Extractive batch reactor

Gunnlaugsdottir and Sivik used a two-phase reactor for continuous extraction of the reaction product from a liquid substrate-enzyme mixture. They adjusted the pressure and temperature of the SCCO2 in the reactor so that the fatty acid 

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Extractive batch reactors (Figure 9.2-2) [22] are used for continuous extraction of products from reaction mixtures (containing liquid substrates and an enzyme preparation), which shifts the reaction equilibrium towards formation of the product. 

The typical SEA process uses a manganese catalyst with a potassium promoter (for solubilization) in a batch reactor. A manganese catalyst increases the relative rate of attack on carbonyl intermediates. Low conversions are followed by recovery and recycle of complex intermediate streams. Acid recovery and purification involve extraction with caustic and heat treatment to further decrease small amounts of impurities (particularly carbonyls). The fatty acids are recovered by freeing with sulfuric acid and, hence, sodium sulfate is a by-product. 

In TBP extraction, the yeUowcake is dissolved ia nitric acid and extracted with tributyl phosphate ia a kerosene or hexane diluent. The uranyl ion forms the mixed complex U02(N02)2(TBP)2 which is extracted iato the diluent. The purified uranium is then back-extracted iato nitric acid or water, and concentrated. The uranyl nitrate solution is evaporated to uranyl nitrate hexahydrate [13520-83-7], U02(N02)2 6H20. The uranyl nitrate hexahydrate is dehydrated and denitrated duting a pyrolysis step to form uranium trioxide [1344-58-7], UO, as shown ia equation 10. The pyrolysis is most often carried out ia either a batch reactor (Fig. 2) or a fluidized-bed denitrator (Fig. 3). The UO is reduced with hydrogen to uranium dioxide [1344-57-6], UO2 (eq. 11), and converted to uranium tetrafluoride [10049-14-6], UF, with HF at elevated temperatures (eq. 12). The UF can be either reduced to uranium metal or fluotinated to uranium hexafluoride [7783-81-5], UF, for isotope enrichment. The chemistry and operating conditions of the TBP refining process, and conversion to UO, UO2, and ultimately UF have been discussed ia detail (40). 

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. 

To illustrate the application of the proposed algorithm the agrochemicals problem already presented in Chapter 4 of this textbook is revisited. It involves a completely batch operation wherein reusable water is generated from liquid-liquid extraction (product washing) operations with water as the aqueous phase in the production of three agrochemicals A, B and D. The data for the production of these products are shown in Table 5.1. These agrochemicals are produced in batch reactors. All three reactions form sodium chloride (NaCl) as a byproduct which is later removed from... 

Dynamics of an Equalisation Basin 560 Dimensionless Kinetics in a Batch Reactor 235 Batch Reactor with Complex Reaction Sequence 240 Single Solute Batch Extraction 442 Mixing and Segregation 394... 

Continuous Multicomponent Distillation Column 501 Gas Separation by Membrane Permeation 475 Transport of Heavy Metals in Water and Sediment 565 Residence Time Distribution Studies 381 Nitrification in a Fluidised Bed Reactor 547 Conversion of Nitrobenzene to Aniline 329 Non-Ideal Stirred-Tank Reactor 374 Oscillating Tank Reactor Behaviour 290 Oxidation Reaction in an Aerated Tank 250 Classic Streeter-Phelps Oxygen Sag Curves 569 Auto-Refrigerated Reactor 295 Batch Reactor of Luyben 253 Reversible Reaction with Temperature Effects 305 Reversible Reaction with Variable Heat Capacities 299 Reaction with Integrated Extraction of Inhibitory Product 280... 

This system was studied by Schwartz. Toluene at 10 ppm, nitric oxide at 1 ppm, and nitrogen dioxide at 1.2 ppm were irradiated with ultraviolet lamps in a 17-m batch reactor for 270 min. Collected aerosols were successively extracted with methylene chloride and then methanol. The methylene chloride extract was fractionated into water-soluble and water-insoluble material, and the latter fraction was further divided into acidic, neutral, and basic fractions. The acidic and neutral fractions were analyzed by gas chromatography and chemical-ionization mass spectrometry the compounds identified are shown in Figure 3-7. The two analyzed fractions represented only about 5.5% of the total aerosol mass. It is noteworthy that classical nitration of an aromatic ring appears to... 

Simple examination of A Hr of a reaction immediately tells us how much heat will be absorbed or hberated in the reaction. This is the amount of heat Q that must be added or extracted to maintain the reactor isothermal. (This heat is exactly the enthalpy change in any flow reactor or in a batch reactor at constant pressure, and it is close to this for other conditions.)... 

Fuel cells and batteries are examples of membrane reactors in which a conducting membrane separates the anode and cathode compartments, which supply fuel and oxidant, respectively. With fuel cells we have the added complexity that we need an ion-conducting electrode, which is also a catalyst at each electrode so that we can extract electrical power from the energy of the reaction. A battery is similar to a fuel ceU except that now the fuel and oxidant are stored and supplied within the ceU rather than being supphed externally. A fuel cell is usually operated as a continuous-flow reactor, while a battery is a rechargeable batch reactor. 

All the thus far formalized steps in defining and performing an experiment are being demonstrated in this example. The process of separating mercury from caustic, as part of the process of extraction in a batch reactor with a mixer, is being tested. 

Batch reactors, use in supercritical extraction of coal, 251-252 Benzylphenylamine... 

In some cases continuous extraction of products allows extended operation and high volumetric efficiency. Reactors run in this mode are referred to as continuous-stirred batch reactors... 

A wide range of dilferent reactor types e.g. continuous, membrane, bubble) have been used to perform large scale processes using alternative solvents. Conventional batch reactors and extraction vessels have been used in many cases. However, process intensification is moving forward hand in hand with alternative solvents and therefore engineering solutions often have an important role to play in this field. Nevertheless, these are not discussed at length in this chapter and will probably be the subject of another book within the green chemistry series. 

Stroeve P and Varanasi PP. Extraction with double emulsions in a batch reactor Effect of continuous-phase resistance. AIChE J 1984 30 1007-1009. 

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