Catalyst bed support modes

Caprolactam hydrogenation, 576,577 Cartridge filters, 319 applications, 323 particle recovery range, 323 Catalyst bed support modes, 587 Catalysts... 

Various types of photocatalytic membrane reactors in which the catalyst was used in different modes have been built with the purpose to have an easy separation of the catalyst from the reaction environment a photocatalyst in suspension in magnetically or mechanically agitated slurries confined by means of a membrane, fixed bed, catalyst deposited or entrapped on an inert support or in a membrane, and so on. 

A question of considerable interest in coal hydroliquefaction chemistry is the amount and nature of "organically bound metals in the coal. One reason for this interest is the observation that when supported metal direct conversion catalysts are used in liquefaction reactors, a primary mode of deactivation is metals deposition Q, 2). In particular, recent work at the Pittsburgh Energy Technology Center (PETC) (4,5) and elsewhere (3) has indicated very high levels of titanium deposition on supported Co Mo catalysts used in the fixed bed continuous reactor system. It has been suggested that the culprits in such deposition are soluble metal species (6 9) The analyses of a Western Kentucky (Homestead) hvBb feed coal and of material deposited between the catalyst pellets in the fixed bed reactor at PETC (4) are shown in Table I. 

Most processes in the fine chemical industry are typically carried out in batch mode, where the powdered catalyst is suspended in the reaction medium. For the production of bulk chemicals extruded or granulated carbon-supported catalysts are used in fixed-bed reactors. To date, the most important carbon supports from an industrial point of view is activated carbon and carbon black. The main reason for the success of those materials is their commercial availability and variety of different grades, so that the final calalyst can be lailored to the end user s requirements. On a worldwide basis, 908,000 metric tons of activated carbon was produced in 2005 [5], Only a small fraction of that is used as catalyst support. Other carbon supports, such as carbon aerogels and carbon nanotubes, are in the focus of modem catalytic research but so far have not been used in commercial processes. Since there are various scientific pubhcations in the field of carbon and its use as catalyst support, the focus of this contribution is on the industrial importance of carbon supports for precious metal powder catalysts, their requirements, properties, manufacturing, and industrial applications. 

Our simulation showed that the reverse-flow operation makes it possible to solve this problem Once ignited, the bed of monolith supported oxidation catalyst is able to maintain high temperatures over all spectrum of engine operation modes, from idle to full load, with adequate methane destmction. Other hydrocarbons and CO are also completely removed. 

A fixed bed reactor has many unique and valuable advantages relative to other reactor types. One of its prime attributes is its simplicity, with the attendant consequences of low costs for construction, operation, and maintenance relative to moving bed or fluidized bed operation. Fixed bed reactors require a minimum of auxiliary equipment and are particularly appropriate for use in small commercial units when investments of large sums for control, catalyst handling, and supporting facilities would be economically prohibitive. Another major advantage of this mode of operation is implicit in the use of the term fixed bed reactor (i.e., there are no problems in separating the catalyst from the reactor effluent stream). (In many fluidized bed systems, catalyst recovery can be quite troublesome and require substantial equipment costs.) Another important attribute of fixed bed reactors is the wide variation in... 

Wasserscheid, P, and Fehrmann, R. (2003) Propene and 1-octene hydro-formylation with silica-supported, ionic liquid-phase (SILP) Rh-phosphine catalysts in continuous fixed-bed mode. CataL Lett., 90 (3-4), 149-153. 

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