Laboratory scale example, containment

Most of the byproduct HCl is used captively, primarily in oxyhydrochlorination processes for making vinyl chloride and chlorinated solvents or for Mg processing (p, 110), The scale of the industry is enormous for example, 5,2 million tonnes of HCl per annum in the US alone (1993), HCl gas for industrial use can be transmitted without difficult over moderate distances in mild-steel piping or in tank cars or trailers. It is also available in cylinders of varying size down to laboratory scale lecture bottles containing 225 g. Aqueous hydrochloric acid consumption (1993) was 1,57 Mt (100% basis). Price for anhydrous HCl is 330/tonne and for 31,4% aqueous acid 73/tonne (1993) depending on plant location and amount required. 

Various experimental conditions have been used for oxidations of alcohols by Cr(VI) on a laboratory scale, and several examples are shown in Scheme 12.1. Entry 1 is an example of oxidation of a primary alcohol to an aldehyde. The propanal is distilled from the reaction mixture as oxidation proceeds, which minimizes overoxidation. For secondary alcohols, oxidation can be done by addition of an acidic aqueous solution containing chromic acid (known as Jones reagent) to an acetone solution of the alcohol. Oxidation normally occurs rapidly, and overoxidation is minimal. In acetone solution, the reduced chromium salts precipitate and the reaction solution can be decanted. Entries 2 to 4 in Scheme 12.1 are examples of this method. 

The majority of applications of crystal population balance modeling have assumed that the solution and suspension in the crystallizer are homogeneous, i.e., the Mixed-Suspension Mixed-Product Removal (MSMPR) approximation (Randolph and Larson 1988). (This is simply the analog of the Continuous Stirred Tank (CSTR) (Levenspiel 1972) approximation for systems containing particles. It means that the system is well mixed from the standpoint of the solute concentration and the particle concentration and PSD. In addition, the effluent is assumed to have the same solute concentration, particle concentration, and PSD as the tank.) This approximation is clearly not justified when there is significant inhomogeneity in the crystallizer solution and suspension properties. For example, it is well known that nucleation kinetics measured at laboratory scale do not scale well to full scale. It is very likely that the reason they do not is because MSMPR models used to define the kinetic parameters may apply fairly well to relatively uniform laboratory crystallizers, but do considerably worse for full scale, relatively nonhomogeneous crystallizers. 

Table 33.5 presents a summary of the various types of dryers, together with examples of pharmaceutical products for which they are used commercially. It should be noted that in most cases alternate dryers are used in practice to dry the same product. Typical operating data for drying of selected pharmaceuticals are given in Table 33.6. The information contained in Table 33.6 is derived from operating dryer performance data as well as from laboratory-scale experiments. Laboratory and often pilot-scale tests are necessary before a commercial-scale dryer may be designed with confidence. For pharmaceutical products, laboratory tests are performed to provide data on the thermal sensitivity, oxidizability, stability, and final product moisture content. This forms the basis for the selection of a dryer and process parameters. If the product is produced in small quantities, a batch dryer may be selected. In large-scale production, energy losses, losses due to deterioration of the product quality, and other losses can be quite substantial if the dryer type and operating parameters are not optimally...

Figure 1-5 Examples of systems (see Example 1.2). The system is indieated by the dashed line, (a) Closed tank that contains some liquid and some gas. (b) The liquid portion in a closed, thermally insulated tank that also contains some gas. (c) Thermally insulated condenser of a laboratory-scale distillation unit.

A reversible lithium-air system was first implemented on a laboratory scale in 1996. In this cell, the gel-polymer electrolyte was pressed between lithium foil on the one side and an air electrode on the other. (Later, usual liquid electrolyte in a porous, for example, glass fabric, separator was often used in lithium-air batteries). The whole cell was sealed into a plastic container ( coffee bag ) and small holes were made in the container wall adjacent to the air electrode to supply air under discharge and remove oxygen under charging. The air electrode was made of a mixture of particles of polymer electrolyte and carbon black with the catalyst supported on its surface (cobalt phthalocyanine). 

In the present study, we show an example of the application of this experimental methodology to the investigation of adsorption characteristic of local bentonite clay. Adsorption / desorption experiment were performed at laboratory scale with model-contaminated gaseous stream containing o-xylene that has been selected as rep resentative VOC because it is environmentally relevant regarding industrial concern. The work aimed to help further development of low cost materials involved in environmental engineering control. 

Although aluminum production is the outstanding example of fused-salt electrochemistry, the laboratory-scale applications of this field are quite wide (17). A recent example is the electrolytic preparation of the spinel XV2O21 (X = Zn, Mg, or Cd) (1 ). A recent bibliography of the synthesis of inorganic compounds by electrochemical means contains more than 4000 references (19). 

Table 29.5 presents a summary of the various types of dryers, together with examples of pharmaceutical products for which they are used commercially. It should be noted that in most cases alternate dryers are used in practice to dry the same product. Typical operating data for drying of selected pharmaceuticals are given in Table 29.6. The information contained in Table 29.6 is derived from operating dryer performance data as well as from laboratory-scale experiments. Laboratory and often pilot-scale tests are necessary before a commercial-scale dryer...

As different cell fines require different medium compositions, adaptation of a cell fine to grow without serum is quite time consuming, and not all cell fines have been adapted to serum-free or protein-free media. Therefore, for laboratory scale, for example, basic cell culture research or cultivation of primary cells, still mostly complex serum-containing media are common. In industrial production with estabfished, optimized cell fines, serum-free, bovine-free, and chemically defined media are state of the art. 

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