Objetivo
The objective of this work has been the development of a highly selective and temperature tolerant catalyst for the synthesis of dimethyl ether (DME). The key steps in DME synthesis are methanol synthesis, partial methanol dehydration and the water gas shift reaction. This combination results in a synergistic effect which relieves the unfavourable thermodynamics which apply to methanol synthesis. Almost full conversion of synthesis gas to DME is achieved in a single pass at moderate pressures. However, the reaction is strongly exothermic and large amounts of heat have to be removed.
The relationships between the catalytic properties of HZSM-5 type zeolites and their degree of dealumination have been investigated. An optimum range of acidity and site density has been identified leading to the preparation of zeolites with a higher temperature tolerance while still preserving sufficient activity to make them suitable as dehydration catalysts. The most promising zeolites were mixed with standard methanol catalysts and were tested. Byproduct selectivity is highly dependent on the way in which the 2 catalysts are mixed.
Long terms catalyst stability has been demonstrated and a 450-hour pilot plant test has been conducted.
Dimethyl ether (DME) and water, rather than methanol, can be reacted with carbon monoxide using a rhodium catalyst to produce acetic acid, which can be derivatised to yield methyl acetate and acetic anhydride. The DME itself can be synthesised directly from synthesis gas much more efficiently, and at lower pressures, than can methanol.
The advantages of using this process are:
the separate synthesis of methanol at high pressure can be avoided;
synthesis gas recycling, which is necessary in the methanol synthesis reactor, is avoided;
separate synthesis of carbon monoxide is avoided since it can be provided by selecting reaction conditions and synthesis gas composition so as to leave over sufficient carbon monoxide in the effluent from the dimethyl ether reactor.
Calculations have shown that this process is much more economical than the conventional methanol carbonylation route.
An improved process has been developed for the conversion of methanol, or preferably dimethyl ether (DME), into liquid hydrocarbons for use as high octane motor fuel.
DME is preferred as feedstock since:
less water is generated and so the catalyst lifetime is increased;
approximately 20% of the heat of reaction can be released before entering the adiabatic reactor, thereby reducing the exit temperature.
One of the achievements of the research programme has been the generation of a comprehensive set of data linking the zeolite catalyst's degree and rate of dealumination to process parameters such as temperature, steam partial pressure and time. The ultimate catalyst lifetime can be extended by applying steam modified zeolites. The concept is based on the application of a ZSM-5 zeolite with an initially high aluminium concentration which is exposed to steam under selected conditions to reduce its activity to a suitable level. The zeolite is then in a state where it suffers only very slow dealumination ensuring a more stable catalytic performance leading to a more uniform product composition.
Similar considerations apply in the production of light olefins for use as diesel or jet fuel.
Steam treatments - mainly of medium pore and, in particular, ZSM-5 type zeolites - were varied systematically by applying different contact times, temperatures and steam partial pressures. Selected zeolites were subjected to additional modifications either before or after steam treatment. All samples were characterised by physical, physico-chemical and chemical (catalytic) techniques. The development of these techniques was initiated at an early stage of the project and methods were refined throughout the research period.
TO OBTAIN AN IMPROVED UNDERSTANDING AT A FUNDAMENTAL LEVEL, OF THE PHENOMENA RELATING TO ZEOLITE STEAM DEALUMINATION AND TO STUDY THE ASSOCIATED CHANGES IN CATALYTIC PROPERTIES.
FURTHER OBJECTIVES COMPRISE THE USE OF ZEOLITE DEALUMINATION AS A MEANS OF TAILORING THE ACIDIC PROPERTIES OF ZEOLITES AND TO SEEK NEW APPLICATIONS OF DEALUMINATED ZEOLITES IN CATALYSIS.
WITHIN THE SCOPE OF THE PROJECT IS THE ESTABLISHMENT OF RELIABLE CHARACTERIZATION METHODS.
Ámbito científico (EuroSciVoc)
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
CORDIS clasifica los proyectos con EuroSciVoc, una taxonomía plurilingüe de ámbitos científicos, mediante un proceso semiautomático basado en técnicas de procesamiento del lenguaje natural. Véas: El vocabulario científico europeo..
- ingeniería y tecnología ingeniería ambiental gestión de residuos procesos de tratamiento de residuos reciclaje
- ciencias naturales ciencias químicas química inorgánica compuestos inorgánicos
- ciencias naturales ciencias químicas química orgánica alcoholes
- ciencias naturales ciencias químicas catálisis
- ingeniería y tecnología ingeniería ambiental energía y combustibles
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Programa(s)
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Programas de financiación plurianuales que definen las prioridades de la UE en materia de investigación e innovación.
Tema(s)
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Datos no disponibles
Las convocatorias de propuestas se dividen en temas. Un tema define una materia o área específica para la que los solicitantes pueden presentar propuestas. La descripción de un tema comprende su alcance específico y la repercusión prevista del proyecto financiado.
Convocatoria de propuestas
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Datos no disponibles
Procedimiento para invitar a los solicitantes a presentar propuestas de proyectos con el objetivo de obtener financiación de la UE.
Régimen de financiación
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Régimen de financiación (o «Tipo de acción») dentro de un programa con características comunes. Especifica: el alcance de lo que se financia; el porcentaje de reembolso; los criterios específicos de evaluación para optar a la financiación; y el uso de formas simplificadas de costes como los importes a tanto alzado.
Coordinador
NAMUR / NAMEN
Bélgica
Los costes totales en que ha incurrido esta organización para participar en el proyecto, incluidos los costes directos e indirectos. Este importe es un subconjunto del presupuesto total del proyecto.