EP1399249A2 - Method for obtaining synthesis gas by partial catalytic oxidation - Google Patents

Method for obtaining synthesis gas by partial catalytic oxidation

Info

Publication number
EP1399249A2
EP1399249A2 EP02751263A EP02751263A EP1399249A2 EP 1399249 A2 EP1399249 A2 EP 1399249A2 EP 02751263 A EP02751263 A EP 02751263A EP 02751263 A EP02751263 A EP 02751263A EP 1399249 A2 EP1399249 A2 EP 1399249A2
Authority
EP
European Patent Office
Prior art keywords
catalyst
silicon carbide
hydrocarbon
gas
water vapor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP02751263A
Other languages
German (de)
French (fr)
Inventor
Cuong Pham-Huu
Marc-Jacques Ledoux
Pascaline Leroi
Sabine Savin-Poncet
Jacques Bousquet
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TotalEnergies Marketing Services SA
Original Assignee
TotalFinaElf France SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TotalFinaElf France SA filed Critical TotalFinaElf France SA
Publication of EP1399249A2 publication Critical patent/EP1399249A2/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/20—Carbon compounds
    • B01J27/22—Carbides
    • B01J27/224—Silicon carbide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
    • C01B3/386—Catalytic partial combustion
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
    • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
    • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
    • C01B3/40—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts characterised by the catalyst
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/025—Processes for making hydrogen or synthesis gas containing a partial oxidation step
    • C01B2203/0261—Processes for making hydrogen or synthesis gas containing a partial oxidation step containing a catalytic partial oxidation step [CPO]
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1005—Arrangement or shape of catalyst
    • C01B2203/1011—Packed bed of catalytic structures, e.g. particles, packing elements
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1041—Composition of the catalyst
    • C01B2203/1047—Group VIII metal catalysts
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1041—Composition of the catalyst
    • C01B2203/1047—Group VIII metal catalysts
    • C01B2203/1052—Nickel or cobalt catalysts
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1041—Composition of the catalyst
    • C01B2203/1047—Group VIII metal catalysts
    • C01B2203/1064—Platinum group metal catalysts
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/10—Catalysts for performing the hydrogen forming reactions
    • C01B2203/1041—Composition of the catalyst
    • C01B2203/1082—Composition of support materials
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
    • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
    • C01B2203/1205—Composition of the feed
    • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
    • C01B2203/1235—Hydrocarbons
    • C01B2203/1241—Natural gas or methane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

  • the present invention has, on the contrary, a method and a system for detecting an information emergence phenomenon, based on sampled digital data that can be implemented in a discrete manner, per user, an implementation for a group of users, or even a population users, which can simply be reduced to a multiplication of implementation of the method respectively of the system object of the present invention, in order to infer statistical results.
  • the catalysts have the advantage of being resistant to double poisoning by coke and metals, since coke is not a problem since the catalyst is easily regenerated and the metals can be recovered due to the chemical resistance of the silicon carbides. used as supports. No advantage of any type relating to the implementation of a controlled oxidation process is however described in EP 313 480 A, in particular as regards the starting of the process and concerning the characteristics necessary for an operation of the process. all security for individuals.
  • the Applicant has developed a method for producing synthesis gas with or without a flame, with which the starting operations are facilitated by a better thermal conductivity within the catalytic bed and a much slower gas flow rate in the reactor where the reaction takes place, making it possible to control it both at a temperature above 1000 ° C. and at a temperature of
  • the subject of the present invention is therefore a process for obtaining synthesis gas by partial catalytic oxidation with or without a flame, consisting in bringing into contact a hydrocarbon in the gaseous state and an oxidizing gas, as well as possibly a small amount of water vapor, in the presence of a catalyst comprising at least one silicon carbide, at a temperature above 800 ° C., characterized in that the silicon carbide has a specific surface area determined by the BET method of less than or equal to 100 m 2 / g, the contact time between the mixture of the gaseous hydrocarbon, the oxidizing gas and optionally water vapor, and the catalyst is greater than 0.05 second and in that the pressure inside the reactor is above atmospheric pressure.
  • reaction temperature a value of between 800 ° C. and 1400 ° C.
  • the process according to the present invention has the advantage of operating in non-critical conditions, particularly with regard to the contact time of the gas mixture (hydrocarbon gases , oxidizing gas and water vapor) with the catalyst.
  • the catalytic support perfectly conducts the heat produced during the start of the reaction, which makes it possible to avoid the phenomena of runaway observed by applying the prior art.
  • This good thermal conductivity of the support makes it possible to maintain a good homogeneity of the catalyst temperature in the bed, and thus to avoid the formation of coke-generating hot spots favoring the sintering phenomena of the active phase observed in the prior art.
  • This makes it possible to use a single bed in a conventional reactor, thereby avoiding the use of still-delicate reactor tubes to be uniformly filled with catalyst grains.
  • Another advantage is to be able to increase the temperature of the catalytic bed, which allows a better conversion to synthesis gas, the reaction takes place in the presence or absence of water vapor, in the context of an application in catalytic ATR or POx units.
  • the oxidizing gas may contain more than 20% by volume of oxygen, preferably between 40 and 100% by volume of oxygen.
  • a molar ratio of the carbon of the hydrocarbon (C) to the oxygen will be chosen close to the stoichiometry of the reaction for obtaining the synthesis gas, that is to say say varying more particularly in a range of 1.6 to 2.6.
  • the catalyst contains more than 50% by weight of silicon carbides having a BET specific surface area determined by the NF XI 1-621 standard of less than 100 m 2 / g, in particular between 15 and 80 m 2 / g, preferably between 20 and 40 m 2 / g.
  • silicon carbides also have a mesoporosity determined by the nitrogen BET method according to the NF XI 1-621 standard of between 20 and 100 nm, a macroporosity determined by the measurement of the mercury porosity between 5 and 100 ⁇ m.
  • the silicon carbide used as support is solid and consists of formed grains or not, or solid foam.
  • formed grains means grains in the form of carbide balls, extrudates of cylindrical, trilobed or other shape, monoliths in the form of discs or cylinder sections.
  • the pressure in the reactor can be maintained at a value between 2 ⁇ 10 5 and 150 ⁇ 10 5 Pa and, preferably, between 5 ⁇ 10 5 and 80 ⁇ 10 5 Pa.
  • Silicon catalyst can be used to support Group VIII metals.
  • the Group VIII metal content is between 0.5 and 20% by weight of the catalyst and preferably between 1 and 10% by weight of the catalyst.
  • the preferred metal of Group VIII is nickel.
  • the catalyst can be obtained by any method known to those skilled in the art. In particular, it can be prepared by impregnating the silicon carbide with a solution containing a salt of at least one Group VIII metal, the impregnated metal salt being subsequently decomposed by calcining in air at 300 to 400.degree. impregnated support.
  • the catalyst can be used as such or reduced in situ in the reactor under a stream of hydrogen, at a temperature between 200 and 400 ° C, before starting the unit.
  • the contact time between the mixture of the gaseous hydrocarbon, the oxidizing gas and, if appropriate, the steam will be regulated. water, at a value between 0.5 and 5 seconds.
  • it will limit the amount of steam introduced at a water vapor / carbon molar ratio of the hydrocarbon (H 2 0 / C) less than or equal to 0.2.
  • the temperature of the catalyst bed is maintained between 900 and 1300 ° C.
  • synthesis such as Fischer Tropsch conversion or methanol production.
  • the gases are preheated between 400 and 650 ° C before entering the catalyst bed.
  • hydrocarbons that make it possible to form synthesis gas are chosen from gasoline, reservoir gas condensates, and hydrocarbons comprising from 1 to 3 carbon atoms, methane being preferred.
  • the method according to the invention can be implemented in existing ATR units.
  • FIG. 1 represents two partial oxidation curves of the methane on the catalyst based on alumina ⁇ (Ci) under the conditions of Example 3 for two contact times, respectively of 0.6 and 3 seconds;
  • FIG. 2 represents a partial oxidation curve of the methane on the SiC (C 2 ) -based catalyst under the conditions of Example 3 for two contact times, respectively of 0.6 and 3 seconds.
  • FIG. 3 represents a partial oxidation curve of the methane on the ⁇ -alumina catalyst under the conditions of Example 3 for a contact time of 3 seconds.
  • EXAMPLE 1 The present example aims to show the effectiveness of catalytic supports based on silicon carbides having a BET specific surface area of less than 100 m 2 / g and, more particularly, between 15 and 80 m 2 / g.
  • a sample of 10 g of silicon carbide (SiC) in the form of 0.4 to 1 mm grains with a BET specific surface area of 40 m 2 / g is used in the present example. It was previously impregnated with a solution of nickel nitrate allowing the deposition of 2.6 g of salt on SiC to obtain a final nickel content of 5% by weight relative to the final catalyst. The impregnated catalyst is dried under air at 100 ° C and then calcined at 300 ° C in dry air.
  • a microreactor 2 g of catalyst supported on SiC are introduced, and the atmosphere of the reactor is then flushed under a stream of air at room temperature.
  • the reactor pressure is then raised to 5 ⁇ 10 5 Pa under a mixture of methane and air with a carbon / oxygen molar ratio equal to 2.6, while the temperature of the catalytic bed is 900 ° C.
  • the circulation rate of the gaseous mixture is adjusted for a contact time of 3 seconds, the mixture at the outlet of the reactor being analyzed online by gas chromatography.
  • the purpose of this example is to show the ability of the silicon carbide carrier to rapidly diffuse the heat generated during the methane oxidation reaction out of the reaction zone, thereby preventing the temperature rise of the system.
  • thermodynamics thermodynamics
  • the excess temperature produced during the first hours of testing on alumina exceeds a few hundred degrees. In this situation, it is likely that methane breaks down essentially into carbon and hydrogen. Then, as the amount of carbon deposited on the catalyst increases, the catalyst becomes more and more conductive and the total conversion returns to that expected for a reaction temperature of 900 ° C.
  • the used catalysts Ci and C 2 have been subjected to oxidative regeneration under air. This consists of increasing the temperature of the reactor from room temperature to a temperature of 900 ° C, with a growth of 10 ° C / min, and then to maintain this temperature for 30 minutes, in order to burn the carbon. After cooling, it was found that the alumina-based catalyst Ci did not resist the oxidative regeneration treatment and was completely destroyed, while the SiC-based catalyst C 2 retained its original texture.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Inorganic Chemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Materials Engineering (AREA)
  • Catalysts (AREA)
  • Silicon Compounds (AREA)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Hydrogen, Water And Hydrids (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

The invention relates to a method for obtaining synthesis gas by partial catalytic oxidation, consisting in bringing a hydrocarbon in a gaseous state into contact with an oxidizing gas, and therefore possibly a small amount of water vapor, in the presence of a catalyst comprising at least one silicon carbide at a temperature of more than 800 °C. According to the invention, the silicon carbide has a specific surface which is determined by the BET method and which is less than or equal to 100 m2/g, the contact time between the mixture of gaseous hydrocarbon, oxidizing gas and silicon carbide being more than 0.05 seconds and the pressure inside the reactor being greater than atmospheric pressure.

Description

PROCEDE D'OBTENTION DE GAZ DE SYNTHESE PAR OXYDATION CATALYTIQUE PARTIELLEPROCESS FOR OBTAINING SYNTHESIS GAS BY PARTIAL CATALYTIC OXIDATION
Avec l'avènement de l'échange d'information par voie numérique, par échange de messages ou d'accès en réseau, le comportement des utilisateurs de ces moyens d'échange a fait l'objet de nombreuses investigations.With the advent of the exchange of information by digital means, message exchange or network access, the behavior of users of these means of exchange has been the subject of numerous investigations.
C'est en particulier le cas dans le domaine du commerce électronique dans lequel il est opportun de déterminer, et, de préférence, d'anticiper les centres d'intérêt, et, finalement les comportements raisonnablement prévisibles d'un ou plusieurs utilisateurs. Alors que de manière connue en tant que telle, indépendamment du domaine spécifique au commerce électronique, les études statistiques permettent une approche globale, relative à des groupements d'individus ou utilisateurs, la présente invention a, au contraire, pour objet, un procédé et un système de détection d'un phénomène d'émergence d'information, à partir de données numériques échantillonnées, susceptibles d'être mis en œuvre de manière discrète, par utilisateur, une mise en œuvre pour un groupe d'utilisateurs, voire une population d'utilisateurs, pouvant simplement être ramenée à une multiplication de mise en œuvre du procédé respectivement du système objet de la présente invention, afin d'en inférer des résultats statistiques.This is particularly the case in the field of electronic commerce in which it is expedient to determine, and preferably to anticipate the interests, and ultimately the reasonably foreseeable behavior of one or more users. While in a known manner, independently of the specific domain of electronic commerce, statistical studies allow a global approach, relating to groups of individuals or users, the present invention has, on the contrary, a method and a system for detecting an information emergence phenomenon, based on sampled digital data that can be implemented in a discrete manner, per user, an implementation for a group of users, or even a population users, which can simply be reduced to a multiplication of implementation of the method respectively of the system object of the present invention, in order to infer statistical results.
Toute information désignant, selon l'acception la plus large, le fait ou la chose que l'on porte à la connaissance de quelqu'un, dans le cadre d'études Parmi les procédés de fabrication de gaz de synthèse par oxydation partielle catalytique du méthane, il est connu d'opérer en présence de catalyseurs à base d'oxydes métalliques à des températures supérieures à 700°C, rarement au-delà de 1000°C, comme il est décrit dans les documents US 5.744.419 A,Any information designating, in the broadest sense, the fact or the thing that is brought to the knowledge of someone, as part of studies Among the processes for manufacturing synthesis gas by catalytic partial oxidation of methane, it is known to operate in the presence of metal oxide catalysts at temperatures above 700 ° C., rarely above 1000 ° C. as described in US 5,744,419 A,
US 6.007.699 A, WO 85/05094 A et EP 0 742 172 A. Ces catalyseurs contiennent généralement un ou plusieurs métaux du groupe constitué par le platine, le palladium, le rhodium, le ruthénium, l'iridium, le nickel, le fer et le cobalt, supportés par au moins un oxyde réfractaire du groupe constitué par l'alumine, l'oxyde de titane, la silice, la zircone et la magnésie. Cependant, le maintien au cours du procédé de températures supérieures à 700°C favorise le frittage de ces catalyseurs et la formation de dépôts carbonés qui bouchent les sites actifs du catalyseur, avec pour conséquence la désactivation du catalyseur. Au cours de ce frittage, on observe en outre une migration de l'espèce active du catalyseur dans le support, ce qui rend plus difficile et plus onéreuse la régénération des catalyseurs et la récupération de la phase active, dans le cas de métaux nobles notamment. En outre, la mise en œuvre de ces procédés de conversion du méthane ou, plus généralement, des hydrocarbures en gaz de synthèse nécessite de travailler avec des temps de contact entre le catalyseur et les flux gazeux qui sont très critiques, car difficilement maîtrisables, de préférence inférieurs à 10 ms (10 millisecondes, soit 0,01 seconde). Si de telles contraintes ne sont pas respectées au démarrage du procédé, la réaction étant très exothermique et le transfert thermique à l'intérieur du lit de catalyseur insuffisant, le système risque de s'emballer et même d'exploser. Comme on peut le comprendre, les industriels hésitent à utiliser ces procédés, compte tenu des dangers pour la sécurité des individus que peuvent représenter de tels procédés.US 6,007,699 A, WO 85/05094 A and EP 0 742 172 A. These catalysts generally contain one or more metals of the group consisting of platinum, palladium, rhodium, ruthenium, iridium, nickel, iron and cobalt, supported by at least one refractory oxide of the group consisting of alumina, titanium oxide, silica, zirconia and magnesia. However, maintaining in the process temperatures above 700 ° C promotes the sintering of these catalysts and the formation of carbonaceous deposits which clog the active sites of the catalyst, with consequent deactivation of the catalyst. During this sintering, a migration of the active species of the catalyst into the support is also observed, which makes the regeneration of the catalysts and the recovery of the active phase more difficult and more expensive, especially in the case of noble metals. . In addition, the implementation of these processes for converting methane or, more generally, hydrocarbons into synthesis gas requires working with contact times between the catalyst and the gas streams which are very critical, because difficult to control, of preferably less than 10 ms (10 milliseconds, ie 0.01 seconds). If such constraints are not observed at the start of the process, the reaction being very exothermic and the heat transfer inside the catalyst bed insufficient, the system is likely to pack and even explode. As can be understood, manufacturers are reluctant to use these methods, given the dangers to the safety of individuals that can represent such processes.
Dans EP 313 480 A, il a été proposé d'utiliser, dans les lits catalytiques pour l'oxydation ménagée d'hydrocarbures tels que le méthane, des carbures de silicium à haute surface spécifique, supérieure à 100 m2/g, mesurée selon la méthode BET, même àIn EP 313 480 A, it has been proposed to use, in the catalytic beds for the controlled oxidation of hydrocarbons such as methane, silicon carbides with a high specific surface area greater than 100 m 2 / g, measured according to the BET method, even at
1000°C, de préférence supérieure à 200 m /g, supportant éventuellement un métal de type tungstène ou nickel. De tels catalyseurs présentent l'avantage de résister au double empoisonnement par le coke et par les métaux, le coke ne constituant pas une gêne, puisque le catalyseur est facilement régénéré, et les métaux pouvant être récupérés, du fait de la résistance chimique des carbures de silicium utilisés comme supports. Aucun avantage d'un type quelconque relatif à la mise en œuvre d'un procédé d'oxydation ménagée n'est toutefois décrit dans EP 313 480 A, notamment en matière de démarrage du procédé et concernant les caractéristiques nécessaires à un fonctionnement du procédé en toute sécurité pour les individus.1000 ° C, preferably greater than 200 m / g, optionally supporting a metal of the tungsten or nickel type. Such The catalysts have the advantage of being resistant to double poisoning by coke and metals, since coke is not a problem since the catalyst is easily regenerated and the metals can be recovered due to the chemical resistance of the silicon carbides. used as supports. No advantage of any type relating to the implementation of a controlled oxidation process is however described in EP 313 480 A, in particular as regards the starting of the process and concerning the characteristics necessary for an operation of the process. all security for individuals.
Pour éviter que des réactions explosives, difficiles à maîtriser, se produisent, la Demanderesse a développé un procédé de production de gaz de synthèse avec ou sans flamme, avec lequel les opérations de démarrage sont facilitées par une meilleure conductibilité thermique au sein du lit catalytique et un débit des gaz beaucoup plus lent dans le réacteur où a lieu la réaction, permettant de contrôler celle-ci aussi bien à une température supérieure à 1000°C qu'à une température deIn order to prevent explosive reactions that are difficult to control, the Applicant has developed a method for producing synthesis gas with or without a flame, with which the starting operations are facilitated by a better thermal conductivity within the catalytic bed and a much slower gas flow rate in the reactor where the reaction takes place, making it possible to control it both at a temperature above 1000 ° C. and at a temperature of
800°C, le lit catalytique résistant mécaniquement à ces températures.800 ° C, the catalytic bed mechanically resistant to these temperatures.
La présente invention a donc pour objet un procédé d'obtention de gaz de synthèse par oxydation catalytique partielle avec ou sans flamme, consistant à mettre en contact un hydrocarbure à l'état gazeux et un gaz oxydant, ainsi qu'éventuellement une faible quantité de vapeur d'eau, en présence d'un catalyseur comprenant au moins un carbure de silicium, à une température supérieure à 800°C, caractérisé en ce que le carbure de silicium a une surface spécifique déterminée par la méthode BET inférieure ou égale à 100 m2/ g, le temps de contact entre le mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, et le catalyseur est supérieur à 0,05 seconde et en ce que la pression à l'intérieur du réacteur est supérieure à la pression atmosphérique.The subject of the present invention is therefore a process for obtaining synthesis gas by partial catalytic oxidation with or without a flame, consisting in bringing into contact a hydrocarbon in the gaseous state and an oxidizing gas, as well as possibly a small amount of water vapor, in the presence of a catalyst comprising at least one silicon carbide, at a temperature above 800 ° C., characterized in that the silicon carbide has a specific surface area determined by the BET method of less than or equal to 100 m 2 / g, the contact time between the mixture of the gaseous hydrocarbon, the oxidizing gas and optionally water vapor, and the catalyst is greater than 0.05 second and in that the pressure inside the reactor is above atmospheric pressure.
Selon une caractéristique importante de ce procédé, on peut ajuster, d'une part, la température de réaction à une valeur comprise entre 800°C et 1400°C, et, d'autre part, le temps de contact du mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, avec le catalyseur est compris entre 0,05 etAccording to an important characteristic of this process, it is possible to adjust, on the one hand, the reaction temperature to a value of between 800 ° C. and 1400 ° C., and, on the other hand, the contact time of the mixture of the hydrocarbon gas, oxidizing gas and optionally water vapor, with the catalyst being between 0.05 and
5 secondes. Outre les avantages liés à la nature même d'une partie du catalyseur, le procédé selon la présente invention présente l'avantage d'opérer dans des conditions non critiques, notamment en ce qui concerne le temps de contact du mélange de gaz (gaz hydrocarbonés, gaz oxydant et vapeur d'eau) avec le catalyseur. En outre, le support catalytique conduit parfaitement la chaleur produite lors du démarrage de la réaction, ce qui permet d'éviter les phénomènes d'emballement observés en appliquant l'art antérieur. Cette bonne conductibilité thermique du support permet de maintenir une bonne homogénéité de la température du catalyseur dans le lit, et donc d'éviter la formation de points chauds générateurs de coke favorisant les phénomènes de frittage de la phase active observés dans la technique antérieure. Cela permet d'utiliser un lit unique dans un réacteur classique, en évitant ainsi l'utilisation de réacteur à tubes toujours délicats à remplir de façon uniforme de grains de catalyseur.5 seconds. In addition to the advantages related to the very nature of a portion of the catalyst, the process according to the present invention has the advantage of operating in non-critical conditions, particularly with regard to the contact time of the gas mixture (hydrocarbon gases , oxidizing gas and water vapor) with the catalyst. In addition, the catalytic support perfectly conducts the heat produced during the start of the reaction, which makes it possible to avoid the phenomena of runaway observed by applying the prior art. This good thermal conductivity of the support makes it possible to maintain a good homogeneity of the catalyst temperature in the bed, and thus to avoid the formation of coke-generating hot spots favoring the sintering phenomena of the active phase observed in the prior art. This makes it possible to use a single bed in a conventional reactor, thereby avoiding the use of still-delicate reactor tubes to be uniformly filled with catalyst grains.
Un autre avantage est de pouvoir augmenter la température du lit catalytique, ce qui permet une meilleure conversion en gaz de synthèse, que la réaction ait lieu en présence ou en l'absence de vapeur d'eau, dans le cadre d'une application dans les unités ATR ou POx catalytique.Another advantage is to be able to increase the temperature of the catalytic bed, which allows a better conversion to synthesis gas, the reaction takes place in the presence or absence of water vapor, in the context of an application in catalytic ATR or POx units.
Dans le procédé de la présente invention, le gaz oxydant peut contenir plus de 20% en volume d'oxygène, de préférence entre 40 et 100% en volume d'oxygène.In the process of the present invention, the oxidizing gas may contain more than 20% by volume of oxygen, preferably between 40 and 100% by volume of oxygen.
Pour mettre en œuvre le procédé de l'invention, on choisira un rapport molaire du carbone de l'hydrocarbure (C) à l'oxygène proche de la stcechiométrie de la réaction d'obtention du gaz de synthèse, c'est-à-dire variant plus particulièrement dans un intervalle de 1,6 à 2,6.To implement the process of the invention, a molar ratio of the carbon of the hydrocarbon (C) to the oxygen will be chosen close to the stoichiometry of the reaction for obtaining the synthesis gas, that is to say say varying more particularly in a range of 1.6 to 2.6.
Contrairement à ce qui avait été envisagé dans l'art antérieur, le catalyseur contient plus de 50% en poids de carbures de silicium présentant une surface spécifique BET déterminée par la norme NF XI 1-621 inférieure à 100 m2/g, en particulier comprise entre 15 et 80 m2/g, de préférence comprise entre 20 et 40 m2/g. Ces carbures de silicium présentent en outre une mésoporosité déterminée par la méthode BET à l'azote selon la norme NF XI 1-621 comprise entre 20 et 100 nm, une macroporosité déterminée par la mesure de la porosité au mercure comprise entre 5 et 100 μm. De préférence, le carbure de silicium utilisé comme support est solide et constitué de grains formés ou non, ou de mousse solide. Par grains formés, on entend des grains sous forme de billes de carbure, d'extrudés de forme cylindrique, trilobé ou autre, de monolithes sous forme de disques ou de sections de cylindre.In contrast to what was envisaged in the prior art, the catalyst contains more than 50% by weight of silicon carbides having a BET specific surface area determined by the NF XI 1-621 standard of less than 100 m 2 / g, in particular between 15 and 80 m 2 / g, preferably between 20 and 40 m 2 / g. These silicon carbides also have a mesoporosity determined by the nitrogen BET method according to the NF XI 1-621 standard of between 20 and 100 nm, a macroporosity determined by the measurement of the mercury porosity between 5 and 100 μm. . Preferably, the silicon carbide used as support is solid and consists of formed grains or not, or solid foam. The term "formed grains" means grains in the form of carbide balls, extrudates of cylindrical, trilobed or other shape, monoliths in the form of discs or cylinder sections.
Dans un mode préféré de mise en œuvre du procédé de l'invention, la pression dans le réacteur peut être maintenue à une valeur comprise entre 2xl05 et 150xl05 Pa et, de préférence, entre 5xl05 et 80x105 Pa. Le carbure de silicium du catalyseur peut servir de support à des métaux du Groupe VIII. La teneur en métal du Groupe VIII est comprise entre 0,5 et 20% en poids du catalyseur et, de préférence, entre 1 et 10 % en poids du catalyseur. Le métal préféré du Groupe VIII est le nickel. Le catalyseur peut être obtenu par toutes méthodes connues de l'homme du métier. En particulier, il peut être préparé par imprégnation du carbure de silicium au moyen d'une solution contenant un sel d'au moins un métal du Groupe VIII, le sel métallique imprégné étant ultérieurement décomposé par calcination sous air entre 300 et 400°C du support imprégné. Pour la mise en œuvre du procédé selon l'invention, le catalyseur peut être utilisé tel quel ou réduit in situ dans le réacteur sous courant d'hydrogène, à une température comprise entre 200 et 400°C, avant démarrage de l'unité. Au démarrage du procédé selon l'invention, pour éviter les problèmes d'emballement incontrôlable de la réaction d'oxydation ménagée, on réglera le temps de contact entre le mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, à une valeur comprise entre 0,5 et 5 secondes. Avantageusement, dans le cadre de la présente invention, on limitera la quantité de vapeur introduite à un rapport molaire vapeur d'eau/carbone de l'hydrocarbure (H20/C) inférieur ou égal à 0,2.In a preferred embodiment of the process of the invention, the pressure in the reactor can be maintained at a value between 2 × 10 5 and 150 × 10 5 Pa and, preferably, between 5 × 10 5 and 80 × 10 5 Pa. Silicon catalyst can be used to support Group VIII metals. The Group VIII metal content is between 0.5 and 20% by weight of the catalyst and preferably between 1 and 10% by weight of the catalyst. The preferred metal of Group VIII is nickel. The catalyst can be obtained by any method known to those skilled in the art. In particular, it can be prepared by impregnating the silicon carbide with a solution containing a salt of at least one Group VIII metal, the impregnated metal salt being subsequently decomposed by calcining in air at 300 to 400.degree. impregnated support. For the implementation of the process according to the invention, the catalyst can be used as such or reduced in situ in the reactor under a stream of hydrogen, at a temperature between 200 and 400 ° C, before starting the unit. At the start of the process according to the invention, in order to avoid the problems of uncontrollable runaway of the controlled oxidation reaction, the contact time between the mixture of the gaseous hydrocarbon, the oxidizing gas and, if appropriate, the steam will be regulated. water, at a value between 0.5 and 5 seconds. Advantageously, in the context of the present invention, it will limit the amount of steam introduced at a water vapor / carbon molar ratio of the hydrocarbon (H 2 0 / C) less than or equal to 0.2.
Dans un mode préféré de mise en œuvre de la présente invention, la température du lit catalytique est maintenue entre 900 et 1300°C. Plus la température est élevée, plus la formation de CO est favorisée par rapport à celle de C02, ce qui a pour effet d'accroître l'efficacité globale des étapes ultérieures de conversion du gaz de synthèse, telles que la conversion Fischer Tropsch ou la production de méthanol.In a preferred embodiment of the present invention, the temperature of the catalyst bed is maintained between 900 and 1300 ° C. The higher the temperature, the more CO formation is favored over that of CO 2 , which has the effect of increasing the overall efficiency of the subsequent stages of conversion of CO 2 gas. synthesis, such as Fischer Tropsch conversion or methanol production.
Cependant, lorsqu'on veut travailler sous de fortes pressions supérieures à 25xl05 Pa, il est préférable d' opérer en au moins deux étapes successives, une première étape de conditionnement du carbure de silicium sous une pression de 5xl05 et lOxlO5 Pa pendant au moins deux heures, puis une deuxième étape sous une pression comprise entre 25xl05 et 80x105 Pa .However, when it is desired to work under high pressures greater than 25 × 10 5 Pa, it is preferable to operate in at least two successive steps, a first step of conditioning the silicon carbide under a pressure of 5 × 10 5 and 10 × 10 5 Pa during at least two hours, then a second step under a pressure of between 25x10 5 and 80x10 5 Pa.
Dans un mode préféré de mise en œuvre de l'invention, en vue de permettre l'auto-allumage de la réaction, les gaz sont préchauffés entre 400 et 650°C avant l'entrée sur le lit catalytique.In a preferred embodiment of the invention, to allow self-ignition of the reaction, the gases are preheated between 400 and 650 ° C before entering the catalyst bed.
Les hydrocarbures permettant la formation de gaz de synthèse sont choisis parmi l'essence, les condensats de gaz de gisement, et les hydrocarbures comprenant de 1 à 3 atomes de carbone, le méthane étant préféré.The hydrocarbons that make it possible to form synthesis gas are chosen from gasoline, reservoir gas condensates, and hydrocarbons comprising from 1 to 3 carbon atoms, methane being preferred.
Tel que décrit précédemment, le procédé selon l'invention peut être mis en œuvre dans les unités ATR existantes.As described above, the method according to the invention can be implemented in existing ATR units.
Des exemples vont être décrits ci-après pour illustrer l'invention, sans toutefois en limiter la portée. Deux figures sont annexées en relation avec l'Exemple 3 :Examples will be described below to illustrate the invention, without limiting the scope thereof. Two figures are appended in relation to Example 3:
La figure 1 représente deux courbes d'oxydation partielle du méthane sur le catalyseur à base d'alumine γ (Ci) dans les conditions de l'Exemple 3 pour deux temps de contact, respectivement de 0,6 et 3 secondes ; La figure 2 représente une courbe d'oxydation partielle du méthane sur le catalyseur à base de SiC (C2) dans les conditions de l'Exemple 3 pour deux temps de contact, respectivement de 0,6 et 3 secondes.FIG. 1 represents two partial oxidation curves of the methane on the catalyst based on alumina γ (Ci) under the conditions of Example 3 for two contact times, respectively of 0.6 and 3 seconds; FIG. 2 represents a partial oxidation curve of the methane on the SiC (C 2 ) -based catalyst under the conditions of Example 3 for two contact times, respectively of 0.6 and 3 seconds.
La figure 3 représente une courbe d'oxydation partielle du méthane sur le catalyseur à base d'alumine α dans les conditions de l'Exemple 3 pour un temps de contact de 3 secondes .FIG. 3 represents a partial oxidation curve of the methane on the α-alumina catalyst under the conditions of Example 3 for a contact time of 3 seconds.
EXEMPLE 1 Le présent exemple vise à montrer l'efficacité des supports catalytiques à base de carbures de silicium de surface spécifique BET inférieure à 100 m2/g et, plus particulièrement, comprise entre 15 et 80 m /g. Un échantillon de 10 g de carbure de silicium (SiC) sous forme de grains de 0,4 à 1 mm, de surface spécifique BET de 40 m2/g est utilisé dans le présent exemple. Il a été préalablement imprégné par une solution de nitrate de nickel permettant le dépôt de 2,6 g de sel sur le SiC pour obtenir une teneur finale en nickel de 5% en poids par rapport au catalyseur final. Le catalyseur imprégné est séché sous air à 100°C, puis calciné à 300°C sous air sec.EXAMPLE 1 The present example aims to show the effectiveness of catalytic supports based on silicon carbides having a BET specific surface area of less than 100 m 2 / g and, more particularly, between 15 and 80 m 2 / g. A sample of 10 g of silicon carbide (SiC) in the form of 0.4 to 1 mm grains with a BET specific surface area of 40 m 2 / g is used in the present example. It was previously impregnated with a solution of nickel nitrate allowing the deposition of 2.6 g of salt on SiC to obtain a final nickel content of 5% by weight relative to the final catalyst. The impregnated catalyst is dried under air at 100 ° C and then calcined at 300 ° C in dry air.
Dans un microréacteur, on introduit 2 g de catalyseur supporté sur SiC, puis on purge l'atmosphère du réacteur sous courant d'air à température ambiante. La pression du réacteur est ensuite montée jusqu'à 5xl05 Pa sous un mélange de méthane et d'air de rapport molaire carbone /oxygène égal à 2,6, tandis que la température du lit catalytique est de 900°C. La vitesse de circulation du mélange gazeux est ajustée pour un temps de contact de 3 secondes, le mélange en sortie de réacteur étant analysé en ligne par chromatographie en phase gazeuse.In a microreactor, 2 g of catalyst supported on SiC are introduced, and the atmosphere of the reactor is then flushed under a stream of air at room temperature. The reactor pressure is then raised to 5 × 10 5 Pa under a mixture of methane and air with a carbon / oxygen molar ratio equal to 2.6, while the temperature of the catalytic bed is 900 ° C. The circulation rate of the gaseous mixture is adjusted for a contact time of 3 seconds, the mixture at the outlet of the reactor being analyzed online by gas chromatography.
Les résultats de conversion et les rapports molaires H2/CO sont donnés dans le Tableau I ci-après.The conversion results and the molar ratios H 2 / CO are given in Table I below.
TABLEAU ITABLE I
Ces résultats sont conformes à ce qui était attendu, soit un rapport molaire H2/CO d'environ 2 et une conversion de plus de 70%.These results are in line with what was expected, namely an H 2 / CO molar ratio of about 2 and a conversion of more than 70%.
Lorsqu'on opère avec un temps de contact plus faible, moins de 0,5 seconde, les conversions et les rapports molaires sont comparables. Ces identités des résultats confirment l'intérêt du procédé qui permet une mise en œuvre plus aisée (temps de contact plus long) de l'oxydation catalytique partielle, avec un lit catalytique unique, du méthane ou de tout autre condensât.When operated with a shorter contact time of less than 0.5 seconds, conversions and molar ratios are comparable. These identities of the results confirm the interest of the process which allows an easier implementation (longer contact time) of the partial catalytic oxidation, with a single catalytic bed, methane or any other condensate.
Parallèlement, on n'a observé aucune désactivation du catalyseur.At the same time, no deactivation of the catalyst was observed.
EXEMPLE 2EXAMPLE 2
Dans cet exemple, on opère avec le même catalyseur que dans l'Exemple I, mais avec un mélange de gaz présentant un rapport méthane/ air égal à 2 (soit CH /02=2). Les résultats sont donnés dans le Tableau 2 ci-après.In this example, one operates with the same catalyst as in Example I, but with a mixture of gases having a methane / air ratio of 2 (ie CH / O 2 = 2). The results are given in Table 2 below.
TABLEAU 2TABLE 2
En opérant avec un rapport HC/02 de 2, comparativement à l'Exemple 1 , on obtient une augmentation de la conversion qui devient proche de 90%, sans que le rapport H2/CO en sortie soit modifié, pour qu'il demeure toujours égal à 2.Operating with an HC / O 2 ratio of 2, compared with Example 1, we obtain an increase in the conversion which becomes close to 90%, without the H 2 / CO ratio at the output being modified, so that always remains equal to 2.
EXEMPLE 3EXAMPLE 3
Le présent exemple a pour but de montrer la capacité du support à base de carbure de silicium à diffuser rapidement la chaleur produite lors de la réaction d'oxydation du méthane hors de la zone réactionnelle, en empêchant ainsi l'emballement en température du système.The purpose of this example is to show the ability of the silicon carbide carrier to rapidly diffuse the heat generated during the methane oxidation reaction out of the reaction zone, thereby preventing the temperature rise of the system.
Dans cet exemple, deux catalyseurs, contenant chacun la même charge de 5 % en poids de nickel, sont testés : l'un (C2) est sur support SiC (grains de 6 mm de long et 2 mm de diamètre), de surface spécifique égale à 25 m /g tandis que l'autre (Ci) est à base d'alumine gamma de haute surface spécifique égale à 224 m2/g. Les supports sont imprégnés selon le même mode opératoire que celui décrit dans l'Exemple 1. La réaction d'oxydation ménagée du méthane est réalisée selon les conditions suivantes : température de réaction : 900 CC ; rapport CH4/O2 : 2,6 ; pression totale : 5.105 Pa ; temps de contact : 3 secondes. Les résultats obtenus sont présentés sur la Figure 1 pour Ci et sur la figure 2 pour C2, pour une durée identique de test. Avec le catalyseur Ci à base d'alumine γ, la chaleur produite lors de la réaction est extrêmement importante, entraînant une conversion totale dépassant largement celle donnée par la thermodynamique (Figure 1). En tenant compte des données thermodynamiques, l'excédent de température produit lors des premières heures de test sur l'alumine dépasse quelques centaines de degrés. Dans cette situation, il est probable que le méthane se décompose essentiellement en carbone et en hydrogène. Puis, au fur et à mesure qu'augmente la quantité de carbone déposé sur le catalyseur, ce dernier devient de plus en plus conducteur et la conversion totale revient au niveau de celle attendue pour une température de réaction de 900 °C.In this example, two catalysts, each containing the same charge of 5% by weight of nickel, are tested: one (C 2 ) is supported SiC (grains 6 mm long and 2 mm in diameter) with a specific surface area equal to 25 m 2 / g while the other (Ci) is based on gamma alumina with a high specific surface area of 224 m 2 / g . The supports are impregnated according to the same procedure as described in Example 1. The oxidation reaction of methane is performed according the following conditions: reaction temperature: 900 C C; CH4 / O2 ratio: 2.6; total pressure: 5.10 5 Pa; contact time: 3 seconds. The results obtained are shown in FIG. 1 for Ci and FIG. 2 for C 2 , for an identical test duration. With the catalyst C 1 based on alumina γ, the heat produced during the reaction is extremely important, resulting in a total conversion far exceeding that given by thermodynamics (FIG. 1). Taking into account thermodynamic data, the excess temperature produced during the first hours of testing on alumina exceeds a few hundred degrees. In this situation, it is likely that methane breaks down essentially into carbon and hydrogen. Then, as the amount of carbon deposited on the catalyst increases, the catalyst becomes more and more conductive and the total conversion returns to that expected for a reaction temperature of 900 ° C.
Avec le catalyseur C à base de SiC, un emballement de la conversion lors du démarrage n'a pas eu lieu (Figure 2), du fait de la forte conductivité thermique du support, qui a permis l'évacuation rapide de la chaleur formée hors de la zone réactionnelle. La comparaison du comportement thermique de ces deux catalyseurs confirme une fois de plus la supériorité d'un catalyseur à base de SiC par rapport à un catalyseur à base d'alumine, le premier diffusant plus rapidement la chaleur produite par la réaction, lors de la phase de démarrage. On constate en outre que la quantité de carbone déposé sur le catalyseur est moins importante sur le catalyseur C2 que sur le catalyseur Ci. De plus, il y a une détérioration de la structure du catalyseur à base d'alumine γ : la surface spécifique chute à 62 m2/g, et la résistance mécanique diminue (une partie du support sous forme d'extrudé a été fragmentée en grains de taille plus petite).With the SiC-based catalyst C, a runaway conversion during startup did not occur (Figure 2), due to the high thermal conductivity of the support, which allowed the rapid evacuation of the heat formed out of the reaction zone. The comparison of the thermal behavior of these two catalysts once again confirms the superiority of an SiC-based catalyst with respect to an alumina-based catalyst, the first one diffusing the heat produced by the reaction more rapidly during the reaction. Beginning phase. It is furthermore noted that the amount of carbon deposited on the catalyst is less important on the catalyst C 2 than on the catalyst Ci. In addition, there is a deterioration of the structure of the catalyst based on alumina γ: the specific surface area drop at 62 m 2 / g, and the mechanical strength decreases (part of the support in the form of extruded has been fragmented into grains of smaller size).
Pour éliminer le carbone et évaluer les possibilités de régénération de ces catalyseurs, les catalyseurs usés Ci et C2 ont été soumis à une régénération oxydante sous air. Celle-ci consiste à augmenter la température du réacteur depuis la température ambiante jusqu'à une température de 900 °C, avec une croissance de 10 °C/min, puis à maintenir cette température pendant 30 minutes, afin de brûler le carbone. Après refroidissement, il a été constaté que le catalyseur Ci à base d'alumine n'a pas résisté au traitement de régénération oxdydante et a été complètement détruit, tandis que le catalyseur C2 à base de SiC a conservé sa texture initiale.To eliminate the carbon and to evaluate the regeneration possibilities of these catalysts, the used catalysts Ci and C 2 have been subjected to oxidative regeneration under air. This consists of increasing the temperature of the reactor from room temperature to a temperature of 900 ° C, with a growth of 10 ° C / min, and then to maintain this temperature for 30 minutes, in order to burn the carbon. After cooling, it was found that the alumina-based catalyst Ci did not resist the oxidative regeneration treatment and was completely destroyed, while the SiC-based catalyst C 2 retained its original texture.
En utilisant un catalyseur de support d'alumine α, de surface spécifique de 5 m2/g, dans les mêmes conditions opératoires avec un temps de contact de 3 secondes, on obtient des résultats comparables à ceux obtenus avec un support alumine γ (voir figure 3) avec cassures des grains. By using an α-alumina support catalyst with a specific surface area of 5 m 2 / g, under the same operating conditions with a contact time of 3 seconds, results comparable to those obtained with a γ-alumina support are obtained (see FIG. Figure 3) with grain breaks.

Claims

REVENDICATIONS
1. Procédé d'obtention de gaz de synthèse par oxydation catalytique partielle, consistant à mettre en contact un hydrocarbure à l'état gazeux et un gaz oxydant, ainsi qu'éventuellement une faible quantité de vapeur d'eau, en présence d'un catalyseur comprenant un carbure de silicium, à une température supérieure à 800°C, caractérisé en ce que le carbure de silicium a une surface spécifique déterminée par la méthode BET inférieure ou égale à 100 m2/g, le temps de contact entre le mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, et le catalyseur est supérieur à 0,05 seconde et en ce que la pression à l'intérieur du réacteur est supérieure à la pression atmosphérique.A method for obtaining synthesis gas by partial catalytic oxidation, comprising contacting a hydrocarbon in the gaseous state and an oxidizing gas, as well as possibly a small amount of water vapor, in the presence of a catalyst comprising a silicon carbide at a temperature greater than 800 ° C., characterized in that the silicon carbide has a specific surface area determined by the BET method of less than or equal to 100 m 2 / g, the contact time between the mixture gaseous hydrocarbon, oxidizing gas and optionally water vapor, and the catalyst is greater than 0.05 second and in that the pressure inside the reactor is greater than atmospheric pressure.
2. Procédé selon la revendication 1, caractérisé en ce que la température de réaction est comprise entre 800 et 1400°C. 2. Method according to claim 1, characterized in that the reaction temperature is between 800 and 1400 ° C.
3. Procédé selon l'une des revendications 1 et 2, caractérisé en ce que le temps de contact du mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, avec le catalyseur est compris entre 0,05 et 5 secondes.3. Method according to one of claims 1 and 2, characterized in that the contact time of the mixture of the hydrocarbon gas, the oxidizing gas and optionally water vapor, with the catalyst is between 0.05 and 5 seconds.
4. Procédé selon l'une des revendications 1 à 3, caractérisé en ce que le gaz oxydant contient plus de 20% en volume d'oxygène, de préférence de 40 à 100% en volume d'oxygène.4. Method according to one of claims 1 to 3, characterized in that the oxidizing gas contains more than 20% by volume of oxygen, preferably 40 to 100% by volume of oxygen.
5. Procédé selon l'une des revendications 1 à 4, caractérisé en ce que le rapport molaire carbone de l'hydrocarbure sur oxygène varie entre 1,6 et 2,6. 5. Method according to one of claims 1 to 4, characterized in that the molar carbon ratio of the hydrocarbon on oxygen varies between 1.6 and 2.6.
6. Procédé selon l'une des revendications 1 à 5, caractérisé en ce que le catalyseur contient plus de 50% en poids de carbure de silicium, de surface spécifique BET comprise entre 15 et 80 m2/g et, de préférence, comprise entre 20 et 40 m /g.6. Method according to one of claims 1 to 5, characterized in that the catalyst contains more than 50% by weight of silicon carbide with a BET specific surface area of between 15 and 80 m 2 / g and, preferably, included between 20 and 40 m / g.
7. Procédé selon l'une des revendications 1 à 6, caractérisé en ce que le carbure de silicium dans le dit catalyseur présente une mésoporosité déterminée par la méthode BET à l'azote comprise entre 20 et 100 nm, et une macroporosité déterminée par la mesure de la porosité au mercure comprise entre 5 et 100 μm.7. Method according to one of claims 1 to 6, characterized in that the silicon carbide in said catalyst has a mesoporosity determined by the BET method with nitrogen between 20 and 100 nm, and a macroporosity determined by the measurement of mercury porosity between 5 and 100 μm.
8. Procédé selon les revendications 1 à 7, caractérisé en ce que le carbure de silicium est solide et constitué de grains formés ou non, ou de mousse solide. 8. Process according to claims 1 to 7, characterized in that the silicon carbide is solid and consists of formed grains or not, or solid foam.
9. Procédé selon l'une des revendications 1 à 8, caractérisé en ce que la pression dans le réacteur est comprise entre 2xl05 et 150xl05 Pa et, de préférence, entre 5xl05 et 80x105 Pa.9. Process according to one of claims 1 to 8, characterized in that the pressure in the reactor is between 2 × 10 5 and 150 × 10 5 Pa and preferably between 5 × 10 5 and 80 × 10 5 Pa.
10. Procédé selon l'une des revendications 1 à 9, caractérisé en ce que le catalyseur comprend 0,5 à 20% en poids d'un métal du10. Method according to one of claims 1 to 9, characterized in that the catalyst comprises 0.5 to 20% by weight of a metal of
Groupe VIII, de préférence de 1 à 10% en poids de métal.Group VIII, preferably from 1 to 10% by weight of metal.
11. Procédé selon la revendication 10, caractérisé en ce que le métal du groupe VIII est le nickel.11. The method of claim 10, characterized in that the group VIII metal is nickel.
12. Procédé selon l'une des revendications 1 à 11, caractérisé en ce que le temps de contact entre le mélange de l'hydrocarbure gazeux, du gaz oxydant et éventuellement de la vapeur d'eau, est compris entre 0,5 et 5 secondes.12. Method according to one of claims 1 to 11, characterized in that the contact time between the mixture of the hydrocarbon gas, the oxidizing gas and optionally water vapor, is between 0.5 and 5 seconds.
13. Procédé selon l'une des revendications 1 à 12, caractérisé en ce que la vapeur d'eau est introduite dans un rapport molaire vapeur d'eau/carbone de l'hydrocarbure (H 0/C) inférieur ou égal à 0,2.13. Method according to one of claims 1 to 12, characterized in that the steam is introduced in a water vapor / carbon molar ratio of the hydrocarbon (H 0 / C) less than or equal to 0, 2.
14. Procédé selon l'une des revendications 1 à 13, caractérisé en ce que la température du lit catalytique est maintenue entre 900 et 1300°C.14. Method according to one of claims 1 to 13, characterized in that the temperature of the catalyst bed is maintained between 900 and 1300 ° C.
15. Procédé selon l'une des revendications 1 à 14 caractérisé en ce qu'il comprend une première étape de conditionnement du carbure de silicium sous une pression de 5xl05 et lOxlO5 Pa pendant au moins deux heures, puis une deuxième étape sous une pression comprise entre 25x105 et 80x105 Pa.15. Method according to one of claims 1 to 14 characterized in that it comprises a first step of conditioning the silicon carbide under a pressure of 5xl0 5 and 10xlO 5 Pa for at least two hours, then a second step under a pressure between 25x10 5 and 80x10 5 Pa.
16. Procédé selon l'une des revendications 1 à 15, caractérisé en ce que les gaz sont préalablement chauffés entre 400 et 500°C, avant d'être mis en contact avec le catalyseur.16. Method according to one of claims 1 to 15, characterized in that the gases are preheated between 400 and 500 ° C, before being brought into contact with the catalyst.
17. Procédé selon l'une des revendications 1 à 16, caractérisé en ce que les hydrocarbures sont choisis parmi l'essence, les condensats de gaz de gisement, et les hydrocarbures comprenant de 1 à 3 atomes de carbone, le méthane étant préféré. 17. Method according to one of claims 1 to 16, characterized in that the hydrocarbons are selected from gasoline, gas condensates deposit, and hydrocarbons comprising 1 to 3 carbon atoms, methane being preferred.
EP02751263A 2001-06-21 2002-06-18 Method for obtaining synthesis gas by partial catalytic oxidation Withdrawn EP1399249A2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0108170 2001-06-21
FR0108170A FR2826293B1 (en) 2001-06-21 2001-06-21 PROCESS FOR OBTAINING SYNTHESIS GAS BY PARTIAL CATALYTIC OXIDATION
PCT/FR2002/002093 WO2003000398A2 (en) 2001-06-21 2002-06-18 Method for obtaining synthesis gas by partial catalytic oxidation

Publications (1)

Publication Number Publication Date
EP1399249A2 true EP1399249A2 (en) 2004-03-24

Family

ID=8864594

Family Applications (1)

Application Number Title Priority Date Filing Date
EP02751263A Withdrawn EP1399249A2 (en) 2001-06-21 2002-06-18 Method for obtaining synthesis gas by partial catalytic oxidation

Country Status (13)

Country Link
US (1) US7101494B2 (en)
EP (1) EP1399249A2 (en)
AR (1) AR034537A1 (en)
BR (1) BR0210564A (en)
CA (1) CA2450447A1 (en)
CO (1) CO5560593A2 (en)
EA (1) EA006849B1 (en)
FR (1) FR2826293B1 (en)
MX (1) MXPA03011763A (en)
NO (1) NO20035720L (en)
NZ (1) NZ530197A (en)
PE (1) PE20030028A1 (en)
WO (1) WO2003000398A2 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004103549A2 (en) * 2003-05-16 2004-12-02 Velocys Inc. Oxidation process using microchannel technology and novel catalyst useful in same
US7220390B2 (en) 2003-05-16 2007-05-22 Velocys, Inc. Microchannel with internal fin support for catalyst or sorption medium
EP1484108A1 (en) * 2003-06-06 2004-12-08 L'air Liquide, S.A. à Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procédés Georges Claude Supported catalyst for producing H2 and/or CO from low molecular weight hydrocarbons
FR2864532B1 (en) 2003-12-31 2007-04-13 Total France PROCESS FOR TRANSFORMING A SYNTHETIC GAS TO HYDROCARBONS IN THE PRESENCE OF SIC BETA AND EFFLUTING THE SAME
FR2864528B1 (en) * 2003-12-31 2006-12-15 Total France PROCESS FOR TREATING METHANE / CARBON DIOXIDE MIXTURES
CA2575165C (en) 2004-08-12 2014-03-18 Velocys Inc. Process for converting ethylene to ethylene oxide using microchannel process technology
FR2900937B1 (en) * 2006-05-15 2008-08-22 Peugeot Citroen Automobiles Sa METHOD FOR INHIBITING THE DEPOSITION ON A METAL SURFACE OF PRODUCTS SUCH AS GUMES, AND A METAL PIECE THUS OBTAINED
US8877206B2 (en) 2007-03-22 2014-11-04 Pds Biotechnology Corporation Stimulation of an immune response by cationic lipids

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2062615A5 (en) * 1969-11-19 1971-06-25 Ustav Pro Vyzkum Vyuziti Nickel/gamma-alumina as catalyst for steam cracking - natural gas
US4394137A (en) * 1980-12-03 1983-07-19 Texaco, Inc. Partial oxidation process
US5023276A (en) * 1982-09-30 1991-06-11 Engelhard Corporation Preparation of normally liquid hydrocarbons and a synthesis gas to make the same, from a normally gaseous hydrocarbon feed
US4914070A (en) * 1987-10-19 1990-04-03 Pechiney Electrometallurgie Process for the production of silicon carbide with a large specific surface area and use for high-temperature catalytic reactions
DZ1918A1 (en) 1994-08-02 2002-02-17 Shell Internaional Res Mij B V Process for partial catalytic oxidation of hydrocarbons.
IT1283585B1 (en) * 1996-04-11 1998-04-22 Snam Progetti EQUIPMENT TO CARRY OUT PARTIAL OXIDATION REACTIONS
US6254807B1 (en) * 1998-01-12 2001-07-03 Regents Of The University Of Minnesota Control of H2 and CO produced in partial oxidation process
US6746650B1 (en) * 1999-06-14 2004-06-08 Utc Fuel Cells, Llc Compact, light weight methanol fuel gas autothermal reformer assembly
US6488838B1 (en) * 1999-08-17 2002-12-03 Battelle Memorial Institute Chemical reactor and method for gas phase reactant catalytic reactions
US6409940B1 (en) * 1999-10-18 2002-06-25 Conoco Inc. Nickel-rhodium based catalysts and process for preparing synthesis gas
US6409939B1 (en) * 2000-05-31 2002-06-25 Uop Llc Method for producing a hydrogen-rich fuel stream
US6911161B2 (en) * 2002-07-02 2005-06-28 Conocophillips Company Stabilized nickel-containing catalysts and process for production of syngas

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO03000398A2 *

Also Published As

Publication number Publication date
FR2826293B1 (en) 2004-01-30
NO20035720D0 (en) 2003-12-19
WO2003000398A2 (en) 2003-01-03
CA2450447A1 (en) 2003-01-03
BR0210564A (en) 2004-05-25
US20050119355A1 (en) 2005-06-02
NZ530197A (en) 2004-09-24
FR2826293A1 (en) 2002-12-27
US7101494B2 (en) 2006-09-05
PE20030028A1 (en) 2003-01-31
AR034537A1 (en) 2004-02-25
NO20035720L (en) 2004-02-19
CO5560593A2 (en) 2005-09-30
WO2003000398A3 (en) 2003-03-13
EA006849B1 (en) 2006-04-28
WO2003000398A9 (en) 2004-01-29
MXPA03011763A (en) 2005-04-19
EA200400060A1 (en) 2004-06-24

Similar Documents

Publication Publication Date Title
EP0624560B1 (en) Preparation of silicium carbide foam from a polyurethane foam impregnated with silicium-containing resin
CA2299667A1 (en) Procedure and device for producing hydrogen through the thermocatalytic breakdown of hydrocarbons
CA2817684C (en) Preparation process for a catalyst implementing a rapid drying stage and its use for fischer-tropsch synthesis
EP1259458A1 (en) Method for producing hydrogen by partial oxidation of hydrocarbons
EP1519789A1 (en) Method for preparing catalysts for heterogeneous catalysis by multiple-phase impregnation, catalysts and use of said catalysts
FR2670400A1 (en) Process for the preparation of multimetallic catalysts
EP1399249A2 (en) Method for obtaining synthesis gas by partial catalytic oxidation
FR3063917A1 (en) CATALYST FOR REVERSE WATER GAS REACTION (RWGS), ASSOCIATED RWGS REACTION AND METHOD FOR IN-SITU REGENERATION OF CATALYST
AU2004224919A1 (en) Modifying catalyst for partial oxidation and method for modification
FR2866248A1 (en) Composition useful as a catalyst for oxidizing carbon monoxide and purifying air comprises gold on a reducible oxide support
EP0712661B1 (en) Combustion process
FR2828012A1 (en) Fuel cell installation has at least two transformation units for catalytic decomposition which enable fuel rich in hydrogen and suitable for fuel cells to be generated continuously from hydrocarbons
JP2004523459A (en) How to use molybdenum carbide catalyst
FR2857003A1 (en) Catalyst and process for the reforming of ethanol and other heavier alcohols, useful for the production of hydrogen
FR2960450A1 (en) PROCESS FOR ANAEROBIC PRODUCTION OF HYDROGEN
US20050239633A1 (en) Control method of catalyst activity
FR2892323A1 (en) Catalyst, useful for the production of gas rich in hydrogen, comprises a support comprising simple or mixed oxide containing cerium base and an active phase deposited on the support
WO2006045951A1 (en) Use of rare earth and metal mixed oxyhydrides for the conversion of alkanes into co and h2 at low temperature
FR2811976A1 (en) PROCESS AND DEVICE FOR PRODUCING A GASEOUS MIXTURE CONTAINING HYDROGEN AND CO BY STAGE OXIDATION OF A HYDROCARBON
FR2864528A1 (en) Reforming methane with carbon dioxide to produce synthesis gas comprises using a catalyst with a support comprising beta silicon carbide
WO2003040029A1 (en) Method for hydrogen production by catalytic decomposition of hydrocarbons, method and installation for electric power production using same
FR3145560A1 (en) Direct gas-to-water conversion reaction by plasma catalysis
EP0896049A1 (en) Process for the conversion of light gaseous hydrocarbons into higher hydrocarbones
CH704017B1 (en) A process for preparing a oxyhydride containing at least one rare earth and its use to catalyze a partial oxidation of an alkane.
BE642544A (en)

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

AX Request for extension of the european patent

Extension state: AL LT LV MK RO SI

17P Request for examination filed

Effective date: 20040106

R17D Deferred search report published (corrected)

Effective date: 20040129

17Q First examination report despatched

Effective date: 20040503

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: TOTAL RAFFINAGE MARKETING

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100105