Reactor design batch

From diese various estimates, die total batch cycle time t(, is used in batch reactor design to determine die productivity of die reactor. Batch reactors are used in operations dial are small and when multiproducts are required. Pilot plant trials for sales samples in a new market development are carried out in batch reactors. Use of batch reactors can be seen in pharmaceutical, fine chemicals, biochemical, and dye industries. This is because multi-product, changeable demand often requues a single unit to be used in various production campaigns. However, batch reactors are seldom employed on an industrial scale for gas phase reactions. This is due to die limited quantity produced, aldiough batch reactors can be readily employed for kinetic studies of gas phase reactions. Figure 5-4 illustrates die performance equations for batch reactors. 

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

Example 2.2 Derive the batch reactor design equations for the reaction set in Example 2.1. Assume a liquid-phase system with constant density. 

Recent reports on other forms of reactors are also available. Immobilized cell bioreactors, upflow sludge blanket reactors, draft-tube airlift reactor and other have been suggested. Each of these reactors has its own pros and cons and the advantages need to be evaluated with the whole process in mind. Further work is necessary in this area. Several process schemes have been considered and evaluated with the batch reactor design as the core BDS reactor ... 

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

The desulfurization experiments were run in a batch reactor designed and constructed at the Ames Laboratory. The reaction crucible (8 in. x 3.5 in. o.d.) was constructed from Inconel tubing. A basket to hold the coal was fashioned from -20 mesh stainless steel screen. The chromel-alumel thermocouple was sheathed in stainless steel. 

For batch reactors, time is the key design variable. The batch reactor design equations answer the question How long does it take to obtain a specified conversion or concentration ... 

Develop a batch-reactor design equation from the mass balance. To find the required holding time, a relationship between reaction time and the rate of conversion of acetylene must be developed. This may be developed from a mass balance on the batch reactor. Since the molar density of the reacting mixture is not constant (there is a net change in the number of moles due to reaction), the pressure of the reactor will have to change accordingly. 

Separate and integrate the batch-reactor design equation. The reaction time required for any given initial composition and conversion of reactants may now be calculated directly from the preceding expression, once this expression has been integrated and solved for t = f(X). The appropriate... 

Because each globule acts as a batch reactor of constant volume, we use the batch reactor design equation to arrive at the equation giving conversion as a function of time ... 

Back-mix reactor design, 721, 728 Baffles in heat exchangers, 595, 610-612 pressure drop over, 599-602, 605-606 Bailee s liahihty, 263 Balance sheet, 140-142 Barometric-leg pumps, 523 Batch operation versus continuous, 35-36 Batch-reactor design, 721-727 Battery-limit additions, definition of, 167 Berl saddles, 688-690 cost of 710... 

This expression may be inserted into the characteristic batch reactor design equation ... 

SOLUTION The assumption of an approximate steady state is applied to components B and C. The batch reactor design equations are... 

Substituting these results into Equation 4.2 gives the general batch reactor design equation. 

These conclusions can be readily quantitatively visualized as shown in Fig. 10.2.b-3, which is based on the geometric nature of the plug flow or batch reactor design equation versus that for the perfectly mixed flow reactor. 

If this reaction is now carried out in a batch reactor designed to operate at constant pressure, determine the time necessary for the concentration of methyl ether to decrease from its initial value to half of that value. The reaction takes place at 504°C in a vessel in which the initial pressure of methyl ether is now 1200 torr. Again, the initial contents of the reaction vessel consist of pure methyl ether. 

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