Heat and Material Balance Assessment

One of the early steps of assessing the distillation system is to obtain good material and energy balances. Otherwise, it could be possible that assessment yields misleading conclusions. 

The material and energy balances can be built based on the input of feeds and energy as well as ouQjuts of products and energy in operation. The purpose of conducting a column material balance is to make sure feeds and products are measured accurately and desirable products are obtained. The energy balance is to verify if all major sources of energy input are accounted for and if efficient use of energy is achieved. 

Heat input is the driving force for fractionation. For a simple fractionation column, heat input comes from feed and bottom reboiling, while heat is removed from products and the overhead condenser. For a complex fractionation column, multiple products are produced, while pump-arounds are located to remove excess heat in the column and recover this heat for process usage. 

Both material and energy balances should be conducted on the basis of steady state operation as this is a stable operation away from any transient excessive flooding or weeping operation. The steady state operation can be viewed from the 

For any fractionation column, there are overall mass balance and component mass balances, which follow the mass conservation law  

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