Packed Column Design by the Group Method

An alternative method for the design of an absorption or stripping column is based on the modular group method (Kremser equation, 12.33), primarily for dilute mixtures. The required number of stages for a specified separation is first determined. Once this is known, the packing height can be estimated from the relation 

The HETP itself has to be estimated because no rigorous methods exist for its evaluation. Its value typically depends on the type and size of the packing material particles, and is usually supplied by the packing vendor. 

To complete the column design, its diameter must be determined such that the 

The design of a packed absorption column is illustrated in Example 15.4. 

The modular group calculation results for four stages, N = 4, are as follows, for the column at an average temperature of 25°C, and 500 kPa pressure  

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