Basket reactor

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). 

Ethylene oxide catalyst research is expensive and time-consuming because of the need to break in and stabilize the catalyst before rehable data can be collected. Computer controlled tubular microreactors containing as Httle as 5 g of catalyst can be used for assessment of a catalyst s initial performance and for long-term life studies, but moving basket reactors of the Berty (77) or Carberry (78) type are much better suited to kinetic studies. 

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

Alcorn and Sullivan (1992) faced some specific and difficult problems in connection with coal slurry hydrogenation experiments. Solving these with the falling basket reactor, they also solved the general problem of batch reactors, that is, a good definition of initial conditions. The essence of their... 

Jankowski et al (1978) discuss in detail the great variety of gradientless reactors proposed by several authors with a pictorial overview in their paper. All of these reactors can be placed in a few general categories (1) moving catalyst basket reactors, (2) external recycle reactors, and (3) internal recycle reactors. 

In moving catalyst basket reactors, the flow regime is ill-defined and the contact between catalyst and gas can be poor even if well-mixed conditions for the fluid phase are achieved. Perhaps the most successful representative of this category is the Carberry reactor (1964, 1966). Even in this model only a single layer of catalyst can be charged in the cruciform catalyst basket because the fluid flows in a radial direction outward and... 

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. 

The kinetics of a mixed platinum and base metal oxide catalyst should have complementary features, and would avoid some of the reactor instability problems here. The only stirred tank reactor for a solid-gas reaction is the whirling basket reactor of Carberry, and is not adaptable for automotive use (84) A very shallow pellet bed and a recycle reactor may approach the stirred tank reactor sufficiently to offer some interest. 

Immobilized enzymes, particularly LAC, have been employed in the degradation of triclosan. The immobilization of LAC from Coriolopsis polyzona through the formation of cross-linked enzyme aggregates (CLEAs) and their subsequent use in an FBR for the removal of endocrine disrupting compounds [42] produced the complete removal of triclosan, nonylphenol, and bisphenol A (5 mg L-1 each) at a HRT of 150 min. The application of CLEAs in a perfusion basket reactor [43]... 

Hydrogenolysis of ethane over a commercial nickel catalyst was studied in a rotating basket reactor containing 40 g of catalyst. 

Equimolal concentrations of A and B are charged to the reactor and the density remains constant. Laboratory tests were made with a rotating basket reactor in which diffusional resistances were effectively eliminated, with the tabulated results. 

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... 

N Stepaniuk, K Tomazi, MC Stapleton. Reactor and method for solid phase peptide synthesis, (basket reactor) US Patent 6,028,172. February 22, 2000. 

The integral reactor can have significant temperature variations from point to point, especially with gas-solid systems, even with cooling at the walls. This could well make kinetic measurements from such a reactor completely worthless when searching for rate expressions. The basket reactor is best in this respect. 

The following kinetic data are obtained in an experimental Carberry type basket reactor using 100 gm of catalyst in the paddles and different flow rates from run to run ... 

The kinetics of a particular catalytic reaction A R are studied at temperature T in a basket reactor (batch-solids and mixed flow of gas) in which the gas composition is kept unchanged, despite deactivation of the catalyst. What can you say about the rates of reaction and deactivation from the results of the following runs Note, to keep the gas concentration in the reactor unchanged the flow rate of reactant had to be lowered to about 5% of the initial value. 

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. 

This reactor is a modification of the conventional moving-basket Carberry reactor. In the design of a falling-basket reactor for coal liquefaction, Alcorn et al. (1974) set five requirements ... 

The falling-basket reactor was developed to meet these requirements. With this device, the catalyst is suspended in the gas phase during the initial stages of the run, then lowered into the liquid for the catalytic reaction portion. Catalyst (25 cc) is loaded in the four arms of the basket assembly, which moves... 

Slurry reactors are often used for intrinsic kinetic measurements. In order to alleviate the effects and complications of the initial heat-up period, as well as the induction period, on the kinetic measurements, novel designs have been introduced. Cup-and-cap reactors, falling-basket reactors, rapid-injection reactors, reactors with induction heaters, and microreactors are five such novel designs. Each of these reactors has been found to be successful the first three, however, consider both induction and heat-up periods. The last two reactors alleviate the complications due to the heat-up period only. All of these... 

Fig. 17. Stirred-tank gas-liquid-solid basket reactor fixed basket. (Germain, 1973 also from Chaudhari et al., 1986, by courtesy of Marcel Dekker, Inc.)...

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