BE596712A - - Google Patents

Description

       

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  "Improvements in hydrocarbon treatments.
The present invention relates to a combined treatment of raw materials or fractions containing mixtures of hydrocarbons, such as petroleum feedstocks, in order to provide gaseous unsaturated hydrocarbon products, especially ethylene, and species of high anti-detriment value. The invention further relates to an improved combined process for converting gasoline fractions into gasoline products.

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 Liquidated gasoline of increased average anti-knock value and lower content of low octane component contributing to gasoline volatility.

   The invention involves an improved combination of a number of processing operations, including reforming of gasoline fractions and burning of selected hydrocarbons or aliphatic hydrocarbon mixtures, to provide predominantly products. gaseous rich in olefins.



   It is known in practice that light aliphatic hydrocarbons can be converted by cracking into products which are rich in unsaturated gaseous hydrocarbons, in particular in ethylene, propylene and butadiene. Some industrial processes have been designed for the manufacture of ethylene and other gaseous olefins in this manner and for their recovery as raw materials or substantially pure petrochemicals. Installations of this kind require the use of very high temperatures for cracking and complicated systems for recovering the products, requiring intense refrigeration.



   Previously, it has been customary to employ C2 to C4 hydrocarbons as feeds for such cracking processes.



  Or has used crude petroleum fractions consisting of C5 to C7 hydrocarbons or portions thereof, either as a gasoline component or as a feedstock which was converted into gasoline components of improved quality.



   Processes for reforming gasoline fractions with a view to improving their anti-knock value are well known in the art. Such processes involve thermal reforming of gasoline fractions at temperatures on the order of 482 to 582 C and usually at pressures above atmospheric pressure, on the order of 14 to 70 kg / cm2. More recently, the reforming of gasoline fractions on catalysts having dehydrogenation or aromatization activity has been claimed. Such processes normally assume temperatures of 4500 to

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 582 C, and the conversion is usually carried out in the presence of hydrogen under pressure.

   In catalytic reforming processes, the main reaction is usually dehydrogenation of naphthenic hydrocarbons to form aromatic compounds. However, isomerization reactions, dehydrocyclization of paraffins to aromatic compounds, dehydrogenation of paraffins to form olefins, and cracking can also occur to a greater or lesser degree, depending on the catalyst used and the operating conditions involved. .



   In some industrial reforming operations, C5 and C6 hydrocarbons were removed from the feed to the reformer and re-mixed into the final gasoline product. In other industrial reforming operations, C5 and C6 hydrocarbons and sometimes C hydrocarbons have been included in the feed to the de-reforming apparatus. Although C4 to C6 aliphatic hydrocarbons tend to a very great extent to go through the reforming process unconverted, these hyarocarbons and certain isomers formed were considered to be relatively advantageous gasoline constituents.



  However, in recent years, anti-knock values. Gasolines, required to suit automobile and aircraft engines, have grown gradually, requiring increasing rigors of reforming. The rigor of reforming has been gradually increased up to! to such an extent that considerable portions of the C4 to C6 aliphatic hydrocarbons, if these were included in the reforming feed, were lost due to the concurrent hydrogen cracking, resulting in conversion of these components to gas. Unconverted C5 and C6 straight chain hydrocarbons passing into the reforming product also tended to lower its overall anti-knock value.

   The C7 hydrocarbons also had the same problems, although to a somewhat lesser degree. The presence of C5 aliphatic hydrocarbons

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C7 further tends to decrease the amount of higher octane C4 hydrocarbons that can be incorporated into gasoline within specifications for volatility. These latter objections also apply to operations in which C5 to C7 hydrocarbons are diverted from the reforming apparatus and added to the final gasoline blend.

   It has been proposed in practice to remove from the feed to the reforming apparatus the C5, 6 or 7 hydrocarbons or all of these hydrocarbons, and to subject them to a quality improvement, by operations such as Catalytic dehydrogenation, isomerization, cracking or other reactions, with a view to converting them, where possible, into improved gasoline components, which are employed in the final gasoline blends. Proposed techniques do not provide a significant improvement with respect to a decrease in volatility, due to the low octane constituents, of the total gasoline produced, and do not provide an improvement in quality or performance. elimination of the straight chain C5 to C7 content of gasoline resulting from reforming.

   In addition, the improvements in anti-knock value deriving from operations of this type often do not justify the expense involved. Furthermore, these proposed processes do not deal with or are not suitable for the manufacture of large quantities of petrochemical raw materials, such as ethylene, acetylenes and butadiene, in conjunction with the operation of. gasoline improvement.



   In a preferred embodiment, the present invention involves a process in which a mixed hydrocarbon or petroleum feedstock boiling in the gasoline boiling range is subjected to fractionation to remove therefrom. charges C4 and lighter hydrocarbons, an isopentane fraction and an aliphatic hydrocarbon fraction
C5 - C6 containing at least the majority of normal pentane and saturated aliphatic hexanes, and to provide a higher boiling gasoline fraction, for use as a reforming feed.

   This is subject to

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 suitable reforming conditions, preferably in the presence of a dehydrogenation or aromatization catalyst, to effect an oonversion to a reformed product containing gasoline of improved anti-knock value. The reformed product is subjected to fractionation to remove therefrom the C4 and lighter hydrocarbons, an isopentane fraction and a C5-C6 aliphatic hydrocarbon fraction containing at least the majority of normal pentane and saturated aliphatic hexanes, and to provide a higher boiling point reforming gasoline.



  The C5 - C6 aliphatic hydrocarbon fraction, recovered from the initial feedstock and reforming products, is cracked at elevated temperatures and controlled conditions to achieve conversion to a product rich in non-gaseous hydrocarbons. saturated. The product may also contain appreciable amounts of aromatic hydrocarbons. The cracked product is subjected to a separation operation to recover therefrom ethylene as product and a fraction rich in olefins containing mainly hydrocarbons from the range of C3 - C4 hydrocarbons (to unsaturated C3 hydrocarbons or unsaturated C4 hydrocarbons. or a mixture of cs hydrocarbons).

   The olefin-rich fraction is alkylated with an isoparaffinic material, such as isobutane, or with other alkylatable hydrocarbons boiling in the gasoline range, under conditions suitable for conversion to an alkylation product. rich in branched chain aromatic or aliphatic hydrocarbons. Alkyl gasoline of high anti-knock value is separated from this alkyl product.

   At least a substantial portion of this alkylation product is mixed with at least a substantial portion of the reforming gasoline and, preferably also but not necessarily, with at least a substantial portion of the isopentane recovered from the feedstock. initial feed and reformed product. An amount

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 Sufficient C4 hydrocarbons, preferably normal butane or isobutane, if available, is added to the mixture to provide a Reid vapor pressure (ASTM-323-56) in the range of about 0.42 at 1.12 kg / cm2.



   In some cases, gasoline resulting from thermal or catalytic cracking of petroleum fractions boiling above the feed to the reforming apparatus may be added, either to the reforming feed or to the final gasoline blend, according to the octane number required for this gasoline obtained by mixing. In addition, additional products can be recovered from the product resulting from the cracking of aliphatic C5 - C6 hydrocarbons, such as butadiene and other diolefins, propane, propylene, acetylenes, fuel gas, aromatic gasoline and a higher boiling point aromatic distillate. The aromatic essence can be added to the final gasoline blend.

   In one embodiment of the invention, C7 and heavier aliphatic hydrocarbons, preferably straight chain hydrocarbons boiling in the gasoline boiling range, can be separated from the gasoline feedstock. reforming apparatus or the product of this apparatus or both and subjected to cracking at the same time as the aliphatic hydrocarbons C5 - C6.



   In general, the present invention encompasses a combined process for making, from a low octane gasoline feedstock, a high anti-knock engine fuel, and ethylene. . In accordance with this process, at least most of the gasoline feedstock is reformed to provide a reformed product containing gasoline of improved anti-knock value.



  At least the major portion of at least one of the aliphatic hydrocarbon materials of the range of C5 to C7 hydrocarbons contained in the gasoline feedstock or in the product

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 reformed or both, is separated by distillation or some other way, and submitted. upon pyrolytic cracking at temperatures in the range of about 760 to 955 C. the separated aliphatic material may be cracked alone or together with other hydrocarbon material from other sources.

   The cracking conditions are adjusted so that the separated aliphatic material: is converted into a cracked product consisting mainly of hydrocarbons having less than 5 carbon atoms per molecule and containing significant amounts of gaseous olefins, in particular ethylene. Ethylene and, if desired, other olefins, such as butadiene and acetylenes, are separated from the cracked products as essentially pure petrochemicals.

   A gaseous feedstock free of C3 or C4 olefins or of these two olefins is also separated from the cracked product and subjected to a combined reaction in which the constituents of this gaseous feedstock form at least a significant part of the reactants, to produce a gasoline having a lower average volatility and a higher anti-knock value than the separated aliphatic hydrocarbon material.



   In another general aspect, the present invention provides certain improvements to an overall refining operation, in which mixed hydrocarbon fractions of different boiling points are subjected to a series of refining processing steps to prepare a series of products. including a series of gasoline fractions forming a refinery stock, each of which is ultimately used as a component in at least one final gasoline product, one of these refinery processing phases including reforming of a valuable gasoline feed relatively low anti-knock to form a reformed product of improved anti-knock value.

   Following this

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 aspect of the present invention, at least the majority of at least one of the aliphatic hydrocarbon materials selected from the group consisting of C5 straight chain hydrocarbons, C6 straight chain hydrocarbons, C6 branched chain hydrocarbons, C7 straight chain hydrocarbons and branched chain C7 hydrocarbons, contained in the crude fraction comprising the gasoline feed to the reforming apparatus, and also in the reforming product, are separated therefrom by distillation or some other way. Preferably, at least the normal pentane and the straight chain C6 hydrocarbons are separated.



   This material is lacquered at high temperatures to form a gaseous product rich in olefins. At least a substantial part of the resulting gaseous oleins, for example olefins
C3 and C4, is subjected to a combined operation to form a gasoline product of lower average volatility and higher anti-knock value than the separated aliphatic hydrocarbon material. The combined reaction can include alkylation of the gaseous olefins with isobutane or benzene, for example. Or, the combined reaction may comprise a polycatalytic to form a merization polymerization gasoline, or another reaction, such as hydration, to form isopropyl alcohol and tertiary butyl alcohol.

   Gasoline of high anti-knock value resulting from the combined operation is used as one of the gasoline fractions of the refinery stock. At least one and usually two or more different grades of motor gasoline are prepared by mixing together fractions of gasoline from the refinery stock, which, to some extent, may have been stored separately. Reforming gasoline is an important component of at least one of these mixed motor gasolines. The gasoline resulting from the combined operation and usually the aromatic gasoline also formed in the cracking reaction are also important components of at least one.

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 gasolines for engines.

   Preferably, significant amounts of the reforming product and the alooylation product are mixed together in at least one of the final motor gasoline blends. Usually, although not always, a compound of high tension, high anti-knock value, combustible, such as normal butane or isobutane, isopentane or C3 hydrocarbons, is added to mixtures forming gasoline for engines in quantities. sufficient to bring them to a suitable Reid vapor pressure in the range of about 0.42 to 1.12 kg / cm2.

   If desired, a fraction of isopentane which has been diverted from the reformer or isopentane from another source can also be added to one or more of the motor gasolines obtained by blending them. Gasoline fractions from refinery stock.



   The fractionation of the initial feedstock and that of the reforming apparatus products can be carried out separately. Moreover, in the preferred embodiment of the present invention, the initial feedstock and the reforming product are fractionated separately to remove C3 and lighter hydrocarbons and to give fractions boiling in the range of C4 hydrocarbons, to an ASTM end point of about 71-93 C or to an ASTM end point of about 99 C, reforming feed gasolines and heavier produced gasolines.

   The C4 light gasoline fractions at 71 -93 C thus obtained are fractionated together to recover an isopentane fraction and a light cracking feedstock formed from eliphatic hydrocarbons boiling above the isopentane but below the isopentane. C7 hydrocarbons and containing at least most of the normal pentane and saturated aliphatic hexanes of this light gasoline. In the case of the C4 fraction at 9900, the light cracking feedstock obtained by end-to-end separation

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 above isopentane and above C8 hydrocarbons.



   The invention can be better understood from the following description given with reference to the drawings.



   Figure 1 is a diagram showing a preferred arrangement for carrying out the invention.



   Figure 2 is a diagram showing in more detail a preferred embodiment of the system for cracking C5 - C6 aliphatic hydrocarbons and recovering valuable products therefrom.



   It should be taken into account that the hydrocarbon feed intended for the process of the present invention may in certain cases be derived from sources other than petroleum; it can act, for example, of mixed hydrocarbons recovered from a. roasting of shale or destructive hydrogenation of coal. The feedstock is preferably of petroleum origin, and the invention will be described in its application to such feeds, although it should therefore be understood that this is not the case. a limitation.



   Considering Figure 1, a crude petroleum raw material 10 having a wide boiling range, containing gasoline components suitable for reforming feed is subjected to fractionation in a suitable overhead separation plant, from fractional distillation and separation of tars, well known in the art; and this at 10, to remove the C3 and lighter hydrocarbons at 10b and to recover from the raw material a light gasoline fraction containing essentially all of the aliphatic C hydrocarbons. C. to C. or C. to and which is practically free of vC4 - C5, C4 to C6 or C4 to C7, and which is practically free of C3 and lighter hydrocarbons.

   The light gasoline fraction preferably confiât essentially all C4 to C6 aliphatic hydrocarbons from the raw material and is practically free of C3 hydrocarbons and more will damage, benzene and C7 hydrocarbons and heavier or more higher boil-. In that case. the fraction of light gasoline 10c will have a 10% ASTI noint

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 in the range of about 38 to 60 C and an end point in the range of about 71 to 93 C.

   It will be understood that the terms "substantially all" and "substantially free of", used previously and hereinafter with the various fractions specified, are intended to mean that the fraction mentioned contains or is free of the specified carbonaceous material. , within the usual limits of a practical industrial fractional distillation plant.



   A higher boiling point gasoline fraction 10d, substantially free of C4 to C6 and lighter hydrocarbons, is also recovered from the raw material, in the preferred embodiment of the invention, or substantially free of. C4 and lighter hydrocarbons and particular hydrocarbon or aliphatic hydrocarbons chosen for the cracking charge, in a wider application form of the invention. In addition, a fraction of virgin gas oil 10e and a fraction of residue 10f, in particular tar, are recovered from the raw material.

   All or part of the residue may be subjected to thermal viscosity cracking at elevated pressures and temperatures in 11 to produce thermal gasoline and gas oil or fuel oil suitable as feed material for a heating operation. thermal or catalytic cracking. The thermal cracking is carried out at temperatures of the order of 426 to 593 ° C., usually at pressures above atmospheric pressure, in an installation which is well known in the art and does not require description here. The products resulting from the thermal cracking unit 11 are subjected to a fractionation in 12 to give fractions of gasoline 12b-12c of cycle charge or of gas oil 12d of fuel oil 12e and tar, C3 hydrocarbons and more light being removed by 12f.

   If desired, a fraction of light gasoline 12a of similar boiling range and content as the fraction separated from the raw material, for example a fraction containing C4 to C6 hydrocarbons, and

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 boiling to an ASTM end point of about 71-93 C (as determined by ASTM distillation) can be recovered from the thermal cracking products, and this fraction can be added with the obtained similar boiling range fraction. of the crude material, a distillation system 17. A higher boiling point thermal gasoline 12b can be added in limited amounts to the final motor gasoline blend in $ 2 (this will be discussed later).

   The higher-boiling thermal gasoline is preferably reformed after 12c, either separately or with the straight-run gasoline fraction 10c of the same boiling range recovered from the raw material. .



   The virgin gas oil obtained from the raw material is subjected to catalytic cracking at temperatures of the order of 426 to 565 ° C and to pressures of the order of 0.35 to 7 kg / cm2 on a suitable catalyst in 13 to convert to catalytic gasoline 14a, C3 and larger hydrocarbons 14b and cycle charge 14c boiling in the fuel oil and heavy gas oil range. These products are recovered at 14 in a conventional conventional fractional distillation plant. Cycle feed 14c can be further cracked or distilled to provide light and heavy household fuel oils.

   Catalytic gasoline 14a can be employed as a separate motor fuel, alone or with thermal gasoline from 12, or it can be added to the final motor gasoline mixture at 25, as will be described hereinafter. Since the C4 fraction at 160-200 F of the catalytic gasoline is of relatively high anti-knock value, it is preferred to use this fraction in the final gasoline blends. However, this is not intended to exclude the possibility, in certain operations, of adding this fraction - or a fraction of boiling range and content similar to those of the fraction of light gasoline recovered from the material.

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 raw, and this to the latter for the subsequent processing described below.

   If desired, a cycle oil or diesel
12d from theimic cracking can also be subjected to catalytic cracking at 13.



   The higher boiling point straight run gasoline fraction 10d, recovered from the raw material, usually contains less than about 1% by weight of the lighter, higher boiling point aliphatic hydrocarbon separated. raw material for inclusion in the cracking feed. Thus, when the light gasoline recovered from the raw material is formed from C4 to C6 aliphatic hydrocarbons, the higher boiling point straight run gasoline fraction will usually contain less than about 10% by weight of C6 or lighter aliphatic hydrocarbons. It is subjected, in part or in whole, to reforming in order to improve its anti-knock value and other characteristics, with a view to its use in fuels for automobiles or for aircraft.

   For example, the feed to the reformer may include the entire fraction boiling above the 71-93 C (ASTM) end-point light gasoline fraction, and having an end point in the range d. about 149-210 C (ASTM distillation). Of course only part of this material can be reformed, or various portions, i.e. light and heavy portions of crude oil, can be reformed separately under different conditions. The reforming can be carried out at 15 in a standard installation and under usual processing conditions, well known in the art.



  In the less preferred embodiments of the invention, the gasoline fraction fed to the reforming apparatus may be subjected to thermal reforming at temperatures in the range of 4810 to 621 ° C and at temperatures. pressures of the order of 14 to 70 kg / cm2, to form a gasoline of increased anti-knock value.

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  The residence time at the reforming temperature is of the order of about 5 to 30 seconds. Thermal gasoline will contain considerable amounts of unsaturated hydrocarbons, as well as aromatics and unconverted paraffinic hydrocarbons.



   It is preferred in the present invention to subject the gasoline feed to the reforming apparatus to catalytic reforming on a suitable catalyst having dehydrogenation and aromatization activity, especially activity promoting aromatization of naphthenes to aromatics and. . advantageously an aromatization of paraffinic hydrocarbons to aromatics because it is known to call a dehydrocyclization reaction.

   Examples of suitable catalysts are sulphides or oxides of Group VI metals, such as molybdenum oxide, chromium oxide, tungsten or vanadium oxides, or mixtures of these oxides, on suitable supports. , such as activated alumina, bauxite or zinc aluminate. A preferred reforming catalyst consists of about 0.3 to 1.5% by weight of platinum or palladium, deposited on a support, such as alumina or a mixture of silica and alumina.

   In some cases, the catalyst may contain small amounts of a halogen or a halogen compound. In general, the catalytic reforming operation can be carried out at temperatures of the order of 454 to 565 C, preferably 468 to 538 C, at pressures of the order of 3.5 to 105 kg / cm2, preferably 7 to 49 kg / cm2, at space velocities on the order of 0.5 to 10, preferably 0.5 to 3 oil feed volumes measured as liquid at 15.5 C ) per hour per total volume of catalyst in the reforming reactor (s), and with hydrogen / hydrocarbon molar ratios of the order of 2 to 20, preferably 4 to 10.

   The reforming product is subjected to fractionation at 16 to remove hydrogen at 16a, hy-

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 C3 and lighter hydrocarbons in 16b and, in the preferred operation, a 16c light reforming fraction consisting of hydrocarbons boiling in the range of C4 hydrocarbons at an end point (ASTM) of about 71 to 93 ° C, and to provide a stabilized 16d reforming gasoline of higher boiling point.

   The 16c light reforming gasoline fraction is, in the preferred form of the invention, essentially free of C3 and lighter hydrocarbons and C7 and heavier hydrocarbons, as well as benzene, while the gasoline of 16d higher boiling reforming is essentially free of hydroca: C6 and lighter aliphatic bides. This fraction contains at least most of the normal pentane and saturated aliphatic hexanes from the reforming gasoline. Or, the light reforming fraction recovered from the reforming product may contain C4-C5 or C4-C7 aliphatic hydrocarbons.



  The ASTM end point of the reformed gasoline may be in the range of about 149 to 210 C. All or a significant portion of this 16d gasoline is added at 25 to the final motor gasoline blend. In some cases, a 16e portion of the reforming product may be employed at 26 in a mixture to form aviation gasoline.



   Light gasolines containing the aliphatic hydrocarbons removed from the sources indicated above, especially 16c light reforming gasoline from 16, for example C4 gasoline fractions at 71 - 93 C, are subjected to a further fractionation at 17 to provide a normal butane fraction 17a, butylene-isobutsne fraction 17b containing normal butane, isopentane fraction 17c and light cracking feed fraction 17d. In the preferred form of application of the invention, this latter fraction 17d may consist especially of normal pentane and saturated aliphatic hexanes.

   In this case, the normal butane fraction may contain small

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 quantities of C5 hydrocarbons and lighter hydrocarbons, mainly C3 hydrocarbons not completely removed in the previous stages of fractionation * This fraction 1? a can be removed from the system as such, or it can be added in whole or in part to the final mixture forming gasoline for 25 engines. In certain cases, the C4 fraction can be subjected to a suitable further treatment to remove any C3 hydrocarbons before addition to the gasoline-forming mixture.



  The butylene-isobutane-butane fraction 17b will, depending on the efficiency of the fractionation, contain relatively small amounts of C3 and C5 hydrocarbons. This fraction can be removed from the process, but is preferably employed as a portion of an alkylation feedstock, as will be specified later. In some operations, especially when the amount of butylene and isobutane in the feed to the distillation system is small, these materials can be included in the normal butane fraction recovered and added to the final gasoline blend.



   When the C4 light gasoline at 71-93 C is derived exclusively from a raw material plus a catalytic reforming product, the olefin content is low and the light cracking feedstock recovered at 17 is made up very largely ( 55-80% by weight) of normal pentane and saturated aliphatic hexanes, although it may in this case contain relatively small amounts of other hydrocarbons, such as cycloparaffins, aromatics and olefins, which would remain due to the practical limits of efficiency of the industrial fractional distillation plant.

   When the light thermal gasoline 12a is also fed to the distillation system at 17, the light cracking feedstock will contain certain amounts of olefinic hydrocarbons 0 -ce * As a general rule, in the preferred application form of l 'in

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 However, the light cracking feedstock shall contain not more than 10% by weight of isopentane and lower boiling point hydrocarbons and not more than 10% by weight of C7 and lower boiling point hydrocarbons superior.

   In some operations, especially when the isopentane content of the light gasoline fed to the distillation system at 17 is insufficient to justify the additional expense required for its separation, the isopentane may be included in the light feed of oracking 17d. . In the preferred form of application of the invention, the light craoking feed contains at least the majority of normal pentane and saturated aliphatic hexanes from the starting raw material or from the starting raw material. reforming apparatus and reforming product. In this case, the fraction has an ASTM end point in the range of about 71 to 93 C.

   On the other hand, when it is desired only to subject the straight chain C5 hydrocarbons to cracking, the fraction will have an ASTM end point of about 38 C or slightly higher. When it is desired to crack the normal pentane and the C6 and C7 aliphatic hydrocarbons from the feed to the reformer and the product thereof, the fraction will have an ASTM end point of about 99 C. In this case , the cracking feedstock will contain about 85 to 100% by weight of normal pentane and saturated aliphatic C6 and C7 hydrocarbons, and not more than about 15% of C8 and heavier hydrocarbons.



   In accordance with the preferred form of application of the present invention and in the more general aspect thereof, involving the provision, in a refining operation in which gasoline is subjected to reforming, of a process allowing the reduction. the overall volatility of the low octane constituents, as well as the increase in the anti-knock value of the total liquid gasoline produced, it is important

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   to remove, for the cracking, the selected low etane number aliphatic hydrocarbons, both from the feed gasoline containing feed to the reforming apparatus, and from the reformed product.

   In the broadest forms of application of the invention, the aliphatic hydrocarbon material chosen =: should consist, at least for the most part, of at least one of the materials from the group comprising: chain C5 hydrocarbons straight, especially normal pentane; aliphatic C6 hydrocarbons, especially straight chain, saturated C6 hydrocarbons; and aliphatic C7 hydrocarbons, especially straight chain, saturated C7 hydrocarbons. When only the straight chain C5 hydrocarbons are cracked, it is preferred to at least also remove the straight chain C6 hydrocarbons from the feed to the reformer and the product thereof, in order to obtain an overall value. maximum anti-knock for gasoline in refinery stock.

   In this case, the straight chain C6 hydrocarbons removed or the aliphatic C6 hydrocarbons removed can be improved by isomerization or sold separately as a component of reactor fuels.



   On the other hand, in this general aspect of the invention involve a combined method for improving a gasoline manufacturing operation with simultaneous manufacture of ethylene and other petrochemicals by pyrolytic cracking of feedstocks. Aliphatic hydrocarbons selected under specially controlled conditions, it is intended that the light cracking feedstock may be derived either from the raw material containing the gasoline feed to the reforming apparatus or from the reformed product, or both.

   However, even in this species of the invention, it is preferable to obtain the crking feedstock, the reforming product and, preferably, both the reforming product and the reforming product. the reforming device.

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   The aliphatic hydrocarbon material separated from the feedstock to the reforming apparatus and from the reformed product may be subjected to cracking, alone or in admixture with other similar hydrocarbon materials derived, for example, from processing operations. catalytic or thermal cracking of gas oils, natural essences or natural gas essences. The cracking feedstock may also include higher boiling straight chain hydrocarbons from the feed containing gasoline feed to the reformer, or from the product. thereof, or both, in addition to the aliphatic hydrocarbon material of the range of C5 to C7 hydrocarbons.



   The light cracking feedstock is subjected to an initial 18 cracking reaction at elevated temperatures, under controlled conditions to effect conversion to a cracked product rich in gaseous olefins and also containing diolefins, aromatics and. certain unconverted paraffinic hydrocarbons as well as lower boiling point paraffins. Although the cracking of the light feed can be carried out in the presence of suitable cracking catalysts, for example silica-alumina catalysts, or mixtures of cracking and dehydrogenation catalysts, it is preferred to conduct the conversion thermally. in the absence of catalysts.

   In general, thermal cracking is conducted at temperatures in the range of about 649 to 982 C or higher, preferably 7600 to 871 C, at furnace outlet pressures ranging from slightly less than atmospheric pressure up to 2 atmospheres, preferably from 1 kg / cm2 to 1.75 kg / cm2, and with periods of residence, at the reaction temperature, of the order of 0.1 to 3, from preference of
0.6 to 1.3 seconds.

   In general, the required residence period is shorter the higher the reaction temperature employed. It is preferred to add steam 18a

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 with the feed to the cracking reactor, the amount of added vapor being generally 30 to 150%, preferably 75 to 125% by weight of the hydrocarbon feed. The cracked products from the pyrolytic cracking unit are immediately cooled to a temperature below the decomposition temperature of the products by injecting a suitable coolant, such as water, into the product stream. in 29. The temperature is reduced below about
7040 to 732 C at this point.

   The temperature can be further reduced to about 371 to 4810 by passing the products through an exhaust heat boiler, not shown. The products then pass through a scrubber 19, where some impurities are removed and the temperature is further reduced. The cooling liquid injected into the scrubber can be water or another suitable liquid, such as a light virgin gas oil, a light or heavy gas oil originating from a catalytic cracking operation, or a fraction of aromatic gas oil. It will be understood that the cooling phase can be effected by other suitable means well known in the art, for example solid contact of the reactive product with cold particles of heat transfer.

   The cooled cracked product passes through a product recovery and processing system 20, which will be described in more detail with reference to Figure 2.



   A fraction of an intermediate gaseous product, rich in ethane, is recovered, along with other products, in the product recovery system. Due to the practical limitations of the fractionation plant, the ethane fraction may contain small amounts of boiling point and higher / lower boiling point hydrocarbons, and a certain amount of ethylene. The 20e ethane fraction is sent to a separate cracking system 21 to effect the conversion to ethylene.

   In reaction system 21, it is preferred to subject the ethane to a cracker.

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 thermal king at temperatures in the range 704 to 982 C, preferably 784 to 871 C, at furnace exit temperatures ranging from slightly less than atmospheric pressure up to about 2 atmospheres, preferably 1 at 1.75 kg / cm2, and with residence periods, at reaction temperatures, of about 0.2 to 3, preferably about 0.5 to 1.5 seconds. Steam 21a can be added in amounts ranging from 20 to 50 of the feed to the reaction apparatus at 21 along with the ethane fraction 20a.



   It is also possible to envisage subjecting the ethane fraction to a catalytic conversion instead of a thermal conversion to form a product rich in ethylene, and this in 21. For example, the ethane fraction can be subjected to a cracking reaction. at high temperatures on a cracking catalyst formed by silica-alumina. Or, the ethane fraction may be subjected to catalytic dehydrogenation by a suitable dehydrogenation lyser at temperatures in the range 4540 to 704 at pressures ranging from below atmospheric pressure to a few atmospheres. , and with periods of residence, at reaction temperatures, of the order of 0.5 to 6 seconds.

   Such catalytic cracking and dehydrogenation operations and the conditions and catalysts employed herein are well known in the art. As examples of suitable dehydrogenation catalysts, there may be mentioned catalysts comprising small amounts of Group VI metal oxides, such as chromium sesquioxide and molybdenum oxide, on supports, such as alumina and silica, and magnesium oxide. A: Another suitable catalyst is a mixture of vanadium and aluminum oxides. In such operations, steam or small amounts of oxygen may be added with the feed.

   It will be understood that, unless otherwise indicated, it is intended that the term "craoking", as applied to the conversion of the oraoking feedstock

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 formed by C5-C6 hydrocarbons, will include, in addition to the initial cracking phase in 18, the catalytic or thermal conversion of the intermediate ethane fraction into a product rich in ethylene, in 21.



   The reaction product stream from 21 is immediately cooled to a temperature below the decomposition temperature of the product by injecting a suitable coolant, such as water, into the product stream at 28. The product is cooled to a temperature below about 760 ° C at this point. The product stream - is further cooled by passing through an exhaust heat boiler to about 371-481 C. The product then passes to a scrubber 22 where some impurities are removed and the temperature is further lowered. The coolant at 22 may be similar to that used in scrubber 19.



  The cooled product is returned to the product recovery system 20, for the recovery of ethylene and other products, along with those formed in the initial cracking reaction 18. Unconverted ethane can be recycled. until exhaustion to the cracking system in 21. Or, the products coming from this 21, after passing through the exhaust heat boiler, can be sent to a scrubber 19 through 21b, at the same time as the products coming from 18.



   In addition to ethylene 20e, other products recovered in system 20 are: fuel gas 20b consisting mainly of methane and containing a certain amount of hydrogen, carbon monoxide and carbon dioxide; butadiene 20c; 20d aromatic essence; a 20f aromatic distillate boiling above the gasoline range (i.e., above about 1490-210 C, ASTM), and propanepropylene and butane-butylene fractions recovered separately or as a single 20g fraction. The propane-propylene fraction can be

  <Desc / Clms Page number 23>

 further fractionated to give propane and propylene as additional products.

   Aromatic gasoline 20d can contain 75 to 95% aromatic compounds and have a theoretical octane number, with 3 cm3 of tetraethyl lead @, of the order of 104. This gasoline can be treated to remove diolefins and other materials. unstable, as a result of which the theoretical octane number, with 3 cm3 of tetraethyl lead, may be in the range of 110 to 115. It will be understood that the octane numbers, referred to here, are determined according to the method of ASTM Test n D-908-55. The aromatic gasoline can be brought to a suitable end point of the order of 149 to 210 C (ASTM) and added in part or entirely to the final blends to form gasoline for engines or for aviation, respectively in 25 and 26, or partially both.

   The aromatic distillate 20f can be sold as such as a valuable petrochemical raw material, which can be treated by oiling for the recovery of pure aromatic compounds, or used as a solvent.



  In addition to the aforementioned products, there can be recovered as products, diolefins, such as propadiene, and acetylenes, such as methyl acetylene.



   Although, as reported, liquid aromatic essence and aromatic distillate can be obtained from the products of the oracking operation, the conditions for the cracking operation, when set as stated previously, are such that the cracked product consists primarily of hydrocarbons having less than 5 carbon atoms per molecule and containing significant amounts of unsaturated, normally safe, hydrocarbons. A substantial portion of the cracked product preferably consists of unsaturated, normally gaseous hydrocarbons.



   The propane-propylene and butane-butylene fractions, resulting from the cracked product, mainly contain pro-

  <Desc / Clms Page number 24>

 pylene and butylene with only small amounts of propane and normal butane, diolefins and acetylenics having been removed. The fraotions can be collected separately or together as a single 20g fraction in the system 20. When collected together or in admixture, they constitute an alkylation feed fraction. rich in olefins, suitable, consisting mainly of C3-C4 hydrocarbons but containing small amounts of C2 and C5-C6 hydrocarbons.

   In general, the olefin-rich C3-C4 fraction contains at least 70% by volume of unsaturated C3-C4 hydrocarbons. This fraction is subjected to alkylation in unit 23 with a suitable alkylatable hydrocarbon material, giving, on alkylation, an alkylation gasoline of high anti-knock value. Examples of such alkylating materials are isobutane and aromatics, or side chain aromatics boiling in the gasoline range, such as benzene. The alkylation phase results in the formation of an alkylation product rich in branched chain aromatic or aliphatic hydrocarbons, boiling mainly in the gasoline range.

   When it is desired to recover propylene as a separate product, the olefinic material subjected to alkylation may comprise C4 olefinic hydrocarbons. The alkylation unit can be of any common type well known in the art, for example sulfuric acid, aluminum chloride or hydrofluoric acid alkylation units.



  In the sulfuric acid type process, the reaction temperature is preferably in the range of 4.4 to 21 ° C and the pressure is in the range of 0.35 to 3.5 kg / cm 2. About 50 to 70% by volume of sulfuric acid is used. This acid can be from a concentration of 98 to 100% at the start of the operation up to about a concentration of 90 when it is discharged. A sufficient amount of isoparaffin hydrocarbons is added to the unit to maintain an isoparaffin hydrocarbon / olefinic hydrocarbon molecular ratio on the order of about 4 to 10,

  <Desc / Clms Page number 25>

 the unconverted isobutane being recovered and recycled to. unity.



  In the case of a hydrofluoric acid alkylation, the reaction temperature is maintained in the range of about 24 ° to 38 ° C. The isobutane 23a for the alkylation phase can be supplied completely from external sources, and in In addition to additional butylenes can be recovered from the initial light gasoline feed and light reforming gasoline in fractionation system 17. As a result, the normal isobutane-butylene-butane fraction 17b from 17b. may be part of the feed to the alkylation unit 23.



   The alkylation product obtained in unit 23 is subjected to a fractionation at 24 to remove the hydrocarbons C3 and, if desired, C4 so as to obtain an alkylation gasoline, of high anti-knock value, stabilized, having a ASTM end point in the range of about 149-210 C and a heavy alkylation product boiling over the alkylated gasoline. The alkylated gasoline 24a may be added in part or totally to the final gasoline blends for automobiles or aircraft respectively at 25 and 26, or partially to both.



  Propane 24b, butane 24c and heavy alkylation product are removed as separate products from product recovery system 24.



   Although, in the preferred form of application of the present invention, the unsaturated hydrocarbons resulting from the cracking operation are subjected to alkylation, according to the more general aspects of the invention, these unsaturated hydrocarbons can be subjected to. other suitable combined reactions, which constitute at least a substantial part of the reactants and are converted under controlled conditions to form a gasoline of lower average volatility and greater anti-knock value than that of the aliphatic hydrocarbon material separated from the streams of feed to reforming apparatus and product, as material

  <Desc / Clms Page number 26>

 supply from oraoking.

   For example, the C3-C4 ol @ - final fraction can be subjected to thermal polymerization at a temperature of 5930 to 621 C and a pressure of 4.2 to 84 kg / cm2 to form an end point polymerization gasoline of 204 C, which, after percolation through fuller's earth to remove ranges, to a theoretical octane number of the order of 89.



  Alternatively, catalytic polymerization over phosphoric acid or sulfuric acid type catalysts can be employed.



  For example, in the selective catalytic polymerization of the butylene fraction obtained from the cracked products, with sulfuric acid at 65 to 74 -100 C, with a contact period of 10 to 15 minutes, a conversion of about 85% in a polymerization gasoline containing mainly octenes. This gasoline is hydrogenated at 930C over a platinum-on-charcoal catalyst to provide gasoline with a theoretical octane number of about 99. Or, the olefinic C3 and C4 hydrocarbons, from the cracking products, can be converted. respectively in isopropyl alcohol and in tertiary butyl alcohol.

   In this way, for example, the liquid propylene combined with recycle hydrocarbons from the hydration process can be absorbed in 75% sulfuric acid (hydrocarbon / acid ratio of about 1.5). Conversion to propylene ester occurs at a temperature of about 29 C. The mixture is diluted with water to an acidic concentration of about 35%, and hydration is performed at about 93 C. From l Isopropyl alcohol is recovered by steam rectification and, on further distillation, diisopropyl ether is also recovered.

   These two compounds constitute interesting mixture components, of high anti-knock value, for motor fuels. By appropriate adjustment of the acid concentration and the temperature, the relative proportions of diisopropyl ether and isopropyl alcohol in the

  <Desc / Clms Page number 27>

 product can be changed. Or, the propylene in the cracking products can be converted to these same products by direct catalytic hydration of propylene in the presence of vapor over a tungsten oxide catalyst. Isobutylenes in the cracking products can be converted to tertiary butyl alcohol by a process similar to that described above.

   Or, isobutylenes can be converted to tertiary butyl acetate by suitable combination reactions well known in the art. Tertiary butyl acetate is a valuable blending component for leaded gasolines when used in small quantities. For example, when 0.75% by volume of tertiary butyl acetate is added to an oatalytic reforming product having a theoretical octane number of 105 with 3 ml of tetraethyl lead, the theoretical octane number is increased. about 1.5.

   The theoretical octane number of the mixture, for diisopropyl ether, isopropyl alcohol and tertiary butyl alcohol, when mixed in an amount of 10% by volume , with a catalytic reforming gasoline of theoretical octane number of 100 (with 3 ml of tetraethyl lead), was 120.7, 113.7 and 111.7, respectively.

   According to one aspect of the invention, unsaturated C2 hydrocarbons can also be subjected to the combined operation, as can C3-C4 hydrocarbons. It will be understood that the term "combined reaction", as used herein, is intended to cover any reaction in which the specified unsaturated hydrocarbon feedstock is subjected to conversion, in one or more phases, either alone or. with suitable added reactants, to form a normally liquid, higher boiling point product boiling in the gasoline range and having a high anti-knock value, and a composition particularly suitable for use as a gasoline. mixture component in motor gasolines, of high anti-knock value.

   The foregoing expression is intended to encompass any-

  <Desc / Clms Page number 28>

 any of the various processes mentioned above, including alkylation.



   It will be understood that the exact sequence of distillation by which the light cracking feedstock is isolated from the raw material containing the feed to the reforming apparatus and from the reforming product may differ somewhat. of that described above. For example, the raw material containing the gasoline feed to the reformer can be subjected to one or more ming / separation operations to remove C3 and lighter hydrocarbons therefrom and to provide a feed of the reformer. gasoline for the reforming machine. Likewise, the reforming product may be separately subjected to one or more separation operations to remove C3 and lighter hydrocarbons and to provide a stabilized reformed gasoline.

   The aliphatic hydrocarbon (s) chosen for cracking can be removed from the raw material containing the feed to the reforming apparatus or from the reforming product or both in one of the separation operations mentioned above. -before. C4 hydrocarbons can also be removed separately from the raw material containing the feed to the reformer or from the reforming product, preferably both, during the aforementioned separation operations.

   Likewise, the aliphatic cracking feed material can be separated from the first manner containing the gasoline feed to the reforming apparatus and the reformed product, by means other than distillation alone. , for example an extra% ion by solvent or the use of molecular sieves, or a combination of these two methods with distillation. Such methods of separation are well known in the art.



   Although, in most operations according to the present invention, the cracking feedstock consists substantially entirely of boiling hydrocarbon material.

  <Desc / Clms Page number 29>

 in the range of C5 to C7 hydrocarbons, it is intended that, in certain cases, a hydrocarbon material boiling outside this range may also be subjected to cracking, in admixture with the C5 to C7 hydrocarbons. For example, virtually all of the straight chain C5 and heavier hydrocarbons can be removed from the gasoline feed to the reformer or from the reforming product or both, and used as the cracking feedstock. .

   This separation can be carried out by means of solvent extraction or, by use of molecular sieves, such as natural chabazite, selective synthetic zeolite or selective alumina silicate.



  For example, a straight run naphtha of the end point range C5 to 1930C can be contacted in vapor phase: at about 232 C with calcium alumina silicate ') - ;. granular, formed of porous crystals having pore diameters of about 5 Angstroms. The adsorbent acts to selectively adsorb virtually all straight chain, normally liquid hydrocarbons, i.e., C5 and heavier hydrocarbons, in gasoline. The straight chain hydrocarbons are removed from the adsorbent at 288 * 0 with steam.

   The fully straight chain hydrocarbon fraction is employed as a pyrolytic cracking feedstock, while the remaining gasoline not adsorbed by the molecular sieve is reformed to improve its anti-knock value.



   It will be noted that FIG. 1 represents a general diagram relating to a complete refining operation, carried out on a crude petroleum or on a crude petroleum fraction. The crude fraction entering at 10 is converted by a series of processing steps including fractional distillation, thermal cracking and catalytic cracking of components heavier than gasoline, and catalytic reforming of straight-run gasoline components. , with or without cracked essences, on

  <Desc / Clms Page number 30>

 catalysts of the aromatization type. A number of products result from this, such as light C3 and higher hydrocarbons turning into fuel gas, normal butane, thermal and catalytic gas oils and fuel oils, tar and a variety of gas fractions. gasoline.

   All of these gasoline fractions, derived from any or all of the reactions of catalytic cracking, thermal cracking, reforming, isomerization, alkylation, gas polymerization and other reactions form of gasoline, as well as isopentane, hydrocarbons
C4 and other tension compounds of high antiknock value will supplement what is known as a pool or aggregate store of refinery gasolines. Relatively small amounts of straight run gasoline or absorber gasoline recovered from refinery gas streams may constitute one or more of the gasoline fractions in refinery inventory.

   Although for simplicity the various gasoline streams are shown in Figure 1 as passing directly to a mixture forming motor or aviation gasoline at 25 and 26 respectively, it will be understood that the various components forming the refinery gasoline stock may be stored separately or partially mixed together, prior to blending to give end gasoline products. Instead of two blends of gasoline, the refinery can prepare several blends from the components of the gasoline stock. For example, two or more engine gasolines of different octane ratings and possibly different boiling ranges can be combined.

   In addition, the refinery can provide for the blending of aviation fuels with a higher anti-knock value and an even different boiling range.



   Although, according to the present invention, it is preferred to remove from the system the ethylene formed in the cracking operation, in the form of a product, according to a general aspect of the invention.

  <Desc / Clms Page number 31>

 a large part of the ethylene can also be converted into gasoline of high anti-knock value by a suitable combined reaction. This ability to use ethylene in the manufacture of another valuable product, during periods when demand for ethylene is low in the market, is a remarkable feature of the combined manufacturing process of ethylene and ethylene. essence of the present invention.



   In general, the most suitable vapor pressure for motor gasoline varies, with climatic and seasonal conditions, within the range of 0.42 to 1.12 kg / cm2 of Reid vapor pressure. For example, at altitudes substantially at sea level, vapor pressures found satisfactory for common automobiles during the summer months range from about 0.42 to 0.7 kg / cm2, while , last the winter months, vapor pressures in the range of 0.7 to 1.12 'are satisfactory. It has been found that, during the summer months, the factor which usually limits the maximum allowable Reid vapor pressure is the vapor buffer or vapor-lock forming in gasoline dispensing pumps and in automobiles.



  The colder seasons last, the limiting factor is usually the problem of ice formation in automotive carburetors. Ice formation or icing in a carburetor can be encountered during relatively cold periods when humidity is relatively high and when gasoline has high volatility. It has been found that, under other equal conditions, the difficulties due to icing in the carburetors increase with increasing Reid vapor pressure, as well as with decreasing average boiling point of gasoline.

   As straight chain C5 and C6 hydrocarbons contribute somewhat to gasoline volatility, their removal from the final gasoline-forming mixture allows incorporation.

  <Desc / Clms Page number 32>

 higher amounts of C4 hydrocarbons for the same final Reid vapor voltage. In addition, since the removal of straight chain hydrocarbons from the final blend results in an increase in the ASTM mean boiling point of gasoline, it has been found that a higher Reid vapor pressure and hence , even larger amounts of C4 hydrocarbons can be used at least during the non-summer months, without increasing carburetor icing tendencies.

   In addition, during the summer months, the overall volatility characteristics of gasoline are improved.



   Although, as previously reported, isopentane can be included in the light gasoline cracking feedstock, it is preferred, due to the relatively high anti-knock value of l. isopentane, add this material to at least one of the final gasoline blends. In the case of an aviation gasoline mixture, isopentane is employed to the exclusion of C4 hydrocarbons in order to provide the desired Reid vapor voltage. In some cases, it may be necessary to feed additional isopentane from an external source to provide the vapor pressure required for aviation gasoline.



   It is intended to use materials other than buta gasoline as tension materials for the forming mixtures. In general, the tension material employed in accordance with the process of the present invention should be a volatile combustible material having a substantially greater anti-knock value than that of the straight chain hydrocarbon material which is stripped from the raw material comprising. the supply of gasoline to the reforming apparatus and of the reforming product, for cracking. As examples of suitable tensioning materials other than normal butane and isobutane and other than C4 hydrocarbons, there may be mentioned C3 hydrocarbons, especially propanes, and isopentane.

   Although it is usually desirable to put under

  <Desc / Clms Page number 33>

 voltage for most motor gasolines, this is not always the case, as noted above. The present invention is therefore not considered to be limited to the use of additions of tension materials to the final gasoline blends.



   The type of cracking reaction involved in the process of the present invention and the products derived therefrom are illustrated in the following examples, in which two light cracking charges are subjected to pyrolytic cracking at a maximum furnace tube temperature of approximately 79300 (tube outlet), at a pressure of 1.4 kg / cm2, at a vapor / hydrocarbon ratio of 1/1 and with a residence time in the cracking zone of the order mentioned above. Light gasoline feed A has an API gravity of 78, and an initial boiling point, 10% point and final point (ASTI-1) of 42, 50.5 and 85 C.

   Light gasoline feed B has an API gravity of 75.3 and an initial boiling point, a point for 10% and an end point (ASTM) of 54.4, 62.75 and 112, 75 C, respectively. The compositions of these light gasoline feedstocks are given in Table I.

  <Desc / Clms Page number 34>

 



     TABLE I Composition of specific light cracking feedstocks
 EMI34.1
 
 <tb>
 <tb> Components <SEP> Power <SEP> of gasoline
 <tb> A <SEP> B
 <tb>
 
 EMI34.2
 in weight)
 EMI34.3
 
 <tb>
 <tb> Propylene <SEP> 0.7 <SEP> 0.1
 <tb> Isobutane <SEP> 0.6 <SEP> 0.4
 <tb> Butane <SEP> normal <SEP> 0.6 <SEP> --Isopentane <SEP> 3 <SEP> 7.3
 <tb> Pentane <SEP> normal <SEP> 26.3 <SEP> 43.9
 <tb> Olefins <SEP> C5-C6 <SEP> 2.7 <SEP> 0.2
 <tb> Hexane <SEP> normal <SEP> 19.7 <SEP> 14
 <tb> 2,2-Dimethyl <SEP> butane <SEP> 1 <SEP> 0.2
 <tb> 3-Methyl <SEP> pentane <SEP> 9.7 <SEP> 5
 <tb> 2,3-Dimethyl <SEP> butane <SEP> 1.8 <SEP> 0.8
 <tb> 2-Methyl <SEP> pentane <SEP> 14.5 <SEP> 8.1
 <tb> Methyl <SEP> cyclopentane <SEP> 6.2 <SEP> 4.4
 <tb> Cyclopentane <SEP> 2.2 <SEP> 1.8
 <tb> Cyclohexane <SEP> 0.6 <SEP> 2,

  9
 <tb> Cyclo-olefins <SEP> C5-C6 <SEP> dienes <SEP> and
 <tb> aromatics <SEP> 0.4 <SEP> --Benzene <SEP> 4.9 <SEP> 1.1
 <tb> Heptane <SEP> normal <SEP> --- <SEP> 4.2
 <tb> Paraffins <SEP> C7 <SEP> 0.8 <SEP> ---
 <tb> 2-Methyl <SEP> hexane <SEP> --- <SEP> 2
 <tb> Paraffins <SEP> C8 <SEP> 0.4 <SEP> ---
 <tb> 3-methyl <SEP> hexane <SEP> --Paraffins <SEP> C9 <SEP> 0.3 <SEP> --Paraffins <SEP> C10 <SEP> 0.2 <SEP> ---
 <tb> 2,2-Dimethyl <SEP> pentane <SEP> --- <SEP> 0.1
 <tb>
 
 EMI34.4
 2,3-Dim4thy1 pentane --- 1,2 2,4-Dimethyl pentane --- 0,2 cycloperaffins C7 and lighter 2,3 ---
 EMI34.5
 
 <tb>
 <tb> 3-Ethyl <SEP> pentane <SEP> --- <SEP> 0.1
 <tb> Toluene <SEP> 0.5 <SEP> --Alcoyl <SEP> C8 <SEP> benzene <SEP> C, 3 <SEP> ---
 <tb>
 
 EMI34.6
 6 'yl C benzene 0.2 ---
 EMI34.7
 
 <tb>
 <tb> @@ <SEP> identification <SEP> 0,

  1 <SEP> --Total <SEP> 100 <SEP> 100
 <tb>
 

  <Desc / Clms Page number 35>

 
The breakdowns of the products from the cracking operation are given in Table II
TABLE II Breakdown of cracking products
 EMI35.1
 
 <tb>
 <tb> Components <SEP> Power <SEP> of gasoline
 <tb> A <SEP> B
 <tb>
 
 EMI35.2
 - # - ############################ z by weight)
 EMI35.3
 
 <tb>
 <tb> Ethylene <SEP> 25.8 <SEP> 26.7
 <tb> Hydrogen <SEP> 0.8 <SEP> 0.8
 <tb> Methane <SEP> 13.4 <SEP> 13.1
 <tb> Acetylene <SEP> 0.5 <SEP> 0.5
 <tb> Ethane <SEP> 3.4 <SEP> 4.8
 <tb> Propylene <SEP> 17.9 <SEP> 21.6
 <tb> Propadiene <SEP> 0.2 <SEP> 0.2
 <tb> Methyl <SEP> acetylene <SEP> 0.5 <SEP> 0.4
 <tb> Propane <SEP> 0.4 <SEP> 0.6
 <tb> Butylenes <SEP> 7 <SEP> 5.6
 <tb> Butadiene <SEP> 4 <SEP> 3.7
 <tb> Isobutane <SEP> normal <SEP> 0.2 <SEP> 1,

  8
 <tb> Pentanes <SEP> and <SEP> compounds <SEP> superior <SEP> 25.9 <SEP> 20.2
 <tb> Total <SEP> 100 <SEP> 100
 <tb>
 
Referring now to Fig. 2, there is presented a diagram showing in more detail a preferred arrangement of the light gasoline cracking system and the feed preparation, product recovery and processing system used in conjunction. to this cracking system. The towers used for the distillation system shown at 17 in Figure 1 are shown at 30, 31 and 32 in Figure 2. The charge
 EMI35.4
 A light cracking feed consisting mainly of C4 to C6 aliphatic hydrocarbons enters the butane separation tower 30 through line 33.

   C4 and lighter hydrocarbons exit at the top of tower 30 through conduit 34 to go to isobutane separation apparatus 31, part of the

  <Desc / Clms Page number 36>

 overhead material being discharged through line 35 after condensation in condenser 36. Isobutane and butylenes are removed from the top of tower 31 through line 38 and can be fed through 38a to the alkylation unit, as reported. previously. Normal butane is removed from the bottom of tower 31 through line 39 and can be used for pressurizing the final gasoline blends at 25 and 26 in Figure 1.

   In some operations, the isobutane separation apparatus can be omitted and the entire C4 hydrocarbon fraction can be recovered from the top of the butane separation tower 30. A fraction consisting primarily of C5-C6 hydrocarbons but containing small amounts of lighter and heavier hydrocarbons passes from the bottom of tower 30 through line 37 to isopentane separator 32. A fraction of isopentane is removed from the top of tower 32 through line 37. pipe 40, while part of the head material is discharged through pipe 41 after condensation in condenser 42. The residue from tower 32 discharges through pipe 43 and is pumped by pump 44 to the cracking system thermal 18, with introduction of steam at 43a.



   Although a single cracking furnace is shown at 18 in Figure 2, it will be understood that the thermal cracking system can encompass the use of a number of tubular-type reaction furnaces, usually arranged in parallel. For example, the reactant can pass in parallel through 17 tube type furnaces. The furnaces are designed in such a way that the temperature of the reactant gradually increases and approaches the maximum desired temperature at such a point in each reactor.

   In order to avoid excessive side reactions leading to the formation of tar and coke, it is important to prevent the reactant from reaching the maximum temperature or experiencing a temperature drop at an intermediate point in the reaction system. -

  <Desc / Clms Page number 37>

 tion.

   In furnaces which require shutdown to allow removal of coke deposits from the tubes, at periodic intervals, for example every 30 to 60 days, provision may be made to allow removal of the coke from the tubes. tubes without interruption in order to obtain a continuous operation, an additional furnace which will be operated together with the 17 furnaces in a spin-type operation involving the use of the 17 reactors for the cracking reaction, while the coke is removed from the tubes in the remaining reactor.

   Cracked products from cracking reactors. 18 are cooled by water injection at 29, to a temperature below 732 C, and sent to one or more cooling boilers 120, in which the temperature is further reduced to 371 -481 by steam generator. The cracked products then pass through a conduit 45, with the introduction of steam at 45a, to a gas scrubber 19, where the gases are purified by a countercurrent circulation of a hydrocarbon 19a having a boiling range. tion from 232 to 343 C. This hydrocarbon is recirculated and acts to further cool the effluent from the furnace, to absorb the resinous material formed by polymerization and to remove the carbonaceous material carried away from the reactors.

   If desired, water can be used as the scrubbing liquid in tower 19 instead of gas oil, which scrubbing liquid can be discharged through 19b. The clean gases are sent through line 47 through condenser 48 to separator 49. Heavy hydrocarbon condensate from separator 49 passes through line 50 to rectifier 51. The condensate is steam rectified to remove butane and lighter materials, and rectified liquid is sent through line 52 to recycling tower 106.



   The vapor coming from the separator 49 leaves it through the pipe 53 and is joined through the pipe 54 by the vapors coming from the rectification device 51. The gas is compressed in one or more

  <Desc / Clms Page number 38>

 two stages in 55. The purpose of this compression is to raise the level of pressure on the volatiles to that required for their separation by fractional distillation at low temperature and at high pressure. Multi-stage compression of the gaseous material from gas scrubber 19 with cooling and separation (not shown) between the stages is desirable in order to avoid high temperatures occurring. would be polymers.

   Water re-cut from the intermediate separators is rejected. The hydrocarbon condensate recovered from the intermediate separators is pumped to the outlet pipe from the neighboring compression stage, where its spongy effect is used. The compressed material, including condensate from the final compression stage, passes through refrigerant 56 where it is cooled to about 18.3 C, and then into separator 57. The purpose of the cooling phase at 56 is to condense as much propylene and heavier hydrocarbon material as possible, thereby excluding them from the methane separation apparatus 69.

   The condensate consisting mainly of propylene and heavier hydrocarbons passes through line 58 to a washing with water and caustic soda being carried out in one or more drums 59. The liquid hydrocarbons are washed with an aqueous solution of caustic soda. and then with water for the purpose of removing hydrogen sulfide and other acidic material. The washed hydrocarbons are sent through line 60 to the pre-fractionator 61, where the ethane and lighter materials are removed at the top through line 62 to go to the suction of compressor 55.



  The pre-fractionator residue containing propylene and heavier hydrocarbons passes through line 63 into the butane separator 86. The pressure of the refractionator is set at about 20 kg / cm2. The peak temperature is not allowed to fall below approx.

  <Desc / Clms Page number 39>

 15.5 C, to avoid hydrate formation. The background temperature in the pre-fractionation apparatus is kept below 126.5 ° C. in order to avoid polymerization of butadiene in the reactants. Deposits from the ethane separation apparatus 78 are fed to the pre-fractionator through line 84 at a rate sufficient to allow proper control of the bottom temperature.

   The overhead products from separator 57 pass through line 64 to a water and caustic soda washing tower 65, where the vapors are washed with caustic soda and water and sent through line 66 to one or more desiccators 67 The hydrocarbons are passed through a suitable drying agent, such as a synthetic alumina waste drying agent, bauxite or activated alumina. The function of the desiccators is to lower the dew point of the gas sufficiently to prevent hydrate formation in the low temperature installation following the desiccators. The dried stream is sent through line 68 to a series of refrigerants (not shown) and cooled to a temperature of the order of -62 ° C., then sent to a methane separation apparatus 69.

   This tower is designed to minimize the loss of ethylene to tail gas, while removing virtually all methane and lighter hydrocarbons from the deposits produced. The overheads of the methane separator 69 are cooled by ethylene evaporation to -101-0, and the tower is subjected to reheating by propylene condensation (reboiler 69a). The pressure of the methane separator can be about 34.5 kg / cm2 and the bottom temperature can be on the order of 15.5 C -. A combustible gas consisting mainly of methane and hydrogen is removed through line 70 from the top of the methane separator 69, and this gas can be used as a fuel in cracking furnaces.

   Deposits from the separation device

  <Desc / Clms Page number 40>

 of methane consist mainly of ethylene, ethane, C4 and C4 hydrocarbons, with a small amount of C5 and heavier hydrocarbons. The deposits from the methane separation tower 69 pass through line 71 into the ethane separation apparatus
72 which can operate at a pressure of the order of 28 kg / cm2, with an overhead product temperature of the order of -9.4 ° C to -4 ° C, and a deposit temperature of the order by 77 C.

   The head products of tower 72 consisting mainly of ethylene and ethane with certain impurities pass through the conduit
73 to an ethane and ethylene separation tower 74, which can operate at a pressure of the order of 7 kg / cm2, with an overhead temperature of the order of -60.5 C and a deposit temperature of 1 ': - order of -40'C. The reheating and condensing functions can be combined in a heat pump arrangement, in which the overhead vapor is compressed in 127 to a pressure of about 20.5 kg / m 2 and condensed in the reboiler 129 to give heat for reheating. Head product leaves tower 74 through the conduits
75 and 134 to an acetylene conversion phase 76.

   The acetylene conversion can be of a common type known in the art.



  The hydrocarbon stream is subjected to moderate hydrogenation over a suitable catalyst to effect selective hydrogenation of the acetylene content of the stream without significant hydrogenation of olefins and diolefins. Catalysts known in the art, which are suitable for this operation, consist of nickel, platinum, iron, cobalt and noble metal oxides on suitable supports, such as silica, pumice stone, carbon. of wood and alumina. Examples are catalysts comprising 3 to 10% of cobalt molybdate on activated alumina or 3 to 10% of a mixture of iron and nickel on pumice stone.

   Suitable operating conditions vary with the catalyst in the range of about 37 to 316 C, with pressures of about 0 to 105 kg / cm2, usually less than 14 kg / cm2, and space velocities on the order of. 30C

  <Desc / Clms Page number 41>

 at 1500 volumes of gas (measured at standard conditions) per hour per volume of catalyst. The reactant feed should contain about 10 to 50% by volume hydrogen.



  If the cracked gas does not contain enough hydrogen, it can be added through line 133. In some operations, small amounts of water vapor can be supplied to the hydrogenation reactor with the feed. If desired, other means of removing acetylene from cracked gases can be substituted for the hydrogenation unit. For example, the mixed gas may be subjected to selective pass-through oxidation, along with sufficient oxygen to oxidize the contained hydrogen and acetylene, over a catalyst, such as activated alumina. temperatures of the order of 343 to 39900 and at pressures close to atmospheric pressure.



   The effluent from the acetylene conversion phase 76 is cooled to approximately -32 ° C. and fed through line 135 to an overhead separation apparatus 77 in order to separate the methane and the soils at a lower point. On boiling, ethylene produced. The head product separation apparatus 77 can operate at a pressure of the order of 23.5 kg / cm2 with a deposit temperature of the order of = 20.5 C to -17.5 C and a temperature of head products of the order of -26 C to -29 C.



  The reheating heat (reboiler 77a) is provided by propylene condensation and the overhead condenser is cooled by refrigerant propylene. The overhead products from tower 77, containing methane, ethylene and a lower boiling point material, pass through line 78 to the suction of gas compressor 55. The tail products are tower 77 pass through line 79 to the bottoms distillation apparatus 80 in order to separate the heavy soils from the ethylene produced. The bottoms distillation apparatus 80 can operate at a pressure of the order of 19 kg / cm2, with a deposit temperature of the order of -20.5 C, at

  <Desc / Clms Page number 42>

 23.5 C and an overhead temperature of the order of -29 C to -31.5 C.

   The reheating heat is provided by propylene condensation and the overhead condenser is cooled by refrigerant propylene. The bottoms of the bottoms still 80 consist essentially of ethylene which is removed from the system through line 81. The bottoms of tower 80 contain a mixture of ethylene and ethylene. ethane are returned through line 82 to the ethane and ethylene separation tower 74. A fraction of ethane is removed from the bottom of tower 74 through line 83, and this fraction is sent to the cracking system d ethane 21.



   The ethane cracking system can consist of one or more tube-type furnace reactors. For example, the ethane can pass through three tube furnaces in parallel, with a fourth furnace provided for spinning type operation, to allow continuous operation during periods of coke removal from the furnace tubes. The reaction products from oven 21 are cooled by injecting water at 28, as soon as they leave the oven in order to reduce the temperature below 732 C, and they pass through one or more cooling boilers 125 where the temperature is further reduced to 371 -481 C by generation of steam.

   The cracked products then join the cracked products from the naphtha cracking section and pass into the gas scrubber 19 where they are purified and further cooled.



   The tail products from the ethane separator 72, consisting mainly of C3 and C4 hydrocarbons with small amounts of C- and heavier hydrocarbons pass through line 84 into the butane separator 86. The butane separator is also fed with the pre-fractionation stream 63 from the pre-fractionator 61, which is of similar composition. A part of

  <Desc / Clms Page number 43>

 deposits from the ethane separator 72 pass through line 85 to the pre-fractionation tower 61.

   This lightweight material is fed therein to lower the reheating temperature of this pre-fractionation tower and to prevent the formation of polymers caused by high temperatures. The butane separation apparatus 86 achieves a clean separation between the butadiene and pentadiene components of the feed streams.



   The butane separator 86 can operate at a pressure of the order of -13.5 kg / cm2 with a bottoms temperature of the order of 168-171 ° C and a temperature of products 1 of. head of the order of 51.5 to 54.5 C. The heat for reheating is supplied by steam, and the overheads are condensed in a water-cooled condenser. The overhead products from tower 86, which are substantially free of C5 and heavier hydrocarbons, pass through line 87 to a propane separator 88 which can operate at a pressure of the order of 17.5 kg / cm2 / with a tail-product temperature of 1 twist from 99 to 101.50 and a top-product temperature of the order of 43 to 46 C.

   The propane separation apparatus 88 separates the methyl acetylene from the butadiene from the feed stream. The overhead condenser of the propane separator 88 uses water as the cooling medium, and the heat for reheating is provided by steam. Overheads consisting mainly of propane and propylene and containing relatively small amounts of impurities, such as methyl acetylene and propadiene are removed through line 89. This stream is sent to the methyl acetylene removal stage. and propadiene. For example, the stream can pass through the hydrogenation reactor 92 where the methyl acetylene and the propadiene are selectively hydrogenated.

   Steam 90b for the conversion is obtained from the deoxygenation reactor 90 in which hydrogen 90a is fed and where a platinum catalyst favors.

  <Desc / Clms Page number 44>

 a reaction between hydrogen and small amounts of oxygen and carbon monoxide present. The oxygen and carbon monoxide conversion phase can be of a common type well known in practice. The temperature of this phase can be around
121 C and the pressure can be about 24.5 kg / cm2. The conversion process may be of a common type well known in the art and may be the same process as that described for the acetylene conversion phase 76. If desired, other means of removal. methyl acetylene and propadiene can be substituted for the hydrogenation unit.

   For example, methyl acetylene and propadiene can be removed by absorption or extraction. The effluent from the conversion phase 92 passes through line 93 and through condenser 94 to the fractional propylene distillation column 95. Light soils introduced with the stream of hydrogen, such as methane and ethane, are removed from the top of tower 95 through the conduit
96 and pass to compressor 55. Tower 95 can operate at a pressure of the order of 24 kg / cm2, having a temperature of about 42.5 C at its top and a temperature of about 59.5 C at the top. its base.

   The propane-propylene fraction removed from the bottom of tower 95 can be withdrawn from the system at this point and ultimately used as a portion of the feed to the alkylation unit or further fractionated to produce an essential propylene stream. - neat and a stream of propane-propylene, as shown in Figure 2. The tail products of tower 95 are sent through line 97 to the propane and propylene separation apparatus 98. This apparatus can be operated. at a pressure of the order of 21 kg / cm2 with a temperature at the base of the order of 54.5 * C and a temperature at the top of 49 * 0. The reheating heat is supplied by steam and the overhead product is condensed in a water-cooled condenser.

   Substantially pure propylene party product is removed through line 99. A tail product fraction, formed from propane and propylene, is removed.

  <Desc / Clms Page number 45>

 through line 100 and is ultimately used as feed for the alkylation unit. Propylene can be removed as one of the burning products. If desired, the separation apparatus 98 can be omitted and the full stream of propanepropylene can be employed as the alkylation feedstock. The fraction of deposits from the propane separation apparatus 88, mainly consisting of butylene and butadiene, is sent through line 101 to the recovery of butadiene 102.



  The C4 fraction is sent to a butadiene extraction unit from which are recovered butadiene, as product, which is removed through line 103, and a butane-butylene fraction which is removed through line 104 and used as a portion of the charge to the alkylation unit ,. The butadiene extraction unit may be of a common type well known in the art. For example, the extraction can be carried out using an aqueous and ammoniacal solution of cuprous acetate or by using furfuraldehyde as an extracting solvent. The product deposits from the butane separation device 86, containing C5 and C6 hydrocarbons and having a higher boiling point, are sent through line 105 to recycling tower 106.

   This recycling tower can operate at a pressure of the order of 0.5 kg / cm2 with a top temperature of about 102 C. Steam is injected into the inlet pipe of the reboiler, in order to maintain the temperature. bottoms below about 215.5 C. A 204 C and above fraction of an aromatic distillate is removed through line 107. The overhead product from tower 106 passes through line 108 to a heater 109 or. it is heated to a temperature of about 173.5 to 204.5 ° C, and vaporized. The vaporized effluent passes through line 110 to earth treatment tower 111. Tower 111 is maintained at a pressure of about 2.8 to 3.5 kg / cm2 and at a temperature of the order of 1490 to 204 C.

   The diolefins present in the overhead product of the recycling tower 106 are polymerized in the tower 111 in a good manner.

  <Desc / Clms Page number 46>

 known in practice. The contact material in tower 111 may consist of Attapulgus earth or bauxite. The treated stream is sent through line 112 to recycling tower 113 in order to recover an aromatic essence which is removed at the top through line 114 and an aromatic distillate which. is removed by 115. This recycling tower can operate at a pressure of about 0.5 kg / cm2, having a top temperature of the order of 126.500 and a bottom temperature of the order of 200 C.



   EXAMPLE 1
As an example of the operation according to the combined process of the present invention, the treatment of 32,589 Hl per day of a mixture of paraffinic crudes, mixed base crudes, and naphthenic crudes may be considered in conjunction with Figure 1. The crude material is fractionated in still 10 to remove C3 and lighter hydrocarbons and to provide about 7790 Hl of waste tar, about 6200 Hl of virgin gas oil, about 1987 Hl of boiling fraction. in the C4 range at 79.5 C, and about 6089 Hl of a heavier gasoline feed to the reformer (79.5 to 187.5 C).

   The virgin gas oil -: and the thermal gas oil having a boiling range of approximately 2380 to 538 C are subjected to a catalytic cracking under usual conditions in a catalytic cracking unit with moving bed in 13. Approximately 4530 Hl of gasoline Catalytic having the properties indicated in Table V are recovered catalytic cracking products by distillation at 14. This gasoline is added to the final engine gasoline mixture at 25.



   The residue is subjected to thermal viscosity reduction at 11 to produce additional catalytic cracking charge. About 429 Hl of thermal gasoline (79.5 -187.5 C) are also formed, and this gasoline is added along with the heavier feed gasoline to the reforming apparatus, to the reforming unit. 15. In addition, about 151 Hl of petrol

  <Desc / Clms Page number 47>

 slight mics are formed; they are added to the distillation system 17 at the same time as the C4-79.5 C fractions from the crude material and from the reforming.



   The resulting 6518 Hl of thermal and straight run gasolines, available as reforming feed, boil in the range 79.5 to 187.5 C by ASTM distillation and are practically free of C5-C6 aliphatic hydrocarbons or containing less About 10% by weight thereof.



  This gasoline stabilized at a thermal octane number with 3 cm3 of tetraethyl lead of 70. This gasoline feed is reformed on a catalyst of the aromatization type, comprising about 0.6% by weight of platinum impregnated on 1 '. alumina.



  The reforming conditions are: 35 kg / cm2 of pressure, a hydrogen / hydrocarbon molar ratio of 9, a space speed / temperature ratio maintained in the range of 0.5 to 2 (volume of oil per hour per volume of catalyst) and a temperature of 454 to 526 C, with formation of a reforming product containing gasoline with an end point of 193 C which, at a Reid vapor pressure of 0.7 kg / cm2, would have an octane number theoretical, with 3 cm3 of tetraethyl lead, of about 102. The reforming products are subjected to fractional distillation to remove C3 and lighter hydrocarbons and an aliphatic hydrocarbon fraction boiling in the C4 hydrocarbons at about 79.5 C.

   Also recovered from the distillation of the high pressure reforming products are approximately 4155 Hl of stabilized reforming gasoline, API gravity 40, end point 71 to 193 C, having an index of. Theoretical octane, with 3 cm3 of tetraethyl lead, of 103.3. Such sterilized reforming gasolines are substantially free from aliphatic C5-C6 hydrocarbons, containing less than 10% by weight thereof. Stabilized reorming gasolines are added to the 25 engine gasoline blend.

  <Desc / Clms Page number 48>

 



   The 79.5 C C4 light reforming gasoline fractions from the high pressure reforming phase amounted to about 1256 Hl. These light reforming fractions are subjected to fractional distillation in System 17, along with 151 Hl of C4-79.5 C thermal gasoline and 1987 Hl of light straight run gasoline.

   The following are recovered from the distillation system 17:
 EMI48.1
 
 <tb>
 <tb> Total, <SEP> Party <SEP> of <SEP> total <SEP> from <SEP>; <SEP>
 <tb> from <SEP> product <SEP> of <SEP> reforming
 <tb> Hl <SEP> light <SEP> Hl
 <tb>
 <tb> Fraction <SEP> C4 <SEP> normal <SEP> 477 <SEP> 108
 <tb> fraction <SEP> iso-C <SEP> + <SEP> C4 <SEP> (including
 <tb> 163 <SEP> Hl <SEP> are <SEP> of <SEP> isobutane) <SEP> 270 <SEP> 159
 <tb> Fraction <SEP> of isopentane <SEP> 477 <SEP> 166
 <tb> Pentane <SEP> normal <SEP> + <SEP> hexanes
 <tb> aliphatic <SEP> saturated <SEP> 1270 <SEP> 731
 <tb>
 
The isopentane and normal butane fractions are added to the motor gasoline mixture at 25. The butylene-isobutane fraction is added to the alkylation reactor 23.



  The normal hexane-pentane fraction contains less than about 5% by weight of O4 and lighter hydrocarbons and less than about 10% by weight of benzene and C7 aliphatic hydrocarbons and higher. Equal parts by weight of this fraction and the steam are fed to the vapor-free pytolytic cracking reactors are fed to the reactors - the pytolytic cracking itself in 18. The operating conditions in the cracking reactor are: inlet temperature of 149 C, and maximum temperature, reached near the outlet of the coil, of 828C; inlet and outlet pressures, respectively 5.6 and 1.4 kg / cm2; and residence time of the reactants in the reactor of about 1 second at temperatures of the order of 1490 to 828 C.

   The cracked product is cooled to a temperature of about 732 C by injecting water at 19 and then cooled in a permanent heat boiler. due until 371 to 481. The cracked products are sent to the product recovery system 20 where approximately 2059 Hl

  <Desc / Clms Page number 49>

 of a fraction of ethane (including recycling at a rate of 882 Hl) are recovered and subjected to pyrolytic cracking in the cracking reactors in 21. Steam is added to the ethane at the rate of about 30 % by weight of the hydrocarbon feed.

   The operating conditions in the ethane reactor are: temperature: - entry of 15.5 C and 854.5 reached near the outlet of the coil; inlet and outlet pressures of 3.85 and 1.4 kg per cm2 respectively; dwell time of reactants in the reactor of about 1 second in the temperature range of 15.5 to 854.5 C.



   About 675 Hl of propane-propylene and butanes-butylene hydrocarbons are recovered from the product recovery system 20. The olefin content of these fractions is about 90% by volume. This material is fed to the alkylation unit 23 at the same time as 270 El of the fraction of butylene-isobutane recovered in the distillation system 17. About 588 Hl of isobutane coming from an external source are also fed to the. unit of alkylation. The alkylation is carried out at a temperature of about 12.5 'and a pressure of about 3.5 kg / cm 2 in the presence of about 50 to 55% by volume of a 99- sulfuric acid catalyst. 89%.

   The alkylation products are subjected to 24-fractionation to recover alkylation gasoline, a heavier alkylation product, propane and butane, as products. If desired, the amount of alkylating gasoline can be increased by also alkylating unsaturated C3 - C4 hydrocarbons from the catalytic cracking products. This fraction can be alkylated separately or at the same time as unsaturated C3 - C4 hydrocarbons from the pyrolytic cracking products.



   The product recovery system 20 is operated in the manner previously described to recover the various products shown in Figure 1. The resulting products

  <Desc / Clms Page number 50>

 combined light gasoline and alkyl cracking operations. tion are as follows:
 EMI50.1
 
 <tb>
 <tb> Gas <SEP> fuel <SEP> 22.604 <SEP> kg
 <tb> Propane <SEP> 1113 <SEP> liters,
 <tb> Butane <SEP> 477 <SEP> liters
 <tb> Ethylene <SEP> (purity <SEP> of <SEP> 99.8%) <SEP> 39.592 <SEP> kg
 <tb> Butadiene <SEP> (purity <SEP> of <SEP> 99.5%) <SEP> 5526 <SEP> kg
 <tb> Gasoline <SEP> aromatic <SEP> 389 <SEP> Hl
 <tb> Distillate <SEP> aromatic <SEP> 111 <SEP> Hl
 <tb> Gasoline <SEP> of alkylation <SEP> 1208 <SEP> Hl
 <tb>
 
Aromatic essence and alkylating essence are added to the mixture:

   25, and their properties, as well as those of the other components of the final gasoline-forming mixture, are given in Table III.

  <Desc / Clms Page number 51>

 



    TABLE III
 EMI51.1
 Components of the mrlane fonmr.mt petrol-for engines
 EMI51.2
 
 <tb> Component <SEP> Gasoline <SEP> Gasoline <SEP> of <SEP> Gasoline <SEP> Gasoline <SEP> Isopen- <SEP> Hydro- <SEP> Gasoline <SEP> Mixture
 <tb> cracked <SEP> reforming <SEP> of <SEP> aromati-- <SEP> of alkyl.a-- <SEP> tane <SEP> c.

    <SEP> C4 <SEP> of absorb- <SEP> total
 <tb> catalyti- <SEP> high <SEP> that <SEP> gadfly <SEP> ption
 <tb>
 
 EMI51.3
 ¯ just 'pressure¯¯ - - ¯¯¯¯¯¯ ##### ####### #######
 EMI51.4
 
 <tb> Quantity <SEP> in
 <tb> the <SEP> mix, <SEP> Wire <SEP> 4530 <SEP> 4165 <SEP> 389 <SEP> 1748 <SEP> 477 <SEP> 1488 <SEP> 397 <SEP> 13194
 <tb> Properties <SEP> API <SEP> 58 <SEP> 40 <SEP> 38.4 <SEP> 71.5 <SEP> 95.7 <SEP> 76 <SEP> 58
 <tb> Distillation <SEP> ASTM
 <tb> Point Boiling <SEP> <SEP> initial <SEP> 46 <SEP> 71 <SEP> 42 <SEP> 58 <SEP> 40.5 <SEP> 40.5
 <tb> 10% <SEP> 63 <SEP> 71 <SEP> 76.6 <SEP> 54.5 <SEP> 51.5
 <tb> 50% <SEP> 110 <SEP> 114.5 <SEP> 91., 5 <SEP> 73.4 <SEP> 99
 <tb> 90% <SEP> 179.5 <SEP> 132 <SEP> 132.5 <SEP> 110 <SEP> 150.5
 <tb> point <SEP> final <SEP> 201.5 <SEP> 193.5 <SEP>, <SEP> 141 <SEP> 204.5 <SEP> 154.5 <SEP> 190.5
 <tb> Voltage <SEP> of <SEP> steam
 <tb> Reid,

    <SEP> kg / cm2 <SEP> 0.37 <SEP> 0.28 <SEP> 0.45 <SEP> 0.28 <SEP> 1.4 <SEP> 3.5 <SEP> 0.7 <SEP> 0.86
 <tb> Clue Octane <SEP>
 <tb> theoretical
 <tb> + <SEP> 3 <SEP> om3 <SEP> lead
 <tb>
 
 EMI51.5
 tetiahbyl 89.3 101 103.6 95 93 95 73 94.5
 EMI51.6
 
 <tb> + <SEP> 2.6 <SEP> cm3 <SEP> lead
 <tb> tetraethyl <SEP> 96 <SEP> 1 () 3.3 <SEP> 104.2 <SEP> 104 <SEP> 102 <SEP> 103 <SEP> 88 <SEP> 100.4
 <tb>
 
 EMI51.7
 m includes 540 Hl of alkylation product resulting from alco: rlation of unsaturated C3 - C4 hydrocarbons.
 EMI51.8
 
 <tb> res <SEP> from <SEP> of <SEP> on <SEP> phase <SEP> of <SEP> cracking Catalytic <SEP>.
 <tb>
 

  <Desc / Clms Page number 52>

 



   A small quantity of absorption gasoline is re-charged by treating the wetted gas streams from refinery gas production units, such as diesel thermal and catalytic cracking units. The absorbent gasoline can be conveniently added to the final gasoline mixture, although this is not essential.



   In addition to the C4 hydrocarbon fraction recovered in the distillation system 17, approximately 1009 Hl of C4 hydrocarbons (approximately 96% normal butane) from an external source are added to the final gasoline blend at 26. to give a Reid vapor pressure of 0.86 kg / cm2. This is an average of the Reid vapor pressures considered satisfactory for annual gasoline production. The amount and properties of the final gasoline blend resulting from the combined process of the previous example are given in Table III.



   EXAMPLE 2 In another example, 32,589 Hl of the crude mentioned in Example 1 are separated into the same fractions as those mentioned in Example 1, except that instead of the C4 -79.5 C fraction, a Fraction C-93 C is removed, this fraction amounting to about 2655 Hl, leaving 5421 Hl of heavier gasoline feed to the reformer from an end point of 93 to 188 C.

   From the products resulting from the reduction in viscosity of the residue fraction, about 383 Hl of 93-188 C end point thermal gasoline is separated and added to the heavier gasoline feed to the reformer, and about 197 Hl of C4-93 C light thermal gasoline are separated and added to the distillation system 17 along with the C4-93 C fraction from the crude.



   The resulting 93 -188 C thermal straight-distillation reformer feed was essentially free of C5-C7 aliphatic hydrocarbons, containing less than about 10% by weight thereof, and amounted to 5805 E1. . This

  <Desc / Clms Page number 53>

 The feed is reformed under the same conditions as those given in Example 1 to provide about 4539 Hl of reforming gasoline free of C3, and in this case comprising the C5 to C7 hydrocarbons.



   The total feed to the distillation system 17 consists of 2655 Hl of C4-93 C light straight run gasoline and 197 Hl of C4-93 C thermal gasoline. The following are recovered from the distillation system 17:
 EMI53.1
 
 <tb>
 <tb> Fraction <SEP> C4 <SEP> normal <SEP> 278 <SEP> Hl
 <tb> Fraction <SEP> Iso-C4 <SEP> + <SEP> C4 <SEP> (including <SEP> 63.6 <SEP> Hl
 <tb> are <SEP> of <SEP> the iso-C) <SEP> 111.3 <SEP> Hl
 <tb> Fraction <SEP> Iso-C5 <SEP> 310 <SEP> Hl
 <tb> C5 <SEP> normal <SEP> + <SEP> hexanes <SEP> and <SEP> heptanes
 <tb> aliphatic <SEP> saturated <SEP> 1955 <SEP> Hl
 <tb>
 
The fraction of @ eptane-pentane, comprising the light thermal gasolines and direct distillation, is subjected to pypolytic cracking under the same conditions as those given in Example 1.

   The ethane recovered from the product recovery system 20 is cracked in the reactors 21. The propane-propylene and butane-butylene fractions, recovered from the system 20, amount to 579 Hl and are alkylated in unit 23 with the 111.3 Hl of butylene-isobutane fraction recovered from the distillation system 17, together with a sufficient quantity of external isobutane to achieve the desired alkylation.

   The products resulting from the combined operation of light gasoline cracking and alkylation are recovered from the system 20 as follows:
 EMI53.2
 
 <tb>
 <tb> Gas <SEP> fuel <SEP> 20.385 <SEP> kg
 <tb> Propane <SEP> 1589 <SEP> liters
 <tb> Butane <SEP> 477 <SEP> liters
 <tb> Ethylene <SEP> (purity <SEP> of <SEP> 99.8%) <SEP> 36.874 <SEP> kg
 <tb> Butadiene <SEP> (purity <SEP> of <SEP> 99.5) <SEP> 5118 <SEP> kg
 <tb> Gasoline <SEP> aromatic <SEP> 359 <SEP> Hl
 <tb> Distillate <SEP> aromatic <SEP> 10.335 <SEP> liters
 <tb> Gasoline <SEP> of alkylation <SEP> 1192.5 <SEP> Hl
 <tb>
 

  <Desc / Clms Page number 54>

 
The aromatic gasoline and the alkylation gasoline are added to the final gasoline mixture at 25.

   Absorbent gasoline is also added as in Example 1, and a sufficient amount of butanes is added to stress the final mixture to a Reid vapor pressure of about 12.3. The components of the final gasoline-forming mixture are given in Table IV.



     TABELAU IV
 EMI54.1
 
 <tb>
 <tb> Components <SEP> " <SEP> of <SEP> mix <SEP> final <SEP> forming <SEP> gasoline <SEP> of <SEP> example <SEP> 2.
 <tb>
 
 EMI54.2
 



  Components Tension of Indiég; ± 8gne Quantity, vapor ### Eoque vapor 30m3 Reid, Net lead of Hl kg / em2 ethyl ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ ¯¯¯¯¯¯ ¯¯¯ ¯¯ ethylē¯¯ ¯¯¯¯¯¯¯
 EMI54.3
 
 <tb>
 <tb> Gasoline <SEP> cracked
 <tb> catalytically <SEP> 0.37 <SEP> 89.3 <SEP> 96 <SEP> 4531
 <tb> Gasoline <SEP> of <SEP> reforming
 <tb> to <SEP> high <SEP> voltage <SEP> 0.38 <SEP> 95 <SEP> 102 <SEP> 4539
 <tb> Gasoline <SEP> aromatic <SEP> 0.44 <SEP> 103.6 <SEP> 104.2 <SEP> 359
 <tb> Gasoline <SEP> of alkylation <SEP> 0.28 <SEP> 95 <SEP> 104 <SEP> 1733
 <tb> Isopentane <SEP> 1.4 <SEP> 93 <SEP> 102 <SEP> 310
 <tb> Hydrocarbons <SEP> C4 <SEP> 0.35 <SEP> 95 <SEP> 103 <SEP> 1574
 <tb> Gasoline <SEP> absorption <SEP> 0.7 <SEP> 73 <SEP> 88 <SEP> 397
 <tb> Mixture <SEP> total <SEP> 0.86 <SEP> 92,

  6 <SEP> 100 <SEP> 13.443
 <tb>
 
EXAMPLE 3
As a further example of the advantage of the process of the present invention over prior processes, consider treating a gasoline feedstock consisting of about 93% straight run gasoline and about 7% straight run gasoline. thermal gasoline. This gasoline has an API gravity of 60 and boils in the range C3 to 188 C. This feedstock is processed in the following various ways.



     A - The gasoline feedstock is fractionated to remove C3 and lighter hydrocarbons and to provide approximately 2138 Hl per day of a 04-79 C light gasoline fraction and approximately 6519 Hl per day of a heavier gasoline fraction 79 - 188 C. The latter fraction, which has a tea-octane number

  <Desc / Clms Page number 55>

 Rique with 3 cm3 of approximately 70 tetraethyl lead is subjected to catalytic reforming as described in Example 1.



  Rowing 167 El of isopentane and 4165 Hl of reforming gasoline stabilized with an end point of 71 -193 0 are recovered from the reforming product and mixed with the C4-79 C light gasoline fraction in the final gasoline-forming mixture. engine. Likewise, 358 Hl of C4 hydrocarbons are recovered from the reforming products, but only 111.3 Hl of these can be added to the final gasoline blend within the carburetor icing limits set for the finished gasoline.



   B - The gasoline feed is fractionated to remove C3 and lighter hydrocarbons and to recover approximately 389 El per day from a fraction of C4 hydrocarbons, 310 Hl per day from a fraction of isopentane, 1439 Hl per day of a fraction C5-C6 containing aliphatic hydrocarbons other than isopentene and 6519 Hl per day of a heavier gasoline fraction with an end point of 79 -188 C. This latter fraction is reformed under the same conditions as 'in A. The C5-C6 fraction from straight-run gasoline and from the recycling of light reforming product is subjected to isomerization over a catalyst formed by a noble metal at about 399 C, at a pressure of 17.5 kg / cm2 and at a space velocity of 2 volumes per hour per volume of catalyst, to produce 2162 Hl of light gasoline containing about 70% isomers.

   The light gasoline produced from the isomerization, the initial isopentane fraction and the end point catalytic reforming product of 65 to 193 C (including the isopentane formed in the reforming) are mixed together into the final gasoline mixture. . Likewise, about 326 Hl of the initial C4 hydrocarbon fraction is added to the final mixture. All of this is all that can be used within the limits of carburetor icing.



   C - The gasoline feedstock is fractionated to remove C3 and lighter hydrocarbons and to provide

  <Desc / Clms Page number 56>

 
389 Hl of a fraction of C4 hydrocarbons, 310 Hl of a fraction of isopentane, 1438 Hl of a fraction containing the hydrocarbons
Aliphatic C5-C6 other than isopentane, and 6519 Hl of gasoline feed (79 -188 C) to the reformer. These fractions are treated as indicated in Example 1, the reforming conditions being the same as in A. The pyrolytic cracking feed is made up of the 1438 Hl of aliphatic C5-C6 hydrocarbons other than isopentane, from the gasoline feed, and by the 731 El of a similar fraction from the catalytic reforming product.

   The conditions for the cracking operations of light gasoline and alkylation are the same as in the preceding examples; - of operation according to the process of the invention. In this case, the gasoline resulting from the thermal or catalytic cracking of the gas oil and the residual portions of the crude are not added to the final gasoline mixture.

   The components of this final mixture are:
Reforming product 71 -193 C 4166 Hl / day
Alkylation product (57 -204 C) 1208 Hl / day
Isopentane 477 Hl / day
Aromatic essence (42 -141 C) 389 Hl / day
Hydrocarbons C4 985 Hl / day, Total: 7225 Hl / day
In the case of each gasoline-forming mixture, a sufficient quantity of C4 hydrocarbons was added from sources belonging to or outside the process, to provide a final gasoline having the same volatility characteristics from the point of view of icing in the process. the carburetor.

   Because the gasoline mixture C had an average boiling point of 50% higher, it was possible to blend it at a high Reid vapor pressure - while still providing engine gasoline of satisfactory volatility characteristics - than in e case of species A and B. Productions and properties

  <Desc / Clms Page number 57>

 of the products resulting from processes A, B. and C are summarized in Table V.



   TABLE V Properties and productions of gasoline for engines
 EMI57.1
 
 <tb>
 <tb> Process <SEP> A <SEP> B <SEP> C
 <tb> Quantity <SEP> of <SEP> mix <SEP> final <SEP> forming
 <tb> gasoline, <SEP> H1 / day <SEP>, <SEP> 7314 <SEP> 7139 <SEP> 7225
 <tb>
 
 EMI57.2
 Quantity of exterior C4 hydrocarbons 675
 EMI57.3
 
 <tb>
 <tb> in <SEP> on <SEP> mix, <SEP> Hl / day <SEP> 375
 <tb>
 <tb>
 
 EMI57.4
 Total hydrocarbons 0.

   in the mixture, EI / Day 501 326 986 mixture, H1 / day 501 326 986
 EMI57.5
 
 <tb>
 <tb> Voltage <SEP> of <SEP> steam <SEP> Reid <SEP> of <SEP> mix,
 <tb> kg / cm2 <SEP> 0.75 <SEP> 0.75 <SEP> 0.94
 <tb> Clue Octane <SEP> <SEP> theoretical <SEP> +
 <tb> 3 <SEP> cm3 <SEP> of <SEP> lead <SEP> tetraethyl <SEP> 98.7 <SEP> 101.5 <SEP> 103.3
 <tb>
 
It will be understood that the examples of operating conditions, arrangements of apparatus and applications of the invention
 EMI57.6
 ua are only 111'nstratifs and are not intended to limit the invention.



  RE-Vblqi-) i C.N-U 10 NS
1. In a refining operation in which a hydrocarbon gasoline feed is subjected to a reforming operation under controlled conditions to give a gasoline product of improved anti-knock value, the process allowing the increase of the overall anti-knock value and the decrease in the overall volatility, due to the low octane constituents, of the total liquid gasoline produced in the refining operation, which process comprises separating from the feedstock containing the gasoline. feed of reforming and of the reforming product, of at least the greater part of at least one of the aliphatic hydrocarbon materials contained chosen from the Group comprising C5 straight chain hydrocarbons, C6 straight chain hydrocarbons,

   branched chain C6 hydrocarbons, straight chain C7 hydrocarbons and branched chain C7 hydrocarbons; cracking the aliphatic hydrocarbon material thus separated at an elevated temperature to convert it to a product rich in gaseous olefins, and

  <Desc / Clms Page number 58>

 applying to a substantial part of these gaseous olefins a combined reaction in which these olefins gazauses constitute at least a substantial part of the reactants, under conditions controlled to form a gasoline product of medium volatility weaker and of higher detonating antiparea value than the aliphatic hydrocarbon material
2.

   In a refining operation in which mixed hydrocarbon fractions of different boiling points are subjected to a series of refining treatment stages, in order to prepare a series of gasoline fractions forming a refinery stock, each of these fractions ultimately being used as a component in at least one final gasoline product, and in which one of these processing steps involves reforming a relatively low antistatic value gasoline feed fraction at a temperature - raised to give a reformed gasoline product of improved anti-knock value,

   a process allowing the increase of the overall anti-knock value of all of these gasoline fractions of the refinery stock and the reduction of the overall content of these fractions of at least the straight-chain aliphatic hydrocarbons boiling in the range of C5 to C7 hydrocarbons, this process comprising: separating from the crude fraction containing this gasoline feed fraction and from the reformed gasoline product, at least the majority of at least minus one of the straight chain aliphatic hydrocarbon materials contained therein, falling within the range of C5 to C7 hydrocarbons;

   cracking the aliphatic hydrocarbon material thus separated at an elevated temperature controlled to convert this material into a product rich in gaseous olefins; applying to at least a substantial portion of these gaseous olefins, an alkylation in the presence of an alkylatable material, suitable to form an alkylation gasoline of high entraining value; the recovery of this gasoline alkylation; and the use of this

  <Desc / Clms Page number 59>

 gasoline as one of the gasoline fractions forming a refinery stock.



   3. In a refining operation in which a gasoline feed is subjected to a reforming operation under controlled conditions to give a reformed gasoline product of improved anti-knock value, the improvement which comprises: separation from the feedstock containing reforming feed gasoline and reforming product, at least the major portion of at least one of the straight chain aliphatic hydrocarbon materials contained therein, falling within the range of C5 to C7 hydrocarbons; cracking this separated aliphatic hydrocarbon material at elevated temperatures to convert it to a point rich in gaseous olefins;

   the application to at least a substantial part of these gaseous olefins of a combined reaction in which the gaseous olefins constitute at least a significant part of the reactants, under conditions controlled to form a gasoline product of medium volatility lower and of higher average anti-knock value than the separated aliphatic material; recovering this gasoline product and admixing at least a substantial part thereof with at least a substantial part of the reforming gasoline from which this aliphatic hydrocarbon material has been separated;

   andadding to the mixture a volatile combustible tension material to bring the mixture to a Reid vapor pressure in the range of about 0.42 to about 1.12 kg / cm2, satisfactory for motor gasoline, this <tension material having a significantly higher anti-knock value than the separated aliphatic hydrocarbon material.



   4. In a process for manufacturing high anti-knock value gasoline in which a petroleum gasoline feed is subjected to a reforming operation under controlled conditions to give a gasoline product of anti-detonation value. improved, the improvement combined with this process,

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 which comprises: fractionating the feed containing the reforming feed gasoline and the reforming product to remove at least the majority of the normal pentane and the saturated aliphatic hexanes contained therein, to provide a feed of cracking feed consisting mainly of C5-C6 aliphatic hydrocarbons; cracking this cracking feedstock at a controlled elevated temperature to convert this feed to a product rich in gaseous olefins;

   the alkylation of at least a substantial portion of these olefins, with a suitable hydrocarbon material which may be alkylated, resulting in alkylation of hydrocarbons of high octane number and gasoline boiling range, so that an alkylation product is formed; separating, from this alkylation product, an alkylation gasoline fraction of high anti-knock value;

   mixing at least a substantial portion of this fraction of alkylating gasoline with at least a substantial portion of the gasoline product resulting from reforming, which remains after removal of the C5-C6 hydrocarbons; and adding a sufficient quantity of C4 hydrocarbons to the resulting mixture to bring it to a Reid vapor pressure in the range of about 0.42 to about 1.12 kg / cm2, so as to provide a gasoline of high anti-knock value and satisfactory volatility characteristics for use as motor fuel.



   5. A combined process for the manufacture of ethylene and a high anti-knock engine fuel from a gasoline feedstock, which comprises: reforming at least the majority of that fuel. gasoline feedstock under conditions adjusted to give a reformed product containing reforming gasoline of improved anti-knock value; separating from at least one of this reformed product and this gasoline feedstock, at least most of at least one of the hydrocarbon materials

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 aliphatics contained therein, falling within the range of hydrocarbons
C5 to C7;

   pyrolytic cracking of the aliphatic hydrocarbons thus separated, at flame temperatures of about
704 to about 9540 and under controlled conditions to convert these materials into a cracked product consisting primarily of hydrocarbons having less than 5 carbon atoms per molecule and containing significant amounts of gaseous olefins, especially ethylene ; application to this cracked product of a separation operation to recover therefrom essentially pure ethylene as product and a rich gaseous feedstock and at least one olefin from the range of C3-C4 olefins ;

   and applying to the last-mentioned feedstock a combined reaction in which the constituents of the latter feed constituting at least a substantial part of the reactants, to form a gasoline product having volatility lower average and a higher antiknock value than the separated aliphatic hydrocarbon material.



   6. In a refining operation in which mixed hydrocarbon fractions from different boiling points are subjected to a refining process stage greenhouse to prepare a series of gasoline fractions forming a stockpile. refinery, each of these fractions being ultimately used as a component in at least one final gasoline product, and in which one of these processing phases involves a re-forming of a gasoline feed fraction of anti-explosive value relatively low at elevated temperature to give a reformed gasoline product of improved anti-knock value, a process for increasing the overall anti-knock value and decreasing overall volatility, due to the low octane constituents, all the gasoline fractions in the refinery stock,

   while also making ethylene as a product, said process comprising: applying to the hydrocarbon fraction containing the feed to the gasoline reformer at least one separation step

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 to provide a fuel supply for the reforming apparatus; reforming the latter feed at an elevated temperature under controlled conditions to achieve conversion to a reformed product containing gasoline of significantly improved anti-detonation value; applying to the reformed product at least one separation operation to remove at least C3 and lighter hydrocarbons and to provide stabilized reforming gasoline;

   separating from the material treated in at least one of the separation operations, at least the major part of at least one of the aliphatic hydrocarbon materials contained therein, falling within the range C5 to C7 hydrocarbons; pyrolytic cracking of the aliphatic hydrocarbon materials thus separated, at temperatures in the range of from about 704 to about 954 C and under conditions controlled to convert these materials into a cracked product consisting mainly of hydrocarbons having less of 5 carbon atoms per molecule and containing significant quantities of gaseous olefins, in particular ethylene;

   to this cracked product, a separation operation to recover therefrom essentially pure ethylene as product, and an alkylation feedstock, rich in at least one olefin from the range of C3-C4 olefins; applying to the last-mentioned feed alkylation with a suitable alkylatable material to form an alkylation gasoline of high anti-knock value; the recovery of this gasoline alkylation; the use of this gasoline as one of the gasoline fractions of the refinery stock; the use of the remaining stabilized reforming product as another gasoline fraction from the refinery stock.



   7. A process according to claim 6, characterized in that the aliphatic hydrocarbon material which is subjected to cracking is separated from the reformed product, and in that at least substantial parts of the alkylating gasoline and of the gasoline. gasoline

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 of stabilized reforming are mixed together in at least one final mixed engine gasoline.



   8. In a refining operation in which crude petroleum fractions are subjected to a series of refining processing stages to prepare a series of gasoline fractions forming a refinery stock, each of these fractions ultimately being used as a component. in forming at least one final mixed gasoline by blending, wherein at least one of the final mixed gasolines is brought to a Reid vapor pressure of about 0;

  42 to 1.12 kg / cm2 by including a volatile combustible tension material having a substantially higher anti-knock value than normal pentane and straight chain aliphatic hexanes and heptanes, and in which further one Processing stages involve the reforming of a gasoline feed fraction at an elevated temperature in the presence of a reforming catalyst to form a reformed gasoline product of improved anti-knock value, a process allowing the '' increase in the overall anti-knock value and decrease in the overall volatility, due to the constituents of low octane number, of all the gasoline fractions forming the refinery stock,

   quickly to allow the inclusion of an increased total amount of the tension material in all of the final mixed gasolines requiring tensioning, while at the same time allowing the manufacture of ethylene as a product, this process comprising : separation from this reformed gasoline product of at least the major part: at least one of the low 3 octane aliphatic hydrocarbon materials contained therein, selected from the group comprising pentane normal, straight chain C6 hydrocarbons, branched chain C6 hydrocarbons,
Straight chain C7 and branched chain C7 hydrocarbons;

   cracking of the aliphatic hydrocarbon material thus separated,

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 at an elevated temperature set to convert it into a product rich in gaseous olefins, in particular ethylene; applying to this cracked product a separation operation in order to recover therefrom ethylene as product, and a gaseous feedstock rich in at least one olefin from the range of C3-C4 olefins;

   the application to at least a significant part of this feedstock, of a combined reaction in which the constituents of the latter feedstock constituting at least a significant part of the reactants, with a view to forming a gasoline product having a lower average volatility and a higher anti-knock value than the separated aliphatic material; recovering gasoline from this combined reaction; the use of this gasoline as one of the gasoline fractions of the refinery stock.



   9. A combined process for making ethylene and a motor fuel of high antiknock value and suitable volatility characteristics, from a gasoline feedstock, which process comprising: from this gasoline feedstock, at least the major part of at least one of the low octane aliphatic hydrocarbon materials contained therein, falling in the range of C5 to C7 hydrocarbons;

   applying to the gasoline feedstock, after separation from the straight chain hydrocarbon material, reforming under controlled conditions to form reforming gasoline of significantly increased anti-knock value; separating from this reforming gasoline at least the majority of at least one of the low octane number aliphatic hydrocarbon materials contained therein falling within the range of C5 to C hydrocarbons; application to the aliphatic hydrocarbon material separated from the feed;

   feed gasoline and reforming gasoline, cracking at high temperatures to convert it into a cracked product containing significant amounts of gaseous olefins,

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 especially ethylene; the application to this cracked product of a separation operation with a view to recovering essentially pure ethylene as product, and of a fraction rich in olefins, consisting of at least one olefin from the range C3-C4 olefins; alkylating this olefin-rich fraction with an alkylatable hydrocarbon material suitable for producing, by alkylation with this olefin-rich fraction, an alkylating gasoline rich in branched chain hydrocarbons;

   recovering this alkylating gasoline and admixing at least a substantial part thereof with at least a substantial part of the reforming gasoline from which the straight chain hydrocarbon material has been separated; and adding to the mixture a volatile combustible tension material to bring it to a Reid vapor pressure in the range of about 0.42 to 1.12 kg / cm2 satisfactory for motor gasoline, this tension material having a significantly higher anti-knock value than the separated straight chain hydrocarbon material subjected to cracking as before.



   10. A process according to claim 9, characterized in that the tension material is a volatile hydrocarbon material.



   11. In a process in which a petroleum gasoline fraction is reformed at elevated temperatures in the presence of pressurized hydrogen over a catalyst having high aromatization activity, to form a reforming product containing a high anti-knock velocity gasoline, and which comprises: the fractionation of a charge the improvement combined with this process / of petroleum re-forming feed to remove therefrom the C3 and lighter hydrocarbons and a light gasoline fraction formed hydrocarbons boiling in the range of C4 hydrocarbons up to about 71 to about 93 C, and to provide a higher boiling gasoline fraction as feed for reforming;

   the

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 fractionation of this reforming product to remove C3 and lighter hydrocarbons and a light reforming product fraction, consisting of hydrocarbons boiling in the range of C4 hydrocarbons up to about 71 to about 93 C, and to produce curing a reforming gasoline of higher boiling point; fractionation of these light gasoline and light reforming product fractions, in order to recover an isopentane fraction and a cracking feedstock boiling essentially in the range of aliphatic hydrocarbons above isopentane and lower than C7 hydrocarbons and containing at least the majority of normal pentane and hexane from these light gasoline fractions;

   cracking the cracking feedstock at elevated temperatures to convert it to a cracked product rich in unsaturated gaseous hydrocarbons; the application to this product of a separation operation to recover therefrom ethylene as a product and a feed: of alkylation consisting of a key-final hydrocarbon material having 3 or 4 carbon atoms per molecule; the alkylation of this alkylation feed with an alkylatable material suitable to produce, by alkylation with this feed, an alkylation product containing substantial quantities of a material in the boiling range of 1 gasoline and of high anti-knock value;

   recovering the alkylation gasoline of high anti-knock value from the alkylation and mixing at least a substantial part of this alkylation gasoline with at least a substantial part of the isopentane fraction and at least a significant portion of the heavier reforming gasoline;

   and adding C4 hydrocarbons to the resulting mixture in an amount sufficient to give a Reid vapor pressure of the mixture, of the gemstone of about 0.42 to about 1.12 kg / cm2, such that normal pentene and hexane from the reforming feed and products thereof are converted to higher value products, while

  <Desc / Clms Page number 67>

 relatively large amounts of C4 hydrocarbons are incorporated into the final gasoline-forming mixture, which is of high anti-knock value and good volatility characteristics for use in gasoline engines.



   12. A combined process for the manufacture, from a mixed hydrocarbon feedstock, of unsaturated gaseous hydrocarbons and gasoline of high antiknock value and having satisfactory volatility characteristics for use as gasoline. for engines, this process comprising: the fractionation of this feedstock to remove therefrom the C4 and lighter hydrocarbons, an isopentane fraction and a C5-C6 aliphatic hydrocarbon fraction containing at least the most of the normal pentane and saturated aliphatic hexenes from this feed and to provide a feed fraction for the reforming apparatus, boiling essentially below about 210 ° C;

   reforming the feed fraction intended for the reforming apparatus under these controlled conditions to form a reforming product of significantly increased anti-knock value; fractionation of the reforming product to remove the C hydrocarbons, and lighter ones, an isopentane fraction and a C5-C6 aliphatic hydrocarbon fraction containing at least most of the normal pentane and aliphatic hexanes saturated from the reforming product and to provide a stabilized reformed gasoline which is substantially free of at least normal pentane and saturated aliphatic hexanes;

   applying at least to normal pentane and saturated aliphatic hexanes recovered from the feedstock and reforming product, cracking at an elevated temperature under controlled conditions to achieve substantial conversion to a high temperature cracking product. holding large quantities of gas olefinic hydrocarbons; Applying to the cracked product a separation operation to provide ethylene as product and an olefin-rich fraction.

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 fines mainly containing hydrocarbons falling within the range of C3-C4 hydrocarbons;

   the alkylation of this olefin-rich fraction with a suitable alkylatable hydrocarbon material to produce, on alkylation with this olefin-rich fraction, an alkylation product containing significant amounts of branched-chain hydrocarbons of high anti-knock value of the gasoline boiling range; separating an alkylation gasoline of high anti-knock value from this alkylation product;

   mixing at least a significant portion of this alkylation gasoline with at least a significant portion of the stabilized reformed gasoline and at least a significant portion of the isopentane recovered from the feedstock and from the reforming product and adding C4 hydrocarbon material to the mixture to bring it to a Reid vapor pressure in the range of about 0.42 to 1.12 kg / cm2, satisfactory for motor gasoline, so as to provide gasoline of An engine of high anti-knock value and having volatility characteristics suitable for use as motor gasoline.



   13. A method according to claim 12, characterized; in that the higher boiling point feed fraction for the reforming apparatus is reformed on a reforming catalyst suitable to promote conversion of naphthenes to aromatics at elevated temperatures in the range of about 454 to 593 C and at pressures in the range 3.5 to 70 kg / cm2, in the presence of hydrogen in an amount of about 0.5 to 20 moles per mole of hydrocarbon feed, cracking, - C5 aliphatic hydrocarbons -C6 being conducted at temperatures in the range of approximately 7040 to 954 C.



   14. A process according to claim 12, characterized in that the cracked product is subjected to a separation phase to recover as products, ethylene, butadiene, an aromatic gasoline, an aromatic distillate boiling above

  <Desc / Clms Page number 69>

 the boiling range of gasoline for engines, and an olefin-rich fraction containing significant amounts of propylenes and butylenes, the latter fraction being alkylated as before with an isoparaffinic material which consists mainly of ' iacbutane, the aromatic essence being added to the mixture of stabilized reformed gasoline, alkylated gasoline, isopentane and C4 hydrocarbon material.



   15.A process according to claim 6, characterized in that butadiene is separated from the cracked product as a separate product, in addition to methylene, and in that the olefin-rich alkylation feed is subjected to. to alkylation with the addition of isobutane.



  * 16. A process according to claim 6, characterized in that in the fractionation of the hydrocarbon fraction containing the feed to the gasoline reforming apparatus, O3 and lighter hydrocarbons are removed and a fraction of es - light gasoline boiling in the excellent range of C4 hydrocarbons to an end point of about 71 to 99 C is recovered in addition to the gasoline feed to the reforming apparatus, and this light gasoline fraction is further fractionated together with a light reforming fraction to separate hydrocarbons
C4, which are subjected to cracking;

   and, in the fractionation of this reformed product, C3 and lighter hydrocarbons are removed and a light reforming fraction boiling in the range of C4 hydrocarbons to an end point of about 71 to 99 C is recovered in addition of the stabilized reforming gasoline, this light reforming gasoline further being fractionated together with the light gasoline fraction.



   17. A combined process for making, from a petroleum gasoline feedstock, petrochemicals and motor fuel of high anti-knock value and suitable volatility characteristics, said process comprising : fractionation of the feedstock to remove C3 and lighter hydrocarbons and to provide

  <Desc / Clms Page number 70>

 light gasoline fraction containing boiling hydrocarbons in the range from C4 hydrocarbons up to about 71 to
93 C and a heavier gasoline fraction boiling above r from about 71 to 93 C and having an ASTM end point in the range of about 149 to 210 C;

   fractionating this light gasoline fraction together with a light reforming product to provide a normal butane fraction, a butylene-isobutane fraction, an isopentene fraction and a light cracking feed consisting primarily of straight chain C5-C6 hydrocarbons; reforming this heavier gasoline on a catalyst having aromatization activity at temperatures in the range of about 454 to 593 C and in the presence of hydrogen under pressure to form a gasoline-containing reforming product of high anti-knock value;

   fractionation of this reforming product to remove C3 and lighter hydrocarbons and to provide a light reforming product boiling in the gem ranging from C4 hydrocarbons at about 71 to 930C and reforming gasoline boiling above about 71 to 93 C and having an ASTM gem end point of about 149-210 C, this reformin-gasoline being substantially free of C6 and lighter aliphatic hydrocarbons; fractionating this light reforming product along with the light gasoline fraction; applying to the light cracking feed, pyrolytic cracking at temperatures in the range of about 704 and 954 C to form a cracked product containing substantial amounts of unsaturated gaseous hydrocarbons and aromatics;

   applying to this cracked product, a separation operation to provide an ethylene fraction, a butadiene fraction, an aromatic gasoline fraction and a C3-C4 hydrocarbon fraction rich in propylenes and butylenes; alkylating the latter fraction together with the added butylene-isobutane and isobutane fraction under controlled conditions to provide a branched chain hydrocarbon rich alkylation product; the separation of a valuable alkylation gasoline

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      high anti-knock from the alkylation product; mixing this alkylating gasoline with the normal butane fraction, the isopentane fraction, reforming gasoline and aromatic gasoline;

   and adding to the mixture a sufficient amount of additional C4 hydrocarbon material to give a Reid vapor pressure in the range of about 0.42 to 1.12 kg / cm2.



   18. A combined process of manufacturing, from a petroleum feedstock, wide boiling unsaturated gaseous hydrocarbons and gasoline of high antiknock value having satisfactory volatility characteristics. for use as motor gasoline, this process comprising: fractionating this feedstock to remove C4 and lighter hydrocarbons therefrom, an isopentane fraction, a light gasoline consisting mainly of C5 aliphatic hydrocarbons -C6 other than isopentane, a higher boiling point gasoline fraction substantially free from saturated aliphatic hexanes and lower boiling aliphatic hydrocarbons, and a boiling distillate above gasoline for engines;

   cracking this distillate at elevated temperatures to provide a first cracked product containing cracked gasoline; fractionation of this product to recover a stabilized cracked gasoline therefrom predominantly of C3 and lighter hydrocarbons;

   reforming this higher boiling gasoline fraction at temperatures in the range of about 454 to 593 C in the presence of hydrogen over a suitable catalyst to effect aromatization of naphthenes to aromatics, from so as to form a reforming product containing significantly increased anti-knock thief gasoline; fractionation of the reforming product to remove C4 and lighter hydrocarbons-) an isopentane fraction, and a light reforming product consisting primarily of C5-C6 aliphatic hydrocarbons other than isopentane and to provide a stabilized reformed gasoline that is sensitive-

  <Desc / Clms Page number 72>

 at least free from normal pentane and saturated aliphatic hexanes;

   pyrolytic cracking of the reformer and light product / light gasoline at temperatures in the range 704 to 95400 under controlled conditions to achieve a substantial conversion to a second cracked product containing large amounts of hydrocarbons gaseous olefins; applying to this cracked gasoline a separation operation to provide at least ethylene as a product and a fraction rich in olefins ocontaining mainly hydrocarbons having 3 or 4 carbon atoms in the molecule;

   applying to the olefin-rich fraction an alkylation with a suitable alkylatable hydrocarbon material to produce, by alkylation with the rich fraction, an alkylation product rich in branched-chain hydrocarbons of 11- gasoline boiling range; separating an alkylation gasoline of high anti-knock value from this alkylation product; mixing at least a significant part of the alkylation gasoline with at least a significant part of the stabilized reformed gasoline and the stabilized cracked gasoline and at least a significant part of the isopentane recovered from the feed d feed and reforming product:

   and adding a C4 hydrocarbon material to the mixture to bring it to a Reid vapor pressure in the range of 0.42 to 1.12 kg / cm2, satisfactory for motor gasoline.



   19. A process according to claim 18, characterized in that at least a part of the cracked gasoline separated from the first cracked product is subjected to catalytic reforming together with the gasoline fraction of boiling point. superior.



   20. A process according to claim 18, characterized in that a fraction consisting mainly of C5-C6 aliphatic hydrocarbons is separated from the first cracked product and is

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 subjected to pytolytic cracking at the same time as the light gasoline fraction and the light reforming product.



   21. In a refining operation in which a gasoline feed is subjected to a reforming operation under controlled conditions to produce a reforming gasoline product of improved anti-knock value, pre-screening which comprises: separating, from the feedstock containing the reforming feed gasoline and from the reforming product, C4 and lighter hydrocarbons and at least the majority of the straight chain, normally liquid hydrocarbons boiling in between boiling gasoline; cracking these normally liquid hydrocarbons at elevated temperatures to convert them to a product rich in gaseous olefins;

   applying to at least a substantial portion of the gaseous olefins a combined reaction in which these gaseous olefins constitute at least a substantial portion of the reactants, under controlled conditions to form a gasoline product of significantly higher anti-knock value that normally liquid hydrocarbons separated; and mixing at least a substantial portion of the gasoline product with the reforming gasoline remaining after separation from these normally liquid hydrocarbons, to provide a gasoline blend of high anti-knock value.



   22. A combined process of making, from a feedstock, gasoline, an engine fuel of high anti-knock value and ethylene, which comprises: reforming at least the major part from the gasoline feedstock to reforming under controlled conditions to form a reformed product containing reforming gasoline of enhanced anti-knock value; separating from at least the gasoline feedstock and / or the reformed product, at least the major part of the saturated hydrocarbons, by heat-

  <Desc / Clms Page number 74>

 not straight, normally liquid, contained therein;

   the pyroly- tic cracking of the liquid straight chain hydrocarbons so separated at temperatures in the range of about 704 to 9540C and under controlled conditions to convert these liquid hydrocarbons to a cracked product rich in gaseous olefins, especially l ethyli ne; applying to the cracked product a separation operation to recover therefrom ethylene as product and a gaseous feedstock rich in at least one olefin from the range of olefins 3 and C4;

   application to the last mentioned feedstock of a combined reaction in which the constituents of the latter feed constitute a substantial part of the reactants, to form a gasoline product having a higher anti-knock value than straight chain hydrocarbons, liquid, separated.



   23. The invention, as described above.