Batch reactors comparison

David, R., Muhr, H. and Villermaux, J., The Yield of a Consecutive-Competitive Reaction in a Double Jet Semi-Batch Reactor Comparison between Experiments and a Multizone Mixing Model, Chem. Eng. Sci. 1992, 47 (9-11), 2841-2846. 

N. Aziz, M.A. Hussain, I.M. Mujtaba, Optimal control of batch reactor comparison of neural network based GMC and inverse model control approach, in Proceedings of the Sixth World Congress of Chemical Engineering, Melbourne, Australia, 23-27 September 2001. 

V. Meille, N. Pestre, P. Fongarland, C. de Bellefon, Gas-liquid mass transfer in small laboratory batch reactors comparison of methods, Ind. Chem. Eng. Res. 2004, 43, 924-927. 

Eigure 2 shows that even materials which are rather resistant to oxidation ( 2/ 1 0.1) are consumed to a noticeable degree at high conversions. Also the use of plug-flow or batch reactors can offer a measurable improvement in efficiencies in comparison with back-mixed reactors. Intermediates that cooxidize about as readily as the feed hydrocarbon (eg, ketones with similar stmcture) can be produced in perhaps reasonable efficiencies but, except at very low conversions, are subject to considerable loss through oxidation. They may be suitable coproducts if they are also precursors to more oxidation-resistant desirable materials. Intermediates which oxidize relatively rapidly (/ 2 / i — 3-50 eg, alcohols and aldehydes) are difficult to produce in appreciable amounts, even in batch or plug-flow reactors. Indeed, for = 50, to isolate 90% or more of the intermediate made, the conversion must... 

A useful classification of lands of reaclors is in terms of their concentration distributions. The concentration profiles of certain limiting cases are illustrated in Fig. 7-3 namely, of batch reactors, continuously stirred tanks, and tubular flow reactors. Basic types of flow reactors are illustrated in Fig. 7-4. Many others, employing granular catalysts and for multiphase reactions, are illustratea throughout Sec. 23. The present material deals with the sizes, performances and heat effects of these ideal types. They afford standards of comparison. 

This paper presents the physical mechanism and the structure of a comprehensive dynamic Emulsion Polymerization Model (EPM). EPM combines the theory of coagulative nucleation of homogeneously nucleated precursors with detailed species material and energy balances to calculate the time evolution of the concentration, size, and colloidal characteristics of latex particles, the monomer conversions, the copolymer composition, and molecular weight in an emulsion system. The capabilities of EPM are demonstrated by comparisons of its predictions with experimental data from the literature covering styrene and styrene/methyl methacrylate polymerizations. EPM can successfully simulate continuous and batch reactors over a wide range of initiator and added surfactant concentrations. 

Comparison between the heat exchanged per unit of volume during oxidation experiment in the Shimtec reactor and the maximal heat exchanged in a classical batch reactor (with a double jacket) highlights the effectiveness of the former. Indeed, in oxidation reaction experiments, a mean value of the heat exchanged per unit of volume in the HEX reactor is estimated with utility stream temperature of 47 °C ... 

S. H., and Stitt, E.H. (2007) intensification of the solvent-free catalytic hydroformylation of cydododecatriene comparison of a stirred batch reactor and a heat-exchange reactor. Catal. Today, 128, 18-25. 

Figure 4.50 Comparison of isomeric ratios for 1,5- and 1,8-dinitronaphthalene. Reaction was performed in a macroscopic batch reactor and micro reactors of different types and from different suppliers [37],...

Figure 4.63 Comparison between the results of the screening of different substrates against one catalyst in a batch reactor (white columns) and micro reactor set-up (gray columns) [llOj.

By comparison with data from a vigorously stirred mini-batch reactor (10 cm ), it could be shown that this micro-reactor operation gave intrinsic kinetic data [111]. This is demonstrated, e.g., by the lower conversion of the branched iso-alcohols respective to the normal-chain ones. 

Figure 1 Comparison of Xyhtol Conversion versus Temperature, 300cc Batch Reactor, 8,300kPa H2, 4-Hour Sample.

In comparison with a batch reactor, the gradual or intermittent addition of a reactant (say, B in A + B -> products, Figure 12.3(a)) in semibatch operation can result in improved control of T, particularly for a reaction with a large... 

A performance comparison between a BR and a CSTR may be made in terms of the size of vessel required in each case to achieve the same rate of production for the same fractional conversion, with the BR operating isothermally at the same temperature as that in the CSTR. Since both batch reactors and CSTRs are most commonly used for constant-density systems, we restrict attention to this case, and to a reaction represented by... 

Figure 4.59 presents the results obtained when the basic system, containing G6PDH and GR, was operated as a fed-batch reactor in the configuration described in Figure 4.58. For comparison, the results of pertinent numerical simulations are also shown. It can be seen that the signal obtained in the experimental system indeed follows the characteristic course shown by the signal calculated, but the actual numerical values are different. This dissimilarity has been attributed to inhibition effects in the reactions involved, effects that were not considered in the calculations. Therefore, a search for potential inhibitors was undertaken.

The interpretation of the experimental results presented in Figure 4.69 was extended to include inhibition of the enzyme G6PDH by NADPH with i.NADPH = 0.027 mM. A comparison between experimental and calculated results is shown in Figure 4.70. In this case better agreement is achieved when lower values of Ki oee are employed, the values being in the range obtained in experiments carried out in a fed-batch reactor (0.15 to 1 mM). 

In the Claisen-Schmidt condensation at the same temperature and with ethanol solvent present, lower yields of a-enones were observed. The best yield corresponds to condensation of the most reactive furfural with acetophenone, giving 95% a-enone after 1 h in a batch reactor. A comparison of the results characterizing the two reactions led to the conclusion that the W-H reaction provides the more efficient and selective synthesis of a-enones however, the CS condensation provides the more economic approach. 

Regarding reactor sizes, a comparison of Eqs. 5.4 and 5.19 for a given duty and for s = 0 shows that an element of fluid reacts for the same length of time in the batch and in the plug flow reactor. Thus, the same volume of these reactors is needed to do a given job. Of course, on a long-term production basis we must correct the size requirement estimate to account for the shutdown time between batches. Still, it is easy to relate the performance capabilities of the batch reactor with the plug flow reactor. 

Metathesis activity. A quantitative comparison of metathesis activities was made in the gas phase homometathesis of propylene. The reaction kinetics are readily monitored since all olefins (propylene, ethylene, cis- and fra/3s-2-butylenes) are present in a single phase. Metathesis of 30 Torr propylene was monitored in a batch reactor thermostatted at 0 °C, in the presence of 10 mg catalyst. The disappearance of propylene over perrhenate/silica-alumina (0.83 wt% Re) activated with SnMe4 is shown in Figure 2a. The propylene-time profile is pseudo-first-order, with kob (1.11 + 0.04) X 10" slightly lower rate constant, (0.67 constants are linearly dependent on Re loading. Figure 3. The slope yields the second-order rate constant k = (13.2 + 0.2) s (g Re) at 0°C. 

Rakels, J.L.L., Paffen, H.T., Straathof, A.J.J. and Heijnen, J.J. (1994) Comparison of enzymatic kinetic resolution in a batch reactor and a CSTR. Enzyme Microbial Technology, 16,791-794. 

A comparison of the various types of reactor concepts, in a general sense, is actually only possible between the batch, the CSTR and the PFR. The cascade of CSTRs, depending on the number of vessels n in the series, more or less behaves as an ideal mixer for n->l or an ideal plug flow for n- - . The fed-batch reactor is more difficult to situate. Although the concentration of compounds important for the rate of reaction can be controlled optimally during the whole fed period, the reactor volume is only partially utilized, especially in the beginning. Nevertheless, this reactor concept certainly has decisive advantages in many cases, as shown by the fact that it is one of the most widely used. 

Table 1.3. Comparison of Continuous Stirred-Tank Reactors and Batch Reactors with Respect to Unit Output W k C0 and Reactor Volume. First-Order Reaction...

Figure 24.9 A comparison of catalytic performances of iso-butane dehydrogenation on vanadium and on vanadium carbide catalysts. The reaction was carried out in a circulating batch reactor. The initial partial pressure of isobutane was 13.3 kPa Torr, which was mixed with He for a total pressure of 100 kPa.

The benzoic acid was quantitatively coupled within 5 min via its cesium salt by using a dedicated multi-mode batch reactor, carried out in standard glassware under atmospheric reflux conditions. In a more extended study, various substituted carboxylic acids (Fig. 7.7) were coupled to chlorinated Wang resin, employing an identical reaction protocol. In a majority of cases, the microwave-mediated conversion reached at least 85% after 3-15 min. These microwave conditions represented a significant rate enhancement, in contrast to the conventional protocol, which took 24-48 h. The microwave protocol has additional benefits in comparison to the conventional method, as the amounts of acid and base equivalents can be reduced and potassium iodide as an additive can be eliminated from the reaction mixture27. 

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