15 9 A separator accepts waste oilPCB mixture that is 80 oil

15) 9. A separator accepts waste oil-PCB mixture that is 80% oil and 20% PCB. The top product stream is pure oil and the bottom stream contains 5% oil. If the flowrate entering the process step is 100 gal/min, how much oil is recovered?

Solution

Let percentage of top product be x and hence the other product (bottom underflow) is 1-x.

Top product is 100% oil whereas bottom is 5% oil.

Thus, % of oil in both is x and 0.05(1-x).

Sum of these is 80% of 100gal/min. x + 0.05 - 0.05 x=0.8 which gives us x=0.7894Thus, oil recovered is x (pure oil only) = 0.7894 *100 gal/min =78.94 gal/min