Chemical Engineering - Industrial Organic Chemistry

Full exam

INDUSTRIAL ORGANIC CHEMISTRY - July 11 th, 2017 SURNAME : __________________ NAME : __________________ ID NUMBER : ________________ A possible way to exploit hydrogen produced by water hydrolysis is th e production of methane according to the Sabatier reacti on (CO2+ 4 H2→ CH4+ 2 H2O). A simplified process layout consists of a heat exchanger (HE), where the fresh feed at 500 K is heated up using the reactor effluent s, and of a reactor where a conversion of 95% of CO2 is achieved when operated at 8 atm . The formatio n of CO is also experienced in the reactor. By assuming that : • The reacting mixture is an ideal mixture of ideal gases • The thermodynamic equilibri um is reached at the outlet of the reactor (species present at equilibrium: CO2,H2,CH 4,H2O,CO ) • The heat exchanger is ideal and the heat losses are negligible • The re actor is designed to remove 7000 cal/mol of charge • The fresh feed is at 500 K and the molar ratio between CO2 and H2 is 1:4 • The pressure drop is negligible 1. Evaluate the composition and the temperature of the stream leaving the reactor H2O H2 CH4 CO CO 2 Temperature 2. Evaluate the temperature of the stream entering the reactor (T in) Temperature 3. Evaluate the temperature of the stream leaving the heat exchanger (T sc) Temperature Thermodynamic data : Sabatier reaction: ������������������ (������)= exp ( 1 1.987 (56000 ������2 + 34633 ������ − 16 .4ln ������ + 0.00557 ������)+ 33 .165 ) where T in [K] Water gas shift reaction: [cal/mol] where T in [K] Reference state : ideal gas at 1 atm H0F(298K) [cal/mol] Cp [cal/mol] H2 0 2207 CO -26420 2253 CO 2 -94050 3284 CH 4 -17890 3438 H2O -57800 2662 Heat capacity can be assumed constant in the range of temperature of interest .   T T GWGS     71.7 8514 0