Exercise 3 Solution

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Prof. Gianpiero Groppi – Exercises – Fundamentals of Chemical Processes – A.A. 2023-2024 1 EXERCISE 3 Outlet temperature of a first stage WGS reactor for CO conversion, applied for the abatement of CO to a fixed value The gas stream exiting from the second stage of a Reformer supplied with air is sent to a two - stage reactor for the conversion of CO, where the following reaction occurs (WGS): CO + H2O ↔ CO2 + H2 With reference to the first stage of the conversion of CO, it can be assumed that the outlet gases reach the thermodynamic equilibrium composition at the outlet temperature Tout. Determine the Tout that enables a CO concentration in the outlet stream equal to 0.39% (vol. basis) with respect to the dry current. DATA Stream IN: T = 360°C P = 30 ata Stream OUT: T = ? P = 30 ata CO/∑dry = 0.39% Volumetric behavior: ideal gases N2, Ar, CH4 can be considered inert species. Flowrates and composition: Species Flowrate (Nm3/h) % Vol. (dry basis) H2 56.36 N2 22.24 CO 12.56 CO2 8.27 Ar 0.27 CH4 0.3 H2O 73411 dry 120264 100.00 Total 193675 Prof. Gianpiero Groppi – Exercises – Fundamentals of Chemical Processes – A.A. 2023-2024 2 Thermodynamic properties: 0B0B0B0B0BSpecie H0F(298K) [J/mol] G0F(298K) [J/mol] a b x 103 c x 105 d x 109 H2 0 0 27.140 9.274 -1.381 7.645 H2O -242000 -228800 32.240 1.924 1.055 -3.596 CO -110600 -137400 30.870 -12.805 2.789 -12.720 CO2 -393800 -394600 19.800 73.440 -5.602 17.150 𝐶𝑝𝑖 = 𝑎 + 𝑏 ∙ 𝑇 + 𝑐 ∙ 𝑇2 + 𝑑 ∙ 𝑇3 T in K Cp in J/mol/K Reference: pure species as ideal gas at 1 atm SOLUTION The problem requires the calculation of the composition and Tout of a WGS reactor that enables a CO concentration in the outlet stream equal to 0.39% (vol. basis) with respect to the dry current, assuming that the outlet stream reaches the thermodynamic…