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Andrea Landella POLITECNICO DI MILANO Industrial Organic Chemistry Exam Sep 2, 2016 Styrene (STY) is industrially produced by catalytic dehydrogenation of ethylbenzene (EB) according to the following reaction: EB → STY + H2 The reactor is fed with ethylbenzene and superheated water steam in molar ratio of 1:10. The inlet mixture is at 600°C and 3 bar. The exit stream consists of EB, STY, H2, H2O. The reactor operates in adiabatic conditions. By assuming that: • The reacting mixture is an ideal mixture of perfect gases; • The thermodynamic equilibrium is reached at the outlet of the reactor; • Pressure drops are negligible; 1. Assess and justify how many reactions have to be considered to evaluate the thermodynamic equilibrium conditions: 2. Evaluate the molar conversion of EB, the outlet temperature and the composition of the stream leaving the reactor: RESULTS: Conversion of EB Outlet temperature EB STY H2 H2O Composition 3. Assess and justify how an increase of reactor pressure affects the EB conversion: Andrea Landella POLITECNICO DI MILANO Thermodynamic data: Gibbs free energy change of the reaction (J/mol) as a function of temperature (K): Δ ( ) 127 619.9 134.02rg T T   The reference state for calculations is perfect gas at 1 atm Specie ΔfH0(298 K) [kJ/mol] CP [J/mol/K] EB 29.8 206.571 STY 147.5 192.597 H2 0 29.254 H2O -242.0 35.225 Heat capacities can be assumed constant with temperature.