated with 15 volume per cent of liquid hydrogen fluoride (based on the volume of the kerosene) in which boron trifluoride was dissolved in an amount to provide a partial pressure of 150 pounds per square inch. The reaction was continued for 15 minutes at F. by agitating the kerosene and the catalyst. After the kerosene and the catalyst have been mixed under the above conditions for the stated time, the agitation was discontinued and the catalyst phase and the hydrocarbon phase, being mutually insoluble in each other, was separated by gravity. If desired, forces greater than gravity, such as centrifuging, could be used in effecting the separation. The lighter or upper layer contains the hydrocarbons and the lower layer comprises the catalyst phase. This separating operation was carried out under the pressure used in effecting the reaction.

7 The upper layer and 400 volume per cent of a pentane fraction was placed in the second stage reaction vessel in the presence of volume per cent of liquid hydrogen fluoride (based on the volume of the kerosene) in which boron trifluoride was dissolved in an amount to provide a partial pressure of 150 pounds per square inch under the reaction conditions. The mixture .is agitated at a temperature of 90 F. for a pe- Hydrocarbons produced (weight per cent of the total hydrocarbons charged) Hydrocarbons charged (weight per cent) Hydrocarbon Propane and lighter Hydrocarbons in catalyst phase -I:

From the above reaction it will be seen that there is a net production of 14.3% boiling within the range of hexane to 300 F. There is a si nificant consumption of kerosene and a large consumption of the pentane fraction, particularly anet consumption of the normal pentane to result in these valuable intermediate boiling hydrocarbons.

The fraction boiling above 300 F. comprising 21.8% can be recycled to the reaction zone as well as the pentanes and butanes, if desired. Since this stock is substantially aromatic free there would be less lower layer hydrocarbon in such a continuous process.

If desired, the fraction boiling from isopentane to 300 F. may be separated. This amounts to 39% of the hydrocarbons charged and is a good grade of gasoline in View of the small amount of normal pentane. The butane fraction may be used in alkylating or may be recycled to the reaction zone and mixedwith the fresh charge of pentanes.

The consumption of kerosene is not as large as in thefollowing examples, but the process is a desirable one in making a hexane to 300 F. gasoline from pentanes. The incidental isobutane formation is desirable since it is a valuable intermediate product.

Example 2 If the entire butane-pentanes fraction from Example 1 is to be recycled or if the butanes are to be recycled with the addition of a fresh charge of pentane, the results that may be obtained are indicated in this example, in which a mixture of butanes and pentanes (approximating the butanes-pentanes fraction from Example 1) is used as the light stock. This light fraction, in an amount of 400 volume per cent (based on the kerosene) is averaged with a kerosene, with the same catalyst and in the same amount, and for the same length of time as in Example 1. The kerosene used contains about 6% aromatics, about of the total hydrocarbons boiling be- 10 low 300F. and about 31% boiling below 400 F. The results are as follows:

Hydrocarbons probHydil locar-d ducgcti in g ons c arge weig 11er- Hydl ocmbon (weight percent of the cent) total hydrocarbons charged) Propane and lighter 0 0. l Isobutane 35. 9 42. 3 Normal butane 4. 9 9. 3 Isopentane 25. 6 l5. 5 Normal pentane.. 8.0 3. 3 Hexane to 300 F l. 2 15.0 300 to 400 F 7.9 2. 4 Above 400 F l6. 5 8. 2 Hydrocarbons in catalyst phase. 3. 9

It will be seen that there is a net production of hydrocarbons boiling in the hexane to 300 F. range and a substantial net consumption of the kerosene and a net consumption of the pentane fraction, particularly of the normal pentane. While there is an increase in the amount of butanes from 40.8%. to 51.6%, this increase is less than the amount of the heavier fraction and the lighter fraction consumed, indicating the the accomplishment of averaging.

By extrapolation ofthe data from the above two examples, and by further research, it has been ascertained thatupon recycling the entire lighter fraction the amount of butanes may be expected to increase until they represent about 80% of the lighter fraction. At this stage there will be a net consumption of both the butanes and the pentanes in the averaging.

The above examples are given merely as illustrative of the results that may be accomplished and not as a limitation upon the scope of the invention as described heretofore.

In the above examples the upper layer comprising the hydrocarbons may be sent to a primary fractionating column and the excess of lighter fraction and any fluorides dissolved in the upper phase may be separated at the top of the column and recycled to the reaction zone. Since an excess of the lighter fraction in the reaction zone is preferable, a part of the feed for for the reaction in a continuous process may comprise the recycled lighter fraction and fresh pentane feed. The amount of the fresh feed stock need be only equal to that which is consumed in the averaging reaction and itmay be all normal pentane.

During the averaging process the normal pentane fed into the averaging reaction zone may become at least partially isomerized and also converted to butanes as shown in the examples. The lighter components that are taken from the top of the primary fractionating' column may be further fractionated in one or more secondary fractionating columns to separate a portion or all of the isobutane for use in other processes, such as alkylation, and the remainder of the excess of the lighter fraction may be returned to the averaging zonep When the alkylation is to be accomplished" with the same catalyst it isnot necessary to separate any fluorides that may distill with the isobutane. Similarly isopentane may be fractionated if it is not to be recycled or taken off in the gasoline fraction. Thus the invention contemplates the ability not only toutilize the normal pentane and convert it into a higher molecular weight hydrocarbon, but at the same time to convert normal pentane to 11 isopentane and isobutane, -a portion-of which may be withdrawn and used in other reactions.

The lighter fraction separated for recycling may be depropanized by fractional distillation, absorption, or any other fractionation or suitable method before recycling, if the propane builds up to an undesirable level.

The wanted products may be withdrawn fro intermediate plates in the primary fractionating column.

The heavier unconverted products may be withdrawn from the bottom of the column. These may or may not be recycled to the reaction zone, depending upon their character, or they may befurther fractionated and a part returned to the reaction zone.

If desired, a single product, such as isopentane or neo-hexane or a mixture boiling from about 75 to 141 F. (since only a small amount of normal pentane remains after the reaction process) may be withdrawn from the fractionating column and all of the lighter (butanes) and all of the heavier (normal hexane and heavier) materials maybe recycled to the averaging reaction zone. This will shift the conditions in the averaging reaction so as to form primarily the product being withdrawn. The pentane averaging process thus may be used essentially for making a single wanted product with the return of all other products as raw materials.

The lower layer or catalyst phase is separated from the hydrocarbons at such a temperature and pressure that the catalyst remains as a distinct liquid phase, in accordance with the preferred embodiment, the catalyst phase may be recycled and reused for the treatment of a fresh supply of raw materials or such as in the countercurrent system for dearomatizing mentioned heretofore. The used catalyst phase may also be employed in other averaging operations which require a less active catalyst. For example, the catalyst may be used initially on a stock which is diflicult to react and after separation from said stock, it may be reused with stocks that are.

easier to react. Alternatively the used catalyst phase may be used as an alkylation catalyst where a less active catalyst is required.

Certain hydrocarbons, notably unsaturates and aromatics, tend to accumulate in the catalyst phase in the form of a complex during the averaging reaction. In the above examples it will be noted that the catalyst phase contains a slight amount of hydrocarbons. A small amount of a complex with an unsaturate in the catalyst phase is thought to be helpful as a promoter, and for this reason the presence of an olefin has been indicated as desirable. But the accumulation of too much hydrocarbon in the catalyst phase exerts a poisoning effect. Therefore, if the amount of hydrocarbon in the catalyst phase is keptat the optimum value, the reaction will proceed more rapidly and less of the catalyst will be required.

To overcome this poisoning effect, a part or all of the used or reused catalyst may be withdrawn and subjected to a relatively high temperature, for example, 250-600 F. This may be by way of a pot still, or by means of flash distillation. Preferably a two-stage treatment is employed, the first stage using a flash distillation at a somewhat lower temperature, preferably at system pressure followed by distillation in a stripper at a higher temperature and lower pressure. At this temperature substantially all of the fluorides are liberated as gases These can 12 be collected and condensed and/or compressed and returned to the mixing zone or stored or otherwise used.

Alternatively, instead of distilling the fluorides, the lower layer or catalyst phase may be treated with a material which exerts a solvent action on the fluorides and which is immiscible with the hydrocarbons in the lower layer, or which forms a chemical compound or complex with the fluorides, and from which the fluorides may be released later, for example, by heating.

Fluorides can be extracted from the upper or lower layers, for example, with an oxyfluoboric acid, such as H3BF2O2 or H4BF'3O2.

The reference .to a hydrocarbon fraction is intended to refer to a pure hydrocarbon as well as a mixture of hydrocarbons.

It will be apparent that the invention is capable of many applications and variations and I intend all of them to be included as are within the following claims.

This application is a continuation-in-part of applications Ser. No. 422,744, filed December 12, 1941; Ser. No. 451,216, filed July 16, 1942, and Ser. No. 529,681, filed April 5, 1944.

I claim:

1. A process of catalytically averaging hydrocarbons which comprises reacting a normally liquid hydrocarbon fraction comprising paraflinic hydrocarbons having at least seven carbon atoms and a lighter hydrocarbon fraction comprising normal pentane, in the presence of a liquid catalyst the inorganic ingredients of which comprise essentially liquid hydrogen fluoride in which is dissolved not over 50 mol per cent of boron trifluoride, and continuing the reaction under a pressure to maintain the hydrogen fluoride liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of hydrocarbons intermediate said liquid hydrocarbon fraction and said normal pentane.

2. A process of catalytically averaging hydrocarbons, which comprises reacting a normally liquid petroleum fraction boiling higher than gasoline, and a hydrocarbon fraction comprising normal pentane, in the presence of a liquid catalyst the inorganic ingredients of which comprise essentially liquid hydrogen fluoride in which is dissolved not over 50 mol per cent of boron trifluoride, and continuing the reaction under a pressure to maintain the hydrogen'fluoride liquid and at a temperature and for a period of time while regulating the activity f the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of hydrocarbons intermediate said liquid petroleum fraction and said normal pentane.

3. A process of catalytically averaging hydrocarbons, which comprises reacting kerosene and a hydrocarbon fraction comprising normal pentane and isopentane, in the presence of a liquid catalyst the inorganic ingredients of which comprise essentially liquid hydrogen fluoride in which is dissolved not over 50 mol per cent of boron trifluoride, and continuing the reaction under a pressure to maintain the hydrogen fluoride liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifiuoride to result in a net production of hydrocarbons intermediate said kerosene and said pentanes.

4. A process of catalytically averaging hydrocarbons, which comprises reacting a normally liquid hydrocarbon fraction comprising paraffinic hydrocarbons having at least seven carbon atoms and a butanes-pentanes hydrocarbon fraction comprising normal pentane, in the presence of a liquid catalyst the inorganic ingredients of which comprise essentially liquid hydrogen fluoride in which is dissolved not over 50 mol per cent of boron trifluoride, and continuing the reaction under a pressure to maintain the hydrogen fluoride liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net consumption of said liquid hydrocarbon fraction and said normal pentane, and to produce hydrocarbons intermediate said liquid hydrocarbon fraction and said pentanes.

5. A process of catalytically averaging hydrocarbons, which comprises reacting a petroleum fraction boiling higher than gasoline and a butanes-pentanes hydrocarbon fraction comprising a normal pentane, in the presence of a liquid catalyst the inorganic ingredients of which comprise essentially liquid hydrogen fluoride in which is dissolved not over 50 mol per cent of boron trifluoride, and continuing the reaction under a pressure to maintain the hydrogen fluoride liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net consumption of said petroleum fraction and said normal pentane, and to produce hydrocarbons intermediate said petroleum fraction and said pentane.

6. A process of catalytically averaging hydrocarbons, which comprises reacting a lighter hydrocarbon fraction comprising normal pentane and a heavier hydrocarbon fraction comprising primarily hydrocarbons having at least seven carbon atoms in a reaction zone in the presence of a liquid catalyst, said catalyst comprising essentially liquid hydrogen fluoride in which is dissolved less than 50 mol per cent of boron trifluoride as the primary inorganic catalytic ingredients, and continuing the reaction under a pressure to maintain the hydrogen fluoride and the hydrocarbons liquid and at a temperature and for a period time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of hydrocarbons intermediate said normal pentane and said heavier fraction, separating the catalyst phase from the hydrocarbons, separating the fluorides from the catalyst phase, and recycling the separated fluorides to the,

reaction zone.

7. A process of catalytically averaging hydrocarbons, which comprises reacting a lighter hydrocarbon fraction comprising normal pentane and a heavier hydrocarbon fraction comprising primarily hydrocarbons having at least seven carbon atoms in a reaction zone in the presence of a liquid catalyst, said catalyst comprising essentially liquid hydrogen fluoride in which is dissolved less than 50 mol percent of boron trifluoride as the primary inorganic catalytic ingredients, and continuing the reaction under a pressure to maintain the hydrogen fluoride and the hydrocarbons liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of hydrocarbons intermediate said normal pentane and said heavier fraction, separating the catalyst phase from the hydrocarbon phase, fractionating the hydrocarbon phase and recycling at least part of the unreacted lighter hydrocarbon fraction to the reaction zone.

8. A process of catalytically averaging hydrocarbons, which comprises reacting a lighter hydrocarbon fraction comprising normal pentane and a heavier hydrocarbon fraction comprising primarily hydrocarbons having at least seven carbon atoms in a reaction zone in the presence of a liquid catalyst, said catalyst comprising essentially liquid hydrogen fluoride in which is dissolved less than 50 mol per cent of boron trifluoride as the primary inorganic catalytic ingredients, and continuing the reaction under a pressure to maintain the hydrogen fluoride and the hydrocarbons liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of isopentane and hexanes, separating the catalyst phase and the hydrocarbon phase, iractionating the hydrocarbon phase to separate a single wanted fraction boiling between isopentane and hexane isomers, and recycling at least part of the remaining heavier hydrocarbons to the reaction zone.

9. A process of catalytically averaging hydrocarbons, which comprises reacting a lighter hydrocarbon fraction comprising normal pentane and a heavier hydrocarbon fraction comprising primarily hydrocarbons having at least seven carbon atoms in the presence of a liquid catalyst, said catalyst comprising essentially liquid hydrogen fluoride in which is dissolved less than 50 mol per cent of boron trifluoride as the primary inorganic catalytic ingredients, and continuing the reaction under a pressure to maintain the hydrogen fluoride and the hydrocarbons liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net production of isobutane and hydrocarbons intermediate the pentane and said heavier fraction, separating the catalyst phase and the hydrocarbon phase, fractionating the hydrocarbon phase to separate isobutane as one fraction and said intermediate hydrocarbons as another fraction.

10. A process of catalytically averaging hydrocarbons which comprises reacting a butanespentanes hydrocarbon fraction comprising normal pentane and a petroleum fraction boiling above gasoline in a reaction zone in the presence of a liquid catalyst, said catalyst comprising essentially liquid hydrogen fluoride in which is dissolved less than 50 mol per cent of boron trifluoride as the primary inorganic catalytic ingredients, and continuing the reaction under a pressure to maintain the hydrogen fluoride and the hydrocarbons liquid and at a temperature and for a period of time while regulating the activity of the catalyst by adjusting the partial pressure of the boron trifluoride to result in a net consumption of said normal pentane and said petroleum fraction, and to produce hydrocarbons intermediate said normal pentane and said petroleum fraction, separating the catalyst phase from the hydrocarbon phase, separating fluorides from the catalyst phase and recycling the separated fluorides to the reaction zone, fractionating the hydrocarbon phase and recycling to the reaction zone at least part of the hydrocarbons lighter than said intermediate hydrocarbons.

ROBERT E. BURK.