Exercise 01 Solution ENG

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Assignment #1: Results 1. Nitrogen injection to recover natural gas Figure 1. Flow diagram of the process. PSA Unit 1 3 7 10 2 4 5 6 8 9 310.93 55.16 56.56 266.48 2.76 18.96 310.93 1.03 55.16 310.93 LEGEND Flow rate [mol/s] Temperature [K] Pressure [bar] Stream number Stream 1 2 3 4 5 N2 [%] 18.00 36.29 3.00 36.29 36.29 CH4 [%] 75.00 63.71 84.26 63.71 63.71 C2H6 [%] 7.00 0.00 12.74 0.00 0.00 Total flow rate [mol/s] 56.56 25.48 31.07 25.48 25.48 Total flow rate [lbmol/h] 448.87 202.24 246.63 202.24 202.24 Stream 6 7 8 9 10 N2 [%] 3.00 78.37 3.00 3.00 3.00 CH4 [%] 97.00 21.63 97.00 97.00 88.26 C2H6 [%] 0.00 0.00 0.00 0.00 8.74 Total flow rate [mol/s] 14.23 11.26 14.23 14.23 45.30 Total flow rate [lbmol/h] 112.90 89.34 112.90 112.90 359.53 2. Distillation column Note: compositions are referred to the lower-boiling (or lighter) component (i.e., benzene). 3. Chemical plant Figure 2. Process flowchart. From the balance on the overall plant (outer dashed box G) it is possible to compute the flow rate of Stream 8 as follows: 1 8 0.65 mm  . Combining the balances on the stream mixing point E, on the second reactor R -2 (dashed box C) and knowing that 𝑚̇ 7 = 0.6·𝑚̇ 5, it is possible to calculate the flow rate of Stream 2 as follows: 8 2 0.7 0.6 0.3 mm   . Then, the flow rate of all streams can be determined. Stream Feed Distillate Bottom Mole fraction 0.4 0.98 0.01 Total flow rate[kmol/h] 100 40.21 59.79 Weight fraction 0.361095 0.976493 0.008491 Total flow rate [kg/h] 8653.02 3151.95 5501.07 Volume fraction 0.356368 0.976017 0.008319 Total flow rate [m3/h] 9.9071 3.5633 6.3439 R-1 R-2 T-1 100 kg/h 30% 70% 40% 60% 15% 15% 10% 20% 5% 35% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A B C D E F G Stream 1 2 3 4 5 6 7 Flow rate [kg/h] 100 174.83 52.45 122.38 52.45 20.98 31.47 Stream 8 9 10…