Bench scale experiments

Acetylene traditionally has been made from coal (coke) via the calcium carbide process. However, laboratory and bench-scale experiments have demonstrated the technical feasibiUty of producing the acetylene by the direct pyrolysis of coal. Researchers in Great Britain (24,28), India (25), and Japan (27) reported appreciable yields of acetylene from the pyrolysis of coal in a hydrogen-enhanced argon plasma. In subsequent work (29), it was shown that the yields could be dramatically increased through the use of a pure hydrogen plasma. 

Bench scale experiments. The reactors used in these experiments are usually designed to operate at constant temperature, under conditions that minimize heat and mass transfer limitations on reaction rates. This facilitates an accurate evaluation of the intrinsic chemical effects. 

In general, all heat that is generated during a reaction in a bench-scale experiment is exchanged with the cooling medium. The maximum heat gen-... 

Energy costs rise substantially with apphed voltage. Costs were extrapolated from bench-scale experiments involving phenol conducted in 1993. Energy costs were estimated to be 0.53 per ton of effluent removed when 25 V were used, and 26.00 per ton when 500 V were used (D13050X, p. 290). 

The technology has been used during bench-scale experiments and field-scale demonstrations. The technology is available for licensing through SUNY, Oswego, and is commercially available through Environmental Oxidation Systems, L.L.C. 

The technology has been evaluated in laboratory- and bench-scale experiments and is not currently commercially available. 

The process design principles of SLM, non-dispersive extraction, and hybrid hquid membrane systems need to be understood through bench scale experiments using feed solution of practical relevance. While the economic analysis of an ELM process can be performed from small scale experiments, such an analysis is difficult for other LM systems. In particular, availability and cost of hollow fiber membranes for commercial application are not known apriori. A simple rule of thumb for cost scale-up may not be apphcable in the case of an HE membrane. Yet we feel that the pilot plant tests would be adequate to make realistic cost benefit analysis of a liquid membrane process, since the volume of production in )8-lactam antibiotic industries is usually low. 

Recycling metal ions is part of the concentration process noted above. It can typically be achieved by treatment of the sorbed metals with dilute nitric acid. This is a strong acid, and the nitrate ion is not a strongly coordinating anion. In addition, recycling can be a useful means of paying for the removal process. Tkn example of this was a laboratory bench-scale experiment to treat water from the Berkley Pit, recycle the copper and sell the copper to help pay the processing costs. The Berkley Pit [11] was once an open pit copper mine that was opened in 1955 and closed in 1982. 

Humic substances were concentrated more than 50-fold on the XAD-4 quaternary resin, but a saturated HCl/methanol solution was required for the desorption. This eluant was not concentrated further because the concentration of humic substances could be measured directly with a spectrophotometer. Total recovery of humic substances was higher in the bench-scale experiments than in the pilot plant studies. On the basis of the pilot plant results (see summary of experiment 3), it appears that the adsorption of humic substances was affected by the higher velocity or the loading capacity because 458 was recovered in the effluent water. The higher velocity in the pilot plant studies did not have a similar effect on other compounds such as quinaldic acid, for example, which was recovered at almost 100. It is believed that caffeine, which was concentrated during bench-scale studies, was also affected by the higher velocity in the pilot plant studies. 

From bench-scale experiments it seems that the effect of finite-rate mixing on SNCR is to narrow the temperature window for the process at high temperatures. Assess whether this is in agreement with model predictions, using an estimated mixing time (90%) of 100 ms. 

The solvent extraction process has not yet undergone pilot plant investigation, and all the above estimates are based on small laboratory or bench scale experiments. If further testing under practical conditions substantiates the laboratory observations, it appears that the solvent extraction process definitely has an area of specialization in the over-all saline water conversion program. 

Zappi, M, Gunnison, D., Pennington, J., Cullinane, J., Teeter, C. L., Brannon, J. M., and Myers, T. (1993) Technical Approaches for In Situ Biological Treatment Research Bench-Scale Experiments, US Army Corps of Engineers, Waterways Experiment Station, Vicksburg, MS, August 1993, Technical ReportNo. IRP-93-3. 

Reaction of Benzothiophene A weight ratio of 1 1 (KOHrNaOH) was chosen for the initial model-compound study, which was based on one of the ratios that the TRW process is using for bench-scale experiments with coal (2). Preliminary experiments with benzothiophene at 375°C and 30-minute reaction times indicated that benzothiophene... 

A recuperative bayonet sulphuric acid decomposition reactor has been designed by researchers at Sandia National Laboratories (SNL) that features all-silicon carbide (SiC) construction for the heated parts, can be made from readily available SiC shapes, makes the most use of heat recuperation, and has all of its fluid connections at sufficiently low temperatures that conventional seal materials can be used. Bench-scale experiments using electric resistance heaters as the energy source have verified that the design functions as intended. 

Bench scale experiments using diesel fuel have shown that for typical fuel sulfur concentrations there is no detectable sulfur in the reformate to at least the sub-ppm level. In the bench scale experiments, when sulfur was added to diesel fuel at a concentration of 2000 ppm by weight only 5 ppm hydrogen sulfide was detected in the reformate. In pilot scale experiments using diesel fuel, the sulfur concentration in the reformate stream was around 15 ppm. If the sulfur was not captured by the pilot-scale reactor, the sulfur concentration in the reformate stream would have been 37 ppm. 

Leonard et al. [43] have used a similar pseudo-kinetic model to predict yields from cracking coils under any operating conditions. Model parameters are obtained by means of bench scale experiments on the given feedstock. Thus, it is very easy both to evaluate a priori a potential feedstock and to determine simultaneously the corresponding optimum operating conditions. The first-order rate coefficient is calculated for the model compound n — Ci6H34. ... 

Savings and Cost/Benefit Analysis. The bench scale experiments were successful Tn overcoming major technical problems while demonstrating that dyebath/auxiliary bath reuse is indeed feasible with reactive dyes on cotton-containing fabrics. In addition, a shortened-cycle dyeing procedure coupled with reuse for cotton/polyester blends was shown to further increase energy, mass, and time savings (Table XXX). 

Dillert et al. have treated biologically pre-treated industrial waste waters from factories in Wolfsburg (Germany) and Taubate (Brazil) of the Volkswagen AG in laboratory and bench-scale experiments [260,261]. The results of the experiments, which have been performed using the DSSR, were so... 

While the reduced models discussed previously invoke only the Bodenstein approximation for trace-level intermediates, the additional streamlining is apt to introduce some errors, and these are hard to estimate beforehand. A safe way to proceed is to compile both a "research model" based on the detailed network, and a streamlined "process model." Apart from its use in evaluation of bench-scale experiments, the research model can serve to assess, by comparison, the nature, direction, and magnitude of the error of the process model under operating conditions of the plant. If found satisfactory, the process model can then be used for reactor design and optimization, possibly after some tuning. 

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