Lab-scale

Research and development efforts have been directed toward improved ceU designs, theoretical electrochemical studies of magnesium ceUs, and improved cathode conditions. A stacked-type bipolar electrode ceU has been operated on a lab scale (112). Electrochemical studies of the mechanism of magnesium ion reduction have determined that it is a two-electron reversible process that is mass-transfer controUed (113). A review of magnesium production is found ia Reference 114. 

Concern for the conservation of energy and materials maintains high interest in catalytic and electrochemistry. Oxygen in the presence of metal catalysts is used in CUPROUS ION-CATALYZED OXIDATIVE CLEAVAGE OF AROMATIC o-DIAMINES BY OXYGEN (E,Z)-2,4-HEXADIENEDINITRILE and OXIDATION WITH BIS(SALI-CYLIDENE)ETHYLENEDIIMINOCOBALT(II) (SALCOMINE) 2,6-DI-important industrial method, is accomplished in a convenient lab-scale process in ALDEHYDES FROM OLEFINS CYCLOHEXANE-CARBOXALDEHYDE. An effective and useful electrochemical synthesis is illustrated in the procedure 3,3,6,6-TETRAMETHOXY-1,4-CYCLOHEX ADIENE. ... 

To understand chemical treatment processes, it must be remembered that a reaction is not a process. A reaction involves the chemical transformation of a material, whether this is carried out on a lab-scale or an industrial-scale. A process, on tbe other hand, is a series of actions or operations needed to make such a reaction occur in a controlled manner. Thus, the development of a process requires the design of the... 

Historical. The action of nitric acid on mannitol was first examined by A. Sobrero who isolated the hexanitrate in 1847 (Ref 3). The prepn on a lab scale was repeated by other workers in the mid-19th century (Refs 2, 4,10 12). It was mfd on a small scale in the Royal Arsenal at Turin, Italy until 1853, when 400g expld with great damage (Ref 33, p 198) later work has been described in Refs 13 15... 

Methylnitropropanediol dinitrate is nearly as powerful an expl as TNT, but more brisant, comparable to Tetryl. It was prepd during WWII on a lab scale in Ger, and examined from the point of view of its gelatinizing properties on NC. Such properties were found to be rather poor, although its volatility, stability, etc were satisfactory (Ref 4)... 

For nitrating on the lab scale, mixts of nitric acid esters or acyl nitrates, eg acetyl nitrate (CH3CONO3) and sulfuric acid may also be used... 

Several lesser known nitrating agents, which have been used on a lab scale are metal nitrates in the presence of acetic acid or acetic anhydride, tetranitromethane and hexanitroethane in an alkaline medium, and nitroguanidine in soln in sulfuric acid, used for the nitration of aromatic... 

Preparation. Its prepn on a lab scale is given in Ref 7. A detailed exptl proc for its prepn on a coml (1000 lb) scale is given in Ref 4 as follows In the reactor is placed 3175 lb of 37% formaldehyde and ca 700 lb of w. To this is added with stirring 1050 lbs of 50% NaOH at a rate so as to keep the temp at 15—20° (with cooling if necessary). Then is added 385 lbs of 99% acetaldehyde under the surface of the soln with vigorous stirring and cooling so as to keep the temp at 20—5°. The mixt is held at 25—30° for several hours and then held at 60° until the acetaldehyde... 

Tlie anhyd salt is obtained when samples are recrystd from w above 53° below this temp a monohydrate is obtained (see below). The pure salt is best obtained on a lab scale by dissolving pure Na carbonate in a slight excess of dil aq perchloric ac, the soln partly evapd, cooled to 50°, the solid centrifuged off, and dried in a current of air at 250°. Similar results were obtained starting with pure Na chloride (Ref 2). On a coml scale it is prepd by the electrolysis of Na chlorate (see Vol 2, C197-R). Processing details and economics of the prepn are given in Refs 5 11. Coned solns are used, and modern plants use continuous electrolytic cells. In 1960 prodn was estimated to be ca 10000 tons/year at a cost of 17.56 /lb (Ref 11, p 87)... 

For any practical classical promotion application in a fixed bed catalytic reactor, tPr must be longer than a year ( 3-107 s). But even for lab scale classical promotion experiments tPR values in excess of 106 s are required (Fig. 11.15). 

Data points are calculated as weighted average values solid line is the cross-section function best fitted to the experimental data broken line represents the results of Maier (10). Ion energies are given in lab. scale in e.v. 

Wang and Zhang also investigated the effects on the xylan extracted from corn cobs enhanced by ultrasound at various lab-scale conditions. Results showed that the optimization conditions of xylan extraction should be carried out using (i) 1.8 M NaOH, (ii) corn cobs to NaOH solution ratio of 1 25 (w/w), (iii) sonication at 200 W ultrasound power for 30 min at 5 min intervals, and (iv) 60 °C (Wang Zhang, 2006). 

This paper describes work on equipment and instrumentation aimed at a computer-assisted lab-scale resin prep, facility. The approach has been to focus on hardware modules which could be developed and used incrementally on route to system integration. Thus, a primary split of process parameters was made into heat transfer and temperature control, and mass transfer and agitation. In the first of these the paper reports work on a range of temperature measurement, indicators and control units. On the mass transfer side most attention has been on liquid delivery systems with a little work on stirrer drives. Following a general analysis of different pump types the paper describes a programmable micro-computer multi-pump unit and gives results of its use. 

There is no longer any reason for lab-scale resin-preps to be poorly controlled with only a skimpy process record. Neither can the close exposure of scientists to the hazards of a live reaction, for frequent control adjustments or data gathering be justified. 

In the writers view, above claims for lab scale polymerisations can be generalised to a much wider range of other chemical reactions. 

Fig. 1. Schematic diagram of a lab-scale sequenciag batch reactor...

The original ASM2d model was modified with the parameter that expresses pH effect and the processes related to glycogen and GAOs. The performance of the modified model was tested with experimental result of lab scale SBRs. The simulation result could describe the experimental result properly. The concentration variation of PAOs and GAOs was predicted by the modified model under different pH conditions. 

The schematic diagram of a lab-scale MSO system with a designed capacity of 0.5 kg PVC plastics/h is shown in Fig. 1. The salt mixture consists of 50 mol% Li2C03 and 50 mol% NaaCO. The eutectic temperature of the used binary salt mixture is 505 C. The selected... 

The process developed on lab scale was transferred to pilot plant scale. The process is a fed-batch fermentation with a growth-phase (24h) on complex sugars and a production phase (48h). During production phase a linear feed is added containing various carbohydrates. 

DiajUtration After concentration has removed permeable components from the system, a new buffer can be added to dilute the retained product back to its original volume. Repeated application of this procedure, known as batch diafiltration, is used to exchange one buffer for another and is conveniently implemented at lab scale. 

At an industrial scale, the esterification catalyst must fulfill several conditions that may not seem so important at lab-scale. This must be very active and selective as by-products are likely to render the process uneconomical, water-tolerant and stable at relatively high temperatures. In addition, it should be an inexpensive material that is readily available on an industrial scale. In a previous study we investigated metal oxides with strong Bronsted acid sites and high thermal stability. Based on the literature reviews and our previous experimental screening, we focus here on application of metal oxide catalysts based on Zr, Ti, and Sn. 

This application was performed on a lab-scale reactor and later in a miniplant-scale reactor. The reaction studied was the vapor phase catalytic amidation/cyclization step in a pesticide process. As shown in Figure 2, two reactions are taking place on the catalyst bed. 

Poly[5-(alkylamino)borazines] 7-10 exhibited suitable viscoelastic and thermal stabilities to be extruded in the molten state through the monohole spinneret of a lab-scale melt-spinning apparatus. Thus, an extruded filament (diameter, 200 gm) was drawn with a windup unit, that is, a graphite spool. This provided green fibers with a wide range of diameters (16 =s (f> =s 50 gm Table 2), depending on polymer architecture. 

Wichmann, R. and Vasic-Racki, D. (2005) Cofactor regeneration at the lab scale. Advances in Biochemical Engineering/Biotechnology, 92, 225-260. 

Overall, the elimination of pharmaceuticals during sludge treatment seems to be a function of the molecule as well as of the conditions prevailing into the treatment system. Data from full-scale and lab-scale monitoring suggest that aerobic conditions permit more efficient elimination of a wider spectrum of molecules. Nevertheless, further research is still needed to identify the main parameters governing the removal of pharmaceuticals. 

Tanghe T, Devriese G, Verstraete W (1998) Nonylphenol degradation in lab scale activated sludge units is temperature dependent. Water Res 32 2889-2896... 

Bao et al. [70] Lab-scale in-vessel composting (20-25 1 identical lab vessels) Broiler manure, layer-hen manure, and hog manure Chlortetracycline (CTC)... 

---