In order to produce low lactose products, milk (lactose content 40 g/L) is fed into the reactor at a flow rate of 10000 L/h and the lactose in the milk content is converted into glucose and galactose in the presence of beta-galactosidase enzyme. In order for people with lactose intolerance to consume, it is desirable to reduce the lactose level in milk below 5 g/L. The reaction related to the hydrolysis of lactose is given below.

Lactose + H2O -> Glucose + Galactose (Km=0.04 mol/L, Vmax=0.8 mol/L hour)

For the most economical way how can we use CTSR and PFR, use any volume of CSTR and PF reactors in any order. For to calculate thisLactose molecular weight: 342 g/mol Reactor operating cost: CSTR 0.1 $/L hour, PFR 0.4 $/L hour Investment cost: 2 million $ Depreciation rate: 15% The business operates 300 days a year and 16 hours a day. Maintenance and repair expenses: 45 thousand $/year Unexpected expense: 18 thousand $/year Fixed tax total: 60 thousand $/year The total salary of the personnel is determined as 180 thousand $/year The amount of enzyme per unit volume is the same in all reactors and its cost is included in the reactor operating expenses Raw material (milk) price: 3 $/L, product (low lactose milk) price: 7$/L (Solve the full problem)