Distillation with optimum distillate rate

Redux Ra.te, The optimum reflux rate for a distillation column depends on the value of energy, but is generally between 1.05 times and 1.25 times the reflux rate, which could be used with infinite trays. At this level, excess reflux is a secondary contributor to column inefficiency. However, when designing to this tolerance, correct vapor—Hquid equiUbrium data and adequate controls are essential. 

Both modes usually are conducted with constant vaporization rate at an optimum value for the particular type of column construction. Figure 13.10 represents these modes on McCabe-Thiele diagrams. Small scale distillations often are controlled... 

Both modes usually are conducted with constant vaporization rate at an optimum value for the particular type of column construction. Figure 13.9 represents these modes on McCabe-Thiele diagrams. Small scale distillations often are controlled manually, but an automatic control scheme is shown in Figure 13.9(c). Constant overhead composition can be assured by control of temperature or directly of composition at the top of the column. Constant reflux is assured by flow control on that stream. Sometimes there is an advantage in operating at several different reflux rates at different times during the process, particularly with multicomponent mixtures as on Figure 13.10. 

Various species and many strains oiyAcetobacter are used in vinegar production (48,49). Aeration rates, optimum temperatures and nutrient requirements vary with individual strains. In general, fermentation alcohol substrates require minimal nutrient supplementation whde their addition is necessary for distilled alcohol substrates. 

With the advent of process simulation packages, modeling of pervaporation and vapor permeation processes in a user added subroutine allows these unit processes to be included in overall separation schemes right from the conceptual stage. This enables many different combinations of pervaporation, for example, distillation to be studied and the optimum operating parameters for the preferred configuration to be selected very quickly. Such parameters include membrane feed temperature, which strongly influences the flux rate and, therefore. 

A distillation column was designed to separate a 1000 kmol/h binary mixture of 50% mole component 1 to produce a distillate of 95% mole component 1 and to recover in this product 90% of component 1 in the feed. The column was constructed to handle a liquid traf-flc of 2500 kmol/h. Due to upstream process changes, the column feed composition dropped to 40% mole component 1 at the same total rate of 1000 kmol/h. While maintaining the required 95% distillate composition and operating at optimum performance, what recovery of component 1 is achievable, and can the column handle the required liquid traffic The column operates with a partial condenser at 100 kPa. The feed is a saturated liquid at feed tray conditions. Thermodynamic data given in Problem 6.1 may be used in this problem. 

The feed, at a flow rate of 100 kmol/h, is sent as saturated vapor to the distillation column. The column is equipped with a partial condenser with a vapor product, and a reboiler. For a solvent rate of 500 kmol/h, it is required to determine the required number of equilibrium stages and the optimum feed location for a reflux ratio of 1.5 times the minimum. The McCabe-Thiele method may be used on a solvent-free basis. 

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