Bench-scale comparison

Bench-Scale Comparison of Catalysts Effect of Heat and Steam, on Activity and... 

Recommendation (Pueblo) EH-1. A bench-scale comparison of the rates of hydrolysis of tetryl and tetrytol should be undertaken before any process for the destruction of tetryl is planned. The rates should not be based only on data from tests with tetrytol. 

The effectiveness of a combined reduction-biological treatment system for the decolorization of nonbiodegradable textile dyeing wastewater has been investigated. The bench-scale experimental comparison of this technique with other reported combined chemical-biological methods showed higher efficiency and lower cost for the new technique [35]. 

Most importantly, none of the methods have, been sufficiently checked to assess how well they reproduce the gas yields or even the LC50 values from the appropriate segments of real-scale fire tests. To begin this process, a comparison procedure has been developed and a few materials have been checked using the NBS bench-scale combustor and the N-gas method (14,15). 

Aspects of coal liquefaction have been much researched, particularly with the re-emeigence of interest caused by the oil crisis in the 1970 s. The type of reactors used in the studies has been various, ranging from small bomb type microautoclaves through larger autoclaves and bench-scale reactors to larger scale pilot or demonstration plants. The use of differently sized and designed high pressure equipment for liquefaction studies further complicates an already complex system and allows only limited comparison of results. 

A.A. Stec, T.R. Hull, J.A. Purser, and D.A. Purser, Comparison of toxic product yields from bench-scale to ISO room, Fire Safety Journal, 44, 62-70, 2009. 

Empirical approaches are useful when macroscale HRR measurements are available but little or no information is available regarding the thermophysical properties, kinetic parameters, and heats of reaction that would be necessary to apply a more comprehensive pyrolysis model. Although these modeling approaches are crude in comparison with some of the more refined solid-phase treatments, one advantage is that all required input parameters can be obtained from widely used bench-scale fire tests using well-established data reduction techniques. As greater levels of complexity are added, establishing the required input parameters (or material properties ) for different materials becomes an onerous task. 

For the reactor inlet temperature to be markedly below 100°C (which avoids the corrosion and plugging problems ), fuel mass fractions equivalent to 25% CH3OH seem to be necessary for the thermal regime of a flame. This value is supported by experiments as well as it is by theory. In a future configuration it can be lowered if the following improvements in comparison to the presented bench-scale reactor are achieved ... 

Risdon, T.J. and Sargent, D.J., Comparison of Commercially Available Greases With and Without Molybdenum Disulfide, Part I - Bench Scale Performance Tests, NLGI Spokesman, 33, 82, (1969). 

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. 

Table VI. Comparison of Test Results on Light Naphtha Isomerization in Bench-scale and Microflow Reactors...

Fig. 20. Comparison of bench-scale and microflow reactors for hydrodesulfurization of a heavy gasoil over diluted catalyst beds.

In this chapter we will describe some of our initial evaluation work on Paraho shale oil. This initial evaluation was not performed in depth rather, this first step consisted of chemical characterizations and high-spot, bench-scale processing of oil shale and several other syncrudes for direct comparisons of chemical feedstocks potential. Conventional analytical and petroleum processing techniques were used in the expectation that these would provide reference data on which to base specifically adapted techniques for evaluations of individual syncrudes. The results represent only our first attempts and except for occasional comparisons, are only for Paraho shale oil. 

Data on a thermal batch bulk polymerization at 150°C (run in a two-litre bench-scale reactor) are presented in Table III and compared with computer predictions. Here, the computer prediction of molecular weight is good (almost independent of conversion) while the predicted conversions are slightly low. Comparison of the model predictions with thermal polymerization data of Hui and Hamielec 6) and Husain and Hamielec (J7) also indicate that the... 

A few random samples taken from a commercial installation most probably will not provide enough insight to determine that the filter is performing as expected. However, by making use of reasonable variations in the most important parameters, the desired correlations can be developed. Bench-scale tests should be run on representative feed samples taken at the same time test runs are made on the commercial unit. The bench-scale tests can be varied over a much wider range to provide a sound basis for both the location and shape of the appropriate correlation. A comparison of these results with the data taken from the commercial installation provides a good measure for efficiency of the commercial unit and a basis for identifying problem areas on the full-scale unit. 

Comparison of Bench-Scale Unit with Commercial Hydrotreater. 

ASTM measurements such as ash fusibility (D1857) have formed the basis for traditional ash behavior predictive techniques. These bench-scale tests provide relative information on a fuel which is used in a comparative fashion with similar data on fuels of known behavior. Unfortunately, these commonly used tests do not always provide sufficient information to permit accurate comparison. 

A few economic factors concerning the dilute acid process are discussed here in comparison to the enzymatic process. It must start with the yield that has been the focus of the reactor analysis and development. Production of fuels and chemicals from biomass is substrate cost intensive with feedstock costs representing roughly one half of total production costs 142, 55]. It is of paramount importance in most bioconversion processes to maximize the yield of the product from the biomass substrates. The most advanced dilute acid process has brought the saccharification yield to above 80% as verified by NREL bench-scale experiments [10]. The actual yield of the enzyme saccharification is dependent on the effectiveness of the pretreatment. However, it rarely surpasses 90% even with a highly efficient pretreatment. The enzymatic process also requires additional substrate because it has to be produced from cellulosic biomass. The amount of biomass feedstock needed for enzyme production is estimated to be about 9% of the total. With these in consideration, the yield of the acid saccharification is about even with that of the enzymatic process. What can... 

Table 2. Comparison of Bench-Scale and MPR Performance of Desulfurizer...

This section deals with the comparison of MOTIF modelling results with three field experiments and a large bench-scale experiment. While the inherent experimental uncertainties in fractured rock environments are such that an absolute validation is difficult to achieve, the comparison provides some confidence in the suitability of the code to model various subsurface processes in fractured or porous rock. 

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