BE440186A - - Google Patents

Description

       

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  Hydrocarbon conversion process
The present invention relates to a process for the selective treatment of hydrocarbon oils, and more particularly of crude mineral oils, with a view to the production of various gasolines as well as iso-octane.



  Its object is a process for finally obtaining a range of final products which essentially correspond to the needs of the market in terms of nature, quality and proportion, and it comprises a series of individual processing stages which are combined. in an improved and advantageous manner to achieve the desired result.



   The present invention makes it possible to obtain, from hydrocarbon oils boiling within the limits of a relatively large scale, a complete range of gasolines, aviation fuels and iso-octane of quality. and in the proportions necessary to satisfy the needs of the market, by a co-ordinated system composed of the treatments which are most suitable for the various fractions.

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 different from the initial material and for the different groups of intermediates generated during the process.



   In practice, the most favorable solution combining various stages of treatment different from the nature envisaged and ensuring an appropriate relationship between these various stages with a view to the desired result is not a simple matter of choice and, on the contrary, presents many. difficulties. The production of the required amount of isoctane, for example, requires a large amount of gas which must be generated in the system, and this gas must have a satisfactory content of isobutene, in addition to the butenes. normal, if we want to obtain the most favorable productions of iso-octane with regard to the quantity relative to the octane number.

   To obtain the gas necessary for this purpose, it is necessary to ensure a suitable relation between the degree and the nature of the treatments giving rise to the gases, on the one hand, and the quantity and nature of the materials to be cracked and reformed. , on the other hand, and this relation must at the same time ensure in an adequate manner the achievement of the desired proportions and qualities of the various gasoline fractions. In addition, appreciable amounts of the gas produced in the intermediate stages of the process cannot be used for the production of isoctane, and it is necessary that there exist between the processes applied to continue the treatment of such gas. and the remaining stages of the process such a relationship as to obtain the desired range of products,

   and a harmonious relationship between all stages of treatment.



   The present invention provides a practical solution of this kind and enables the production of the desired gasolines concurrently with a maximum of iso-octane from a hydrocarbon crude oil feed in an extremely efficient and economical manner.

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   In general, the process according to the invention resides in the combination of the cooperating processing steps which consist in catalytically cracking a hydrocarbon oil, in separating the gasoline and the resulting gases from the petroleum products. higher boiling point conversion of catalytic cracking and from each other to increase gasoline yield by subjecting at least a portion of said higher boiling point conversion products to further cracking, to separate a fraction of butane-butene with the gases resulting from the cracking of the oil during the process, to generate iso-ootenes by selective polymerization of the separated fraction of butanes-butenes,

   in separating an isoctene fraction and a residual fraction of butanes-butenes from the products of the selective polymerization and from each other, in subjecting said residual fraction of butanes-butenes to non-selective polymerization, thereby converting at least a substantial portion of the content of butenes to boiling hydrocarbons on the gasoline scale, separately collecting the residual butanes and the boiling polymers on the gasoline scale from with the products of non-selective polymerization and to produce iso-octanes by hydrogenation of said iso-octene fraction.



   In its application to the treatment of a feed of crude hydrocarbon oils, the invention mainly comprises the catalytic cracking of a gas oil fraction of the crude hydrocarbon oil, the catalytic treatment of gasoline generated in catalytic cracking, thermal reforming of the heavy gasoline fraction from crude oil concurrently with thermal cracking of recycle gas oil from catalytic cracking, polymerization of the propane fraction -propene separated from the normally gaseous hydrocarbons obtained in the

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 catalytic cracking and in the cracking and thermal reforming stage,

   the selective polymerization of the butane-butene fraction separated from the normally gaseous hydrocarbons obtained in the catalytic cracking and in the cracking and thermal reforming stage, the hydrogenation of the iso- octenes produced in the selective polymerization for the production of iso-octane, the non-selective polymerization of the residual butane-butene fraction from the selective polymerization and the hydrogenation of low-point butene polymers boiling and normally liquid from non-selective polymerization.



   The butanes obtained in the process can be used by adding them to process products which boil on the gasoline scale to impart a desired vapor pressure to such products, and the invention further provides the dehydrogenation of the butanes obtained during the process, for example the residual fraction of butanes collected from the products of the non-selective polymerization, with a view to the production of butenes suitable for use to give additional quantities of hydrocarbons of the type gasoline with a high anti-detonating power.



  Thus, the mixture of butanes-butenes resulting from the aforesaid dehydrogenation can advantageously be brought to the selective polymerization stage after having combined it with the fraction of butanes-butenes separated from the normally gaseous hydrocarbons obtained in the gas. cracking treatment or the cracking and reforming treatment of process oils.



   By "thermal cracking" and reforming "is meant here the conversion of hydrocarbon oils boiling above the range of boiling points of gasoline into hydrocarbons boiling within this range and the treatment of essenoe in order to improve its indioe

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 of octane without significantly modifying its boiling scale. By "catalytic cracking" is meant the conversion of hydrocarbons boiling above the gasoline scale and hydrocarbons boiling in this scale in the presence of catalytic materials. By "dehydrogenation" is meant the dissociation of the bonds between carbon and hydrogen for the production of olefinic hydrocarbons from paraffinic hydrocarbons.

   By “selective polymerization” is meant. Controlled interpolymerization of iso-butene and normal butenes for the production of iso-octenes, while "non-selective polymerization" refers to the polymerization of butenes in general. When the term "polymerization is not followed by the words" selective "or" non-selective ", this is understood to mean the polymerization of hydrocarbons of the propene type into normally liquid polymers.



   In a particular embodiment, a large scale boiling hydrocarbon oil, such as a crude or synthetic mineral oil, is fractionated to obtain a relatively light straight run gasoline fraction, a. heavier gasoline fraction or naphtha, one or more gas oil fractions and a distillation residue, the relatively light gasoline fraction is collected, the distillation residue is also collected or subjected to whole or part- tie to cracking in order to obtain gasoline, at least a fraction of gas oil from fractional distillation is subjected to catalytic cracking suitable for converting a significant portion of this fraction into gasoline, the products of the cracking are separated catalytic into normally gaseous products containing butenes,

   in an oatalytically cracked gasoline fraction and in a recycle gasoline, the catalytically cracked gasoline fraction is subjected to an oatalytic treatment to obtain an essentially saturated gasoline, it is subjected

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 the fraction of naphtha from fractional distillation to pyrolytic reforming and recycle gas oil from catalytic cracking to pyrolytic cracking in a combined system of cracking and pyrolytic reforming, for the production of gasoline, and products normally gaseous containing large quantities of butenes, the conversion products of the pyrolytic cracking and reforming treatment are separated into normally gaseous products, into a pyrolytic gasoline and a cracked residue,

   the pyrolytic gasoline and the cracked residue are collected, the normally gaseous products from the catalytic cracking and the pyrolytic reforming and cracking treatment are combined, the normally gaseous materials thus combined are subjected to a fractional separation to obtain a fraction. of light gas, which is essentially composed of C2 hydrocarbons and lighter gases and removed from the system, into a propane-propene fraction and a butanes-butene fraction, the propane-propene fraction is polymerized to convert a substantial portion thereof into normally liquid polymers boiling in the motor fuel scale, these polymers being collected as a process product,

   the butane-butene fraction resulting from gas separation is subjected to selective polymerization to convert substantially all of the iso-butene and a portion of the normal butenes to iso-octenes, the polymerization products from the selective polymerization in a residual fraction of butanes-butenes, in an iso-octene fraction and in a fraction of heavy polymers composed mainly of trimers of butenes, the latter fraction is collected, the residual fraction of butanes is subjected to butenes to non-selective polymerization to convert to polymers substantially all r

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 the butenes present, the products of the non-selective polymerization are separated into a fraction of butane, into a fraction of polymers of the butenes,

   mainly composed of dimers, and in a fraction of heavy polymers, mainly composed of trimers of butenes, the latter fraction is collected, the butane fraction is subjected to dehydrogenation in order to convert a substantial portion thereof into butenes, the hydrogen fraction is separated from the dehydrogenated products and the latter are returned to the selective polymerization stage, the isootene fraction from the selective polymerization stage and the butene polymer fraction are subjected from the stage of non-selective polymerization to hydrogenation to produce iso-octane and hydrogenated C4 polymers, and iso-octane and hydrogenated polymers are collected.



   In the preferred embodiment of the present invention, when treating hydrocarbon oil feeds containing normally gaseous hydrocarbons, means are also provided for separating the butane and isopentane by separating therefrom. at the same time a fraction of gasoline from straight distillation; subjecting a portion of this butane to dehydrogenation to which the residual butane fraction collected from the products of the non-selective polymerization is subjected; collecting said isopentane and another portion of butane in order to finally mix them with other gasolines or gasoline fractions so as to regulate their composition and vapor pressures;

   and to fractionate the gasoline-like product resulting from the catalytic cracking and a relatively low boiling point gasoline fraction suitable for the preparation of an aviation gasoline and into a low-boiling gasoline fraction. relative boiling

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 high and suitable for addition to other gasoline fractions obtained during the process, for example pyrolytic gasoline.



   The gasoline-type product obtained by the catalytic cracking of one or more of the diesel fractions of the feed can, if desired, be subjected to an additional catalytic treatment by its contact with a catalyst of the type used in catalytic cracking, in order to improve its nature with respect to the properties of an aviation gasoline, and gasoline constituents boiling in the boiling point scale of aviation gasoline can then be collected from the catalytically cracked and catalytically reprocessed gasoline.

   It is often advantageous to subject aviation gasoline recovered from the products of catalytic cracking to hydrogenation to convert it to a more fully saturated product, whether the catalytic cracking has been carried out in a single stage or has been. carried out in several stages.

   according to one of the procedures of the present process, the fractional distillation of the initial charge can be carried out mainly in three stages, the straight-run gasoline fraction and the lighter products being obtained in the first stage, naphtha and a or several fractions of gas oil being separated in the second stage, and the remaining portion of the charge, of higher boiling point, being subjected to a third stage of distillation, carried out in vacuum, for the separation of a vacuum distillate of the gas oil type which is fed to the catalytic burning stage, together with one or more gas oil fractions from the second distillation stage,

   the residue from vacuum distillation being rewashed as a process product.

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 However, without departing from the scope of the invention, modify the fractional distillation of the initial charge by collecting a fraction of straight-run gasoline and, where appropriate, lighter components in a first stage of distillation and then fractionating the gasoline. remainder of the feed, in a second fractional distillation stage, in a naphtha fraction, in one or more gas oil fractions and in a distillation residue, one or more of said gas oil fractions, and preferably all of them, being brought to the catalytic cracking stage, while the naphtha fraction and the distillation residue are brought to the pyrolytic cracking and reforming system,

     to which is also fed the recycle gas oil from the catalytic cracking system for further conversion.



   According to another embodiment, the present process can consist in treating a fraction of light oil, such as a fraction of gas oil the boiling points of which cover a relatively large scale to remove the asphaltic materials giving rise. to carbon, in subjecting the treated oil to catalytic cracking carried out under conditions suitable for ensuring the most favorable conversion into hydrocarbons boiling in the gasoline boiling scale, in essentially separating the products of said catalytic cracking into a normally gaseous hydrocarbon fraction, a light gasoline fraction, a heavier gasoline fraction, a fraction consisting essentially of intermediate conversion products and a liquid residue fraction, to be collected as the residue,

   to bring the intermediate conversion products back to the cracking stage * to collect said fraction of es-

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 relatively heavy gasoline, in subjecting the light gasoline fraction to an oatalytic treatment to collect therefrom a substantially saturated light gasoline fraction, in separating a fraction of butanes-butenes from the lighter gases contained in said fraction of hy - mainly gaseous hydrocarbons, these lighter gases being collected, subjecting the butane-butene fraction to selective polymerization to ensure the most favorable interpolymerization between normal butenes and isobutene in order to obtain isoctenes, essentially separating the products of the selective polymerization into a residual fraction of butanes-butenes,

   in a fraction of iso-octenes and in a fraction of heavy polymers, to collect the latter fraction, to subject the fraction of iso-octenes to a hydrogenation in order to collect iso-octane, to subject the residual fraction of butanes-butenes to a polymerization of the normal butenes to polymerize almost completely the remaining butenes, to essentially separate the products of the polymerization of the normal butenes into a residual butanes fraction, into a polymer fraction, mainly composed of the dimers of butenes, and in a fraction of heavy polymers, mainly composed of trimers of butenes and of heavier hydrocarbons, to collect the latter fraction,

   subjecting the polymer fraction to hydrogenation in order to recover a hydrogenated polymer gasoline therefrom, combining the residual fraction of butane with butane introduced from an external source and subjecting the mixture to dehydrogenation, separating the hydrogen from products of this dehydrogenation, in bringing together the products, after separation of the hydrogen, with the said fraction of butanes-butenes in order to subject it to the previous treatment.

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 dementingly. and to bring controlled quantities of this separated hydrogen to the various stages of hydrogenation mentioned above to provide them with at least a portion of the hydrogen which they require.



   As the invention mainly relates to the improved and advantageous manner in which the various stages of the process have been combined, and not to the apparatus in which the. various treatments can be carried out, the attached operating diagram is only intended to make the invention more clearly understood than would be possible if the numerous details of the various stages were represented. Generally speaking, this diagram indicates the individual stages of the process, and these stages will be described below in such a way as to bring out the most essential details.



   Figures 1 and 2 of the accompanying drawings represent the two parts of the same diagram, these figures having to be considered as extensions of one another.



   The feed or initial material to be treated, which is preferably a crude oil or a similar material composed of large-scale boiling hydrocarbons, is introduced through a pipe 1 into a separation zone 2. This zone 2 can comprise a fractionation zone in which the oil is subjected to fractional distillation yielding a light gasoline fraction, which contains the normally gaseous hydrocarbons, a heavier gasoline fraction, a gas oil fraction light, a heavier diesel fraction and a distillation residue.

   The separation zone 3 may further comprise a depropanization zone, in which the light gasoline fraction is freed from propane and the lighter normally gaseous hydrocarbons, and a debutanization zone, in which the light gasoline fraction is free. almost completely debutanized to provide a butane fraction intended to be @

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 used as we will see later. The debutanization zone can be operated so that the fraction of light gasoline which is separated therefrom has the desired vapor pressure.

   The preferred procedure, however, is to completely debut the light gasoline and to incorporate into the gasolines or blends of various gasoline fractions obtained in the process sufficient quantities of additional butane to achieve the desired vapor pressure.



   The light gas fraction, containing propane and lighter normally gaseous hydrocarbons, leaves zone 2, in the case shown, through pipe 5, to be collected and stored or to receive any other suitable destination. The fraction of light gasoline leaving zone 2 through pipe 4 is collected as a product of the process. The fraction of light gas oil, leaving zone 2 through pipe 5, can be collected in whole or in part as a product of the process. The still residue leaving zone 2 through a pipe 7 can be fed to a vacuum still zone 8 in which, by the application of a partial vacuum and the addition of heat, the still residue is obtained. separated into a fraction of gas oil and a residue proper.

   The vacuum distillation zone 8 can use a vacuum varying, for example, from 125 to 735 mm of mercury and a temperature, at the top, of the order of 3830 to 266 C The residue separated in zone 8 leaves this area through a pipe 9 and is collected as a product of the process. In the treatment of certain crude hydrocarbon oils, however, it may be preferable, in order to obtain the best results, to subject the entire distillation residue to thermal cracking in order to obtain a cracked gasoline, a residue. cracked and a gas

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 containing olefins.

   In such an embodiment of the invention, the vacuum distillation step would be omitted, and the residue from the atmospheric distillation would be directed through pipes 7 and 7 to the oraoking and thermal reforming system. 20, which will be described later.



   The heavy diesel fuel from zone 2 passes through a pipe 11 into the catalytic cracking system 1a in which it is subjected to the catalytic cracking while it is in the vapor state. The heavy direct gas oil fraction can be combined in pipe 11 with the gas oil fraction arriving in pipe 10 from the vacuum distillation stage, when this latter stage is applied, and the mixture can also contain, if desired, the mixture. fraction of direct light gas oil, instead of this latter fraction being collected separately through pipe 5, or alternatively, if desired, a portion or all of the fraction of direct light gas oil leaving zone 2 through pipe 5 can go through a pipe 6 (drawn in dotted lines because it is optional) and be joined, in pipe 11,

    with the oil distillates supplied to the catalytic cracking system 12. In addition, the oil distillates from the pipe 11 can, if desired, be combined with a light oil fraction, such as gas oil or gasoline. oil of similar characteristics, introduced from an external source.



   If desired, before subjecting all the material intended to be catalytically cracked to catalytic cracking in zone 12, it can be subjected to a treatment which removes compounds harmful to the catalyst therefrom and which also improves the properties of the oil. to such an extent that noticeably increased productions of gasoline and easily polymerizable gaseous olefins are obtained.

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 appropriate to the initial oil charge, the carbon deposition on the catalyst is significantly reduced.



   As materials having, in general, advantageous results in the above-mentioned treatment of hydrocarbon oil, there will be mentioned mineral acids, such as sulfuric, phosphoric, hydrochloric acids, acidic substances, such as acid sulphates, alkaline solutions, aqueous or not, adsorbents, such as fuller's earth. Other interesting treatments are exhaustion with the aid of solvents, treatment with halogens such as chlorine and bromine, treatment with metal oxides, such as copper oxides, and hydrogenation cata. - lytic.



   The processing materials indicated above represent only a few of the materials which may be used for the desired result, and it should therefore be understood that their enumeration does not limit the invention. known to those skilled in the art which can in fact be used without departing from the general scope of the invention.



   The production of gasoline, and more particularly of aviation fuels, by catalytic cracking involves the treatment of the catalytic cracking charge in a system which is operated continuously and which mainly comprises a vaporization zone communicating, for the purpose of operation, with two reaction vessels which contain the cracking catalyst and which are kept alternately during cracking and during regeneration.



  The duration of the cracking and regeneration cycles of the catalyst varies under the influence of many factors,

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 such as the cracking temperature, the nature of the catalyst used, the contact time, the nature of the cracking charge, this duration being able for example to vary from 10 to 60 minutes. The catalytic cracking system can include any desired number of reaction vessels. The conversion of the oil fractions supplied to system 12 can be carried out in this system by a single stage treatment or by a treatment in several separate stages.



   Among the catalysts which have given effective results in the catalytic cracking of hydrocarbon vapors, there will be mentioned pellets or granules made of a product containing silica or other siliceous and refractory materials and of compounds selected from the group : alumina, zirconium oxide, vanadium oxide and thorium oxide. In addition, alumina hydrosilicates, acid-treated bleaching earths or the like have also given beneficial results in cracking hydrocarbon vapors.



   Although the catalysts listed above are generally preferred, the invention is not limited to their application, as various other catalysts well known to those skilled in the art can be used without departing from the general scope of the invention. invention. The temperatures applied during the conversion can, for example, vary from 427 to 650 ° C and a pressure between substantially atmospheric pressure and 7 atmospheres or a higher pressure can be applied, this pressure, as well as all the pressures indicated during the description, being gauge pressures, as opposed to absolute pressures.



   Conversion products leaving the

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 zone or system 12 pass through a pipe 13 into a separation zone 14, which may include a vaporization and separation zone in which the vaporous conversion products are separated from the heavier liquid residue. In any event, zone 14 will normally include a fractionation zone in which the vaporous conversion products are fractionated in order to separate the gasoline and lower boiling constituents from the lower boiling constituents. higher boiling, the latter being condensed in the fractionation zone as a recycle fraction.

   The fractionation zone can at the same time be used to separate a heavy gasoline fraction, as an intermediate condensate, from a fractionated vapor mixture containing a light gasoline and normally gaseous hydrocarbons. In addition to the above-mentioned zones, the separation zone 14 preferably comprises a debutanization zone to which fractionated vapors are supplied, in order to separate the normally gaseous hydrocarbons from the gasoline or the light gasoline fraction. In the example shown, the fraction of catalytically cracked residue leaving zone 14 through pipe 15 is cooled and collected as process product.

   In some cases, however, it may be of interest to direct this residue from zone 14 through pipes 151 and 19 to thermal cracking and reforming system 20, as will be described later. If desired, instead of transferring the intermediate conversion products or the recycling of the catalytic cracking to the thermal cracking stage, all the intermediate conversion products passing through pipe 19 can be brought back to the catalytic cracking zone 12 through a pipe 80 opening into pipe 11 where they mix with the materials subjected to

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 treatment in zone 12.

   The catalytically cracked light gasoline and heavy gasoline fractions are withdrawn from zone 14 through pipes 16, 17, respectively, and collected as a process product through pipes 16 11 and 171, respectively.



  In some cases, particularly when all of the gas oil fractions of the initial oil of the charge are subjected to catalytic cracking, it is desirable; also isolating a fraction of gas oil coming from the products of the catalytic cracking and removing this fraction from the separation zone 14 via a pipe 191, as a product of the process.



   The catalytically cracked light gasoline fraction can be subjected to any refining suitable to improve the characteristics of this fraction with a view to its use as a feedstock for aviation fuels. This refining treatment may for example consist of contact with sulfuric acid (this contact may however appreciably decrease the final production of basic components of aviation fuels), or of hydrogenation. whose purpose is to convert the fraction of light gasoline into a more or less completely saturated product.



  The catalytically cracked heavy gasoline fraction can be finally mixed with other gasoline fractions and other gasolines generated in the process; for example, it can be mixed with the straight run light gasoline fraction from the initial separation of the feed with the gasoline of normal boiling point from the thermal cracking and reforming system 20 described below and with polymers obtained as described below using of proprene and butenes, the mixture obtained giving a motor fuel

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 extremely satisfying.



   The value of the gasoline fractions resulting from the catalytic cracking of the diesel fuel can be increased, if desired, by a new catalytic treatment of said fractions, whether in the same system 12, which is obtained by making it work alternately this system 12 as a cracking zone and as a treatment zone, or either in separate catalytic treatment zones 69 or 74, which will be described below in more detail.

   The second preferred catalytic treatment is carried out at an elevated temperature with a catalyst of the same type as that used in the catalytic cracking of gas oil and, preferably, at lower space speeds and temperatures somewhat lower than. those applied in the stage of catalytic cracking of gas oil. For example, by subjecting fractions of gas oil, under the preferred conditions, namely temperatures of approximately 455-525 C, pressures of the order of 2 to 5, 5 atmospheres and space velocities (volumetric feed rates) of about 4 to 6 volumes per hour and per volume of catalyst, in contact with a cracking catalyst of the type described above,

   and in particular with catalyst particles obtained by purifying and calcining a mixture of aluminum hydrate and silica, gasoline can be isolated from those of the products of the catalytic cracking of the gas oil which boil above and below the gasoline boiling range and then subjecting the gasoline thus isolated to a new treatment consisting of contact with the same type of catalyst under a pressure of the same order as that applied in the cracking catalytic gas oil, but at a lower temperature, between approximately 260 and 482 C, and at a lower space velocity, preferably of the order of 1 to 2 volumes per hour per hour.

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 catalyst volume.

   The resulting catalytically cracked and reprocessed gasoline can then be subjected to debutanization and then fractionated with a view to separating and separately obtaining the light and heavy gasoline fractions catalytically cracked and subjected to a second catalytic treatment.
When a hydrogenation treatment is applied, the catalytically cracked heavy gasoline fraction can be collected through pipes 17 and 171 as a process product. On the other hand, the catalytically cracked light gasoline fraction is transferred. via pipes 16 and 161 to a hydrogenation zone 74 where it is subjected to the treatment which will be described below.

   The hydrogen intended for the treatment in zone 74 can be one of the products of the dehydrogenation which will be described later and is introduced into this zone through pipes 41 and 75. The hydrogenated products leaving zone 74 pass through pipe 76. in a separation zone 77 in which the excess unused hydrogen is separated from the hydrogenated product. The hydrogenated material from zone 77 can be collected by pipe 78 and excess unused hydrogen can be collected by pipe 79 or, if desired, the excess returned to hydrogenation zone 74 by means. well known, not shown.



   The second preferred catalytic treatment can be accomplished by combining the light and heavy gasolines from zone 14 in pipe 17 and introducing the mixture into catalytic treatment zone 69 where it is treated as previously described. Conversion products leaving zone 69 are fed through a pipe 70 to a separation zone 71 in which light gasoline, preferably boiling below 150 C, is separated from the higher boiling point constituents. gasoline thus separated can be collected as a product of the process by a

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 pipe 72.

   The higher boiling constituents separated in zone 71 may, when they contain only hydrocarbons boiling in the gasoline scale, be collected as a process product through a pipe 73.



    However? if the fraction contains hydrocarbons boiling above the gasoline scale, it can be subjected to heat treatment or catalytic treatment by passing it through pipe 731 into pipe 19 where it combines with the fraction of recycling diesel.



   When desired, instead of the treatment described in the preceding paragraph, the light gasoline fraction from the catalytic cracking can be subjected to hydrogenation. This treatment tends to slightly lower the octane number of the final product, but it increases its susceptibility to lead, which makes it easy to raise the octane number to a value equal to, if not greater than, the octane number of the initial product (unhydrogenated) by the addition of relatively small amounts of tetraethyl lead.

   - In addition, the hydrogenation of the catalytically cracked light gasoline fraction greatly reduces the losses due to refining, in particular in comparison with the refining treatment with sulfuric acid, and also decreases the heating test. by the acid of the final product, which significantly increases the value of this product as an aviation fuel. The hydrogenation of the catalytically cracked light gasoline fraction can be carried out at temperatures of the order of 120 to 235 ° C. under pressures ranging, for example, from substantially atmospheric pressure to 7 atmospheres or more,

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 with the aid of catalysts of the kind described in connection with the hydrogenation carried out in zone 50, as will be described later.



   The straight-run heavy gasoline fraotion from zone 2 passes through pipe 18 and can be combined with a relatively heavy gasoline charge arriving through pipe 83 from an external source, the mixture being subjected to thermal reforming. in thermal cracking and reforming system 20. The thermal cracking and reforming treatment applied in system 20 preferably consists of converting the heavier hydrocarbon oils to boiling hydrocarbons in the gasoline scale. and further heat-treating the lighter hydrocarbons such as gasoline and naphtha, improving the octane number of these hydrocarbons without unduly changing their boiling range.



  The thermal cracking and reforming system 20 can be set up and operate in accordance with well known and commonly adopted practice in this industry. For example, without departing from the scope of the invention, it can apply the Dubbs process or any other process in in which relatively heavy oils are thermally cracked to produce a strongly anti-detonating gasoline and in which rela. Very light, for example heavy gasolines or naphtha, are converted by reforming into a strongly anti-detonating gasoline, this conversion being accompanied by the production of normally gaseous products, including butenes,

   The preferred treatment performed in system 20 is to thermally crack the recycle gas oil fraction in a heating coil and a reaction chamber in communication with this coil and to reform the heavy gasoline fraction in a separate heating coil.

     When we

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 intends to thermally convert an atmospheric distillation residue arriving through pipe 71 and / or a heavy oil feed arriving through pipe 84 and / or a liquid residue coming from the catalytic cracking system 12, it is preferable to combine these oils to the recycle gas oil fraction undergoing thermal cracking in the heavy oil cracking portion of the combined thermal cracking and reforming system 20, while the straight run heavy gasoline fraction is reformed in a heating coil light oil being part of the same system. However, if desired, both the recycle diesel fraction and the heavy gasoline fraction can be treated in the same heating coil, and in this case

   a reaction chamber may or may not be used. If separate heating coils are used, in the heating coil receiving the recycle gas oil fraction (or the mixture of this fraction with other high boiling point oils) it is possible to apply a temperature of exhaust included, for example between 454 and 538 C, with a pressure of the order of 14 to 40 atmospheres or higher, and it is possible to apply for the heating coil receiving heavy gasoline an exhaust temperature of the order from 482 to 566 C, for example and a pressure of the order of 20 to 70 atmospheres, for example.

   When the recycle gas oil fraction and the heavy gasoline fraction are processed in the same heating coil, the exhaust temperature of the heating coil may for example be between 482 and 555 ° C, using a pressure of 1 of the order of 27 to 54 atmospheres or more, for example.



   The conversion products obtained in the thermal cracking and reforming system are transferred through one or more pipes 21 to a separation zone 22, which may include a separation zone of.

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   vapors. in which a non-vaporous liquid residue is separated from the vaporous conversion products, and a fractionation zone in which the vaporous conversion products are fractionated to separate the vapors boiling in the gasoline scale from the conversion products heavier vapors, the latter being condensed in the fractionation zone as reflux condensate.

   In addition, the separation zone 22 may include a debutanization or stabilization zone, in which normally gaseous hydrocarbons are substantially removed from the fractionated vapors. The cracked residue fraction, in the example shown, is removed from separation zone 22 through pipe 23 and collected as a product of the process. However, if desired, this fraction can be subjected to further treatment, such as coking treatment or solvent stripping. The reflux condensate is returned through pipe 24 to pipe 19 as a recycle product from the thermal cracking and reforming process or, if desired, can be collected as a process product by well known means, not represented.

   The cracked and reformed gasoline passes through pipe 25 to a cooling apparatus and is collected as a process product in a storage tank.



   The normally gaseous hydrocarbons separated in zone 14 leave this zone through pipe 26 and are combined with a similar fraction which originates from zone 22 and has been withdrawn therefrom through pipe 27, the mixture being introduced into a concentration zone 28. Zone 28 may include a de-ethanization zone in which a fraction of dry gas composed essentially of normally gaseous 0: 3 and lighter hydrocarbons and hydrogen is separated from the heavier normally gaseous hydrocarbons. In addition, this zone may include an area of

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 Depropanization in which the normally gaseous, relatively heavy hydrocarbons are separated into a propane-propene fraction and a butane-butene fraction.

   The de-ethanization zone preferably comprises an absorption zone in which the heavier normally gaseous hydrocarbons are dissolved in a suitable absorption oil, the dry gas fraction remaining undissolved. When such an absorption zone is used, a rectification zone is used in which the heavier normally gaseous hydrocarbons separate from the enriched adsorber oil. Ordinarily, the depropanization treatment will include fractionation at a pressure above atmosphere and relatively high. The dry gas fraction from zone 28 passes through pipe 29 into a storage tank or is used as a source of gas. fuel in the process or in any other suitable manner.



   The propane-propene fraction from zone 28 can be transferred through a pipe 50 to a polymerization zone 31 where a substantial portion of the propane contained in this fraction is converted to normally liquid polymers or, if desired. , collected as a product of the process through pipes 30 and 301.

   The phosphoric acid catalyst, which will be described in more detail in connection with a subsequent polymerization stage, can advantageously be used in this zone. Polymerization temperatures of between 177 and 288 C can be applied, for example, with a pressure of the order of 7 to 136 atmospheres or above. The products of the polymerization carried out in zone 31 pass through a pipe 32 into a separation zone 33, in which the residual propane-propene fraction is separated from the propene polymers, this fraction being withdrawn from zone 33 by a pipe 34 and collected as a product of the process or

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 receiving any other desired destination Polymers separated in zone 33, and mainly composed of propene dimers and trimers,

   are led by pipe 35 to cooling and storage devices and are collected as a product of the process.



   The fraction of butane from zone 2, and containing iso-butane and normal butanes, passes through a pipe 36, a connection 37 of which can, if desired, withdraw a portion of this fraction intended to be used for to give the desired vapor pressure to the final distillates 0 The residual portion of the butane fraction is combined with the residual fraction of butanes-butenes produced as will be described later and, if desired, with a fraction of butane arriving from an external source through a pipe 21;

   and the mixture is subjected to dehydrogenation in zone 38 to convert a substantial portion of the normal isobutane and butanes to their corresponding olefins. Dehydrogenation is carried out in zone 38 in the presence of a mass. catalytic which, in general, may be composed of pellets or granules made of a product of alumina or other refractories and of compounds in particular oxides - elements chosen from the group consisting of the elements in the left columns of groups 4 , 5 and 6 of the periodic table.



   The dehydrogenation catalysts mentioned above are preferred by the Applicant but should not be considered as limiting the invention, since various other catalysts capable of carrying out the desired reaction and well known to those skilled in the art can be applied without depart from the general scope of the invention. Dehydrogenation temperatures of the order of 4820 to 650 ° C and dehydrogenation pressures between atmospheric pressure and about 7 atmospheres can be applied.



    @

 <Desc / Clms Page number 26>

 
The conversion products leaving the dehydrogenation zone 38, and composed essentially of hydrogen of iso and normal butenes and of iso and normal butanes, are led through a pipe 39 into a separation zone 40 in which the hydrogen separates from the products. dehydrogenated.

   The hydrogen separated in zone 40 passes respectively through pipes 41 and 42 in zones 62 and 50, to be used there as will be described later, and in zone 74, by pipes 41 and 75, to be used there. used as described above. When the quantity of hydrogen generated in the dehydrogenation stage is not sufficient for the needs of the process, additional hydrogen can be introduced into the system through a pipe which opens into the pipe 75 where it joins the separated hydrogen in zone 40.



   Dehydrogenated products from zone 40 pass through pipe 43 and are combined with the butane-butene fraction arriving from zone 28 through pipe 44, and the mixture is subjected to selective polymerization in zone 45 before conversion. all or substantially all of the iso-butene and a portion of the butenes normal to iso-octenes. A catalyst containing sulfuric acid or phosphoric acid can be used in polymerization zone 45 , and the temperature and pressure conditions applied with either of these catalysts can be controlled so as to polymerize substantially all of the isobutene and a portion of the normal butenes.

   However, sulfuric acid is more selective, as regards the polymerization of iso-butene to iso-octenes, than the phosphoric acid catalyst and, since the production obtained with sulfuric acid as catalyst - sor is approximately half that obtained with the phosphoric acid catalyst, with an increase

 <Desc / Clms Page number 27>

 ment of the octane number of 2 or 3 points only for the final hydrogenated product, this catalyst is less useful as a polymerization catalyst in this process. However, a catalyst containing sulfuric acid is particularly advantageous when it is desired to obtain a substantially pure iso-octane.

   Temperatures which may be applied with sulfuric acid as the curing agent are in the approximate range of 270-93 ° C, and preferably sufficient "superatmospheric" pressures are applied to maintain. a constant flow of acid and hydrocarbon mixture through the system.



   It is well known to those skilled in the art that, when a mixture of iso and normal butenes is polymerized in the presence of a catalyst containing phos "phoric acid, the temperature and pressure conditions can be adjusted in such a way. in effecting a substantially complete polymerization of iso-butene and a polymerization of 1 to 1.5 volumes of normal butenes per volume of iso-butene, to obtain a mixture of iso-octenes.



    It is this catalyst which is therefore preferred. The phosphoric acid catalyst is generally cons. containing a relatively inert support, such as kieselguhr, impregnated with orthophosphoric acid or pyrophosphoric acid, this mixture preferably being calcined before use. Polymerization temperatures of between about 66 and 232 and Pressures in the range of 54 to 89 atmospheres or higher can be applied when the catalyst used is the phosphoric acid catalyst.



   The polymerization products of zone 45, which are composed essentially of liquid polymers containing a high proportion of iso-octenes and a small amount of a heavier fraction, and the residual fraction of butane-butene composed mainly of

 <Desc / Clms Page number 28>

 iso and normal butanes and normal butenes, are fed through a pipe 46 to a separation zone 47. The separation zone 47 usually comprises a fractionation zone in which the iso-octene fraction and the residual butanes fraction. butenes are separated from the normally liquid polymers of higher boiling point.

   In addition, this zone may include a de-utanization zone in which the residual fraction of butanes-butenes is separated from the fraction of iso-octenes. The fraction of heavy polymers separated in zone 47 passes through a pipe.
48 in cooling and storage devices or, if desired, can be transferred to the thermal reforming and cracking stages, by means not shown, to be converted to boiling hydrocarbons in the scale of. boiling points of gasoline.



   The fraction of iso-octenes is brought via a pipe 49 to a hydrogenation zone 50 in which, using suitable catalysts and hydrogen introduced as previously described, the iso-ootenes are converted into iso-octanes.



   The hydrogenation carried out in zone 50 can be carried out in the presence of a catalyst which, in the preferred embodiment of the invention, consists of nickel deposited on relatively porous particles of a relatively inert and siliceous support. , such as kieselguhr. This catalyst can be prepared by precipitating nickel carbonate on kieselguhr, compressing the product in the form of globules, drying them and reducing them directly with hydrogen at 4000G.



  However, other hydrogenating catalysts, well known to those skilled in the art, for example the oxides of chromium, molybdenum and tungsten, can be used when desired. Temperatures ranging, for example, from 1210 to 232 ° C. and "superatmospheric" pressures of the order of 1 to 14 atmospheres or higher may be applied.

 <Desc / Clms Page number 29>

 quées in the hydrogenation treatment in zone 50.



   The hydrogenated products and the excess, unused hydrogen pass from zone 50, through pipe 51, into a separation zone 52 in which the excess unused hydrogen and the normally gaseous hydrocarbons liable to break down. which have been generated in the reaction are separated from the iso-octanes. The excess unused hydrogen which has been separated in zone 52 passes through pipe 53 into a hydrogen collecting tank or, if desired, can be brought back to zone 50 to be reused there, by well-known means not shown. The hydrogenated polymers, composed primarily of iso-octanes, are withdrawn through pipe 54 and collected as a product of the process.



   The residual butane-butene fraction separated in zone 47 and composed essentially of iso and normal butanes and normal butenes passes through pipe 55 to a normal butene polymerization zone 56 in which substantially all of the butenes are converted to normally liquid polymers. .



     Preferably, a phosphoric acid catalyst is used in zone 56, which can be prepared in the same manner as that described in connection with the polymerization carried out in zone 45. Preferably, the conditions are controlled. temperature and pressure in zone 56 so as to effect substantially complete polymerization of the butenes, which exist mainly in the form of normal butenes. Temperatures of the order of about 163 to 218 ° C. and pressures of about of the order of 20 to 65 atmospheres or higher, these advantageously being able to reach 82 atmospheres.



   Polymerization products leaving zone 56 together with unconverted normally gaseous hydrocarbons, which consist primarily of butanes

 <Desc / Clms Page number 30>

 normal and iso, are brought by a pipe 57 to a separation zone 58. This zone 58 will usually include a fractionation zone in which the heavy polymers, composed essentially of the trimers of the butenes and a small quantity of heavier polymers. , are separated from the normally liquid polymers, consisting essentially of the dimers of the butenes and of the residual fraction of butanes. In addition, this zone may include a debutanization zone in which the residual fraction of butanes is separated from the normally liquid polymers.

   The fraction of heavy polymers separated in zone 58 can be brought through a pipe 59 to a storage tank or, if desired, returned to the cracking or thermal reforming stage, by means not shown, to be converted there. hydrocarbon stage of the gasoline boiling scale. The residual fraction of butanes is transferred through a pipe 60 to pipe 36, in which it is combined with the fraction of butanes from zone 2, the mixture then being dehydrogenated in zone 38.



   The fraction of normally liquid polymers leaving zone 58 may pass through a pipe 61 into a hydrogenation zone 62, in which hydrogen which has been introduced as previously described is used, or, if desired. , is collected as a product of the process through pipes 61 and 611. The hydrogenation can be carried out in zone 62 in the presence of catalysts which are essentially of the same type as those described for hydrogenation zone 50 '. . Temperatures of the order of 121 to 232 C, for example, and pressures of the order of 10 to 17 atmospheres or higher can be applied in this zone.



   The hydrogenated products and unused hydrogen are transferred through a pipe 63 from the zone 62 to a separation zone 64 in which the excess hydrogen not '

 <Desc / Clms Page number 31>

 used is separated from the polymers of hydrogenated butenes.



  These can exit zone 64 through pipe 65 and be collected as a process product. Excess unused hydrogen can be removed through pipe 66 and either stored or, if desired, returned to the zone. 62, by means not shown, to be reused there.



     Separate hydrogenation treatments for the iso-octene fraction from the selective polymerisation and for the dimer fraction of the butenes from the non-selective polymerisation have been described above and shown schematically in the drawings, but it It is of course understood that these two hydrogenation treatments can be combined in a single operation and that the dtiso-octenes fraction can be hydrogenated after having combined it with the fraction of the dimers of the butenes under conditions included in the scales indicated below for the treatments carried out in the hydrogenation zones 50 and 62.



     If desired, a light catalytically cracked gasoline from zone 14, the iso-octane fraction from zone 52 and the hydrogenated polymer fraction from zone can be mixed together. 64, to obtain an excellent aviation fuel, and butane removed from the process, as previously described, can be added to the mixture to give it the desired vapor pressure. The heavy catalytically cracked gasoline which comes from the zone 14, the fraction of cracked and reformed gasoline that comes from zone 22,

   the fraction of the propane polymers from zone 33 and the light gasoline fraction from zone 2 can be mixed to give an excellent motor fuel. The butane removed from the process, as previously described,

 <Desc / Clms Page number 32>

 can be added to the mixture to give it the desired vapor pressure.



   An example of a particular procedure of the process, carried out by applying the preferred conditions and catalysts, is as follows: The initial feedstock or oil to be treated, which is a crude oil having a density of 0.8212 and contains approximately 3.2% by weight of butane added, is heated to a temperature of 37 ° C and subjected to fractional distillation at a pressure of 1.7 atmospheres, such that a light gasoline fraction normally containing hydrocarbons is obtained. gas and having a final boiling point of about 100 C, a heavy gasoline fraction having a final boiling point of about 245 C, a gas oil fraction and a distillation residue fraction The gasoline fraction is treated light in a depropanizer maintained under a pressure of 18.7 atmospheres,

   working at a top temperature of 29 ° C to remove propane and lighter, normally gaseous hydrocarbons. This fraction, which corresponds to approximately 0.575 of the feed, by weight, is used in the process as a heat source. The residue of the de-propanizer is introduced into a debutanizer under a pressure of 4.1 atmospheres while working at a temperature, at the top, 54 ° C. The fraction emerging from the top of the debutanizer, composed essentially of butanes and corresponding to about 4% by weight of the feed, is treated in the manner which will be described later.

   A fraction constituting approximately 0.4% by weight of the feed and composed of isopentane is removed from the debutanization zone, as an intermediate fraction, this fraction being collected through pipe 68 as a product of the process. A light gasoline with a final boiling point of 100 C and an octane number of 70 (measured by

 <Desc / Clms Page number 33>

 the motor method, which is about 8.6% by weight of the load) is collected as a product of the process.



   The still residue withdrawn from the fractional distillation zone is subjected to a second fractionation in a vacuum distillation zone maintained under a pressure of 685 mm Hg, controlling the temperature at the top of the fractionation tower so that 'a distillate is obtained with a final boiling point of approximately 400 0. A heavy residue, which is approximately 13.2% by weight of the feed, is collected from the vacuum distillation zone as a product of the process.



   The fraction of gas oil from the fractional distillation stage and the gas oil from the vacuum distillation zone are combined with a mixture of kerosene and a fraction of gas oil having an average density of approximately 0.8681 and the whole is in - produced (through a pipe 67) from an external source, in an amount representing 11.4% of the total hydrocarbon feed intended for the process. The resulting mixture is subjected to contact in vapor phase with a catalyst cracking compound essentially composed of silica, alumina and zirconium oxide, at 500 C under a pressure of 4 atmospheres and with a space velocity of 4.

   The conversion products of this catalytic cracking are transferred to a separation zone maintained under a pressure of 2.7 atmospheres, in which a non-vapor liquid residue, corresponding to approximately 5.2% by weight of the feed, is separated from the products. vaporous conversion products and collected as a product of the process. The vaporous conversion products are fractionated at substantially the same pressure as maintained in the separation zone to separate fractionated vapors having a boiling point.

 <Desc / Clms Page number 34>

 final of about 1500 from the heavier vaporous conversion products, the latter being condensed in the fractionation zone as a heavy gasoline fraction and reflux condensate.

   The fractionated vapors are subjected to cooling and condensation and the resulting distillate and gas are collected and separated. The resulting distillate is vaporized and heated to 400 G and subjected to contact with a catalyst of silica, alumina and zirconium oxide in a treatment zone at a pressure of about 7 atmospheres and with a speed. space of 1. The vapors from the catalytic treatment zone are introduced into a debutanization zone maintained at a pressure of 4 atmospheres and a top temperature of 54, to remove substantially all of the normally gaseous hydrocarbons from the gasoline.

   The gasoline collected in this treatment, which has a final boiling point of approximately 165 ° C. and an octane number of 70 and which represents approximately 9% of the weight of the feed, is one of the products of the process. Catalytically cracked heavy gasoline, which has a final boiling point of approximately 204 C and an octane number of 63 (determined by the engine method) and represents approximately 9.1% by weight of the charge, is collected of the fractionation zone as a product of the process.



   The recycle gas oil from the reflux condensate of the catalytic cracking is mixed with the heavy gasoline portion from the first-mentioned fractional distillation, and the mixture is subjected to a thermal cracking and reforming treatment at a temperature. temperature of 538 and under a pressure of 41 atmospheres. The conversion products of the thermal cracking and reforming treatment are introduced into the fractionation zone maintained at a pressure of 11.5 atmospheres in

 <Desc / Clms Page number 35>

 which fractional vapors having a final boiling point of about 2040 are separated from the heavier conversion products, the latter, which represent approximately 7.2% by weight of the feed,

   being condensed and collected from the fractionation zone as a product of the process. The fractionated vapors from the cracking and reforming treatment are introduced into a debutanization zone maintained at a pressure of 4 atmospheres and working with a temperature at the top of 54 C, with a view to separating substantially all the normally gaseous hydrocarbons from the thermally cracked and reformed gasoline, the end point of which is 204 C, this gasoline which represents about 26.8% of the weight of the feed, which has an octane number of 68, being collected as a product of the process.



   The normally gaseous hydrocarbons from the catalytic cracking and the thermal cracking and reforming treatment are introduced into an absorber maintained at a pressure of 6.8 atmospheres, in which these normally gaseous hydrocarbons are brought into contact with an absorbent oil which eliminates the hydrocarbons. normally gaseous heaviest, composed essentially of gaseous C3 and C4 hydrocarbons, a light gas fraction, composed of C2 hydrocarbons and lighter gases,

   the latter fraction being removed from the absorber and used as a heat source for the process. The enriched oil in the absorber is transferred to a rectifying tower maintained at substantially the same pressure as that of the absorber. The heavier normally gaseous hydrocarbons are separated from the absorber oil in the rectification tower $ the treated oil being returned to the absorption zone
The heavier normally gaseous hydrocarbons are introduced into a depropanization zone in the

 <Desc / Clms Page number 36>

 which prevails a pressure of 18.7 atmospheres and a temperature, at the top, of 49 C, so as to separate a fraction of propane-propene from the fraction of butanes-butenes.



   The propane-propene fraction is subjected to polymerization in the presence of a phosphoric acid catalyst at 246 ° C and a pressure of 41 atmospheres.



  The residual propane-propene fraction is separated from the propene polymers and collected, as a process product, these polymers, which represent about 1.6 by weight of the feed and have an octane number of about 82 determined by the engine process).



   The butane fraction separated as described above and the butane produced as will be described later are subjected together to dehydrogenation in the presence of an alumina-chromium oxide catalyst, at 538 C, under pressure. of 2.7 atmospheres.



  After separation of the hydrogen, the dehydrogenated products are combined with the fraction of butanes-butenes, separated as mentioned above, and the mixture is subjected to selective polymerization in the presence of a phosphoric acid catalyst, at 107 C, under a pressure of 51 atmospheres. The products of the selective polymerization are introduced into a fractionation zone in which there is a pressure of 0.34 atmosphere and a temperature at the top of 121 C, to separate the fractionated vapors composed essentially of iso-octenes and the residual fraction of butanes-butenes originating from the heaviest liquid polymers, the latter fraction being removed from the fractionation zone,

   as a product of the process. The fractionated vapors are then introduced into a debutanization zone maintained at a pressure of 4 atmospheres and which is worked at a temperature of 54 C, at the top of the tower, to separate the residual fraction of butanes-butenes from

 <Desc / Clms Page number 37>

 the iso-octene fraction. This latter fraction is subjected to hydrogenation in the presence of a nickel catalyst at 149 C and under a pressure of 17 Atmospheres ¯ and a fraction of iso-octene is collected as the product of the process. octane corresponding to approximately 3.2% by weight of the charge and having an octane number of 95 (determined by the engine method).



   The residual butane-butenes fraction resulting from the last-mentioned selective polymerization is subjected to a non-selective polymerization carried out in the presence of a catalyst based on phosphoric acid at 204 ° C. under a pressure of 34 ° C. atmospheres, to convert substantially all of the remaining butenes to normally liquid polymers. The products of the non-selective polymerization are subjected to fractionation at an "over-atmospheric" pressure of 0.34 atmospheres pbur to separate the heavy liquid polymers from the poly- Normally lighter liquids, composed essentially of the dimers of the butenes and the residual fraction of butane, and collects the heavy polymers as a product of the process.

   The normally liquid polymers containing the residual fraction of butane are introduced into a debutanization zone maintained at a pressure of 4 atmospheres and at a top temperature of 54 ° C., in order to separate the residual fraction of butane from it. usually liquid polymers. The residual butane fraction is returned to the dehydrogenation stage in order to treat it there in the manner previously described.

   The normally liquid polymers were subjected to hydrogenation in the presence of a nickel catalyst at 177 ° C. and under a pressure of 17 atmospheres, and as a product of the process, hydrogenated polymers representing about 1.4% by weight of the product were collected. load and having an octane number of approximately 85 (determined by the engine method).



   The productions indicated above correspond to a liquid weight of approximately 85.7%, the remainder being attributed mainly to gas and losses.

 <Desc / Clms Page number 38>

 
 EMI38.1
 



  Uk ", REVENDTCr.TIONS t4 Êàm4tltt" 1 -A process for manufacturing gasoline, both automotive type and aviation type, this process consisting of catalytically cracking a hydrocarbon oil, separating the gasoline and the gases generated by this catalytic cracking of the higher boiling point conversion products and each other to increase gasoline yield by subjecting at least a portion of these high boiling point products. higher boiling at additional cracking to separate a fraction of butanes-butenes from the above gases, to generate iso-octenes by selective polymerization of said fraction of butanes-butenes,

   in separating a fraction of iso-octenes and a residual fraction of butanes-butenes from the products of the selective polymerization and one from the other, in subjecting said residual fraction of butanes-butenes to a non-selective polymerization by converting at least a substantial portion of the butenes content of boiling hydrocarbons in the gasoline boiling point scale, to be collected separately the residual butanes and the polymers boiling in the gasoline scale from the products of said gasoline non-selective polymerization and to produce iso-octanes by the hydrogenation of said iso-octene fraction.



     2 -Procédé claimed in claim 1, characterized in that a light gasoline and a heavy gasoline are separated from the lightest and heaviest point products of the catalytic cracking, the heavy gasoline is collected, the gasoline is converted. 'light gasoline to a light gasoline substantially saturated by an additional catalytic treatment, the products of the non-selective polymerization are essentially separated into residual butanes, in a normal fraction.

 <Desc / Clms Page number 39>

 liquid element, which boils in the gasoline scale and is composed essentially of dimers of butenes, and in a fraction of heavy polymers, boiling essentially above said fraction of dimers of butenes,

   the heavy polymer fraction is collected and the butene dimer fraction converted by hydrogenation to a substantially saturated gasoline product.



     50-The process according to claims 1 or 2, wherein the residual butanes collected from the products of the non-selective polymerization are converted, by dehydrogenation, into a mixture mainly composed of butenes, unconverted butanes and hydrogen; and a fraction of butanes-butenes, separated from the products of this dehydrogenation, is then subjected to selective polymerization in combination with the fraction of butanes-butenes separated from the gases of the catalytic cracking.



   4 -Process according to claims 1 to 3, wherein the hydrogen gas is separated from the products of the dehydrogenation of butanes and used to hydrogenate the fraction of isoctenes from the selective polymerization, hydrogenate the normally liquid polymers, boiling in l 'gasoline scale, derived from the non-selective polymerization and, where appropriate, also hydrogenate the light gasoline of.

   oatalytic cracking, the latter hydrogenation being of the non-destructive catalytic type 5-0-Process according to claims 1 to 4, characterized in that a cracked residue of high boiling point is separated and an intermediate recycling fraction * essentially boiling below said residue and ** above the gasoline fractions. with the products of the catalytic cracking and each other and a portion of said recycling fraction, intermediate to the

 <Desc / Clms Page number 40>

 catalytic cracking stage for further conversion.



     6 -A process according to claims 1 to 5, this process consisting in subjecting a charge of hydrocarbon oils boiling essentially above the scale of the boiling points of gasoline to a catalytic cracking, by separating the conversion products obtained into normally gaseous products, in a light gasoline fraction, in a heavy gasoline fraction, in intermediate conversion products and in a catalytically cracked residue, to collect the latter residue and the heavy gasoline fraction) in subjecting the light gasoline fraction to a further catalytic treatment to convert it into a substantially saturated gasoline product, in separating a fraction of butanes-butenes from said normally gaseous products, the residual portion of the latter being collected,

   subjecting said fraction of butanes-butenes to a selective polymerization, in which iso-octenes are generated by polymerizing substantially all of the iso-butene and a portion of the normal butenes, essentially separating the iso-octenes from the residual fraction of butanes-butenes and hydrogenating said fraction to obtain iso-octanes, subjecting the residual fraction of butanes-butenes to non-selective polymerization in which substantially all of the butenes present in normally liquid polymers are polymerized, separating normally liquid polymers on the same boiling scale as gasoline with the residual fraction of butanes and all other products generated in the non-selective polymerization and hydrogenate these polymers,

   in subjecting the residual fraction of butanes to dehydrogenation in order to convert a substantial portion thereof to butenes, in separating the hydrogen from the butenes and from the unconverted butanes, in collecting the hydrogen and combining

 <Desc / Clms Page number 41>

 butenes and butanes not converted to the butanes-butenes fraction in order to treat them in the above-indicated manner.



     7 -Process according to claims 1 to 6, wherein the catalytic cracking is carried out in the presence of a catalyst made essentially of a silica product and of compounds selected from the group: alumina, zirconia oxide, vanadium oxide . thorium oxide, at temperatures of the order of 4270 to 65C C and under pressures between substantially atmospheric pressure and 7 atmospheres (at the manometer);

   the selective polymerization is carried out in the presence of a phosphoric acid catalyst at a temperature of 66 to 232 C and under a pressure of 54 to 89 atmospheres; the non-selective polymerization of butenes is carried out in the presence of a catalyst with l phosphoric acid at a temperature of 1630 to 218 C and under a pressure of 20 to 82 atmospheres; and the hydrogenation of the isoctene fraction is carried out in the presence of a nickel catalyst at 121-232 C and under a pressure of 1 to 14 atmospheres.



     80-Process according to claims 3 or 6, in which the dehydrogenation of the butanes to be dehydrogenated is carried out in the presence of a catalyst consisting essentially of a product of alumina and of compounds - preferably the oxides - of the elements. group of left columns of groups 4,5 and 6 of the periodic table at temperatures of the order of 482 -650 C and at a pressure of the order of zero (atmospheric pressure) at 7 atmospheres.



     9 '- In a process for making gasoline both of the motor type and of the aviation type, the combination of processing steps consisting of catalytically cracking a gas oil and at the same time subjecting a heavy oil and a gasoline heavy to cracking and thermal reforming treatments, respectively, to

 <Desc / Clms Page number 42>

 collect separately the gasoline generated in the catalytic cracking and the gasoline generated in the thermal cracking and reforming treatments, to separate the gases generated in the catalytic cracking and in the thermal cracking and reforming treatments in a fraction of light gas, in a fraction of propane-propene and in a fraction of butanes-butenes, to be converted into iso-octenes the fraction of butanes-butenes by selective polymerization,

   followed by non-selective polymerization of the residual butane-butene fraction from said selective polymerization, polymerizing the propane-propene fraction to obtain gasoline -polymer and hydrogenating the iso-octenes generated in the selective polymerization.



   10. A process according to claim 9, wherein a feedstock of hydrocarbon oil boiling within the limits of a large scale is fractionated into a normally gaseous hydrocarbon fraction, into a distilled light gasoline fraction. direct lation, in a heavy gasoline fraction, in one or more gas oil fractions and in a distillation residue;

   the fraction of normally gaseous hydrocarbons, the fraction of straight-run light gasoline and, where appropriate, a fraction of light gas oil are collected, as process products, at least one of the gas fractions is fed Oil, preferably a relatively heavy fraction, in the catalytic cracking stage, a substantially saturated gasoline is produced by subjecting to a catalytic treatment in addition to catalytically cracked light and heavy gasoline fractions, the distillation residue is subjected to catalytic treatment. thermal cracking at the same time that the heavy gasoline fraction of the fractional distillation is subjected to thermal reforming, the conversion products of these thermal cracking and reforming treatments are separated into products normally

 <Desc / Clms Page number 43>

 gaseous,

   a thermally produced gasoline and a cracked residue; the latter and the thermally produced gasoline being collected as products of the process, the normally gaseous products of the catalytic cracking and the thermal cracking and reforming treatments are combined, the mixture of these normally gaseous materials is fractionated in a system gas separator to obtain a fraction of light gases composed essentially of C2 hydrocarbons and lighter gases and which is collected in a fraction of propane-propene and a fraction of butanes-butenes, a substantial portion of the fraction of propane-propene, by polymerization, in hydrocarbons boiling in the scale of the boiling points of motor fuels, these hydrocarbons being collected as a product of the process,

  substantially all of the iso-butene and a portion of the normal butenes are polymerized to obtain iso-octenes by selective polymerization, the products of which are separated into a residual butane-butene fraction, into an iso-butene fraction. octenes and a heavy polymer fraction, substantially all of the butenes in the residual butane-butene fraction are subjected to a non-selective polymerization, the products of which are separated into a butanes fraction, a polymer fraction consisting essentially of dimers of butenes and a heavy polymer fraction, a substantial portion of the butanes fraction is converted into butenes by catalytic dehydrogenation, the hydrogen fraction is separated from the dehydrogenated products and these products are brought back to the stage of selective polymerization,

   and separately hydrogenating the isoctene fraction from the selective polymerization and the butene dimers from the non-selective polymerization.



   11. A process according to claim 9 or claim 10 in which a recycling fraction analogous to a

 <Desc / Clms Page number 44>

 Gas oil is separated from the catalytic cracking products and subjected to thermal cracking 12 * -A process according to claim 9 or claim 10, wherein the heavy hydrocarbons are catalytically cracked and boiling points higher than gasoline, which comprise the components of the cracked residue, are combined, after having been separated from the products of the catalytic cracking, with the residue of the fractional distillation, the mixture of heavy oils then being subjected to thermal cracking.



     13 -Procédé according to any one of claims 9 to 11, characterized in that the products of the catalytic cracking are separated into normally gaseous products, into light and heavy gasoline fractions catalytically cracked, into light and heavy gas oil fractions catalytically cracked and to a catalytically cracked residue, the catalytically cracked light gas oil fraction and residue are collected as process products and only the catalytically cracked heavy gas oil fraction is transferred from the catalytic cracking stage. at the thermal cracking stage
14 -Process according to claim 10, in which the fraction of normally gaseous hydrocarbons from the fractional distillation stage is separated into a fraction of light gases,

   composed essentially of C3 and lighter gases, which is collected as a product of the process, and in a fraction of butanes, a portion of the fraction of butanes is subjected, combined with the fraction of residual butanes collected from the products of the polymerization. - Non-selective sation of butanes, to dehydrogenation and another portion of said fraction of butanes is collected as a product of the process.



   15 - Method according to any one of claims

 <Desc / Clms Page number 45>

 10 to 14, wherein the catalytic cracking is carried out in the presence of a catalyst consisting essentially of a product of silica and compounds selected from the group of alumina, zirconium oxide, vanadium oxide and thorium oxide, at temperatures of 1 'of the order of 427 to 650 C and at pressures between zero (atmospheric pressure) and 7 atmospheres; the thermal cracking is carried out between 454 and 538 C and under a pressure greater than 14 atmospheres; the thermal reforming is carried out at 482 -566 C and under a pressure greater than 20 atmospheres;

   the polymerization of the propane-propene fraction is carried out in the presence of a phosphoric acid catalyst at 177 -288 ° C. and under a pressure of 7 to 136 atmospheres; the selective polymerization is carried out in the presence of a phosphoric acid catalyst. at 66-232 C and at a pressure of 54 to 89 atmospheres; the non-selective polymerization of the butenes is carried out, in the presence of a phosphoric acid catalyst, at 163-218 C and under a pressure of 20 to 82 atmospheres; hydrogenation of
 EMI45.1
 fraction of iso-ootenes is carried out in the presence of a nickel catalyst * at 121-232 C and under a pressure of 1 to 14 atmospheres;

   the hydrogenation of the normal butene polymers is carried out in the presence of a nickel catalyst at 121-232 C, under a pressure of 10 to 17 atmospheres; and the dehydrogenation of the butanes fraction is carried out, in the presence of a catalyst consisting essentially of a product of alumina and preferably composed of the oxides - elements of the left columns of groups 4,5 and 6 of the Periodic Table, at temperatures on the order of 4820 to 650 ° C and at a pressure approximately between atmospheric pressure and 7 atmospheres.



     160-Method according to any one of the claims

 <Desc / Clms Page number 46>

 1 to 15, wherein the fraction of butanes from the non-selective polymerization stage is mixed with butane from another source prior to its dehydrogenation.



   17 - In a process for manufacturing gasoline both of the motor type and of the aviation type, the combination of the processing steps consisting in essentially separating a hydrocarbon oil whose boiling points open a relatively temperature scale. broad into a normally gaseous hydrocarbon fraction, in light and heavy direct gasoline fractions, in light and heavy gas oil fractions and in a distillation residue, to collect said normally gaseous hydrocarbon fraction, said light direct fraction and said fraction of light gas oil, subjecting the fraction of heavy gas oil to catalytic cracking to convert a substantial portion thereof into gasoline, separating the products of the catalytic cracking into normally gaseous products, into fractions of light gasoline and heavy catalytically cracked,

   into intermediate conversion products and into a catalytically cracked residue, to collect the normally gaseous products and the catalytically cracked heavy gasoline fraction and to subject the latter fraction to an additional oatalytic treatment to obtain a substantially saturated gasoline therefrom, to combine the residue catalytically cracked and intermediate conversion products to the distillation residue and subjecting the mixture to thermal cracking concurrently with which the direct heavy gasoline fraction is subjected to thermal reforming, separating the products of thermal cracking and thermal reforming into products normally gaseous, into a thermally obtained gasoline and a thermally obtained cracked residue and to separate and collect these three products as products of the process.

   

 <Desc / Clms Page number 47>

 



     18 -Procédé according to any one of claims 1 to 17, characterized in that the gasoline or gasoline fraction ingests resulting from the conversion of oil boiling point higher than that of gasoline in the catalytic cracking is subjected to hydrogenation in the presence of a nickel catalyst at temperatures of the order of 1200 to 235 0 and at a pressure of approximately between atmospheric pressure and 7 atmospheres
19 -Process according to any one of claims 1 to 17, wherein the gasoline resulting from the conversion of oils heavier than gasoline in catalytic cracking is subjected to an additional catalytic treatment by its contact with a catalyst of the type used in catalytic oraoking,

   this treatment being carried out at a lower temperature and a lower space speed than those applied in the catalytic cracking, said lower temperature being of the order of 260 -482 C
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 20 "! 'Method according to any one of claims 10 or 17, characterized in that a fraction of isopentane is separated from the fraction of light gasoline collected in the stage of the fractional distillation and that 'the two fractions thus obtained are then collected as products of the process * 21, -The process for converting hydrocarbons into a substance, as described, 22 - @ as new industrial products,

   motor fuels and aviation fuels obtained by practicing the process particularly described and specified.