Typical Material Balance Problems in Chemical Processes

1 Typical Material Balance Problems in Chemical Processes 

As has been stressed throughout the book, and particularly in the previous chapter, a correct procedure is, again, essential to solving material balance problems for reactive systems. Warm-up examples 4 and 5 focus on managing material balances for reactors. 

Warm-Up Example 4. A reactor is fed with a mixture of oxygen (O2) and propane (CsHg). Oxygen is in excess and the conversion of the reaction is 70 %. At the output of the reactor, the presence of 21 [mol] of CO2 and 40 [mol] of O2 has been analytically determined, (a) What is the fractional excess of oxygen (b) How many moles of propane were fed to the reactor (c) What is the molar composition of the output stream  

we need to write down the balanced equation for the reaction between oxygen and propane  

Second, we will develop a table (Table 8.1) that simulates what is happening in the reactor, i.e., a column listing all compounds (reagents and products) and then columns for input moles, reaction moles, and output moles, where x is the moles of the limiting reagent (in this case propane) and y is the excess moles of oxygen. 

---