The stream from the CATOX reactor, is fed to a distillation column where unreacted A is separated and product R, after being dissolved in a suitable solvent, is fed to a subsequent reactor system where the first-order reaction, R → S, is taking place. The reaction rate constant is, k = 1h-1, and inlet reactant concentration, CR,0 = 1 mol/m3. The reactor system is a cascade consisting of two CSTRs in series of equal volume, each one 1 m3 (overall cascade volume V = 2 m3). The overall reactor cascade space time is 0.67 h. There is a malfunction and reactant conversion drops, so the engineer stops the reaction and performs a pulse tracer experiment, finding the following residence time distribution. The measured RTD is composed by a sharp peak (E1(t)) at t = 0 h, where the area under this peak is 0.33 (blue arrow), followed by an orange broad peak E2 (see Figure 1). The exact values of E2(t) are reported in the Table 1.
b) What could be the reason for the malfunction? Suggest and sketch a compartment model that fits quantitatively the RTD measured and calculate all the parameters of this compartment model. c) Calculate the conversion of the reactor after the malfunction, using the compartmental model derived in b).
Figure 1. Residence time distribution obtained from the experiment conducted RTD 0.6 0.5 0.4 0.3 E, h-1 0.2 0.1 o -1 0 1 2 3 4 5 6 7 8 -0.1 th
Table 1. Residence time distribution infomation E2, hrt t, h 0 0.001 0.025 0.05 0.1 0.15 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 th 0 2.6 0.00266 1339 2.7 0.063415295 2.8 0.120644989 2.9 0.2183282013 0.296327288 3.1 0.357504025 3.2 0.439049309 3.3 0.479284228 3.4 0.490505922 3.5 0.481910739 3.6 0.460314333 3.7 0.430712572 3.8 0.396717332 3.9 0.3608940894 0.325022598 4.1 0.290297451 4.2 0.25748 1738 4.3 0.227024234 4.4 0.199148273 4.5 0.173918737 4.6 0.151292157 4.7 0.131153868 4.8 0.113345244 4.9 0.097683407 5 0.08397523 5.1 0.072027061 5.2 0.061651259 5.3 0.052670381 5.4 0.044919647 5.5 E2, hit th 0.038248 5.6 0.032519 5.7 0.027611 5.8 0.0234 135.9 0.01983 6 0.016777 6.1 0.014179 6.2 0.01 1971 6.3 0.010098 6.4 0.008511 6.5 0.007167 | 6.6 0.006031 6.7 0.0050716.8 0.004261 6.9 0.0035787 0.003003 0.002519 0.002111 0.00 1769 0.001481 0.001239 0.00 1037 0.000867 0.000725 0.000605 0.000506 0.000422 0.000352 0.000294 0.000245 E2, h- 0.000204 0.00017 0.000142 0.0001 18 9.83E-05 8.18E-05 6.81E-05 5.66E-05 4.71E-05 3.92E-05 3.26E-05 2.71E-05 2.25E-05 1.87E-05 1.55E-05