Exercise 4 Solution

Pagina 1

Prof. Gianpiero Groppi – Exercises – Fundamentals of Chemical Processes – A.A. 2023-2024 1 EXERCISE 4 Outlet temperature and composition of a first stage WGS reactor for CO conversion 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 reactor is adiabatic and that the outlet gases reach the thermodynamic equilibrium composition 20°C above the exit temperature TOUT. Determine the TOUT and the composition at the outlet. DATA Stream IN: T = 360°C P = 30 ata Stream OUT: T = ? P = 30 ata 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: 0B0 B0BSpecie H0F(298K) [cal/mol] a b x 103 c x 106 d x 109 H2 0 6.483 2.215 -3.298 1.826 N2 0 7.440 -3.24 6.400 -2.790 CO -26420 7.373 -3.070 6.662 -3.037 CO2 -94050 4.728 17.54 -13.38 4.097 Ar 0 4.969 -0.0077 0.0123 0.000 CH4 -17890 4.598 12.450 2.860 -2.709 H2O -57800 7.701 0.4595 2.521 -0.859 𝐶𝑝𝑖=𝑎+𝑏∙𝑇+𝑐∙𝑇2+𝑑∙𝑇3 T in K Cp in cal/mol/K Δ𝐺𝑅,𝑊𝐺𝑆 0 (𝑇)=−8514+7.71⋅𝑇 cal/mol 600K < T < 1500K Reference: ideal gas at 1 atm SOLUTION For the solution of this problem, we have to evaluate the molar composition and temperature of an adiabatic reactor for the Water Gas Shift (WGS) reaction, assuming that the o utlet stream reaches an outlet composition corresponding to that reached at the thermodynamic equilibrium…