Laboratory-scale packing

Fig. 15.25. Schematic for a laboratory-scale packed-bed electrode, a, Bed of particles b, current collector c, Luggin capillary d, thermometer e, purging gas in f, gas out g, bubbler h, gas collector i, Luggin capillary j, reference electrode k, Nation film I, counter-electrode m, septum for gas analysis and n, solution flow-in or flow-out. (Reprinted from J, O M. Bockris and J. Kim, J. Appl. Electrochem. 27 625, copyright 1997.)...

The separation efficiency for the different laboratory-scale packings is considerably high (HETS between 0.33 and 0.25m), while for the industrial-type KATA-PAK -S 250.Y it is lower because of the smaller specific surface area (see Table 10.3). The laboratory-scale internals mainly differ in catalyst content. Further information on KATAPAK -S and MULTIPAK is given elsewhere (see, e.g. [105]). 

The experiments were carried out in a continuous laboratory-scale packed bed reactor (Table 15.1). 

Feasibility of the novel processes was demonstrated with experiments in a laboratory scale packed column (Rev et al., 2002). The column was made of glass with a height of 1.5 m and inside diameter of 5 cm. The initial still hold-up was 1 litre in all of the experiments. 

Four column systems are available from Amersham Pharmacia Biotech that can be used to pack SEC media for various applications at the laboratory scale. These include C, XK, SR, and HR column systems. All of the laboratory-scale columns are constructed with borosilicate glass tubes. Columns for larger scale process applications include INdEX, BPG, EineLINE, BPSS, and Stack columns. The larger scale columns are constructed to meet stringent validation requirements for the production of biopharmaceuticals. Each of the column types are described. 

Chlorine oxidation of sodium chlorite has also been used on both an industrial scale (by mixing concentrated aqueous solutions) or on a laboratory scale (by passing CVair through a column packed with the solid chlorite) ... 

The value for is conservatively interpreted as the particle diameter. This is a perfectly feasible size for use in a laboratory reactor. Due to pressure-drop limitations, it is too small for a full-scale packed bed. However, even smaller catalyst particles, dp 50 yum, are used in fluidized-bed reactors. For such small particles we can assume rj=l, even for the 3-nm pore diameters found in some cracking catalysts. 

Factors re.sponsible for the occurrence of scale-up effects can be either material factors or size/shape factors. In addition, differences in the mode of operation (batch or semibatch reactor in the laboratory and continuous reactor on the full scale), or the type of equipment (e.g. stirred-tank reactor in the laboratory and packed- or plate- column reactor in commercial unit) can be causes of unexpected scale-up effects. A simple misuse of available tools and information also can lead to wrong effects. 

For gas phase heterogeneous catalytic reactions, the continuous-flow integral catalytic reactors with packed catalyst bed have been exclusively used [61-91]. Continuous or short pulsed-radiation (milliseconds) was applied in catalytic studies (see Sect. 10.3.2). To avoid the creation of temperature gradients in the catalyst bed, a single-mode radiation system can be recommended. A typical example of the most advanced laboratory-scale microwave, continuous single-mode catalytic reactor has been described by Roussy et al. [79] and is shown in Figs. 10.4 and... 

A plug-flow reactor (PFR) may be used for both liquid-phase and gas-phase reactions, and for both laboratory-scale investigations of kinetics and large-scale production. The reactor itself may consist of an empty tube or vessel, or it may contain packing or a fixed bed of particles (e.g., catalyst particles). The former is illustrated in Figure 2.4, in which concentration profiles are also shown with respect to position in the vessel. 

On the laboratory scale, 8.5 cm x 2.1 cm columns packed with Deloxan THP II or MP (9 g wet) were tested for their effectiveness at removing Pd (II) as either 3 or H2PdCl4 (5) from their toluene or DMF solutions, respectively. The purpose of these experiments was to see if having... 

In order to determine the model parameters, several experiments were performed at laboratory scale. Pressure drop experiments were carried out in glass columns, with a total packing height of 1 m at ambient pressure. Air/water was used as a test system, with a circulating liquid phase set at a constant temperature of 20°C. 

PACKED BED PLUG-FLOW CATALYTIC REACTOR 9.8.1 Laboratory Scale Reactor... 

The UMR process can be improved by introducing calcium oxide, a carbon dioxide sorbent, into the packed bed. The potential advantages of using calcium oxide as a carbon dioxide sorbent have been previously recognized. The use of calcium oxide to enhance the steam reforming process has been patented by Gluud et al.( 1931). More recently Harrison and coworkers (Han and Harrison, 1994) have reported laboratory-scale data for the steam reforming of methane in the presence of calcium oxide. 

Once the packing and the eluent have been selected, some important physicochemical parameters must be determined at the laboratory scale. All that is required at this stage, is a simple laboratory procedure, and that there is no need to use an SMB system. 

Major chemical engineering projects involving structures, tray or packed columns, reactors, separators, heat exchangers and heaters, reservoirs and special deposits, fluid pumping as well as compressing devices, frequently involve the use of small scale studies using laboratory scale devices. According to the context. 

Figure 11. Comparison of calculated macroscopic dispersivities (solid curve) to experimentally measured megascopic (laboratory scale) dispersivities. d is the grain diameter for the packing in the experimentSl measurements and the correlation length for the calculated curve. Better agreement could be obtained by letting d be about live times the correlation length in the calculated curve. (Reproduced from Ref. 4.)...

P4-9 Sargent Nigel Ambercromby. Scoundrels Incorporated, a small R D company has developed a laboratory scale process for the elementary, solid-cata-lyzed-gas-phase reaction A + B C -F D (names coded for proprietary reasons). The feed is equal molar in A and B with the entering molar flow r e of A is 25 mol/min and the volumetric feed is 50 dm /min. Engineers at Scoundrels calculated that an industrial scale packed bed reactor with 500 kg of a very rare and expensive metal catalyst will yield a 66% conversion when run at 32 C and a feed pressure of 25 atm. At these conditions the specific reaction rate is 0.4 dm /mol-min-kg catalyst. Scoundrels sells this process and catalyst to Queless Chemicals who then manufactured fee packed bed. When Oueless put the process onstream at the specifications provided by Scoundrels, they could only achieve 60% conversion with 500 kg catalyst. Unfortunately the reaction was carried out at 3U°C rather than 32°C. The... 

Use pre-packed columns of Sephadex G-25 gel filtration media, for rapid sample clean-up at laboratory scale, as shown in Table 2. 

For column packing Sephadex G-25 is available in a range of bead sizes (Superfine, Fine, Medium and Coarse). Changes in bead size alter flow rates and sample volumes which can be applied (see Figure 29). For laboratory scale separations use Sephadex G-25 Fine with an average bed height of 15 cm. 

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