2:40 PM C O U a 48 dra-rcqh-gdv > Problems 87 flowsheets: the recycle and the bypass. We noted that these configurations are readily accommodated by means of a special process unit called the flow splitter. Finally, we concluded the chapter with examples illustrating the use of basis re- location and balance set selection which can often reduce a multiunit problem to a sequence of zero degree-of-freedom single-unit problems. At this stage, you should be able to formulate and solve most multiunit material balance problems that do not involve chemical reactions. PROBLEMS (a) A feed stream to a dryer is specified as 1000 lb,„/h. What is the rate in kg/min? (b) The production rate of ammonia in a process is given as 10° lbmol/day. What is the equivalent rate in gmol/h? 2.1 2.2 A still produces a mixture of 90 mol % ethanol (C,H,OH) and the rest water. (a) Calculate the mass fraction of ethanol. (b) If the production rate is 1000 lbmol/h, calculate the equivalent rate in kg/min. (c) For the production rate in (b), calculate the molar flows of the stream components in kgmol/h. 2.3 A stream consisting of: H,O 0.4 C;H¿OH 0.3 CH,ОН 0.1 CH,СOОH 0.2 all in weight fractions, is fed to a distillation column at the rate of 1000 lb/ h. Convert these stream variables to: (a) Molar species flows rates. (b) Total molar flow and mole fractions. (c) Mole fractions, water-free basis. A solution containing Na,S, NaOH, and Na,CO, in water is called "white liquor" and is used in the paper industry to process wood pulp. Suppose that laboratory analysis indicates 50 g/l Na,S, 250 g/l NaOH, and 100 g/1 ! Na,CO3. If the solution density is 1.05 g/cm³, calculate the species molar flows corresponding to a total stream flow of 1000 kgmol/h. 2.4 A process for producing methane from synthesis gas and steam is fed 6 kgmol/min of a gas consisting of 50% H2, 33}% CO, and the rest CH, (all on a mole basis) as well as 72 kg/min of steam (H,0). The products are 3 kgmol/min of liquid water and 96 kg/min of a gas consisting of 25% CH4, 2.5 Alfiana Adhitasari is presenting