Industrial production of whey protein concentrate (WPC80) and lactose monohydrate (crystals of lactose) from cheese whey The process starts with cheese whey, a liquid residue derived from cheese production, containing 6.7% of total solids (the remaining is water). Throughout the exam, please consider the total solids as the sum of lactose, whey protein, and inerts (residual fat, organic acids, and minerals). The total solids within the cheese streams are made of 71.64% lactose, 17.91% protein, and 10.44% inerts, all expressed on a dry basis. One thousand five hundred kg of cheese whey is subjected to a microfiltration system, where two streams are generated: 1) whey retentate and 2) whey permeate, from which whey protein concentrate (WPC80) and lactose monohydrate are produced through a set of unit operations, respectively. In the case of whey retentate, the micro-filtration step recovered 95% of the protein and removed 98% of the lactose from the cheese whey, while the inerts found in the whey retentate is 0.25% on a wet basis. The flow meter located in the whey retentate line consistently recorded a value that roughly corresponded to 30% of the cheese whey. Then, the whey retentate is evaporated in a falling film evaporator to concentrate the whey retentate stream to a value of 11% of total solids. Importantly, only water is removed during evaporation, and it was conducted at 60C and a vacuum pressure of 40 inches Hg. The concentrated whey retentate leaving the evaporator is fed in a spray dryer to obtain a powder of 6% water content. A stream of dried and hot air is fed into the drying chamber at 180C and 5 bar. The exhausted air leaves the drier at 70C and 1 atm of pressure. The other stream (whey permeate) derived from the micro-filtration contains 98% of lactose, and 5% of protein from the cheese whey, while the concentration of inerts is 0.45%. Then, the whey permeate is concentrated in a falling film evaporator to obtain a saturated solution of lactose at 80C. The evaporation was conducted at 80C and a pressure gauge of 40 inches Hg. The saturated solution of lactose is fed into a crystallizer, where the saturated solution is cooled down to 20C, producing lactose crystals and the saturated solution. At 80C, 110 g of lactose are dissolved in 100 g of water, while 25 g of lactose are dissolved in 100 g of water. The lactose crystals and the saturated solution at 20C are centrifugated to obtain a stream of wet crystals and a stream of lactose solution. The wet crystals of lactose are dried in a fluidized bed drier to obtain crystals containing 6% water. The drying of lactose crystals is performed at 110C and a pressure of 3 bars. 5) Obtain the mass of lactose crystals produced (100 points) 6) Obtain the volume of water removed in the evaporation during the lactose production (40 points) 7) Obtain the volume of air needed for the drying of lactose (40 points) 8) Obtain the yield of crystals produced with respect to the initial amount of lactose (40 points) 9) Demonstrate that the process yields a powder containing at least 80% protein (20 points) Industrial production of whey protein concentrate (WPC80) and lactose monohydrate (crystals of lactose) from cheese whey The process starts with cheese whey, a liquid residue derived from cheese production, containing 6.7% of total solids (the remaining is water). Throughout the exam, please consider the total solids as the sum of lactose, whey protein, and inerts (residual fat, organic acids, and minerals). The total solids within the cheese streams are made of 71.64% lactose, 17.91 % protein, and 10.44% inerts, all expressed on a dry basis. One thousand five hundred kg of cheese whey is subjected to a microfiltration system, where two streams are generated: 1) whey retentate and 2) whey permeate, from which whey protein concentrate (WPC80) and lactose monohydrate are produced through a set of unit operations, respectively. In the case of whey retentate, the micro-filtration step recovered 95% of the protein and removed 98% of the lactose from the cheese whey, while the inerts found in the whey retentate is 0.25% on a wet basis. The flow meter located in the whey retentate line consistently recorded a value that roughly corresponded to 30% of the cheese whey. Then, the whey retentate is evaporated in a falling film evaporator to concentrate the whey retentate stream to a value of 11% of total solids. Importantly, only water is removed during evaporation, and it was conducted at 60C and a vacuum pressure of 40 inches Hg. The concentrated whey retentate leaving the evaporator is fed in a spray dryer to obtain a powder of 6% water content. A stream of dried and hot air is fed into the deine chamber at 1800 and 5 har The exhausted air leaves the drier at 70C and 1 atm of pressure. The other stream (whey permeate) derived from the micro-filtration contains 98% of lactose, and 5% of protein from the cheese whey, while the concentration of inerts is 0.45%. Then, the whey permeate is concentrated in a falling film evaporator to obtain a saturated solution of lactose at 80C. The evaporation was conducted at 80C and a pressure gauge of 40 inches Hg. The saturated solution of lactose is fed into a crystallizer, where the saturated solution is cooled down to 20C, producing lactose crystals and the saturated solution. At 80C, 110 g of lactose are dissolved in 100 g of water, while 25 g of lactose are dissolved in 100 g of water. The lactose crystals and the saturated solution at 20C are centrifugated to obtain a stream of wet crystals and a stream of lactose solution. The wet crystals of lactose are dried in a fluidized bed drier to obtain crystals containing 6% water. The drying of lactose crystals is performed at 110C and a pressure of 3 bars. 2) Obtain the mass of WPC80 produced (100 points) 3) Obtain the volume of water removed in the evaporation during the WPC80 production (40 points) 4) Obtain the volume of air needed for the drying of WPC80 (40 points) 5) Obtain the mass of lactose crystals produced (100 points) 6) Obtain the volume of water removed in the evaporation during the lactose production (40 points) 7) Obtain the volume of air needed for the drying of lactose (40 points) 8) Obtain the yield of crystals produced with respect to the initial amount of lactose (40 points) 9) Demonstrate that the process yields a powder containing at least 80% protein (20 points)