Continuous reactors batch reactor 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. 

Burgener, M., Furrer, R., Mallat, T., and Baiker, A. (2004) Hydrogenation of citral over Pd/alumina comparison of supercritical COj and conventional solvents in continuous and batch reactors. Appl. Catal., A Gen., 268, 1-8. 

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. 

On the other hand, very few ncdels for nulticonponent systans have been reported in the literature. Apart from models for binary systems, usually restricted to "zero-one" systans (5) (6), the most detailed model of this type has been proposed by Hamielec et al. (7), with reference to batch, semibatch and continuous emilsion polymerization reactors. Notably, besides the usual kinetic informations (nonomer, conversion, PSD), the model allows for the evaluation of IWD, long and short chain brandling frequencies and gel content. Comparisons between model predictions and experimental data are limited to tulK and solution binary pwlymerization systems. 

Our treatment of Chemical Reaction Engineering begins in Chapters 1 and 2 and continues in Chapters 11-24. After an introduction (Chapter 11) surveying the field, the next five Chapters (12-16) are devoted to performance and design characteristics of four ideal reactor models (batch, CSTR, plug-flow, and laminar-flow), and to the characteristics of various types of ideal flow involved in continuous-flow reactors. Chapter 17 deals with comparisons and combinations of ideal reactors. Chapter 18 deals with ideal reactors for complex (multireaction) systems. Chapters 19 and 20 treat nonideal flow and reactor considerations taking this into account. Chapters 21-24 provide an introduction to reactors for multiphase systems, including fixed-bed catalytic reactors, fluidized-bed reactors, and reactors for gas-solid and gas-liquid reactions. 

As can be expected, continuous SSP is mainly controlled by the flow rate of the nitrogen stream and the temperature. Due to the differences in reactor designs exact comparisons regarding the conditions cannot be presented. It is easy to understand that the process depends on the individual design and special characteristics of the equipment. The reaction temperature is in the same range as in the batch process [46], According to this patent, it should be noted that the SSP reaction is influenced additionally by the content of EG and the side products,... 

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...

Fig. 1.22. Comparison of size and cost of continuous stirred-tank reactors with a batch or a tubular plug-flow reactor first-order reaction, conversion 0.9 ...

Fig. 1.28. Reactions in series—comparison between batch or tubular plug-flow reactor and a single continuous stirred-tank reactor. Consecutive first-order reactions,...

We have demonstrated that vegetable oils and fatty acid esters can be selectively hardened in liquid, near-critical, or supercritical C02 or propane and in mixtures thereof at temperatures between 60 °C and 120 °C and at a total pressure up to 20.0 MPa. Table 14.2 summarizes the results for the selective hydrogenation of vegetable oils in supercritical C02 in comparison with hydrogenation reactions performed in a discontinuous (i.e., batch or semibatch) stirred-tank reactor and in a continuous trickle-bed reactor. 

This means that as long as a CSTR is used as the first stage reactor and all the recipe ingrediants are fed into the first stage reactor, one cannot have more than 57% of the number of particles produced in a batch reactor with the same recipe as in continuous operation. The validity of these expression is clear from the comparison between the experimental and theoretical values shown in Figure 5. From Figure 5, it is found that the optimum mean residence time of the first stage reactor is about 10 minutes under these reaction conditions. Equation(30) predicts 10.0 minutes, while experimental value is 10.4 minutes where the number of polymer particles is about 60% of that produced in a batch reactor. 

Kim, S. H., Han, S. K., and Shin, H. S. 2005. Performance comparison of a continuous-flow stirred-tank reactor and an anaerobic sequencing batch reactor for fermentative hydrogen production depending on substrate concentration. Water Sci. Technol., 52 (10-11), 23-29. 

The reports on catalytic isomerization using various zeolitic catalysts, in comparison to the conventional catalysts previously used, gives results of reactions carried out discontinuously in a batch reactor in liquid phase, as well as for those carried out continuously in a fixed bed reactor in the vapor phase. The results in the liquid phase over heterogeneous catalysts are summarized in Table 15.2. 

Comparative tests have been performed in the semi-batch reactor system to evaluate the Ru/Ti02 cataly versus a more conventional nickel-based catalyst. These tests show that rutlienium at only 3% metal loading has about the same activity as nickel at S0% metal loading. This comparison is only for short-term activity of the catalyst. As demonstrated in the continuous flow tests, the nickel catalyst loses activity readily in tlie first hours on stream, while the ruthenium maintains its activity. 

Free enzyme versus immobilized enzyme can influence the yield of lOS, additionally an immobilized system would be favorable economically as the biocatalyst can be reused, enables continuous production and the end product is free of contamination. Kim et al. [275] intended to make a comparison between the reaction kinetics of free and immobilized endo-inulinases in a batch reactor however significant differences were observed in the reaction behavior and product composition due to the form of enzyme used and the initial concentration of substrate. Yun et al. [276] investigated the effect of inulin concentration on the production of lOS by free and immobilized endo-inulinase from Pseudomonas sp. Their findings corroborate those of Kim et al. [275] whereby different products are formed depending on the form of enzyme a soluble enzyme yielded inulobiose and DP3 products, whereby the immobilized form predominantly produced inulobiose. As the concentration of inulin increased the yield of lOS did not increase in the soluble system and in the immobilized the yield remained the same. Although the enzyme was derived from Pseudomonas the immobilized form required a differ-... 

Figure 7 A comparison of the enantiomeric excesses (ee) of (it)-l-hydroxy-l-phenylpropanone in a continuous fixed bed reactor ( ) and in a batch reactor ( ).

Figure 7.19 Comparison of productivity of a continuous UF reactor and a batch reactor for the Promine D-Pronase system at pH 8.0. Volume replacement for the continuous UF reactor calculated as J t/V.19...

This nucleation/emulsifier utilization phenomena is one reason why batch kinetics and product characteristics are difficult to extrapolate from batch reactor to continuous stined-tank systems. A comparison of Equations (8.4) and (8.10) illustrates this in a quantitative manner for Smith-Ewart Case 2 kinetics. It should be noted that both formulation and operational variables (such as ) can influence nucleation and polymerization rates differently in the two reactor systems — even for the same kinetic model. One can change some aspects of this potential disadvantage of a CSTR by use of a small particle size seed in the feed stream or by placing a continuous tubular reactor upstream of the CSTR. These techniques can remove the nucleation phenomena tom the CSTR system which can then be used exclusively to grow the seed particles. 

A comparison between continuous and batch equipment is given in Figure 7.34, with defining parameters required by the fed-batch reactor summarized in Table 7.2. These results provide for a convenient point of reference when conversions between batch and continuous reactors are carried out. 

Figure 7.34 Comparison between continuous and batch reactive equipment. All three continuous reactors required to form the AR share equivalent batch structure. Adapted from Ming et al. (2013).

Simon, J., Wiese, J., and Steinmetz, H. (2006), A comparison of continuous flow and sequencing batch reactor plants concerning integrated operation of sewer systans and wastewater treatment plants, Water Science Technology, 54(11) 241 -248. 

Some variation in the final nanoshell size (100-200 nm) was obtained as a consequence of the particle size distribution of the silica cores (2—4 nm), which was caused by the radial velocity profiles leading to a range of reaction times in the first reaction stage. In spite of this, nanoshells with suitable properties were obtained with good reproducibility. The synthesis was carried out continuously and, in a controlled manner, provided that a fast mixing of the reactants was achieved in each stage. By comparison, the same process carried out in a batch reactor system was considerably more expensive in terms of time, reactants, and more heterogeneous products. 

Rawlings, J. B. and Ray, W. H. (1988b) The modeling of batch and continuous emulsion polymerization reactors. Part II Comparison with experimental data from continuous stirred tank reactors, Polym. Sci. Eng. 28 (5), 257-74. 

The c ability of a comprehensive computer code for simulating stirred tank gas-liquid reactors, recently proposed in the literature, is tested by comparison with experimental data concerning the oxidation of p-xylene and the uncatalyzed oxidation of calcium bisulfite performed in a semi-batch and in a continuous reactor, respectively. 

Tubular reactor Development of a pulsation operation mode to eliminate reactor fouling and plugging comparison between batch and continuous stirred-tank reactors review on tubular reactors 173... 

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