Question

8) Ethylene oxide is produced by the catalytic oxidation of ethylene. C2Ha(g)+1/202(g) C2H4O(g) An undesired competing reaction is the combustion of ethylene to CO2. The feed to a reactor contains 2 mol C2H4/mol O2. The conversion in the reactor is 25% , and 0.70 mol of CaHeO is produced per mol of C2H4 consumed. A multiple- unit process is used to separate the products: C2H4 and O2 are recycled back to the reactor, C2H4O(g) is produced as a product (at 25 C and atmospheric pressure), and CO2 and H2O(I) are discarded. The reactor inlet and outlet streams are each at 450°c, and the temperature of the makeup gases (and fresh feed) and the unrecycled products is 25°C. (55 pts total; Use additional paper to complete the problem if necessary) a) Taking a basis of 50 mol O2 fed to the reactor, calculate the flow rate (kg/h) and the composition of the fresh foed needed to eventually scale production to 1500 kg CaHaO/day. b) Calculate the volumetric flow rate (L/h) of the ethylene oxide produced. c) Set up the equations but do not calculate the net heat requirement (kW) for the entire process and that for the reactor alone.

Answer 1

Undesired: C Hy30 (9) Recyclo (R HYand Proderct (soHo feed (F CD and H Basis 50 mol 02 feed contain mol 2 2 mol teed Given, O 1 moles kH40 produccd pe mole e conoumed . duced pe mole Hy Connunied for qrodueten mole Comumcd for I500 bOduchicn SH - Kmole A4x0-7 tonguneO

kmol 48.1 consumQ dy Yate Kmol 48.1 .029 kmel/ 4u 48.7 hr 24 Mut. CaHy 2 8 Floo 2029 x 28 56.81 e So moles molo C2 Hy There tore fo2.029 mol Kmol {0146 E 0146 x32 3.2. 461 Mut. 0232 feed 56.81 kg/ Kg/kv 32.467 Composihon 56 81 63 63 56. 81+32.467 36.36

Is00 kday b) Flow Tate o H40 kmol SOO Kg day G 25 298 k (01.325 K Pa kmo uxgu) k Pa m3 8.314

PV nRf 101 32 xV - 8-314 x29 8 4x44 SODX 8.314 x2ge m3 24x 44 x 101 3 2 34.7325 m3 34.7325 x 000 34732.5 ilre / fni hal keedl T25 C finaProdu ct H , Co2 H20 heat-cgpeachon let 6ergy BalancingOveael Energy fed + m. к Ср х 293 + Evequined 298 + hнв megto CPoнао 298 t Co2 x298 M 18 Reaclor prmtine Gисny Balaning = Qcut tampentuo 45oc723k Ereqund mosx CPosx23 x723 mcoPee 12 3 mHgo P 72?