MX2008008205A - Catalysts and methods for reforming oxygenated compounds - Google Patents

Abstract

Disclosed are catalysts and methods that can reform aqueous solutions of oxygenated compounds such as ethylene glycol, glycerol, sugar alcohols, and sugars to generate products such as hydrogen and alkanes. In some embodiments, aqueous solutions containing at least 20 wt%of the oxygenated compounds can be reformed over a catalyst comprising a Group VIII transition metal and a Group VIIB transition metal, preferably supported on an activated carbon-supported catalyst. In other embodiments, catalysts are provided for the production of hydrogen or alkanes at reaction temperatures less than 300°C.

Description

CATALYSTS AND METHODS TO REFORM OXYGENATED COMPOUNDS RESEARCH 0 FEDERALLY SPONSORED DEVELOPMENT This invention was made with the support of the government of the United States granted through DOC NIST ATP concession No. 70NANB3H3014 and DOE concession No. DE-FG36-04GO14258. The United States has certain rights in this invention. TECHNICAL FIELD The present invention is directed to catalysts and methods for reforming oxygenates, including compounds derived from biomass, to form products such as hydrogen or alkanes by reforming processes, such as reformation in aqueous phase. The catalysts and processes described herein can be used, for example, to reform aqueous solutions of glycerol, saccharose alcohols, sugars or polyols such as ethylene glycol and propylene glycol, as well as hydrocarboxylic acids. BACKGROUND There are finite quantities of non-renewable fossil fuels such as crude oil and natural gas, which are currently used to generate energy. Biomass (material derived from plants) is one of the most important renewable energy resources. The conversion of biomass into fuels, chemicals, materials and energy, reduces dependence on foreign oil and natural gas. Currently, biomass provides the only renewable alternative for liquid transportation fuels. The use of biomass strengthens rural economies, decreases America's dependence on imported oil, reduces air and water pollution and reduces greenhouse gas emissions. A key challenge to promote and sustain the vitality and growth of the industrial sector, is to develop efficient and environmentally benign technologies for general fuels, such as hydrogen, from renewable resources. The generation of energy from renewable resources such as biomass reduces the net rate of production of carbon dioxide, an important greenhouse gas that contributes to global warming. This is because biomass itself consumes carbon dioxide during its life cycle. Aqueous phase reformation (APR) is a catalytic reforming process that generates fuel gas rich in hydrogen from oxygenated compounds derived from biomass (glycerol, sugars, saccharose alcohols). The resulting fuel gas can be used as a fuel source for the generation of electricity by PEM fuel cells, solid-oxide fuel cells, genset for internal combustion engines or genset for gas turbines. The APR processes can generate light hydrocarbons (e.g., methane, ethane, propane, butane, propane and hexane) and / or hydrogen by reacting the oxygenated compounds with liquid water at low temperatures (e.g., less than 300 ° C). The key discovery of the APR process is that the reformation can take place in the liquid phase. The APR process can occur at temperatures (e.g., from 150 ° C to 270 ° C) in which the water-gas exchange reaction is favorable, making it possible to generate hydrogen with low amounts of CO in a single chemical reactor. The advantages of the APR process include: (i) carrying out the reaction at pressures (typically 15 to 50 bar) in which the hydrogen-rich effluent can be effectively purified; - (ii) generation of hydrogen-rich fuel gas at low temperatures without the need to volatilize the water, which represents an important energy saving, (iii) operation at temperatures in which the water-gas exchange reaction is favorable, making it possible to generate high quality fuel gas with low quantities of CO in a single chemical reactor, (iv) operation at temperatures that minimize the undesirable decomposition reactions typically encountered when carbohydrates are heated to elevated temperatures, and (v) utilization of the raw materials derived from agriculture found in the U.S.

The APR process takes advantage of the thermodynamic properties of the oxygenated compounds that contain a C: 0 stoichiometry of 1: 1 to generate hydrogen from these oxygenates at relatively low temperatures in a single reaction stage (see Figure 1), in contrast to certain multi-reactor systems used to produce hydrogen by hydrocarbon steam reforming. Figure 1 was constructed from the thermodynamic data obtained from the Chemical Properties Handbook, CL, Yaws, cGraw Hill, 1999. Reaction conditions for producing hydrogen from hydrocarbons can be dictated by thermodynamics for steam reforming ally to form CO and H2 (reaction 1) and the water-gas exchange reaction to form CO2 and H2 from CO (reaction 2). CnH2n + 2 + nH20 < ? nCO + (2n + 1) H2 (1) CO + H20 «C02 + H2 (2) Figure 1 shows the changes in the standard Gibbs free energy (AG ° / RT (Amb. Temp.)) associated with reaction 1 for a series of alkanes (CH4, C2H6, C3H8, C6Hi4), normalized by mol of the CO produced. Steam reforming of alkanes is thermodynamically favorable (i.e., negative values of AG0 / RT) at temperatures greater than about 675 K. Oxygenated hydrocarbons having a C: 0 ratio of 1: 1 produce CO and H2 of According to reaction 3. CnH2yOn ~ nCO + yH2 (3) Relevant oxygenated hydrocarbons having a C: 0 ratio of 1: 1 include methanol (CH3OH), ethylene glycol (C2H4 (OH) 2), glycerol (C3H5 (OH ) 3), and sorbitol (C6H8 (OH) 6). In Figure 1, dotted lines show the values of ln (P) for vapor pressures against the temperature of CH3 (OH), C2H4 (OH) 2, C3H5 (OH) 3, and C6H8 (OH) 6 (pressure in units of atmosphere). Figure 1 shows that the steam reforming of these oxygenated hydrocarbons to produce CO and H2 can be thermodynamically favorable at temperatures significantly lower than those required for alkanes with similar numbers of carbon atoms. Accordingly, the steam reforming of oxygenated hydrocarbons having a C: 0 ratio of 1: 1 would offer a low temperature path for the formation of CO and H2. Figure 1 also shows that the AG ° / RT value for the water-gas change from CO to C02 and H2, is more favorable at lower temperatures. Consequently, it is possible to produce H2 and C02 from the steam reforming of oxygenated compounds using a one-stage catalytic process, since the water-gas exchange reaction is favorable at the same low temperatures when reformation by Steam of carbohydrates. Although Figure 1 shows that the conversion of Oxygenated compounds in the presence of water at H2 and C02 is highly favorable at this low temperature, the subsequent reaction of H2 and C02 to form alkanes (CnH2n + 2) and water, is also highly favorable at low temperatures. For example, the equilibrium constant at 500 k for the conversion of C02 and H2 to methane (reaction 4) is of the order of 1010 per mole of C02. C02 + 4H2 ~ CH4 + 2H20 (4) The reforming reaction can be optimized not only to produce hydrogen, but also to produce hydrocarbons. For example, the complete reformation of sorbitol produces 13 moles of hydrogen for every 6 moles of the C02 produced: C6H1406 + 6H20? 6C02 + 13 H2 (5) However, the most thermodynamically favorable reaction consumes hydrogen to produce a mixture of water and hydrocarbons: C6H1406 + xH2? aH20 + bCH4 + cC2H6 + dC3H8 + eC4Hi0 + fC5H12 + gC6H14 (6) With reference to Figure 2, the individual reactions for the production of methane, ethane and hexane, are all thermodynamically favorable (ie, AG ° / RT < ) through the total temperature range presented in the graph. In addition, the production of these hydrocarbons is more favorable than the generation of hydrogen from the reaction of water with sorbitol. Thermodynamics for the formation of propane, butane and pentane fits smoothly within the homologous series (between - ethane and hexane), but these traces have been omitted from Figure 2 for clarity. Therefore, as described fully below, the present reaction can be optimized to produce a product mixture comprising almost exclusively hydrocarbons rather than hydrogen. Figure 2 was constructed from the thermodynamic data obtained from the Chemical Properties Handbook, C.L. Yaws, McGraw Hill, 1999. The US Patent. 6,699,457 for Cortright et al., As well as the US patent application. 2005/0207971 A1 with serial number 11/124717 and filed May 9, 2005, which are incorporated herein by reference, disclose a method for producing hydrogen from oxygenated hydrocarbon reagents, including the examples showing the conversion of reserves comprising up to 10% glycerol, glucose or sorbitol in hydrogen. The method can take place in the vapor phase or in the condensed liquid phase. The method can include the steps of reactivating water and a water-soluble oxygenated hydrocarbon having at least two carbon atoms, in the presence of a metal-containing catalyst. The catalyst contains a metal selected from the group consisting of Group VIII transition metals, their alloys, and mixtures of the same. The described method can be operated at lower temperatures than those used in the conventional steam reforming of alkanes. The U.S. Patent 6,953,873 to Cortright et al., Which is incorporated herein by reference, discloses a method for producing hydrocarbons from oxygenated hydrocarbon reagents, such as glycerol, glucose or sorbitol. The method can take place in the vapor phase or in the condensed liquid phase (preferably in the condensed liquid phase). The method can include the steps of reactivating water and a water-soluble oxygenated hydrocarbon having at least two carbon atoms, in the presence of a metal-containing catalyst. The catalyst may contain a metal selected from the group consisting of the transition metals of Group VIIB, their alloys and mixtures thereof. these metals can be supported on supports that exhibit acidity, or the reaction is conducted under liquid phase conditions at acidic pHs. The described method allows the production of hydrocarbons by the reaction of the liquid phase of water with oxygenated compounds derived from biomass. The Patents of E.U. Nos. 6, 964, 757 and 6, 964, 758 for Cortright et al., Which are incorporated herein by reference, describe a method for producing hydrogen from reagents. oxygenated hydrocarbon, such as methanol, glycerol, sugars (e.g., glucose and xylose), or saccharose alcohols (e.g., sorbitol). The method can take place in the condensed liquid phase. The method may include the steps of reactivating water and an oxygenated hydrocarbon soluble in water, in the presence of a metal-containing catalyst. The catalyst contains a metal selected from the group consisting of the transition metals of Group VIIB, their alloys and mixtures thereof. The described method can operate at lower temperatures than those used in the conventional steam reforming of alkanes. The U.S. Patent No. 4, 223, 001 for Novotny et al., Describes methods for generating hydrogen from an aqueous reserve comprising water-soluble alcohol, such as methanol or ethylene glycol, using a catalyst comprising a Group VIII metal, such as a catalyst containing homogeneous rhodium (eg, RhCl3 3H20) in the aqueous phase. Cortright et al., Describe the conversion of oxygenates, methanol, ethylene glycol, glycerol, sorbitol and glucose by reformation in aqueous phase over a 3% Pt / AI203 catalyst. Reaction temperatures varied from 498 to 538 K, system pressures varied between 29 and 56 bar, and feed concentrations of 1% by weight of the oxygenated compound.

Cortright R.D .; Davda R.R .; Dumesic J.A. , Nature, Vol. 419, p. 964, 2002. Davda et al. Describe the reaction kinetics studies of the 10% by weight aqueous phase reformation of ethylene glycol solutions on silica supported metal catalysts. The reaction temperatures for this investigation were 483 and 498 K and the reaction pressure of 22 bar. The results of this document show that the total catalytic activity of these catalysts decreases in the following order: Pt-Ni > Ru > Rh-Pd > Go . Davda, R.E .; Shabaker J.W .; Huber G.W .; Cortright R.D .; Dumesic J.A .; Appl. Cat. B: Environmental, Vol. 43, p. 13, 2003. Shabaker et al., Describe the reaction kinetics studies of the 10% by weight aqueous phase reformation of ethylene glycol solutions on Pt-black and Pt supported on Ti02, A1203, activated carbon, Si02, Si02- Al203, Zr02, Ce02 and ZnO. The reaction temperatures were 483 and 498 K, and the reaction pressures were 22.4 and 29.3 bar, respectively. High activity was observed for H2 production by reformation in aqueous phase on Pt-black and on Pt supported on Ti02, carbon, and A1203; a moderate catalytic activity is demonstrated for the production of hydrogen by Pt supported on Si02-Al203 and Zr02; and a lower catalytic activity is exhibited by Pt supported on Ce02, ZnO and Si02. The Pt supported on Al203, and to a lesser degree Zr02, exhibit greater selectivity for the production of H2 and C02 from the reformation in the aqueous phase of ethylene glycol. Shabaker J.W .; Huber G.W .; Davda R.R .; Cortright R.D .; Dumesic J.A .; Catalysis Letters, Vol. 88, p. 1, 2003. Davda et al., Describe the desired reaction conditions for generating hydrogen with low concentrations of CO by reformation in the aqueous phase of ethylene glycol to 3% by weight of the catalyst Pt / Al203. The reaction temperatures ranged from 498 K to 512 K, the system pressure between 25.8 and 36.2 bar, and the ethylene feed concentrations between 2 and 10% by weight. Davda R.R .; Dumesic J.A.; Angew. Chem. Int. Ed., Vol. 42, p. 4068, 2003. Huber et al., Describe the reaction of sorbitol to produce Cl through C6 alkanes on a platinum-based catalyst with varying amounts of hydrogen added as a co-feed. In this document, the platinum was loaded either in alumina or silica-alumina. This document addresses the mechanism for this process through a bi-functional pathway involving an acid-catalyzed dehydration reaction followed by a metal-catalyzed hydrogenation reaction. Reaction temperatures were between 498 and 538 K, pressures between 25.8 and 60.7 bar, and feed concentrations of 5% by weight of sorbitol. Huber G.W. Cortright R.S .; Dumesic J.A., Angew. Chem. Int. Ed., Vol. 43, p. 1549, 2004. Davda et al., Reviewed the reformation in aqueous phase of oxygenated compounds. The effects of the supports, supported metals, reaction conditions, and reactor configurations are discussed. The concentrations of the oxygenated compounds were less than 10% in this document. Davda R.R .; Shabaker J.W .; Huber G.W .; Cortright R.D .; Dumesic J.A .; Appl. Cat. B: Environmental, Vol. 56, p. 171, 2005. Huber et al., Describe the effectiveness of the tin-based nickel-based catalyst for the reformation in aqueous phase of oxygenated compounds such as ethylene glycol, glycerol and sorbitol at 498 K and 538 K. Oxygenated compounds in this investigation were less than 5% by weight. Huber, G.W .; Shabaker J.W .; Dumesic J.A .; Science, Vol. 300, p. 2075, 2003. Prior patents and literature describe methods for the aqueous phase reformation of water soluble oxygenated compounds in concentrations of 10% by weight or less. The energy balances in the APR system indicate that significant energy losses can occur due to the vaporization of water in the reactor system to maintain the partial pressure of the water in the hydrogen gas bubbles formed in the reactor.

Therefore, there is a need for catalyst systems and processes that have higher levels of activity to support the high conversion of high concentrations of oxygenated hydrocarbon reserves in an aqueous reforming system. SUMMARY In a first mode, reforming catalysts are provided. The reforming catalysts preferably comprise a mixture of transition metals of Group VIIB and Group VIII and mixtures thereof. preferably the reforming catalyst comprises Re and at least one transition metal selected from the group consisting of: Ir, Ni, Pd, Pt, Rh and Ru. Optionally, the catalyst further comprises Ce or La. Examples of suitable bimetallic catalysts include: IrRe, NiRe, PdRe, PtRe, Rh3Re, RhRe and RuRe. Pti.0Re2.5 is an example of a particularly preferred catalyst. The reforming catalyst can adhere to a stable aqueous support. For example, the catalyst can be adhered to a support comprising one or more materials selected from the group consisting of: carbon, zirconia, titania or ceria. Preferably, the catalyst is adhered to a carbon support. The carbon supports can be modified with other materials such as titanium, vanadium, tungsten or rhenium. In a particular aspect, the catalyst it can be adhered to a support such that the catalyst and support combination comprises 0.25% -10% by weight of the Group VIII metal in the catalyst, and the catalyst comprises Re and the Group VIII metal. The atomic ratio of Re to Group VIII metal is preferably between 0.25 and 10. A preferred catalyst comprises Pti.0Re2.5 adhered to a carbon support. In a second embodiment, methods are provided for reforming an oxygenated hydrocarbon from a solution of oxygenated hydrocarbon feedstocks, comprising the step of contacting the raw material solution with a reforming catalyst. The oxygenated hydrocarbon is preferably a water-soluble hydrocarbon, including polyol compounds, with any suitable number of carbon atoms, such as water-soluble oxygenated hydrocarbons with 1 to 12 carbon atoms, preferably 1 to 6 carbons . Examples of preferred oxygenated hydrocarbons include ethylene glycol, glycerol, and sorbitol. Methods for reforming an oxygenated hydrocarbon include methods for producing hydrogen, as well as methods for producing mixtures of hydrogen and alkanes, from one or more oxygenated hydrocarbons in a reservoir. The raw material solution can be an aqueous solution with at least 20 percent of the total raw material solution of a hydrocarbon oxygenated that has at least one oxygen. For example, the raw material solution may comprise at least about 20%, 30%, 40% or 50% of the oxygenated hydrocarbon. The raw material solution can be contacted with the reforming catalyst under conditions of reaction temperature and reaction pressure effective to produce nitrogen gas, as described herein. The reaction temperature and pressure are preferably selected to maintain the reserve in the liquid phase. For example, the reaction temperature may be between about 80 ° C and about 300 ° C and the reaction pressure may be between about 10 bar (145 psi) and about 90 bar (1300 psi). More preferably, the reaction temperature may be between about 120 ° C and about 300 ° C, even more preferably between about 150 ° C and about 300 ° C, and the reaction pressure may be between about 10 bar (145 psi) and approximately 50 bars (725 psi). Liquid phase modifiers such as water soluble salts of alkali or alkaline earth metals can optionally be added to the reserve in a range of 0.1 to 10% by weight of the aqueous solution to optimize the reaction products. For example, the addition of compounds to improve The pH of the reserve can increase the amount of hydrogen production in the reaction products. Methods for reforming oxygenated hydrocarbons can produce a variety of useful reaction products, such as hydrogen, carbon dioxide and / or light hydrocarbons (eg, methane, ethane, propane, butane and pentane) from a pool comprising sorbitol or glycerol. In one aspect, methods of producing alkanes are provided which include contacting the raw material solution with a reforming catalyst. The stock may include an aqueous solution having about 10-60% of one or more C 1 -C 6 oxygenated hydrocarbons, preferably glycerol, ethylene glycol and / or sorbitol. The reserve may be contacted with a catalyst comprising one or more metals selected from the group consisting of platinum, rhodium and rhenium. In one aspect, hydrogen production methods are provided which include contacting the raw material solution with a suitable reforming catalyst, as described herein. In a third embodiment, methods are provided for producing a reforming catalyst. In one aspect, a method for preparing a catalyst can include the steps of oxidizing a carbon support by heating a carbon support at a temperature of about 450 ° C, introducing air to form an activated carbon support, and contacting a carbon support with a catalyst. For example, the activated carbon can be heated to the desired temperature in an inert gas vapor, such as nitrogen, and then contacted with an air vapor at a suitable flow rate, added to the nitrogen. The carbon can be treated for a suitable period and then allowed to cool under flowing nitrogen. The method for preparing a catalyst further comprises the step of incorporating a metal oxide into the activated carbon support by an incipient wetting of the activated carbon support with a solution comprising a metal alkoxide comprising the metal oxide. Preferably, the metal oxide is incorporated without suspending the carbon support in solvent. For example, the functionalized carbon surfaces can be modified by impregnation of the metal oxides prior to impregnation of the catalyst precursors. Organic solutions of the suitable metal oxides, such as titanium n-butoxide or vanadium oxide triisopropoxide in anhydrous isopropanol can be added by incipient wetting for the oxidation to the air of the functionalized carbon and the wet carbon can be subsequently dried. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graph that represents the thermodynamics for the conversion of hydrocarbons and oxygenated hydrocarbons in carbon monoxide and hydrogen (H2); Figure 2 is a graph that represents the thermodynamics for the conversion of sorbitol to hydrogen, carbon dioxide, water and various hydrocarbons; Figure 3 is a graph depicting the effect of the feed composition on thermal efficiency at 100% conversion in an aqueous phase reforming system; Figure 4 is a schematic diagram of a reactor system that can be used to evaluate the aqueous phase reformation activity of the catalysts according to one embodiment of the present invention; and Figure 5 is a graph depicting the conversion of glycerol to gas phase products using the aqueous phase reformation according to one of the embodiments of the present invention. DETAILED DESCRIPTION Various methods for reforming high concentrations of oxygenated hydrocarbons with water at low temperatures and in the liquid phase are described herein. Unless stated otherwise, the following terms are defined herein, as indicated below. The term "reformation" should generically denote the total reaction of an oxygenated hydrocarbon and water to producing a product mixture comprising hydrocarbons and / or hydrogen and C02, regardless of whether the reaction takes place in the gas phase or in the condensed liquid phase. When the distinction is important, it should be noted as such. The term transition metal of "Group VIII" refers to an element selected from the group consisting of: Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Hs, Mt and Ds, in a state of oxidation. The term transition metal of "Group VIIB" refers to an element selected from the group consisting of: n, Te, Re and Bh, in an oxidation state. When the reforming of the oxygenated hydrocarbons is carried out in the liquid phase, the present invention makes possible the production of hydrocarbons from aqueous solutions of oxygenated hydrocarbons having limited volatility, such as sugars (glucose and xylose) and polyols of a heavier molecular weight such as xylitol and sorbitol. Abbreviations and Definitions: "GC" = gas chromatograph or gas chromatography. "GHSV" = gas space velocity per hour, "psig" = pounds per square inch in relation to atmospheric pressure (i.e., calibrated pressure). "Space velocity" = the mass / volume of the reagent per unit of the catalyst per unit of time. "TOF" = replacement frequency. "WHSV" = space velocity in weight per hour = mass of the oxygenated compound per mass of the catalyst per hour. "WGS" = water-gas change. Oxygenated Hydrocarbons Oxygenated hydrocarbons for the reforming processes described herein are preferably water soluble. Desirably, the oxygenated hydrocarbon has from 1 to 12 carbon atoms, and more preferably from 1 to 6 carbon atoms. For the raw material concentrations of about 30%, oxygenated hydrocarbons with 1 to 6 carbon atoms are particularly preferred. Preferred oxygenated hydrocarbons comprise at least 1 oxygen atom in the oxygenated hydrocarbon and oxygen to carbon ratios ranging from 0.50: 1.00 to 1.50: 1.00, including proportions of 0.25: 1.00, 0.33: 1.00, 0.66: 1.00, 0.75: 1.00 , 1.00: 1.00, 1.25: 1.00, 1.5: 1.00, as well as the proportions between them. Preferably, the oxygenated hydrocarbons have an oxygen to carbon ratio of 1: 1. The oxygenated hydrocarbon can also be a polyol. Non-limiting examples of preferred water-soluble oxygenated hydrocarbons can be selected from the group consisting of: methanol, ethanol, ethanediol, ethanedione, acetic acid, propanol, propanediol, propionic acid, glycerol, glyceraldehyde, dihydroxyacetone, lactic acid, pyruvic acid, malonic acid, butanediols, butanoic acid, aldotetroses, tautharic acid, aldooses, aldohexoses, ketotetroses, ketooses, ketohexosas and alditols. Of the 6-carbon oxygenated hydrocarbons, the aldohexoses and the corresponding aldithioles are particularly preferred, with glucose and sorbitol being more preferred. Xylose, arabinose, arabinol and xylitol are particularly preferred oxygenates having 5 carbon atoms. Sucrose is a preferred oxygenated hydrocarbon having more than 6 carbon atoms. The vapor phase reformation requires that the oxygenated hydrocarbon reagents have a sufficiently high vapor pressure at the reaction temperature so that the reagents are in the vapor phase. In particular, preferred oxygenated hydrocarbon compounds for use in the vapor phase method of the present invention include, but are not limited to, methanol, ethanol, ethanediol, glycerol and glyceraldehyde. When the reaction is to take place in the liquid phase, sugars such as sucrose, glucose, xylose and polyols such as xylitol and sorbitol, are the most preferred oxygenated hydrocarbons. In the methods of the present invention, the Oxygenated hydrocarbon compound is preferably combined with water to create an aqueous solution. The ratio of water to carbon in the solution is preferably from about 0.5: 1 to about 7: 1, including those provided therein such as 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6 : 1 and any proportion between these values. This range is provided as an example of a preferred non-limiting range. Water to carbon ratios outside this range are also included within the scope of this invention. The raw material solution can be an aqueous solution with at least 20 percent by weight of the total raw material solution of an oxygenated hydrocarbon having at least one oxygen. For example, the raw material solution may comprise at least about 20%, 30%, 40%, 50% or 60% of one or more oxygenated hydrocarbons. Unless otherwise specified, references to a percentage of the oxygenated hydrocarbon in the reserve refer to the total amount of oxygenated hydrocarbon species in the stock solution, which may include mixtures of multiple species of oxygenated hydrocarbons. Preferably the balance of the raw material solution is water. In some embodiments, the raw material solution consists essentially of water, one or more oxygenated hydrocarbons and, optionally, one or more of the reserve modifiers described herein, such as salts or alkali or alkaline earth acids. The raw material solution may preferably contain calculable amounts of hydrogen, preferably less than about 1 bar of partial pressure. In preferred embodiments, hydrogen is not added to the reserve. An aqueous reformation process can be operated at feed concentrations in this range using different catalysts. For example, Shabaker et al., Describe the aqueous phase reformation of 5 and 63% by weight ethylene glycol solutions of a NiSn catalyst. Shabaker J.W .; Simonetti D.A .; Cortright R.D .; Dumesic J.A.; J. Catal., Vol. 231, p. 67, 2005. As shown in Figure 3, the thermal efficiency of the system can be improved by operating the system with higher reservoir concentrations. Figure 3 shows that as the feed concentration increases from 10% by weight to 60% by weight, the calculated system efficiency increases from less than 10% to more than 80% at a 100% conversion of ethylene glycol . Figure 3 was constructed using the thermodynamic and vapor pressure data, taken from the Chemical Properties Handbook, C.L., Yaws, McGraw Hill, 1999. Catalysts Preferred metal catalyst systems for use in the present invention, comprise one or more Group VIII metals combined with one or more of the Group VIIB metals. Preferred VIIB Group metals would be rhenium or manganese. The preferred Group VIII metals would be platinum, rhodium, ruthenium, palladium, nickel or combinations thereof. The preferred loads of Group VIII metals would be in the range of 0.25% by weight to 25% by weight on carbon, including the percentages by weight of 0.10% and 0.05% increments between these values, such as 1.00%, 5.00%, 10.00%, 12.50%, 15.00% and 20.00%. the preferred atomic ratio of the metals of Group VIIB to those of Group VIII is in the range of 0.25 to 1 to 10 to 1, including the proportions between them such as 0.50, 1.00, 2.50, 5.00, and 7.50 a 1. The preferred catalyst composition is further achieved by the addition of Group IIIB oxides and the associated rarefied earth oxides. In this case, the preferred components would be the oxides of either lanthanum or cerium. The preferred atomic ratio of the Group IIIB compounds to the Group VIII metals is in the range of 0.25 to 1 to 10 to 1, including the proportions between them such as 0.50, 1.00, 2.50, 5.00 and 7.50 to 1. Unless otherwise specified, the citation of a catalyst composition as "X: Y" herein, wherein X and Y are metals, refers to a group of catalyst compositions comprising at least the metals X and Y in any suitable stoichiometric combination and, optionally, including other materials. Similarly, the citation of a catalyst composition as "X1.0Y1.0" refers herein to a composition comprising at least the metals X and Y in a stoichiometric molar ratio of 1: 1. Accordingly, the particularly preferred catalyst compositions are bimetallic metal compositions described by the fla X: Y, wherein X is a Group VIII metal and Y is in Group VIIB metal. For example, the catalysts designated "Re: Pt" include the bimetallic catalysts Rei.0Pti.0 and Re2.5Pt1.0- In addition, the citation of a bimetallic catalyst X: Y may include additional materials in addition to X and Y, such as La or Ce. For example, the catalysts designated "Re: Rh" herein include catalysts such as Rei.oRhi.o, Rei.0R 3.8, Rei.oRh2.oCe2.o, Rei.0R i.0Cei.0 and Rei.0Rhi.0La3.o · In some embodiments, the catalysts can be provided with adequate support. The catalyst systems can be supported on a support fthat is stable under the selected reaction conditions. Any suitable support may be used, but the supports are preferably sufficiently stable in a stock solution, such as a raw material solution. watery, to operate at a desired level. A particularly preferred catalyst support is carbon. It is preferred that such carbon supports have relatively high surface areas (greater than 100 square meters per gram). Such carbons include activated carbon (granulated, powdered or in pills), fabrics, plush or activated carbon fibers, nanotubes or nanoparticles, carbon fullerene, high surface area carbon honeycombs, carbon foams (cross-linked carbon foams) , and carbon blocks. The carbon can be produced by chemical or steam activation of peat, wood, lignite, coal, coconut shells, olive seeds and oil-based carbon. A preferred support is granulated activated carbon produced from coconut. Other catalyst supports useful for the practice of the invention include, but are not limited to: silica, silica-alumina and alumina.

Preferably, the catalyst system is platinum on silica or silica-alumina, the platinum being allied or further mixed with nickel or ruthenium. The support can also be treated, by surface modification, to modify the residues such as hydrogen and hydroxyl. Hydrogen and hydroxyl surface groups can cause local variations in pH that would affect the catalytic efficiency. The support can be modified, for example, by treating it with a modifier selected from the group which consists of sulfates, phosphates, tungstenatos and silanes. It is preferred that the selected carbon be pre-treated with either steam, oxygen (from the air), inorganic acids, or hydrogen peroxide to provide more surface oxygen sites. The preferred pre-treatment would be the use of either oxygen (air) or hydrogen peroxide. The pre-treated carbon can be modified by the addition of the Group IVB and Group VB oxides. It is preferred to use titania oxides, vanadium, zirconium and mixtures thereof. The catalyst systems of the present invention can be prepared by conventional methods known to those skilled in the art. These methods include evaporation impregnation techniques, incipient wetting techniques, chemical vapor deposition, washing-coating, magnetron disintegration techniques, and the like. The method selected for manufacturing the catalyst is not particularly critical to the function of the invention, with the proviso that different catalysts will produce different results, depending on considerations such as total surface area, porosity and the like. Reformation Methods The method of liquid phase reformation of the present invention should be carried out generally at a temperature at which the thermodynamics of the proposed reaction is favorable. The pressure selected for the reactions varies with temperature. For the reactions in the condensed liquid phase, the pressure inside the reactor must be sufficient to keep the reactants in the condensed liquid phase at the reactor inlet. The vapor phase reforming method of the present invention should be carried out at a temperature at which the vapor pressure of the oxygenated hydrocarbon compound is at least about 0.1 atmospheres (and preferably much higher), and the thermodynamics of the reaction is favorable. This temperature will vary depending on the specific oxygenated hydrocarbon compound used, but is generally in the range of from about 100 ° C to about 450 ° C for the reactions that take place in the vapor phase, and more preferably, about 100 ° C up to about 300 ° C for the vapor phase reactions. For the reactions that take place in the condensed liquid phase, the preferred reaction temperature should not exceed about 300 ° C. The condensed liquid phase method of the present invention can also be carried out, optionally, using a modifier that increases the activity and / or the stability of the catalyst system. It is preferred that the water and the oxygenated hydrocarbon are reactivated at a suitable pH of from about 1.0 to about 10.0, including pH values in 0.1 and 0.05 increments between them. Generally, the modifier is added to the raw material solution in an amount ranging from about 0.1% to about 10% by weight compared to the total weight of the catalyst system used, although amounts outside of this invention are included within the present invention. rank. Optionally, alkali or alkaline earth salts can be added to the raw material solution to optimize the proportion of hydrogen in the reaction products. Examples of suitable water soluble salts include one or more selected from the group consisting of alkali metal hydroxide or alkaline earth metal salt, carbonate, nitrate or chloride. For example, the addition of alkali (basic) salts to provide a pH of about a pH of 4 to a pH of 10 can improve the hydrogen selectivity of the reforming reactions. Alkene production methods are provided which include contacting the raw material solution with a reforming catalyst. The reserve may include an aqueous solution having approximately 10.60%, preferably 20% or 30% or more, of one or more Ci-C6 oxygenated hydrocarbons, preferably glycerol, ethylene glycol, and / or sorbitol. The reserve may be contacted with a catalyst comprising one or more metals selected from the group consisting of platinum, rhodium and rhenium. As described in the examples, catalysts suitable for use in methods for producing alkanes include PtRe and RhRe catalysts with varying amounts of each metal. Preferred methods for the production of alkanes provide products containing about 3-50%, 5-25% or 10-20% of alkanes in the product vapor. Preferably, the alkanes produced have 1, 2, 3, 4, 5, 6, 7, 8 or more carbons and can be straight or branched hydrocarbons. Optionally, acidic compounds can be added to a pool or reactor system to provide improved alkene selectivity of the reforming reactions. It is preferred that the water soluble acid is selected from the group consisting of nitrate, phosphate, sulfate and chloride salts and mixtures thereof. If an optional acidic modifier is used, it is preferred that it be present in an amount sufficient to lower the pH of the aqueous feed stream to a value between about a pH of 1 and about a pH of 4. The pH decrease of a feed stream, in this way, it can increase the proportion of alkanes in the reaction products. Methods for generating both hydrogen and alkanes by means of reformation in an aqueous phase of the oxygenated hydrocarbons containing at least one carbon and one oxygen are described below. These methods use a combination of the Group VIIB and Group VIII metals supported on activated carbon generated from coconut, the carbon can be functionalized either by treatment in acid, treatment with hydrogen peroxide or treatment with oxygen, the carbon support can be functionalized also by adding oxides either titanium, vanadium, tungsten, molybdenum. Performance is further enhanced by the addition of Group IIIB oxides and the associated rarefied earth. The process is thermally efficient if the process operates at a feed concentration greater than 20% by weight of the oxygenated compound, preferably greater than 30% by weight, more preferably greater than 40% by weight or 50% by weight. In one aspect, preferred material compositions are provided. The compositions can be isolated before, during or after carrying out one or more of the methods or processes described herein and can be isolated within a portion of a reactor system. A preferred composition comprises in one or more phases: a catalyst composition of APR, sorbitol, hydrogen, carbon dioxide and hydrocarbons such as methane, ethane, propane, butane, pentane and hexane. Another preferred composition comprises, in one or more phases: an APR catalyst composition, glycerol, hydrogen, carbon dioxide and light hydrocarbons such as methane, ethane, propane, butane and pentane. The catalyst composition in both compositions preferably includes one or more metals selected from the group consisting of: platinum, rhenium and rhodium. In particular, a composition comprises a solid phase that includes a catalyst comprising platinum, rhenium and / or rhodium, an aqueous phase that includes sorbitol, a gas phase that includes hydrogen, carbon dioxide and methane, and organic or gaseous phases that include Ethane, propane, butane, pentane and hexane. Another composition comprises a solid phase which includes a catalyst comprising platinum, rhenium and / or rhodium, an aqueous phase including glycerol, a gas phase including hydrogen, carbon dioxide and methane and organic or gaseous phases including ethane and propane. EXAMPLES The following examples should be considered illustrative of the various aspects of the invention and should not be construed as limiting the scope of the invention, which is defined by the claims annexes. Example 1 (Method 1) Monometallic catalyst systems supported on activated carbons were prepared by impregnating the carbon with metal precursor solutions using incipient wetting techniques. (1) Activated carbons that were impregnated were dried under vacuum at -100 ° C overnight and stored in sealed containers until used. (2) A solution containing the metallic precursor (s), in a volume equal to the volume of incipient wetting to impregnate the carbon, was applied by dripping, while stirring, to the activated carbon. (3) Moistened carbon was dried under vacuum as in step 1. (4) If additional applications were required to achieve the desired metal loading, steps 2 and 3 were repeated until sufficient metal precursor had been applied. Example 2 (5% by weight of Pt on C) A 5% platinum catalyst was prepared by weight on activated carbon according to the general method of Example 1. An aqueous solution, 22.49 g, containing 3.34 g of hexahydrate was added. of hexachloroplatinate dihydrogen (IV) to 22.49 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 3 (5% of Ru on C) A 5% ruthenium catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution was added., 38 ml, containing 0.98 g of ruthenium nitrosilnitrate (III) (Alfa Aesar, 1.5% Ru) to 47.52 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Three additional applications were carried out using 39 ml of this solution, then one last application using 14 ml of this solution diluted to 38 ml. The carbon mixture was dried at 100 ° C under vacuum between each application. Example 4 (5% by weight of Rh on C) A 5% rhodium catalyst was prepared by weight supported on activated carbon according to the general method of Example 1. Se. added an aqueous solution, 38 ml, containing 18.54 g of rhodium nitrate solution (Alfa Aesar, 13.84% Rh) to 47.51 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 5 (5% by weight of Re on C) A 5% rhenium catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution, 7.5 ml, containing 0.882 g of solution was added. from perrhenic acid (Alfa Aesar, 76.41% of HRe04) to 9,502 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 6 (5% by weight of Pd on C) A 5% palladium catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution, 7.6 ml, containing 5,916 g of nitrate was added. from palladium (II) (Alfa Aesar, 8.5% Pd) to 9,501 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 7 (5% by weight of Ir on C) A 5% by weight iridium catalyst was prepared on activated carbon according to the general method of Example 1. An aqueous solution, 62 ml, containing 5.03 g of hydrate was added. of dihydrogen hexachloroiridate (IV) (Strem, 47.64% of Ir) to 44.87 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 8 (15% by weight of Ni on C) A 15% nickel catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution, 7.3 ml, containing 7,807 g of water was added. nickel (II) nitrate hexahydrate (Alfa Aesar, 19.4% Ni) to 8,587 g of activated carbon (Calgon OLC-AW, sieved to 12-40 mesh). The mixture was dried at 100 ° C under vacuum.

Example 9 The catalysts were evaluated for their APR activity using the test systems illustrated in Figure 4. The catalysts were loaded into a stainless steel tube reactor 1, which is installed in an aluminum block heater 2 to maintain the isothermal conditions. The reaction temperature is controlled by the temperature control sub-system. The critical components of the temperature control sub-system (not shown in Figure 4) are a thermocouple inserted into the tube reactor, resistance heaters installed on the aluminum block and a PID controller. The substrate solutions (ie, stock solutions) are fed continuously into the reactor using an HPLC pump 3. The material exiting the reactor is cooled as it passes through the heat exchanger 4 before entering the phase separator 5. The gases leave the phase separator by means of a gas manifold 6 which is maintained at a constant pressure by means of the pressure control sub-system. The critical components of the pressure control sub-system are the sensor. pressure 7, the pressure control valve 8 and the PID controller 9. The amount of gas released by the Pressure control valve 8, is measured by a mass flow meter 10. The composition of this gas is monitored by gas chromatography. The level of the liquid in the phase separator 5 is maintained at a constant level by the level control sub-system. The components of the level control sub-system include the level 11 sensor in the phase separator, a level control valve 12 and a PID controller 13. The aqueous solution drained from the phase separator during an evaluation experiment of the catalyst, it is collected, and the quantity collected is measured gravimetrically. The analysis of this solution * may include, the pH, the total concentration of organic carbon, GC to determine the concentrations of the unreacted substrate and of the specific intermediates and by-products. Example 10 The monometallic catalyst systems described in Examples 1 to 8 were tested in the apparatus described in Example 9. The catalysts were treated under fluid hydrogen at 250 ° C before introducing the feed liquid containing 10% ethylene glycol to the catalyst. catalyst at 230 ° C. Table 1 below describes the results of the reformation of the ethylene glycol solution on the catalyst at 430 psig. Table 1 shows that, of the monometallic catalytic materials supported on Group VIII carbon, platinum and ruthenium show appreciable activity. Rhenium supported on carbon also shows some reforming activity. Table 1. Monometallic Catalyst Activity for the 10% APR of Ethylene Glycol Example Gas composition Catalyst APR P WHSV Conversion H2 Aléanos C02 T (° C) (PSIG) (hr-1) a to gas (%) (%) (%) 5% Pt 2 230 430 0.80 13% 84% 1% 15% % Ru 3 230 430 0.77 27% 9% 39% 52% % Rh 4 230 430 0.71 0% NA NA NA % Re 5 230 430 0.84 4% 67% 4% 29% % Pd 6 230 430 0.78 0% NA NA NA % Ir 7 230 430 2.38 0% NA NA NA % Ni 8 230 430 0.58 0% NA NA NA aThe spatial velocities in weight per hour (WHSV) are based on the feed rate of the oxygenated substrate Example 11 (Bimetallic Laughter Catalyst, 5% by weight of Ir, 1: 1 molar ratio of Re: Ir) A solution of perrhenic acid (Alfa) was diluted Aesar, 76.41 & from HRe04), 0.87 g, to 7.6 ml with DI water and added by incipient wetting to 10.00 g of 5% by weight of Ir on the carbon catalyst of Example 7. The mixture was dried at 100 ° C under vacuum. Example 12 (ReNi bimetallic catalyst, 5% by weight of Ni, 1:16 molar ratio of Re: Ni) Nickel (II) nitrate hexahydrate (Alfa Aesar, 19.4% Ni), 2.577 g, and perrhenic acid solution (Alfa Aesar, 76.4% of HRe04) were dissolved, 0.163 g, in enough DI water to produce a 7.6 ml solution. This solution was added by incipient wetting to 9,409 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. Example 13 (RePd bimetallic catalyst, 5% by weight of Pd, Re: Pd molar ratio 1: 1) An aqueous solution, 7.6 ml, containing 4.577 g of perrhenic acid solution (Alfa Aesar, 76.4% of HRe04) and 5,906 g of palladium (II) nitrate (Alfa Aesar, 8.5% of Pd) was added to 9,503 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting. The mixture was dried at 100 ° C under vacuum. Example 14 (bimetallic RePt catalyst, 5% by weight of Pt, 1: 1 molar ratio of Re: Pt) A 5% platinum catalyst was prepared by weight on activated carbon according to the general method of Example 1. added an aqueous solution, approximately 26 ml, containing 4,261 g of hexahydrochloride dihydrogen hexahydrate (IV) (Alfa Aesar, 39.85% Pt) to 32.34 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. An application was added of the aqueous solution, 7.6 ml, containing 0.87 g of perrhenic acid solution (Alfa Aesar, 76.41 &HRe04) to 10.03 g of the dry platinum / carbon mixture. The mixture was dried at 100 ° C under vacuum. Example 15 (bimetallic ReRh catalyst, 5% by weight of Rh, 1: 3.8 molar ratio of Re: Rh) An aqueous solution, approximately 7.6 ml, containing 3.55 g of rhodium (III) nitrate (Alfa Aesar, 13.93 % Rh) to 9.51 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting. The mixture was dried at 100 ° C under vacuum. An additional application of the aqueous solution, 7.6 ml, containing 0.42 g of perrenic acid solution (Alfa Aesar, 76.41% of HRe04) was carried out. The mixture was dried at 100 ° C under vacuum. Example 16 (ReRh bimetallic catalyst, 5% by weight Rh, 1: 1 molar ratio of Re: Rh) An aqueous solution, 24.2 ml, containing 1.60 g of perrhenic acid solution (Alfa Aesar, 76.41% of HRe04) was added. ) at 10.01 g of a dry Degussa catalyst G106 NB / at 5% by weight of Rh by incipient wetting. The mixture was dried at 100 ° C under vacuum. Example 17 (ReRu bimetallic catalyst, 5% by weight of Ru, 1: 1 molar ratio of Re: Ru) The perrhenic acid solution (Alfa Aesar, 76.41% of HRe04), 1.63 g, was diluted to 7.3 ml with DI water and added by incipient wetting to 10.01 g of 5% by weight of Ru on the carbon catalyst of Example 3. The mixture was dried at 100 ° C under vacuum . Example 18 The modified rhenium catalyst systems described in Examples 11 to 17 were tested in the apparatus described in Example 9. The catalysts were treated under fluid hydrogen at 250 ° C, before introducing the feed liquid containing 10% by Weight of ethylene glycol to the catalyst at 230 ° C. Table 2 below describes the results of the reformation of the ethylene glycol solution on the catalyst at 430 psig. Table 2 shows that the combination of rhenium and Group VIII metals supported on activated carbon, significantly improves the activity for the reformation of ethylene glycol compared to the results of Example 10. ,twenty Table 2. Monometallic Catalyst Activity for the 10% APR of Ethylene Glycol Proportions Gas composition Catalyst Example Wt (%) Molars WHSV Conversion H2 Aléanos C02 (MRe) M (Re: M) (hr-1) aa gas (%) (%) (%) IrRe 11 5% Ir 1: 1 0.76 76% 39% 19% 35% NiRe 12 5% Ni 1: 16 0.68 4% 74% 20% 6% PdRe 13 5% Pd 1: 1 0.73 20% 54% 27% 19% PtRe 14 5% Pt 1: 1 0.72 74% 38% 36% 28% RhRe 15 5% Rh 1: 3.8 0.80 75% 65 6% 28% RhRe 16 5% Rh 1: 1 1.73 100% 52% 20% 28% RuRe 17 5% Ru 1: 1 1.98 83% 21% 45% 32% aSpace velocities in weight per hour (WHSV) are based on the rate of feed of the oxygenated substrate Example 19 (RhReCe catalyst, 5% by weight of Rh, 1: 2: 2 molar ratio of Re: Rh: Ce) An aqueous solution, 7.6 ml, containing 3.64 g of rhodium (III) nitrate (Alfa Aesar, 13.93 Rh%), 0.82 g of the perrhenic acid solution (Alfa Aesar, 76.49% of HRe04), 2. 18 g of cerium nitrate (III) was added to 9.50 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting. The mixture was dried 100 ° C under vacuum. Example 20 Hydrogen peroxide has been used to functionalize activated carbons to provide supports improved for catalysts of APR, S.R. from Miguel, O.A. Scelza, M.C. Roman-Martinez, C. Salinas Martinez de Lecea, D. Cazorla-Amoros, A. Linares-Solano, Applied Catalysis A: General 170 (1998) 93. Activated charcoal, 45 g, was slowly added to 1200 ml of peroxide solution of hydrogen at 30%. After completing the carbon addition, the mixture was left overnight. The aqueous phase was decanted and the carbon was washed three times with 1200 ml of DI water, then dried under vacuum at 100 ° C. Example 21 (RhReCe catalyst, 5% by weight Rh, 1: 1: 1 molar ratio of Re: Rh: Ce) Functionalized hydrogen peroxide carbon was prepared using the method described in Example 20 and Calgon OLC-AW, sieved to 18-40 mesh. After functionalization, the carbon was dried at 100 ° C under vacuum. An aqueous solution, 7.6 ml, containing 2.12 g of cerium (III) nitrate was added by incipient wetting to 9.46 g of the functionalized carbon of hydrogen peroxide. The mixture was dried at 100 ° C under vacuum. A further application of the aqueous solution, 7.6 ml, containing 3.64 g of rhodium (III) nitrate (Alfa Aesar, 12% Rh) and 1.61 g of the perrhenic acid solution was carried out. The mixture was dried at 100 ° C under vacuum. Example 22 (RhReLa catalyst, 5% by weight Rh, 1: 1: 3 molar ratio of Re: Rh: La) A 5% rhodium catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution, approximately 7.6 ml, containing 3.72 g of rhodium (III) nitrate (Alfa Aesar, 13.65% by weight of Rh) was added to 9.5 g of activated carbon (Calgon OLC-AW, sieved at 18-40 mesh). The mixture was dried at 100 ° C under vacuum. A further application of the aqueous solution, 7.6 ml, containing 1.60 g of the perrhenic acid solution (Alfa Aesar, 76.41% of HRe04) and 6.33 g of lanthanum nitrate hexahydrate (III) (Alfa Aesar, 99.9) was carried out. % of La (N03) 3). The mixture was dried at 100 ° C under vacuum. Example 23 The Rh / Re catalysts modified with the Group IIIB compounds described in Examples 19 to 22 were tested in the apparatus described in Example 9. The catalysts were treated under fluid hydrogen at 250 ° C before introducing the liquid of feed containing 10% ethylene glycol to the catalyst at 230 ° C. Table 3 below describes the results of the reformation of the ethylene glycol solution on the catalyst at 430 psig. Table 3 shows that the addition of these Group IIIB compounds improves the selectivity to hydrogen.

Table 3. Activity of the RhRe catalysts attenuated with Ce or La for the APR of 10% of Ethylene glycol Proportions Wt Molars Composition of% Rh gas (Re: Rh: Ce or WHSV Conversion H2 Aléanos C02 Catalyst Example La) (hr "1) a gas (%) (%) (%) RhRe 16 5% 1: 1: 0 1.73 100% 52% 20% 280% RhRe Ce 19 5% 1: 2: 2 1.8 56% 63% 6% 27% RhRe Ce _21_ 5% 1: 1: 1 2.0 95% 63% 8% 31% RhRe La 22 5% 1: 1: 3 0.5 97% 55% 11% 28% aThe space velocities in weight per hour (WHSV) are based on the feed rate of the oxygenated substrate Example 24 A Pt / Fe on carbon catalyst (Degussa CF105) was tested using various concentrations of glycerol in water. This catalyst contained a load of 5% by weight of Pt and 0.5% by weight of Fe. The catalyst was pre-treated under fluid hydrogen at 250 ° C before introducing the feed liquid containing glycerol to the catalyst at 230 ° C. Table 4 shows the results of the reformation of the different glycerol solutions on this Pt / Fe catalyst.

Table 4. Activity of 5% by weight of Pt / 0.5% by weight of Fe on activated carbon Wt% APR P WHSV Conversion to Gas Composition Glycerol T (° C) (PSI) (hf1) to gas H2 Aléanos C02 (%) (%) 10 230 433 1.8 62% 67% 5% 28% 230 428 3.6 32% 66% 4% 30% 230 431 5.4 21% 64% 4% 32% 40 235 429 7.2 13% 62% 4% 34% 50 238 432 9.0 9% 60% 4% 36% 60 237 431 10.8 6% 56% 3% 41% aThe space velocities in weight per hour (WHSV) are based on the oxygenated substrate feed rate Example 25 (PtRe catalyst, 5% by weight of Pt, 2.5: 1 molar ratio of Re: Pt) Dihydrogenhexachloroplatinate hexahydrate (IV) (Alfa Aesar 39.85% of Pt) was diluted 1.18 g, and perrhenic acid solution (Alpha Aesar 79.18% of HRe04) 1.92 g, at 10.75 ml. The solution was added by incipient wetting to 8.95 g of functionalized hydrogen peroxide (Example 20) UO 60 x 120 carbon meshes, and dried at 100 ° C under vacuum. Example 26 Oxidation with air has been used to functionalize the activated carbons to provide improved supports for APR catalysts. The activated carbon, 23 g, was placed in a quartz tube U and heated to 450 ° C in a stream of nitrogen, 150 ml / min. Once the temperature was stabilized, an air current of 50 ml / min was added to the nitrogen. The carbon was treated for 10 hours, then allowed to cool under flowing nitrogen. Example 27 (RhReCe catalyst, 5% by weight Rh, 1: 1: 1 molar ratio of Re: Rh: Ce) Rhodium, rhenium and cerium were added to the activated carbon which was oxidized by air using the method of Example 26. An aqueous solution, 9.3 ml, containing 4.34 g of rhodium (III) nitrate solution (Alfa Aesar, 13.82% Rh), 1.85 g of perrhenic acid solution (Alfa Aesar, 79.18% of HRe04), 2.53 g of nitrate of cerium (III) was added to 11.4 g of carbon oxidized by air (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting. The mixture was dried at 100 ° C under vacuum. Example 28 (PtRe catalyst, 5% by weight of Pt, 2.5: 1 molar ratio of Re: Pt) Dihydrogenhexachloroplatinate hexahydrate (IV) (Alfa Aesar 39-85% of Pt) was diluted 1.18 g, and perrhenic acid solution (Alfa Aesar 79.18% of HRe0), 1.92 g, at 10.75 mi. The solution was added by incipient wetting to 8.95 g of UU carbon oxidized with air of 60 x 120 mesh and dried at 100 ° C under vacuum.

Example 29 (RhReCe catalyst, 5% by weight of Rh, 1: 1: 1 molar ratio of Re: Rh: Ce) Rhodium (III) nitrate dihydrate was diluted 1.37 g (Alfa Aesar 31.91% Rh) , perrenic acid solution (Alfa Aesar 79.18% of HRe04) and cerium (III) nitrate hexahydrate, 1.85 g, at 13.2 ml. The solution was added to 8.31 g of UU activated carbon of 120 x 200 mesh by incipient wetting and dried at 100 ° C under vacuum. Example 30 The functionalized carbon surfaces were modified by impregnation of the metal oxides prior to impregnation of the catalyst precursors. Titanium n-butoxide, 1.95 g, was diluted to 12 ml with anhydrous isopropanol. This solution was added by incipient wetting to the functionalized carbon of oxidation by air (see Example 26 above), 10 g. The wet carbon was dried under vacuum at 100 ° C overnight. Example 31 (RhReCe catalyst, 5% by weight, 1: 1: 1 molar ratio of Re: Rh: Ce) Rhodium (III) nitrate, 3.86 g, perrhenic acid, 1.64 g, and cerium nitrate hexahydrate were dissolved. (III), 2.21 g, in enough DI water to produce 12 ml of solution. This solution was added by incipient wetting to titanium modified carbon of Example 30, and then dried under vacuum at 100 ° C overnight.

Example 32 The catalysts of Examples 25 to 31 were pretreated under fluid hydrogen at 250 ° C before introducing the feed liquid containing the oxygenates to the catalyst at the desired reaction temperature. Table 5 shows the results of the reformation of the different solutions on these catalysts. When compared with the results for the conversion of higher concentrations of the glycerol presented in Example 24, Table 5 shows that the combination of rhenium and Group VIII metals supported on activated carbon, significantly improves the activity for reforming concentrations. highest of the oxygenated compounds.

Table 5. Activity for APR catalysts that reform substrates at high concentration Materia Cataliza Pretrata_% in Proportion WHSV Conver Gas composition Primeor Axis Weight Weight (hr ") ation to H2 Aléanos C02 de M Molares gas (%) coal (Re: Rh: Ce or Re: Pt) 30% RhReCe 27 Air 5% Rh 1: 1: 1 4.8 47% 61% 10% 29% Ethylene Glycerol 30% PtRe 25 5% Pt 2: 5: 1 2.0 81% 45% 17% 35% Glycerol 30% PtRe 28 5% Pt 2: 5: 1 2.2 57% 36% 12% 47% Sorbitol 30% RhReCe 29 None 5% Rh 1: 1: 1 2.0 28% 36% 16% 48% Sorbitol 30% PtRe 25 H202 5% Pt 2: 5: 1 3.2 66% 43% 16% 40% Glycerol 30% RhReCe 31 Air 5% Rh 1: 1: 1 1.8 81% 49% 19% 35% oxidized Glycerol Ti Modifi ed 30% RhReCe Air 5% Rh 1: 1: 1 1.8 60% 41% 14% 46% oxidized Sorbitol Ti Modifi ed to Space velocities by weight per hour (WHSV) are based on the feed rate of the oxygenated substrate Example 33 The functionalized carbon surfaces were modified by impregnation with metal oxides prior to impregnation of the catalyst precursors. Vanadium oxide triisopropoxide 0.67 g was diluted to 12 ml with anhydrous isopropanol. This solution was added through incipient wetting of the functionalized carbon of hydrogen peroxide (see Example 20 above), 10 g. the moist carbon was dried under vacuum at 100 ° C overnight. Example 34 (RhReCe catalyst, 5% by weight Rh, 1: 1: 1 molar ratio of Re: Rh: Ce) Rhodium (III) nitrate, 3.82 g, perrhenic acid, 1.69 g and cerium nitrate hexahydrate were dissolved. (III), 2.21 g, in enough DI water to produce 12 ml of solution. This solution was added by incipient wetting to vanadium-modified carbon, and then dried under vacuum at 100 ° C overnight. Example 35 The catalysts of Examples 29, 31 and 34 were pretreated under fluid hydrogen at 250 ° C before introducing the feed liquid containing the oxygenates to the catalyst at the desired reaction temperature. Table 6 shows the results of the reformation of 30% by weight of sorbitol at 240 ° C and 495 psig. This table shows that the addition of either Ti or V significantly improves the conversion of sorbitol.

Table 6. Activity for APR Catalysts, sorbitol, supported on modified carbons.

Cataliza Pretrata% in Proportion WHSV Conversion Gas composition Ejem. Molar Weighting (hr'1) aa gas (%) H2 Aléanos C02 carbon M (Re: Rh: Ce or (%) (%)% Re: Pt) RhReCe 29 None 5% Rh 1: 1: 1 2.0 RhReCe 31 Air 5% Rh 1: 1: 1 1.8 oxidized Ti Modified RhReCe 34 H202 5% Rh 1: 1: 1 1.8 83% 47% 12% 42% V Modified aSpace velocities in weight per hour (WHSV) are based on the feed rate of the oxygenated substrate Example 36 It has been found that the addition of bases significantly increases the amount of hydrogen generated during the reformation in aqueous phase. Table 7 shows the effects of adding various amounts of NaOH and KOH.

Table 7. Effect of Adding Base to Food in Activity and Selectivity for APR Catalyst Material Catalyze Base% Proportion WHS Conver Gas composition Prime dor Weight sion a H2 Aléanos C02 M Molares (hr "') gas (%) (%)% (Re: Rh: Ce o Re: Pt) 30% RhReCe Na "None 5% Rh 1: 1: 1 1.8 70% 47% 12% 40% Sorbitol 30% RhReCe b 0.5% 5% Rh 1: 1: 1 1.7 71% 53% 8% 39% Sorbitol NaOH 30% RhReCe B 1.25% 5 % Rh 1: 1: 1 1.8 78% 57% 8% 37% Sorbitol NaOH 30% RhReCe B 1.5% 5% Rh 1: 1: 1 1.8 75% 56% 8% 34% Sorbitol NaOH 30% RhReCe B 1.65% o 5% Rh 1: 1: 1 1.8 73% 56% 8% 34% Sorbitol NaOH 30% PtRe 28 None 5% Pt 2.5: 1 2.2 57% 36% 12% 47% Sorbitol 30% PtRe 2.5% 5% Pt 2.5: 1 2.2 64% 55% 7% 36% 28 KOH Sorbitol 50% RhReCe None 5% Rh 1: 1: 1 1.8 81% 49% 19% 35% 31 Sorbitol 50% RhReCe 1.65% 5% Rh 1: 1: 1 1.8 75% 57% 12% 33% Sorbitol NaOH aThe spatial velocities in weight per hour (WHSV) are based on the oxygenation substrate feed rate bla preparation of this catalyst (on vanadium modified H202 carbon) was not described in any example, but the procedure was similar to Example 34.

Example 37 A 3% platinum catalyst by weight on activated carbon was prepared according to the general method of Example 1. An aqueous solution, approximately 9.5 ml, containing 0.75 g of hexachloroplatinate hexahydrate dihydrogen (IV) (Alfa Aesar 39.85% of Pt) and 1.22 g of perrhenic acid solution (Alfa Aesar 79.18% of HRe04) was added to 10.0 g of carbon functionalized with peroxide (Calgon UU, sieved to 60,120 mesh, functionalized using the method of Example 20). The mixture was dried at 100 ° C under vacuum. Example 38 The catalyst of Example 37 was pre-treated under fluid nitrogen at 350 ° C, before introducing the feed liquid containing the oxygenates to the catalyst at the desired reaction temperature. Figure 5 shows the time-dependent results of the fractional conversion to gas to reform 50% by weight of glycerol at 260 ° C, 600 psig, and a WHSV of 0.55 based on the glycerol feed rate. Example 39 (bimetallic ReRh catalyst, 5% by weight Rh, 1: 2 molar ratio of Re: Rh) An aqueous solution, 7.6 ml, containing 0.85 g of perrhenic acid solution (Alfa Aesar 76.41% of HRe04 was added to 10.0 g of 5% by weight of the Rh catalyst, Example 4, by incipient wetting The mixture was dried at 100 ° C under vacuum Example 40 (ReRh bimetallic catalyst, 5% by weight Rh, 1: 1 molar ratio from Re: Rh) An aqueous solution, 7.6 ml, containing 1.61 g of perrhenic acid solution (Alfa Aesar 76.41% of HRe04 was added to 10.0 g of 5% by weight of the Rh catalyst, Example 4, by incipient wetting.) The mixture was dried at 100 ° C under vacuum Example 41 (bimetallic ReRh catalyst, 5% by weight of Rh, 1: 1 molar ratio of Re: Rh) An aqueous solution, 15 ml containing 3.15 g of rhodium (III) nitrate (Alfa Aesar) was added to 19.0 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting, the mixture was dried at 100 ° C under vacuum, an additional application of the aqueous solution was carried out, 15.2 ml. , containing 3.14 g of the perrhenic acid solution (Alfa Aesar 79.2% of HRe04) The mixture was dried at 100 ° C under vacuum Example 42 (ReRh bimetallic catalyst, 5% by weight Rh, molar ratio 2: 1 from Re: Rh) An aqueous solution, 7.6 ml, containing 1.57 g of rhodium (III) nitrate (Alfa Aesar) and 3.11 g of sol Perric acid acid addition (Alfa Aesar 76.41% of HRe04 was added to 9.53 g of activated carbon (Calgon OLC-AW, sieved to 18-40 mesh) by incipient wetting. The mixture was dried at 100 ° C under vacuum. Example 43 It has been found that the increase in the charge of Rhenium will improve the production of alkene products. Table 8 shows the results of the reformation of two concentrations of ethylene glycol on catalysts with variable ratios from Re to Rh. As this proportion increased, the concentration of alkanes in the product gas increased. Table 8. Effect of the increase in the ratio of Re: Rh in the activity and selectivity for APR catalysts. Matter Catalyst T (° C)% in Proportion_ WHSV Conver Gas composition Prime Allous Weight to Alkanes C02 M Molars gas (%) (%)% (Re: Rh) 10% RhRe 15 210 5% 1: 3.8 0.8 36% 65% 7% 27% Ethylene Glycol 0% RhRe 39 210 5% 1: 2 0.7 89% 59% 12% 29% Ethylene Glycol 10% RhRe 40 210 5% 1: 1 0.7 100% 48% 24% 27% Ethylene Glycol 30% RhRe 41 230 5% 1: 1 2.2 19% 60% 10% 28% Ethylene Glycol 30% RhRe 42 230 5% 2: 1 2.1 20% 53% 17% 30% Ethylene Glycol aSpace velocities in weight per hour (WHSV) are based on the rate of oxygenated substrate feed. described modalities and examples should be considered in all aspects, only as illustrative and not as restrictive and, consequently, the The scope of the invention is indicated by means of the appended claims rather than by means of the foregoing description. All the changes that fall within the meaning and range of equivalence of the claims are within its scope.

Claims (18)

1. CLAIMS 1. A method for reforming oxygenated hydrocarbons comprising the step of contacting a solution of raw materials comprising water and at least 20 percent by weight of the total raw material solution of an oxygenated hydrocarbon with a reforming catalyst under conditions of reaction temperature and reaction pressure, effective to produce hydrogen gas and alkanes having from 1 to 8 carbon atoms, wherein the oxygenated hydrocarbon has at least one oxygen atom, and wherein the reforming catalyst comprises rhenium and at least one transition metal of Group VIII on a stable aqueous support. The method of claim 1, wherein the conversion to hydrogen gas is greater with the reforming catalyst than the conversion to hydrogen gas using the same raw material solution and the same rhenium absent from catalyst. The method of claim 1, wherein the conversion to alkanes with the reforming catalyst is greater than the conversion to alkanes using the same raw material solution and the same rhenium absent from catalyst. 4. The method of claim 1, wherein the support comprises activated carbon and wherein the combination of rhenium and the at least one transition metal of Group VIII on the activated carbon significantly improves the activity to reform the oxygenated hydrocarbon compared to a catalyst monometallic comprising Pt, Ru, Rh, Re, Pd, Ir or Ni. 5. The method of claim 1, wherein the stable aqueous support comprises activated carbon and wherein the combination of rhenium and the at least one transition metal of Group VIII on the activated carbon significantly improves the activity to reform the oxygenated hydrocarbon. in comparison with a Pt / Fe catalyst on carbon. The method of any of claims 1-5, wherein the reforming catalyst comprises Re and at least one transition metal selected from the group consisting of: Ir, Ni, Pd, Pt, Rh and Ru. 7. The method of any of claims 1-6, wherein the reforming catalyst further comprises Ce or La. The method of any of claims 1-7, wherein the stable aqueous support comprises one or more materials selected from the group consisting of: carbon, zirconia, titania, ceria and combinations thereof. The method of any of claims 1-7, wherein the stable aqueous support comprises carbon modified with titanium, vanadium, tungsten or rhenium. The method of any of claims 1-9, wherein the atomic ratio of the Re to the Group VIII metal in the catalyst is 0.25 to 1 to 10 to 1, and the catalyst and carrier combination comprises 0.25. % by weight to 10% by weight of Group VIII metal. The method of any of claims 1-10, wherein the catalyst is selected from the group consisting of: Rei.0Rh3.8, 'Rei.0Rhi.0, ii.0Rei6.o Rei.oRh2.oCe2.o , Rei.0Rhi.0Cei.0, Rex.oRhi.oLaa.o and Re2.5Pti.0. The method of any of claims 1-11, wherein the raw material solution comprises at least 50% of the oxygenate. The method of any of claims 1-12, wherein the reaction temperature is between about 80 ° C and about 300 ° C and wherein the reaction pressure is between about 10 bar (145 psi) and about 50 bars (725 psi). 14. A supported reforming catalyst in aqueous phase comprising: (a) a carbon support impregnated with titania, vanadia or a combination thereof, and (b) a catalytic composition adhered to the carbon support, the catalytic composition Re comprising a second metal selected from the group consists of: Ir, Ni, Pd, Pt, Rh and Ru and a third metal of Ce or Adhered to a carbon support or to the catalytic composition. 15. The aqueous phase reforming catalyst of claim 14, wherein the catalyst composition is selected from the group consisting of: Re1.0R 3.8 ii.oRei6.0f Rei.oRh2.oCe2.Of ei.oR i.0Cei. 0, Rei.oRhi.0La3.o and Re2.5Pt1.0- 16. A composition of matter comprising: (a) a reforming catalyst comprising rhenium, a Group VIII metal and Ce or La; (b) an aqueous phase comprising hydrogen, methane, carbon dioxide and one or more compounds selected from the group consisting of: ethane and propane, and (c) a liquid phase comprising an oxygenated hydrocarbon Ci-Cg. The composition of claim 16, wherein the liquid phase comprises an organic phase comprising hexane, pentane and propane and an aqueous phase comprising sorbitol. 18. The composition of claims 16 or aqueous phase comprising: (a) a carbon support impregnated with titania, vanadia or a combination thereof, and (b) a catalytic composition adhered to the carbon support, the catalytic composition Re comprising a second metal selected from the group consists of: Ir, Ni, Pd, Pt, Rh and Ru and a third metal of Ce or Adhered to a carbon support or to the catalytic composition. 15. The aqueous phase reformation catalyst of claim 14, wherein the catalyst composition is selected from the group consisting of: Rei.oRh3.8, Nii.0Rei6.o > Rei.0Rh2.oCe2.o, ei.o hi.oCei.o, Rei.o hi.0La3.o and Re2.5Pt1.0- 16. A composition of matter comprising: (a) a reforming catalyst comprising rhenium , a metal of Group VIII and Ce or La; (b) an aqueous phase comprising hydrogen, methane, carbon dioxide and one or more compounds selected from the group consisting of: ethane and propane, and (c) a liquid phase comprising a C1-C6 oxygenated hydrocarbon. The composition of claim 16, wherein the liquid phase comprises an organic phase comprising hexane, pentane and propane and an aqueous phase comprising sorbitol. 18. The composition of claims 16 or