Calculate and compare the total volume requirements for the following BOD reactor systems; "Single CFSTR" "Two CFSTRS" connected in series a) b) c) d) "Four CFSTRS" connected in series "PF Reactor". It is desired that the BOD concentration be reduced from 175 mg/l to 20 mg/l for a flow of 2.5 MGD (Million US Gallons per Day). Assume that the BOD reaction follows first-order kinetics, and the rate constant, K 1.25 day'.

4-23. A mixture of ethanol (A) and water (B) is separated in a distillation column. The volumetric flow rate of the feed stream is 5 m'/hr. The concentration of ethanol in the feed is c,=2,800 mol/m'. The distillate leaves the column with a concentration of ethanol c, =13,000 mol/m. The volumetric flow rate of 3 distillate is one cubic meter per hour. How much ethanol is lost through the bottoms of the column, in kilograms of ethanol per hour?

5) The flowsheet of high-density polyethylene (HDPE) production process is given in Figure. a) Fill the blanks in table by writing the corresponding stream numbers. b) Define and explain the purpose of recycle and purge streams. 8 7 centrifuge 5 6 reactor 4 13 9 10 11 HDPE 12 run-down 3 reactor extruder blending storage silo silo 2 Figure. Flowsheet of HDPE production process. Stream of Stream Number/Numbers Fresh Feed Recycle Purge Net Product