9. Determine the mass and the composition of stream FT. Feed (5% A, 12% B, 39% C, 44% D) 100kg/hr AC (94% A, 1%B, 1% C, 4% D) - 90% recovery of A RC RT ST CT BC (1% A, 90% B, 6% C, 3% D) 70% recovery of B ST EC FT

A stream containing propionic acid and water at 70:30 mass ratio is fed to a mixer at 3.181 kg/s with pure cyclohexane as solvent. What should be the flow rate of the solvent in order to attain 30:70 mass ratio of solute and solvent in the extract (solvent-rich) stream? Prepare graphical and computational solution. Propionic acid 0.0 1.0 0.1 0.9 0.2 0.8 0.3 0.7 +1 0.4 + ++ 0.6 0.5 0.5 0.6 0.4 0.7 0.3 0.8 0.2 0.9 0.1 1.0 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Cyclohexane Water

Reverse Osmosis is used by water bottling companies to produce desalinized water from sea water. Giventhe figure below, determine the fraction of brine leaving the RO cell that is recycled.

Example 5.4. Redo the Example 5.2. once again, but consider the case that there is no recycle of the filtrate to be mixed with the fresh feed. Determine (a) the amount of K2Cro, produced per hour and (b) the rate that we need to evaporate water. Without the recycle of the filtrate, we can re-draw the flow chart as shown on the next page. We then try performing the balances around the whole process, as done previously. water vapour mz kg FIlter cake me kg K crystals (100%) makg 36.4% K 63.6% w 100% w Feed m -4.500 kg 33.3% makg 4941 50.6% w Crystalliser & Fater Evaporator Filtrate me kg 36.4%K 63.6% w

If the slurry is filtered using a larger filter press with an area of 15 m2 at a constant rate of 450 L/h, calculate the volume of filtrate that will be recovered and the time it will take to reach a pressure of 1000 kPa.

Background (adapted from US EPA CERI-89-11) The operations at an industrial waste complex have contributed to a seven-acre hazardous waste disposal area located on the site. Figure 1 represents the general layout of the industrial complex. Site Description The site geological setting, as determined from existing surveys of the area is: Surface layer at the site is a sandy soil with a high permeability and a depth of 3 -5 ft. The subsurface has been characterized as a silty sandy clay that is moderately permeable and has a depth of approximately 30 feet. The depth to groundwater from the surface averages 30 feet across the site, and the depth to bedrock is approximately 65 feet. Groundwater flow is towards the east. The bedrock consists of an impermeable limestone. The climate in this area is very humid and has an average temperature of 72°F and an annual precipitation of 53.4 inches. The high and low temperatures in January are 74°F and 49°F and in August are 92 °F and 72°F,…