Page 56 - Chemical engineering design
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FUNDAMENTALS OF MATERIAL BALANCES
                   With 1 per cent loss, polymer entering sub-system
                                                 10,000                                    39
                                               D       D 10,101 kg
                                                  0.99
                     Take the next boundary round the reactor system; the feeds to the reactor can then be
                   calculated.

                                                              Short stop
                                              Water
                                                                     10,101 kg
                                                       Reactor
                                    Monomer                          polymer
                                               Cat.
                                       Recycle
                   At 90 per cent conversion, monomer feed

                                                 10,101
                                               D       D 11,223 kg
                                                   0.9

                   Unreacted monomer D 11,223   10,101 D 1122 kg
                   Short-stop, at 0.5 kg/1000 kg unreacted monomer

                                           D 1122 ð 0.5 ð 10  3  D 0.6kg

                   Catalyst, at 1 kg/1000 kg monomer

                                            D 11,223 ð 1 ð 10  3  D 11 kg


                   Let water feed to reactor be F 1 , then for 20 per cent monomer

                                                 11,223
                                         0.2 D
                                               F 1 C 11,223
                                               11,223 1   0.2
                                          F 1 D              D 44,892 kg
                                                    0.2

                   Now consider filter-dryer sub-system again.
                   Water in polymer to dryer, at 5 per cent (neglecting polymer loss)

                                             D 10,101 ð 0.05 D 505 kg


                   Balance over reactor-filter-dryer sub-system gives flows to recovery column.

                                       water, 44,892 C 10,101   505 D 54,448 kg

                                      monomer, unreacted monomer, D 1122 kg
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