Reactor spinning basket

Deviations from the ideal frequentiy occur in order to avoid system complexity, but differences between an experimental system and the commercial unit should always be considered carefully to avoid surprises on scale-up. In the event that fundamental kinetic data are desired, it is usually necessary to choose a reactor design in which reactant and product concentration gradients are minimized (36), such as in the recycle (37) or spinning basket reactor designs (38,39). 

Kinetic studies were made with a spinning basket reactor using catalyst HaldorTopsoe MK 101, at three pressures and three temperatures. 

In summary, external recycle reactors are expensive and their usefulness is limited. They can be practical for simple chemical systems where no condensation can occur and neither high pressure nor high temperature is needed. For example Carberry et al (1980) preferred an external recycle reactor over a spinning basket reactor for the study of CO oxidation in dry air at atmospheric pressure. 

In previous studies, the main tool for process improvement was the tubular reactor. This small version of an industrial reactor tube had to be operated at less severe conditions than the industrial-size reactor. Even then, isothermal conditions could never be achieved and kinetic interpretation was ambiguous. Obviously, better tools and techniques were needed for every part of the project. In particular, a better experimental reactor had to be developed that could produce more precise results at well defined conditions. By that time many home-built recycle reactors (RRs), spinning basket reactors and other laboratory continuous stirred tank reactors (CSTRs) were in use and the subject of publications. Most of these served the original author and his reaction well but few could generate the mass velocities used in actual production units. 

Spinning basket reactor, 21 352, 353 Spinning-cup atomizers, 23 659 Spinning-cup sulfur burner, 23 660 Spinning machines, 19 749 Spinning processes, hollow-fiber, 16 7-12 Spinning pump, for olefin fiber extrusion, 11 231... 

The oxidation of gaseous ethanol (first-order reaction) was studied in a spinning basket reactor with Pt/Al203 on a ceramic monolith as catalyst. The inlet concentration of ethanol... 

Pant and Chanda [247] report a kinetic study with a sintered V2Os catalyst carried out with a spinning basket reactor. The following selec-tivities are observed at 450—517° C, independent of conversion (20— 40%) and temperature 80% phthalic anhydride, 10% maleic anhydride, 10% carbon oxides. The authors propose a parallel reaction scheme. However, these data, and the absence of tolualdehyde at this conversion level prove that the reactor did not function as a well-stirred reactor, but suffered considerable bypassing (mass transfer limitation with respect to... 

Unlike most studies performed on one single reactor type, Turek et al [43] compared 4 reactors STR, TBR, spinning basket reactor, piston recycling reactor, with different nickel on silica particle sizes (glucose hydrogenation). See also [44]. 

In three-phase systems, where the solid catalyst is in contact with a liquid reactant or its solution plus a gaseous reactant, efficient agitation is required to effect dissolution of the gaseous molecule into the liquid and its transport to the catalyst surface. Such systems easily become mass-transport limited, especially when a very active catalyst is used. In a batch reactor, rapid shaking or stirring is needed, and catalyst particles must be small it may operate at atmospheric pressure, or at superatmospheric pressure as an autoclave. Large catalyst particles can however be used with liquid reactants either in a trickle-column reactor or a spinning-basket reactor. 

Figure 5.6 The spinning basket reactor (a) general view (b) the catalyst disposition (from Carber-...

Modified types of rotating basket reactors of similar basic principles have been developed [51,52], The spinning basket reactor apparently can be a good mixer under nonreaction conditions but its effectiveness in reducing interface temperature and concentration differences under reaction conditions is doubted. In this reactor, the true gas velocity relative to the pellets is unknown, because the gas tends to spin along with the basket. Therefore, despite the baffles, an increased speed of rotation does not necessarily reduce the interface temperature and concentration differences to any great extent. This is especially true for smaller catalyst particles and fast reactions. 

Tank reactors for solid-catalyzed gaseous or liquid reactions are seen much less frequently than tubular reactors because of the difficulty in separating the phases and in agitating a fluid phase in the presence of solid particles. One type of CSTR used to study catalytic reactions is the spinning basket reactor, which has the catalyst embedded in the blades of the spinning agitator. Another is the Berty reactor, which uses an internal recycle stream to achieve perfectly mixed behavior." These reactors (see Chapter 5) are frequently used in industry to evaluate reaction mechanisms and determine reaction kinetics. 

Fig. 6.12. Carberry spinning basket reactor.26 (Courtesy of Autoclave Engineers.)...

Figure 2.3.a-1 Variotis types of experimental reactors, (a) Tubular reactor, (b) tubular reactor with recycle, (c) spinning basket reactor, and d) reactor with internal recycle. 

Transfer resistances between the fluid and the solid, which will be discussed more quantitatively in Chapter 3, may be minimized by sufficient turbulence. With the tubular reactor this requires a sufficiently high flow velocity. This is not so simple to realize in laboratory equipment since the catalyst weight is often restricted to avoid a too-high consumption of reactant or to permit isothermal operation. With the spinning basket reactor the speed of rotation has to be high. 

CSTR One type of catalytic CSTR is the spinning basket reactor in which each experiment is carried out at a given inlet... 

Figure 2.5 Types of laboratory catalytic reactors mostly used (a) plug-flow packed-bed reactor and (b) spinning basket reactor mimicking CSTR performance.

Multiphase Kinetic Studies with a Spinning Basket Reactor... 

The spinning basket reactor was used to study the desulfurization kinetics of a model sulfur compound—dlbenzothlophene in white oil. This study is confirming data for an earlier study by Frye and Mosby (8) with a trickle bed type reactor and actual petroleum fractions. There is good agreement between the two kinetic studies. This current study has achieved a further... 

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