Exercise 12 Exam simulation solutions

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Prof. Gianpiero Groppi – Exercises – Fundamentals of Chemical Processes – A.A. 2023-2024 1 EXERCISE 12 Exam simulation – PART 1 Consider the following layout for the oxidation of SO2 to SO3: SO2 + 0.5 O2 → SO3 Stream (1) contains 8% SO 2 on a molar basis in dry air (i.e., 79% N 2 and 21% O 2) at the temperature of 300°C. Stream (1) is then pre -heated in heat exchanger (H) using stream (3) exiting from reactor (R1). (R1) is adiabatic, and operates at the fixed pressure of 10 atm. The thermodynamic equilibrium composition is reached at the outlet of (R1) with a conversion of SO2 equal to 90%. After heat exchanger (H), stream (4) is fed to reactor (R2). Reactor (R2) operates at the same pressure of 10 atm, and it is designed to reach the thermodynamic equilibrium composition at the outlet while removing 1 kJ per mol of stream (4). Assuming that: - the volumetric behavior is that of ideal gases; - heat losses are negligible in heat exchanger H; Prof. Gianpiero Groppi – Exercises – Fundamentals of Chemical Processes – A.A. 2023-2024 2 the candidate is asked to evaluate: 1. Temperature in stream (2) T(2) [K] 681 2. Temperature and molar composition in stream (3) y SO2 [-] 0.0083 y SO3 [-] 0.0747 y O2 [-] 0.1631 y N2 [-] 0.7539 T(3) [K] 892 3. Temperature in stream (4) T(4) [K] 790 4. Temperature and molar composition in stream (5) y SO2 [-] 0.0014 y SO3 [-] 0.0818 y O2 [-] 0.1602 y N2 [-] 0.7565 T(5) [K] 781 DATA: Δ𝐺𝑅 0 = −23156 + 22.08 ∙ 𝑇 [cal mol⁄ ] T in K Reference: ideal gas at 298 K and 1 atm. 𝐶𝑝𝑖(𝑇) = 𝑎𝑖 + 𝑏𝑖 𝑇 + 𝑐𝑖 𝑇2 + 𝑑𝑖 𝑇3 [J mol⁄ ] T in [K] 𝚫𝑯𝑭 𝟎(𝟐𝟗𝟖𝑲) a b c d SO2 -296.8 2.3850E+01 6.6990E-02 -4.9610E-05 1.3280E-08 O2 0 2.8110E+01 -3.6800E-06 1.7460E-05 -1.0650E-08 N2 0 3.1150E+01 -1.3570E-02 2.6800E-05 -1.1680E-08 SO3 -395.7 1.9210E+01 1.3740E-01 -1.1760E-04…