We saw that there were several different ways that we could go through the table and use it to help us solve the problem. In fact, there were a couple of different ways that we could have gone once we got some of the information filled in. Let's think back to the four different ways we put information into the table:
1) We put numbers into the table directly from the problem statement.
2) We used a total flowrate and a mass fraction to fill in a component stream.
3) We used the fact that the total flowrate was the sum of the components in the stream.
4) We used a mass balance where the mass flowing into the process must be equal to the mass flowing out of the process.
When you think about it, number 2 and number 3 are just restatements of each other. If we look at number 2, all of the mass fractions have to add up to 1.0 so we just end up with number 3 again.
Really, that's all there is to material balances. All we have to remember are three steps and we can solve any problem. Do you think you are ready for another example? When you are, click the button below...