JP2013512317A - Increasing octane number of light naphtha using germanium-zeolite catalyst - Google Patents

Abstract

The present invention relates to a process for increasing the octane number of a naphtha hydrocarbon feed having predominantly paraffin content using a germanium-containing zeolite catalyst. The catalyst is a non-acidic germanium zeolite on which a noble metal such as platinum is deposited. The zeolite structure may be MTW, MWW, MEL, TON, MRE, FER, MFI, BEA, MOR, LTL or MTT. Zeolites are made non-acidic by base exchange with alkali metals or alkaline earth metals such as cesium, potassium, sodium, rubidium, barium, calcium, magnesium and mixtures thereof, reducing acidity. The catalyst is sulfur resistant. The hydrocarbon feed may contain up to 1000 ppm sulfur. The present invention is applicable to feed streams that are primarily naphthenes and paraffins.

Description

  The present invention relates to a naphtha hydrocarbon feed mainly having a paraffin content using a base exchange zeolite, such as Pt / CsGeZSM-5, having germanium in the crystal framework and having a noble metal deposited on the zeolite. It relates to the process of increasing the octane number.

Naphtha is a mixture of mainly linear, branched and cycloaliphatic hydrocarbons, light naphtha with 5 to 9 carbon atoms per molecule and heavy naphtha with 7 to 9 carbons per molecule. . Typically, light naphtha comprises naphthenes such as cyclohexane and methylcyclopentane, and linear and branched paraffins such as hexane and pentane. Light naphtha typically contains 60% to 99% by weight paraffins and cycloparaffins. Light naphtha is a petroleum oil having a molecular weight range of 70-150 g / mol, a specific gravity range of 0.6-0.9 g / cm ³ , a boiling point range of 50-320 ° F., and a vapor pressure of 5 to 500 mmHg (torr) at room temperature. It can be characterized as a distillate. Light naphtha can be obtained from crude oil, natural gas condensate or other hydrocarbon streams by various processes such as distillation.

  The octane number of liquid hydrocarbons is an evaluation standard for ignition properties when burned with a standard (spark ignition internal combustion) engine. The higher this number, the less likely the hydrocarbon will be “knocked” (explosions caused by its premature combustion in the combustion chamber). Octane number represents a mixture of HYPERLINK "http://en.wiktionary.org/wiki/isooctane" \ o "isooctane" isooctane and n-heptane with the same anti-knock properties as fuel, i.e. a carbonization with an octane number of 92 Hydrogen has the same knock as a mixture of 92% isooctane and 8% n-heptane. The octane number is often determined by standard tests such as ASTM 2699 or ASTM 2700. In general, the octane number is increased by reducing the amount of linear paraffins in the hydrocarbon.

  One means of reducing the amount of hydrocarbon linear paraffins is by isomerizing paraffins primarily from linear to predominantly branched. US Pat. No. 7,414,007 discloses a catalyst and process for the isomerization of paraffin feedstocks to obtain higher octane hydrocarbons. The catalyst is an oxide or hydroxide support of a group IVB metal (zirconium, titanium or hafnium), which is tungsten by treatment with a tungsten compound to form a strong acid, on which a phosphorus compound and a platinum compound are formed. Has been deposited. The catalyst is used in an isomerization process that converts linear paraffins to isoparaffins.

Another means of reducing hydrocarbon linear paraffin content is by selective adsorption. US Pat. No. 7,037,422 contacts a hydrocarbon feed of a mixture of isomers of C ₅ and C ₆ paraffins with a CFI zeolite, such as CIT-5, in an adsorption zone, and thus C ₅ and C 6 _For selectively producing high RON (Research Octane Number, ASTM C2699) naphtha by selectively adsorbing branched isomers of ₆ paraffins compared to linear isomers and recovering the naphtha product from the adsorption zone Disclose the process. At a certain carbon number, the shortest and most branched isomer tends to have the highest octane number, so increasing the proportion of these high octane isomers in the hydrocarbon increases the octane number of the overall hydrocarbon. CFI zeolite can also be a hydroisomerization catalyst that selectively isomerizes n-C ₅ and n-C ₆ to branched isomers. CFI zeolites may contain metals active for hydroisomerization, such as platinum, palladium, iridium or a mixture of platinum and palladium. US Pat. No. 7,029,572 discloses a similar process using an ATC zeolite, such as SSZ-55.

  Another means of reducing the amount of hydrocarbon paraffins is by aromatizing paraffins to aromatics. US Pat. No. 6,083,379 discloses a process for desulfurizing and increasing octane number by aromatizing hydrocarbons. The catalyst is an activity promoter such as a zeolite having a metal or metal oxide of group IA, IIA, IIIA, IVA, VA, VIA, IIB, IIIB, IVB, VB, VIB or VIII, such as ZSM-5.

US Pat. No. 6,245,219 discloses a naphtha-containing hydrocarbon feed stream comprising at least about 25 wt% C ₅ to C ₉ aliphatic and cycloaliphatic hydrocarbons, ZSM-5 catalyst and dehydrogenated metal, For example, a process for modifying with gallium, zinc, indium, iron, tin or boron is disclosed, wherein the catalyst is sufficient to neutralize 50% -90% of the surface acidic sites with a Group IIA alkaline earth. Modified with a similar metal, such as barium, or an organosilicon compound. Aromatization of n-paraffins to aromatics results in a higher octane number of the resulting product.

US Pat. No. 6,177,374 describes the oxidation of silicon, zinc and aluminum used to produce high octane aromatics such as benzene, toluene, xylenes from natural gas condensate (NGC) and light naphtha. A product catalyst is disclosed. The catalyst is represented as M _{2 / n} O, xAl ₂ O ₃ , ySiO ₂ , zZnO, where M is a proton and / or metal cation, n is the valence of the cation, and x, y and z is the number of moles of Al ₂ O ₃ , SiO ₂ and ZnO, and y / x (SiO ₂ / ZnO mole ratio) is a number in the range of 5 to 1000.

  US Pat. No. 5,510,016 discloses catalytic desulfurization of cracked fractions in gasoline by a hydrotreating step that reduces the octane number followed by treatment with self-bonded or binderless zeolite to recover lost octane. Disclose a process for doing this. Light naphthas generally do not provide higher octane numbers without modification. While catalytic reforming can increase the octane number by converting some of the paraffins and cycloparaffins to aromatics, platinum-type reforming catalysts are generally not sulfur resistant. Hydrodesulfurization reduces the octane number of the feed, which can be achieved by, for example, selective cracking of heavy paraffins to lighter paraffins by converting lower octane paraffins to higher octane products. Recovered by decomposition of low octane paraffins, formation of olefins, ring opening to obtain a high octane component, and dehydrocyclization and aromatization of paraffins to alkylbenzenes.

US Pat. No. 7,414,007 US Pat. No. 7,037,422 US Pat. No. 7,029,572 US Pat. No. 6,083,379 US Pat. No. 6,245,219 US Pat. No. 6,177,374 US Pat. No. 5,510,016

  It would be advantageous to have a sulfur tolerant catalyst for increasing the octane number of naphtha hydrocarbon feeds having predominantly paraffinic content.

  The octane number of a naphtha hydrocarbon feed having a predominantly paraffinic content is increased by contacting the hydrocarbon feed with a catalyst comprising a non-acidic germanium zeolite on which a noble metal such as platinum is deposited. Zeolite is non-acidic. Examples of zeolite structures are MTW, FER, MEL, TON, MRE, MWW, MFI, BEA, MOR, LTL or MTT. In one embodiment of the invention, the zeolite has an MFI structure. The term “ZSM-5” is used herein to mean a zeolite having an MFI structure. Zeolites have silicon, germanium, and optionally aluminum, in a zeolite framework crystal framework. An example of a catalyst is an aluminosilicate zeolite with germanium in the framework, for example Pt / CsGeZSM-5, which has been base exchanged, rendered non-acidic, and has platinum deposited thereon. This catalyst is sulfur resistant up to a level of 1000 ppm in the hydrocarbon feed.

The process for increasing the octane number of the hydrocarbon feed is: a) simultaneously isomerizing n-paraffins to isoparaffins, further isolating isoparaffins to more highly branched isoparaffins, and converting n-paraffins to Having C ₆ -C ₈ alkanes in conditions for decomposing into smaller n-isoparaffins, dehydrogenating both n- and isoparaffins, and dehydrocyclizing n-paraffins to aromatics Hydrocarbon feed containing naphtha is contacted with a catalyst comprising non-acidic medium or large pore zeolites, including silicon, germanium and optionally aluminum, on which precious metals are deposited. And b) recovering the hydrocarbon product. The naphtha feed may have a C ₆ -C ₈ content of at least 30%, at least 40% or at least 50%.

Zeolite is a crystalline hydrated aluminosilicate that can contain elements other than aluminum and silicon in the crystal framework. The term “zeolite” includes not only aluminosilicates, but also materials in which aluminum is replaced by other trivalent elements and materials in which silicon is replaced by other tetravalent elements. Generally, zeolites have a TO ₄ tetrahedral structure, which forms a three-dimensional network by sharing oxygen atoms, where T represents a tetravalent element, such as silicon, and a trivalent element, such as aluminum. Zeolites are known catalysts for isomerization, toluene disproportionation, transalkylation, hydrogenation and alkane oligomerization and aromatization. Some zeolite catalysts, especially those containing Group VIII deposited metals, are susceptible to sulfur poisoning.

  The germanium zeolite (Ge-zeolite) catalyst on which the noble metal is deposited is base-exchanged with an alkali metal or alkaline earth metal to reduce acidity. Base substitution may occur before or after the noble metal is deposited. The catalyst is used to increase the octane number of natural gas condensate, light naphtha or raffinate from aromatic extraction and other purification or chemical processes, provided that the condensate, naphtha or raffinate has a significant amount of paraffin. As a condition.

Silicon to aluminum atomic ratio of the zeolite (Si: Al ₂₎ is a 40-∞. An example is a Si: Al ₂ atomic ratio in the range of 40 to 500 without limiting the present invention. Another example does not limit the invention, but Si: Al ₂ atomic ratios in the range of 50 to 150.

  The zeolite of the present invention is a medium pore zeolite or a large pore zeolite. As used herein, the term “medium pore” should be construed to mean that the average pore size is in the range of about 5 to about 7 angstroms. As used herein, the term “large pore” should be construed to mean that the average pore size is in the range of about 7 to about 10 angstroms. These ranges can overlap, and certain zeolites can be considered either medium pore zeolites or large pore zeolites. Zeolites with an average pore size of less than about 5 Angstroms, ie “small pore” zeolites, would not be considered either medium pore zeolites or large pore zeolites. Small pore zeolites do not allow molecular diffusion of molecules of the desired aromatic product within the pores and channels, such as benzene, ethylbenzene, toluene and xylenes. Some zeolites have two separate channels of different sizes, for example, MOR has a 7.0 x 6.5 angstrom 12 ring channel and an <5 angstrom 8 ring channel. Multichannel zeolites having at least one channel within the above range for medium pore zeolites or large pore zeolites are considered to be within the scope of zeolites useful in the present invention. Examples of medium and large pore zeolites are MFI, BEA, LTL, MOR and MTT, without limiting the present invention.

  The germanium content of the zeolite ranges from 1.0% to 10.0% by weight. One example of the germanium content of the zeolite is from 3.5% to 6.0% by weight.

  The noble metal is deposited on the zeolite by any known method for depositing the metal on the zeolite. Typical methods for depositing metals on zeolites are ion exchange and impregnation. Due to the deposition of the noble metal, the noble metal will be present not only in the surface of the zeolite but also in the pores and channels of the zeolite. In one example of the present invention, the noble metal is present in the catalyst in the range of 0.05% to 3% by weight. In another example of the invention, the precious metal is 0.2% to 2% by weight. In another example, the precious metal is 0.2 to 1.5% by weight. Examples of noble metals are platinum, palladium, iridium, rhodium, ruthenium and combinations thereof.

  The zeolite of the present invention is non-acidic. As used herein, one meaning of the term “non-acidic” is base exchanged with an alkali metal or alkaline earth metal such as cesium, potassium, sodium, rubidium, barium, calcium, magnesium, lithium and mixtures thereof; It should be taken to mean a zeolite with reduced acidity. Base substitution can occur during the synthesis of the zeolite with alkali metal or alkaline earth metal added as a component of the reaction mixture, or occurs with crystalline zeolite before, after, or simultaneously with the deposition of the noble metal there is a possibility. Zeolite is base exchanged to the extent that most or all of the cations associated with aluminum are alkali or alkaline earth metals. An example of a monovalent base: aluminum molar ratio in the zeolite after base substitution is at least about 0.9. In one embodiment of the invention, cesium is an alkali metal and is present in a molar ratio ranging from about 1 to about 2 with respect to aluminum.

  Another meaning of “non-acidic” within the present invention is an aluminum free zeolite. Zeolite that does not contain aluminum may be non-acidic but not base exchanged. The aluminum-free zeolite may contain other tetravalent or trivalent elements such as titanium, iron, gallium, boron, germanium or tin. “No aluminum” means having an aluminum content of 0.4 wt% or less. Within that sense, for the purposes of the present invention, the zeolite can be made “non-acidic” by substitution with a base or by having a low aluminum content.

  The zeolite may contain accelerators or modifiers known in the art. These promoters or modifiers are present in a catalytically effective amount, for example from about 0.1% to about 1.0% by weight. Examples of accelerators or modifiers are rhenium, iridium, palladium and tin.

  The catalyst is used to change the physical properties of the catalyst, such as materials, such as metal oxides; mixed metal oxides, such as magnesium, aluminum, titanium, zirconium, thorium, silicon or mixtures thereof; clays, such as, for example Kaolin or montmorillonite; carbon such as carbon black, graphite, activated carbon, polymers or charcoal; metal carbide or nitride such as molybdenum carbide, silicon carbide or tungsten nitride; zeolites; metal oxide hydroxide such as boehmite It may be supported on or combined with them.

  The hydrocarbon feed may contain up to 1000 ppm of sulfur. In one embodiment of the invention, the hydrocarbon feed contains about 1 ppm to about 500 ppm sulfur. In another embodiment of the present invention, the hydrocarbon feed contains about 10 ppm to about 100 ppm sulfur.

One particular example of a hydrocarbon conversion process using a zeolite catalyst is disclosed in US Patent Application Publication No. 2008/0255398, which was published on October 16, 2008, which is incorporated herein by reference. Thus, dehydrocyclization of alkanes to aromatics, for example, C ₆₊ alkanes to aromatics, primarily benzene, toluene and xylenes. The dehydrocyclization process promotes cyclization and dehydrogenates the ring to their individual aromatics.

  US Pat. No. 6,784,333 (incorporated herein by reference) discloses an aluminum-silicon germanium zeolite catalyst having platinum deposited thereon. The catalyst can be used in the aromatization of alkanes, in particular in the aromatization of lower alkanes such as propane. The catalyst may be an MFI zeolite, ie Pt / Ge-ZSM-5, in which germanium is incorporated in the crystal framework. The catalyst may be sulfided before or during the aromatization process.

In accordance with the IUPAC recommendation, an example of a catalyst for the present invention is represented as follows:
(Cs ⁺ ₂ Pt _0.37 ([Si ₁₀₅ Ge ₄ Al ₂ O ₂₂₂ ] -MFI

The present invention increases the octane number by several reaction mechanisms that convert hydrocarbons having a relatively low octane number to hydrocarbons having a relatively high octane number. Non-stoichiometric examples of these reaction mechanisms are shown below. One example is the isomerization of n-paraffins to isoparaffins, for example:

Another example is the further isomerization of isoparaffins to more highly branched isoparaffins, for example:

Another example breaks down n-paraffins into smaller n- and isoparaffins, for example:

Another example is dehydrogenation of both n- and isoparaffins, for example:

Another example is dehydrocyclization of n-paraffins to aromatics, for example:

  The above chemical reaction is presented to illustrate the reactants and products in the process of the present invention that convert hydrocarbons that are not chemically balanced but have a relatively low octane number to hydrocarbons that have a relatively high octane number. It should be noted that.

  The catalyst of the present invention can simultaneously function as an isomerization, cracking, dehydrogenation and dehydrocyclization catalyst. The octane number for the above hydrocarbons is the ASTM Technical Technical Publication # 225, “Knocking Characteristics of Pure Hydrocarbons” and the Research Octane Number (RON) MON Octane Number (ON): The average value of motor octane number), that is, (RON + MON) / 2.

The process feed may include hydrocarbons and non-hydrocarbons other than C ₆ -C ₈ alkanes, ie compounds that are not hydrocarbons. This may include lower alkanes such as pentane, and higher alkanes such as nonane and decane. The process feed may contain isoparaffins, olefins, naphthenes and even aromatics. Those components of the feed that are not C ₆ -C ₈ alkanes may be catalytically reacting hydrocarbons or catalytically non-reactive or inert hydrocarbons or non-hydrocarbons, such as diluents. In one embodiment, the process feed is naphtha having at least 30% C ₆ -C ₈ alkanes. In another embodiment, the process feed is naphtha having at least 40% C ₆ -C ₈ alkanes. In another embodiment, the process feed is naphtha having at least 50% C ₆ -C ₈ alkanes.

Aromatization process, the liquid hourly space velocity ranging between 0.1 h ^-1 and 100h ^-1, 200 ° C. and 600 ° C. range between the temperature, be performed at a pressure ranging between 1psia and 315psia Good.

  Having generally described the invention, the following examples are provided as specific embodiments of the invention to demonstrate their implementation and advantages. It is understood that the examples are provided for purposes of illustration and are not intended to limit the specification or the claims that follow in any way.

<Catalyst preparation>
The catalyst used in the examples was prepared according to the following procedure.

  Solution # 1 was made by diluting 15.84 g of a 50 wt% NaOH solution with 131.25 g of deionized (DI) water and then dissolving 7.11 g of germanium dioxide. Solution # 2 was made by diluting 3.84 g sodium aluminate solution (23.6 wt% alumina and 19.4 wt% sodium oxide) with 153.9 g DI water. Solution # 1 was added to 150 g Ludox AS-40 (40 wt% silica in colloidal state) and stirred vigorously for 10 minutes to obtain a homogeneous mixture. Solution # 2 was placed in this mixture with stirring. After stirring vigorously for 15 minutes, 105.42 g of tetra-n-propylammonium hydroxide (TPAOH) was added and the mixture was stirred for 60 minutes. Finally, 23.32 g of glacial acetic acid was added to the gel and the pH of the mixture was adjusted to about 9. This mixture was placed in a 1 L stainless steel autoclave and heated at 160 ° C. for 36 hours with stirring. The resulting solid was then filtered from the mother liquor and washed with DI water. The resulting solid was calcined at 550 ° C. for 6 hours in an oven with airflow. The solid MFI structure was confirmed by measuring the powder X-ray diffraction pattern.

GeZSM-5 prepared as described above was washed with an aqueous CsNO ₃ solution (0.5 M) and then filtered. The filtrate was then rewashed 3 times more with 0.5M CsNO ₃ and rinsed with distilled water during final filtration. The zeolite powder was then calcined in air at 280 ° C. for 3 hours. 1% Pt was added by an initial wet impregnation method by adding a solution of Pt (NH ₂ ) ₄ (NO ₃ ) ₂ dissolved in deionized water dropwise to Cs-exchanged GeZSM-5. The material was dried in a 110 ° C. drying oven for 1 hour and then calcined at 280 ° C. for 3 hours.

Prior to the test, the catalyst powder was pressed to a size of 20-40 mesh. 2.16 cm ³ of the sized catalyst was mixed with 5.84 cm ³ of inert silicon carbide chips and pretreated in a stream of hydrogen at 460 ° C. for 1 hour.

<Catalyst test>
The catalyst prepared by the above procedure was tested as follows.

  Catalyst particles mixed with inert silicon carbide chips were placed in a 1/2 "OD plug reactor. A synthetically blended light naphtha was disclosed for light naphtha in US Pat. No. 6,884,531. The composition is calculated based on PIONA analysis, each component is individually weighed to obtain the desired mole fraction, and the components are mixed to produce a feed mixture that is produced and evaporated to about 150 The gas mixture was passed through a reactor maintained at the specified conditions in the table below, and the reaction products were analyzed by gas chromatography, the results being shown in Table 1 below. The octane number increased from 51 in the naphtha feed to 95 in the reformate.

  The octane number was estimated by using the pure component values for research octane number (RON) and motor octane number (MON) from ASTM Special Technical Publication # 225, “Knock Properties of Pure Hydrocarbons”. The numerical average of each component [(RON + MON) / 2] was weighted to estimate the octane number of the feed and reformate.

  The concentration of low octane components such as n-hexane, 2-methylpentane and 3-methylpentane decreased from 87.4% to 26.2%. The concentration of the high octane component increased (2,2 and 2,3-dimethylbutane: 5.3% to 6.0%, benzene: 1.4% to 38.5%, n-butane, isobutene and isopentane: 0.0% to 2.5%, cyclic and branched olefins such as 2-methylpentane related olefins, 3-methylpentane related olefins, methylcyclopentenes and isobutene: 0.0% to 16.0%) .

  Fuel standards may limit the amount of olefins present in gasoline and may require that some or all of the olefins be hydrogenated to the corresponding paraffins. Table 2 shows the calculated composition and octane number of the product stream when all of the olefins are hydrogenated. The octane number will be increased from 51 for the naphtha feed to 89 for the reformate.

  Due to its important value as a chemical intermediate, benzene may be extracted from the reformate. Table 3 shows the calculated composition and octane number of the reformate when all benzene is removed. The octane number will increase from 51 for naphtha to 78 for reformate.

  It should be noted that the octane number is increased even in the absence of benzene in the product. Therefore, the increase in octane number is not only an increase in the amount of aromatics by aromatizing n-paraffins, but also isomerization of n-paraffins into isoparaffins, and isoparaffins that are more highly branched from isoparaffins. By breaking down n-paraffins into smaller n-isoparaffins and dehydrogenating both n- and isoparaffins. The concentration of low octane components such as n-hexane, 2-methylpentane and 3-methylpentane is reduced and high octane components such as 2,2 and 2,3-dimethylbutane, n-butane, isobutene, isopentane, 2- The concentrations of methylpentane related olefins and 3-methylpentane related olefins, and methylcyclopentenes were increased. This data demonstrates that the process and catalyst of the present invention embody mechanisms other than paraffin aromatization.

The catalyst of the present invention is suitable for reforming a hydrocarbon feed having a linear C ₆ -C ₈ alkane content of at least 25%, such as a conventional acidic reforming catalyst, such as a Group VIII metal on an oxide support, such as May be present in a series of processes with platinum deposited on alumina or silica. Conventional acidic reforming catalysts may include promoters such as rhenium, tin, cobalt, nickel, iridium, rhodium, ruthenium and combinations thereof. In one embodiment, the acidic reforming catalyst is platinum and either rhenium or iridium deposited on alumina. Either catalyst can be the first catalyst in a series of processes. In one example, an acidic reforming catalyst comprising platinum deposited on alumina or silica is the first catalyst and comprises silicon, germanium, and optionally aluminum, including Pt / CsGeZSM-5. The non-acidic medium pore or large pore zeolite on which the noble metal is deposited is the second catalyst.

  Many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.

Claims (33)

A process for increasing the octane number of a hydrocarbon feed comprising:
a) At the same time, n-paraffins are isomerized into isoparaffins, the isoparaffins are further isomerized into more highly branched isoparaffins, the n-paraffins are broken down into smaller n-isoparaffins, and n-paraffins And a feed containing naphtha with C ₆ -C ₈ alkanes under conditions for dehydrogenating both isoparaffins and dehydrocyclizing n-paraffins to aromatics, silicon, germanium, and Optionally contacting with a catalyst comprising non-acidic medium pore or large pore zeolite comprising aluminium, on which a noble metal is deposited, as required;
b) recovering the hydrocarbon product;
Including the process.   The process of claim 1, wherein the zeolite is a medium pore zeolite.   The process of claim 2 wherein the average pore size ranges from about 5 to about 7 angstroms. The process of claim 1, wherein the zeolite has a Si / Al ₂ atomic ratio of 40-500. The process of claim 1, wherein the zeolite has a Si / Al ₂ atomic ratio of 50-150.   The process of claim 1, wherein the germanium content of the zeolite ranges from 1.0 wt% to 10 wt%.   The process of claim 6, wherein the germanium content of the zeolite ranges from 3.5 wt% to 6 wt%.   The process of claim 1, wherein the noble metal is present in the range of 0.05% to 3%.   The process of claim 8, wherein the noble metal is present in the range of 0.2% to 2%.   The process of claim 9, wherein the noble metal is present in the range of 0.2% to 1.5%.   The process of claim 1, wherein the noble metal is platinum.   The process according to claim 1, wherein the zeolite is rendered non-acidic by base substitution with an alkali metal or alkaline earth metal.   The process of claim 12, wherein the alkali metal is cesium present in a molar ratio to aluminum in the range of about 1 to about 2. Contact between said alkane catalyst takes place in the range of liquid hourly space velocity of between 0.1 h ^-1 and 100h ^-1, the process according to claim 1, wherein.   The process of claim 1, wherein the contact between the alkane and the catalyst occurs at a temperature in the range between 200 ° C. and 600 ° C. Contact between said alkane catalyst, a liquid hourly space velocity ranging between 0.1 h ^-1 and 100h ^-1, the temperature in the range between 200 ° C. and 600 ° C., in the range between 1psia and 315psia The process of claim 1 occurring at pressure.   The process of claim 1, wherein the zeolite has an MFI structure.   The process of claim 1, wherein the feed further comprises up to 1000 ppm sulfur.   The process of claim 1, wherein the catalyst is supported or bound. The process of claim 1, wherein the catalyst has the following formula:
(Cs ⁺ ₂ Pt _0.37 ([Si ₁₀₅ Ge ₄ Al ₂ O ₂₂₂ ] -MFI   The process of claim 1, wherein the zeolite comprises an additional element of titanium, iron, gallium, boron or tin.   The process of claim 1, wherein the catalyst is Pt / CsGeZSM-5. The process of claim 1, wherein the hydrocarbon feed comprises naphtha having at least 30% C ₆ -C ₈ alkanes. The process of claim 1, wherein the hydrocarbon feed comprises naphtha having at least 40% C ₆ -C ₈ alkanes. The process of claim 1, wherein the hydrocarbon feed comprises naphtha having at least 50% C ₆ -C ₈ alkanes.   The process of claim 1, wherein the feed further comprises higher and lower alkanes, isoparaffins, olefins, naphthenes and aromatics.   The process of claim 1, wherein the feed further comprises pentane, nonane, decane and non-hydrocarbons that are catalytically non-reactive or inert. A process for increasing the octane number of a hydrocarbon feed comprising:
a) contacting a hydrocarbon feed having a C ₆ -C ₈ alkane content of at least 50% with a first catalyst under conditions to form a reformed product;
b) contacting the reformed product with a second catalyst;
c) recovering the hydrocarbon product;
Including
One catalyst comprises an acidic reforming catalyst comprising a Group VIII metal on an oxide support,
Processes where the other catalyst is a non-acidic medium or large pore zeolite comprising silicon, germanium and, optionally, aluminum, on which a noble metal is deposited.   27. The process of claim 26, wherein the acidic reforming catalyst comprises platinum deposited on alumina or silica.   30. The process of claim 29, wherein the acidic reforming catalyst further comprises rhenium, tin, cobalt, nickel, iridium, rhodium, ruthenium and combinations thereof.   32. The process of claim 30, wherein the acidic reforming catalyst comprises platinum and either rhenium or iridium deposited on alumina.   27. The non-acidic medium or large pore zeolite comprising silicon, germanium and optionally aluminum, on which a noble metal is deposited, comprises Pt / CsGeZSM-5. Process.   An acidic reforming catalyst containing platinum deposited on alumina or silica is the first catalyst, including Pt / CsGeZSM-5, silicon, germanium, and optionally aluminum, on top of which 27. The process of claim 26, wherein the non-acidic medium or large pore zeolite on which the noble metal is deposited is the second catalyst.