Stirred reactors batch

Specific reactor characteristics depend on the particular use of the reactor as a laboratory, pilot plant, or industrial unit. AH reactors have in common selected characteristics of four basic reactor types the weH-stirred batch reactor, the semibatch reactor, the continuous-flow stirred-tank reactor, and the tubular reactor (Fig. 1). A reactor may be represented by or modeled after one or a combination of these. SuitabHity of a model depends on the extent to which the impacts of the reactions, and thermal and transport processes, are predicted for conditions outside of the database used in developing the model (1-4). 

In terms of cost and versatility, the stirred batch reactor is the unit of choice for homogeneous or slurry reactions and even gas/liquid reactions when provision is made for recirculation of the gas. They are especially suited to reactions with half-lives in excess of 10 min. Sam-... 

Wang, Y.-D. and Mann, R., 1992. Partial segregation in stirred batch reactors effect of scale-up on the yield of a pair of competing reactions. Transactions of the Institution of Chemical Engineers, 70, 282-290. 

Fletcjjhr. P. The Chemical Engineer. London No 435 (1987) 33. Heat transfer coefficients for stirred batch reactor design. 

Peaking and Non-isothermal Polymerizations. Biesenberger a (3) have studied the theory of "thermal ignition" applied to chain addition polymerization and worked out computational and experimental cases for batch styrene polymerization with various catalysts. They define thermal ignition as the condition where the reaction temperature increases rapidly with time and the rate of increase in temperature also increases with time (concave upward curve). Their theory, computations, and experiments were for well stirred batch reactors with constant heat transfer coefficients. Their work is of interest for understanding the boundaries of stability for abnormal situations like catalyst mischarge or control malfunctions. In practice, however, the criterion for stability in low conversion... 

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. 

With PI, traditional proeess design criteria (particularly those focused around stirred batch reactors) are thrown out and the equipment is designed to mateh the chemistry. It is not unexpected, therefore, to find that PI has been successfully applied to reactions that are very fast and exothermic, where the process is being limited by poor design. Traditionally these proeesses have been handled either by the use of large amounts... 

As noted above, stirred batch reactors are the most common type of reactor used for the production of fine and pharmaceutical chemicals. This is partly to do with tradition and partly with the need to produce a flexible reactor design in which a whole range of products can be made. Spinning... 

If the process is carried out in a stirred batch reactor (SBR) or in a plug-flow reactor (PFR) the final product will always be the mixture of both products, i.e. the selectivity will be less than one. Contrary to this, the selectivity in a continuous stirred-tank reactor (CSTR) can approach one. A selectivity equal to one, however, can only be achieved in an infinite time. In order to reach a high selectivity the mean residence time must be very long, and, consequently, the productivity of the reactor will be very low. A compromise must be made between selectivity and productivity. This is always a choice based upon economics. 

The stirred batch reactors are easy to operate and their configurations avoid temperature and concentration gradient (Table 5). These reactors are useful for hydrolysis reactions proceeding very slowly. After the end of the batch reaction, separation of the powdered enzyme support and the product from the reaction mixture can be accomplished by a simple centrifugation and/or filtration. Roffler et al. [114] investigated two-phase biocatalysis and described stirred-tank reactor coupled to a settler for extraction of product with direct solvent addition. This basic experimental setup can lead to a rather stable emulsion that needs a long settling time. 

The reaction was carried out in a well-stirred batch reactor at 40 °C. Under these conditions,... 

The starting point for the development of the basic design equation for a well-stirred batch reactor is a material balance involving one of the species participating in the chemical reaction. For convenience we will denote this species as A and we will let (— rA) represent the rate of disappearance of this species by reaction. For a well-stirred reactor the reaction mixture will be uniform throughout the effective reactor volume, and the material balance may thus be written over the entire contents of the reactor. For a batch reactor equation 8.0.1 becomes... 

The data below are typical of those recorded in a well-stirred batch reactor. Initial concentrations were as follows. 

LAC from T. versicolor Stirred batch reactor with the compound spiked in wastewater... 

The tests are carried out in a stirred batch reactor. 100 mL of n-dodecane is put in the reactor, pressurized with nitrogen to 25 bar. The fuel is heated up to the operating temperature and kept at the same temperature for 1 h. At the end of the test, the batch reactor is cooled down. Liquid and gas phases are collected and analyzed. 0.3 g of zeolite is used in each test. 

Fletcher, F., "Heat Transfer Coefficients for Stirred Batch Reactor Design," The Chemical Engineer, 33 (1987). 

Table 6 Stirred batch reactor ARO of epoxides catalyzed by a dimeric (R,R)-Cr(III)(salen) complex 65 immobilized in a supported ionic liquid phase compared to the dimeric complex impregnated on silica 64-silica and the reported homogeneous reactions with the monomeric Cr(salen) complex 63...

The catalyst/substrate ratio is 1.5 mol% for the supported ionic liquid phase (SILP) catalyst, 3 mol% for the impregnated catalyst and 2 mol% for the homogeneous reaction aRuns 1 -4 are consecutive experiments with the same catalyst in a stirred batch reactor. bDimeric Cr (salen) catalyst impregnated on silica cHomogeneous reaction at 0-2 OC optimized for product selectivity dHomogeneous reaction at room temperature optimized for product selectivity... 

The nonfertilizer calcium phosphates are manufactured by the neutralization of phosphoric acid with lime. The processes for different calcium phosphates differ substantially in the amount and type of lime and amount of process water used. Relatively pure, food-grade monocalcium phosphate (MCP), dicalcium phosphate (DCP), and tricalcium phosphate (TCP) are manufactured in a stirred batch reactor from furnace-grade acid and lime slurry, as shown in the process flow diagram of Figure 3. Dicalcium phosphate is also manufacmred for livestock feed supplement use, with much lower specifications on product purity. 

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