ExamD

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CRE – 08.09.15 - Exam D 1 096116 Chemical Reaction Engineering 8 September 2015 Family name _________________________________________________ First name _________________________________________________ ID number _________________________________________________ Signature _________________________________________________ Please, consider that the sum of perc entages of proposed exercises (4 ) is equal to 110%. This means that the maximum mark you can reach is 33. Remember to write on the top of each sheet you submit: your name, ID number, and signature. Use of mobile phones and internet connection is not allowed. 1. Packed bed reactor and CSTR in series (40%) The irreversible elementary gas phase reaction: 2𝐴𝐴→ 𝐵𝐵+ 𝐶𝐶 is currently carried out in a packed bed reactor containing 50 kg of catalyst. The entering pressure is 20 atm and the exit pressure is 8 atm. Currently, 80% conversion is achieved. It is proposed to add a CSTR with 1 00 kg of catalyst downstream of the PBR. There is no pressure drop in the CSTR. The flow rate and temperature remain unchanged. a. What would be the overall conversion in such an arrangement (PBR+CSTR)? b. Is there a better way to carry out the reaction, and if so what is it? Please explain in max 6 lines. 2. Catalytic reaction (20%) The catalytic reaction 𝐴𝐴→ 𝐵𝐵 to be carried out in a flow reaction system has the following rate law: 𝑟𝑟= 𝑘𝑘𝐶𝐶𝐴𝐴 (1 + 𝐾𝐾𝐴𝐴𝐶𝐶𝐴𝐴)2 � 𝑘𝑘= 1 𝑚𝑚𝑚𝑚𝑚𝑚−1 𝐾𝐾𝐴𝐴= 1 𝑑𝑑𝑚𝑚3 𝑚𝑚𝑚𝑚𝑚𝑚 The entering mix ture is pure A 𝐹𝐹𝐴𝐴 𝑚𝑚𝑚𝑚= 2 𝑚𝑚𝑚𝑚𝑚𝑚/𝑚𝑚𝑚𝑚𝑚𝑚 and the inlet concentration of A is 2 mol/dm3 and the entering flow rate. What type of reactor or combination of reactors (CSTRs and PFRs) would have the smallest volume (please, quantify it) to: a. achieve 50% of conversion? b. achieve 80% of conversion? CRE – 08.09.15 - Exam D 2 3.…