Reactors, batch jacketed

Example 5.5 Ingredients are quickly charged to a jacketed batch reactor at an initial temperature of 25°C. The jacket temperature is 80°C. A pseudo-first-order reaction occurs. Determine the reaction temperature and the fraction unreacted as a function of time. The following data are available ... 

The first-order consecutive exothermic reaction sequence, A —> B —> C, is carried out in a thick-walled, jacketed batch reactor, provided with both jacketed heating and cooling, as shown below. 

Phosphoms trichloride is manufactured by loading liquid phosphoms into a jacketed batch reactor. Chlorine is bubbled through the liquid, and phosphoms trichloride is refluxed until aU the phosphoms is consumed. Cooling water is used in the reactor jacket and care is taken to avoid an excess of chlorine and the resulting formation of phosphoms pentachloride. Phosphoms oxychloride is manufactured by the reaction of phosphoms trichloride, chlorine, and solid phosphoms pentaoxide in a batch operation. Liquid phosphoms trichloride is loaded to the reactor, solid phosphoms pentoxide added, and chlorine bubbled through the mixture. Steam is... 

Consider a jacketed batch reactor in which the same network of irreversible exothermic reactions adopted in Chap. 5 takes place. In order to design the FD framework, the state-space model (5.15) is rewritten in a slightly different form, i.e.,... 

The effectiveness of the proposed approach has been tested in simulation by considering a jacketed batch reactor in which the phenol-formaldehyde reaction presented in Chap. 2 takes place. The complete system of differential equations given by the 13 mass balances presented in Sect. 2.4 has been simulated in the MATLAB/SIMULINK environment. 

Kinetics studies were conducted at 65 1°C in a jacketed batch reactor. Five hundred milliliters or 1 L of buffer was added to the reactor and heated to the assay temperature. The buffer pH was chosen according to the optima specified by the enzyme manufacturers. Corn flour (100-300 g/L) was then added to the reactor, along with a specified quantity of either soluble or immobilized amylase to initiate hydrolysis. Samples were collected at regular intervals over 30-60 min, and centrifuged to separate solids. The supernatant was analyzed for sugar content by measuring the %Brix with an optical refractometer. 

Figure 4-2. Jacketed batch reactor. (Source D. B. Gooch, Autoclaves Pressure—Temperature Reactions, Ind. Eng. Chem., 35, 927-946, 1943. Used with permission from the American Chemical Society.)...

Start up of a jacketed batch reactor requires control of the heat-up and cool-down rates. This involves determining and setting the jacket heat transfer fluid temperatures. An alternative is to make a trial heat-up and incorporate the results into a time-dependent heat transfer equation ... 

Various levels of models can be used to describe the behavior of pilot-scale jacketed batch reactors. For online reaction calorimetry and for rapid scale-up, a simple model characterizing the heat transfer from the reactor to the jacket can be used. Another level of modeling detail includes both the jacket and reactor dynamics. Finally, the complete set of equations simultaneously describing the integrated reactor/jacket and recirculating system dynamics can be used for feedback control system design and simulation. The complete model can more accurately assess the operability and safety of the pilot-scale system and can be used for more accurate process scale-up. 

The suspension polymerization for the production of EPS is carried out in a jacket batch reactor with a stirrer and usually two or more baffles. The volume of the vessels is normally between 20 and 100 m3. 

The major problem in temperature control in bulk and solution batch chain-growth reactions is the large increase in viscosity of the reaction medium with conversion. The viscosity of styrene mixtures at I50°C will have increased about 1000-fold, for example, when 40 wt % of the monomer has polymerized. The heat transfer to a jacket in a vessel varies approximately inversely with the one-third power of the viscosity. (The exact dependence depends also on the nature of the agitator and the speed of fluid flow.) This suggests that the heat transfer efficiency in a jacketed batch reactor can be expected to decrease by about 40% for every 10% increase in polystyrene conversion between 0 and 40%. 

The ratio of the temperature gradient at the surface to some reference temperature gradient. For a jacketed batch reactor this represents the temperature gradient existing at the interface between the inner reactor wall and reaction fluid. It is a measure of the film heat transfer coefficient. 

A PID controller is used to control the temperature of a jacketed batch reactor by adjusting the flow rate of coolant to the jacket. The temperature controller has been tuned to provide satisfactory control at the nominal operating conditions. Would you anticipate that the temperature controller may have to be retuned for any of the following instrumentation changes Justify your answers. 

The production technique is quite well known [4-6] and no sophisticated equipment or controls are needed. The reaction is carried under an inert atmosphere in a jacketed batch reactor equipped with a stirrer and cooler. The resin produced has a pale straw color mainly due to hydroquinone added as an inhibitor, and its viscosity is such that it resembles honey. 

FIGURE 5.13 Basic stirred, jacketed batch reactor. For solution polymerizations, solvent, monomer, and intiator are charged. For suspension polymerization, water and a protective colloid such as poly(vinyl alcohol) form one phase, whereas the monomer and initiator form a second phase. In emulsion polymerization, a water-soluble initiator such as potassium persulfate is used together with a surfactant such as sodium stearate. 

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