Laboratory-scale Plant

As the next step in multiphasic hydrogenation, the design and implementation of a continuously driven loop reactor as a laboratory-scale plant model led to comparable selectivity applying the same water soluble ruthenium-based catalyst system. 

The experiments on the PGSS of PEG were performed in a laboratory-scale plant with sample sizes of about 200-400 g powder, and in a small pilot plant with sample sizes of 1-3 kg powder. Depending on the nozzles (orifices 0.4 / 0.5 /1.0 mm, spraying angles 30° and 90°), the kind of PEG (MW 1500/4000/8000/35000) and on pressure (100-250 bar) and temperature (45-70°C) three classes of particles were obtained fibres, spheres and sponges as presented in Figure 9.8-17. 

The pressure is applied by a direct or indirect compression method. In the former, a piston coaxial with the container is required and the compressions are particularly fast this method is employed only in laboratory-scale plant because of the sealing problem between the piston and the internal surface of the container (Fig. 9.10-1). The more widespread method is the indirect one, with a pressure booster to pump the liquid from the pressure-medium tank to the cell, until the desired pressure value is reached (Fig. 9.10-2). 

The extraction of essential oil from oxegano-Origanum virens L.- using liquid carbon dioxide (7 MPa and 298 K) and supercritical carbon dioxide (10 and 15 MPa and 313 K) was investigated. Experimental results were obtained in a laboratory scale plant equipped with a 100 mL tubular extractor. 

As it has been pointed out in the previous paragraph, the aim of the present work is to provide more information about the behaviour, during pyrolysis and gasification of the alkaline black liquor from the pulping of straw. All experiments were performed in a fixed bed reactor on a laboratory scale plant. 

The laboratory scale plant is shown in Fig. /. The reactor consists of a stainless steel tube, 90 mm inner diameter and 230 mm length, placed inside a concentric furnace. The particles of solid black liquor were placed in a tray of 40 pm mesh inside the reactor. Downstream the reactor exit, two ice traps and a cotton filter were installed to collect tars. Gas samplers and a CO/CO2 I.R- analyser, permitted to follow the exit gas conposition during the experiments. 

This is a second interesting technology proposed to exploit salinity gradient for direct electric power generation. As for the PRO technology, the reverse electrodialysis (RED) concept has been proved by experimental laboratory-scale plants to be capable of generating a net power output. A detailed description of this technology is presented in this section. 

In the extraction from solids, scale up from 20 to 50 1 vessels to extractors of several m seems possible (scale up factor of 100 to 1000), if the experiments are carried out in a pilot plant unit. While a laboratory size plant has to be as flexible as possible, in order to be able to experimentally demonstrate the feasibility of a process step under a broad range of processing conditions, a pilot plant is designed to demonstrate the technical feasibility of certain process steps on a larger scale. Ideally, a pilot plant is a small version of a processing plant, but normally only parts of the technical process can be simulated on this scale. The variability of the plant is much more limited than that of a laboratory scale plant. 

The basic R D flow sheet is a direct result of the optimization process during the feasibility study. This and the first experiments with process parameters are the basis for a laboratory-scale plant for a possible further process optimization. 

A continuous laboratory-scale plant was adapted to fit the needs of the process. In the first step, a high-pressure version of IMM s SIMM was used. This was due to the known good mixing quality and the high reachable temperature. After first successful... 

Due to short residence times inside the micromixer almost no heat was released there. In the residence time tube, temperatures up to 150 °C have been observed. In these experiments, we were able to show that it is possible to finish the first reaction step on the continuous microreactor laboratory-scale plant in less than 60 s. The same reaction step in the cooled batch vessel of the production plant took about 4 h. With these results, we came to the conclusion that it should be possible to realize the first exothermic step of the process in a microreactor. After finishing this step continuously in a closed system, the reaction solution could be transferred into the existing batch vessel and be heated there to finish the second reaction step. As the time for the first step is reduced from several hours to a few minutes for the same amount of product, it should be possible nearly to double the capacity just by installing a microreactor right before the existing batch vessel to mix the first two educts. 

Figure 4 shows the CO conversion curves (calculated from a mass balance on the amount of carbon in CO and of all the hydrocarbons, revealed by the detector of the gas-chromatograph) vs time for two RU/AI2O3 samples (1% Ru w/w). The runs were performed at 275 C, 5 bar in a tubular continuously fed reactor, with a molar ratio H2/CO = 2. Pd/C catalysts were tested in the hydrogenation of acetophenone in ethanol at 25°C and atmospheric pressure with flowing H2 as reactant in a slurry laboratory-scale plant. The activity values were measured by the consumed hydrogen in mL-min i. 

Experiments were conducted on the laboratory-scale plant rotoklon introduced on Figure 5. 

Experimental work at Windscale indicated the best combination of filters and demisters and the appropriate impregnation for the charcoal for the clean-up plant in order to handle air of high relative humidity which would arise following a depressurization accident (refs 2, 3). With this Impregnated charcoal, decontamination factors for methyl iodide better than 105 can be achieved with laboratory scale plant. The work has also indicated the useful life to be expected from the charcoal when the clean-up plant is in continuous use as it is in the prototype reactor. Tests on the actual clean-up plants have shown decontamination factors for methyl iodide of about 105, which is nearing the practical limit of sensitivity for full scale tests. 

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