Apparatus batch

Continuous-zone-melting apparatus has been described by Pfann (op. cit., p. 171). This technique offers the advantage of a close approach to the ultimate distribution, which is usually impractical for batch operation. 

However, attempts to reuse the ionic catalyst solution in consecutive batches failed. While the products could readily be isolated after the reaction by extraction with SCCO2, the active nickel species deactivated rapidly within three to four batch-wise cycles. The fact that no such deactivation was observed in later experiments with the continuous flow apparatus described below (see Figure 5.4-2) clearly indicate the deactivation of the chiral Ni-catalyst being mainly related to the instability of the active species in the absence of substrate. 

The experimental semibatch apparatus and procedure have been described in several places through the text of Wisseroth s publications ( 1, 7-9). so the details will not be repeated here. For nearly all of his work the reactor volume was one liter, temperature was 80 C, pressure was 30 atm (441 psia), and the feed was polymerization grade I assume that the reactor gas composition was 99% CsHgand 1% inerts. The range of catalyst loading was from 11 to 600 mg of TiCils per batch. The reaction time was varied from 0.5 to 6 hours. The weight ratio of alkyl-to-TiC 3 in the catalyst recipe was varied from 0.5 to 32. No data are reported from a continuous gas phase reactor. 

A process for the depolymerisation of Nylon 6 carpet fibre in the presenee of steam under medium pressure (800 to 1500 KpA, 100 to 200 psig) is described. The feasibility of the seheme was demonstrated using a small laboratory apparatus and the best run produced a 95% yield of crude eaprolaetam. The data obtained were used to construct a computer model of the process for both batch and continuous flow stirred reactors. 6 refs. 

The main limitation of HEX reactors is the short residence time, typically from a few seconds to a few minutes. Indeed, the apparatuses are smaller than the traditional ones and fast flow velocities are necessary in order to maintain good level of heat-transfer coefficients. However, as described in the previous paragraph, the highlighted transfer properties of HEX reactors allow us to operate in a few minutes, whereas it takes many hours in batch or semibatch mode. 

Therefore, consideration of this mass in heat-transfer phenomenon leads to a significant temperature decrease reached after deviation and increases the time to maximum rate. This reveals an intrinsically safer behavior of this apparatus compared to that of batch reactors. 

The choice of the material is also strategic for two reasons to obtain an apparatus resisting to the corrosion of the different chemical products, like glass for glass-lined batch reactors, but also to keep high heat transfer performances, like aluminum in the case of HEXs. Steel and more so SiC appear to be very interesting compromises for both aspects. 

The absorption rates of CO2 were measured in such non-aqueous solvents as toluene, NMP, and DMSO with GMA concentration ranging Ifom 0.5 to 3 kmol/m in a semi-batch flat-stirred agitated vessel constructed of pyrex glass of 0.075 m inside diameter and of 0.13 m in height. The apparatus and the experimental procedure are the same as those described by... 

The pyrolysis of the plastics was carried out in a semi-batch reactor which was made of cylindrical stainless steel tube with 80mm in internal diameter and 135mm in height. A schematic diagram of the experimental apparatus is shown in Fig. 1, which includes the main reactor, temperature controller, agitator, condenser and analyzers. 

A chemical reactor is an apparatus of any geometric configuration in which a chemical reaction takes place. Depending on the mode of operation, process conditions, and properties of the reaction mixture, reactors can differ from each other significantly. An apparatus for the continuous catalytic synthesis of ammonia from hydrogen and nitrogen, operated at 720 K and 300 bar is completely different from a batch fermenter for the manufacture of ethanol from starch operated at 300 K and 1 bar. The mode of operation, process conditions, and physicochemical properties of the reaction mixture will be decisive in the selection of the shape and size of the reactor. 

Hence, both Cp and U can be evaluated for the physical and geometrical system under consideration instead of using literature correlations with an accuracy of 30 %. For a single reaction the rate of heat generation qp is the product of the reaction rate, the volume of the reaction mixture, and the heat of reaction, which for a batch apparatus can be written as ... 

Batch Experimental Apparatus and Methods. The activity of the rhodium catalyst was tested in a 125 mL reactor with a pressure rating of 3000 psi at 350°C and a pressure relief valve that is rated for 1500-2200 psi. If the pressure valve releases, the gaseous contents of the autoclave are safely vented through a 1/4" stainless steel line and the liquid/vapor content in the autoclave is collected in a metal container and the vapor vented out through the hood. The reactor was heated in a silicone oil bath with a digitally controlled heat/stir plate. 

Apparatus. Since all the polymer modification reactions presented in this paper involved gas consumption, an automated gas consumption measuring system was designed, fabricated and used to keep constant pressure and record continuously the consumption of gas in a batch type laboratory scale reactor. Process control, data acquisition, and analysis was carried out using a personal computer (IBM) and an interface device (Lab-master, Tecmar Inc.). 

The test apparatus chosen for disintegration testing and dissolution testing should be one of those described in the Ph Eur unless another pharmacopoeial or a noncompendia method can be justified. The test conditions and the proposed release rates should be justified in terms of batch reproducibility. 

Details of the specific types of apparatus need not normally be given except for nonstandard processes. A flow chart of the manufacturing operation and the in-process controls (and acceptance limits) is required. Proposals for alternative processes will need to be supported by appropriate data to show that the finished products resulting from these are consistent with the finished product specification. Certain manufacturing operations such as mixing may require additional information on quality parameters monitored during production and prior to batch release. Appropriate quality parameters should be included in the finished product specification regardless of the outcome of validation studies (e.g., content uniformity for solid and semi-solid products). 

A lot of attempts have been made to describe the time dependence of the attrition rate in batch fluidized bed processes. Gwyn (1969) studied the degradation of catalysts in a small-scale test apparatus and defined the elutriated particles as the only attrition product. He described the increase of the elutriated mass, Wel, with time, t, based on the initial solid bed mass, Wbed 0, by the now widely known Gwyn equation ... 

Fig. 14 Dissolution-time profiles for a batch-type dissolution apparatus (A), and a continuous-flow dissolution apparatus (B). (Reproduced with permission of the copyright owner, John Wiley and Sons, Inc., from Ref. 1, p. 476.)...

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