Question

5. (40 points) A set of reactors processes 20 cfm through two basins in series: one of these basins has dimensions of 10' deep x 20' wide x 50' long, while the other has dimensions of 10' deep x 20' wide x 100' long. One of these will operate as an ideal plug flow operation, and the other as an ideal continuously stirred tank reactor (CSTR). A reaction will be performed in this sequence of reactors, for which k 0.05 min-1. The initial concentration of the reacting species A is 1000 mg/L (a) Your assignment is to achieve the lowest concentration of species A in the effluent from the second of the two basins in series. To do so, identify whether the larger or smaller basin should be first, and whether the first basin should have a plug or CSTR configuration (which would make the second basin have the other configuration). (i.e. there are four possible combinations). (b) Draw a schematic of the sequence that provides the lowest concentration of species A. (c) Under this lowest concentration scenario, compute the effluent concentration of species A that leaves the second basin. (Example of one possible configuration) 20 cfm PLua nlno CSTR

Answer 1

②. tank@ plug (DCSTR And m e an d tanki 10x20 xtoo 20000 fts. STR elag deknthm hime 110000 scomin -0-005( too) 6.333 .20 나m CST R C) 2 0005 (300 C 8203 ngl. Ci Cy- 13.68mg/L (+0005(100) 2 8 S, 귀u 1.925 mglu o.oos (koo Plug 2 c o CO C. The loweyt Conceutatm com bi nah am 16667 0-005( soo) = 13.68 mgle. Plug Ll 1000 mg IL