Performing Non  Reactive Mass and Energy Balances
Now that we know how to write the equations that will get us started for balances, we need to worry about when they are useful.How do we know when to write these equations, or how many we need ?
 Perform single  unit mass balances

 Perform a degree  of  freedom analysis for a single  unit mass balance process
 Do the calculations suggested in the degree  of  freedom analysis
Real processes often include more than one process unit.How do we handle arbitrary numbers of units ? arbitrarily complex arrangements of those units ?
 Identify relevant sub  systems within a multi  unit process on which to perform a degree  of  freedom analysis(and subsequently do the required calculations)
 Perform mass balances(degree  of  freedom plus calculations) for systems with recycle, bypass, and purge streams
Energy balances can be used as an additional equation in mass balances.
 Simplify and solve the General Energy Balance for non  reactive systems