A light-hydrocarbon feed stream contains 45.4 kmol/h of propane, 136.1 kmol/h of isobutane, 226.8 kmol/h of n-butane, 181.4 kmol/h of isopentane, and 317.4 kmol/h of n-pentane. This stream is to be separated in a sequence of three distillation columns, similar to that in Figure, into four products: (1) propane-rich, (2) isobutane-rich, (3) n-butane-rich, and (4) combined pentanesrich. However, the distillate from the first column is to be the propane-rich product; the distillate from Column 2 is to be the isobutane-rich product; and the distillate from Column 3 is to be the n-butane-rich product, with the combined pentanes being the bottoms from Column 3. The recovery of each main component in each product is to be 98%. For example, 98% of the propane in the feed stream is to appear in the propane-rich product, and 98% of the combined pentanes in the feed stream is to appear in the bottoms product from Column 3.(a) Draw a process-flow diagram, similar to Figure.(b) Complete a material balance for each column and summarize the results in a table similar to Table 1.5. To complete the material balance, you will have to make some assumptions about the flow rates of: (1) isobutane in the distillates for Columns 1 and 3 and (2) n-butane in the distillates for Columns 1 and 2, consistent with the specified recoveries. Assume that propane will not be found in the distillate from Column 3 and pentanes will not be found in thedislillate from Column 2.(c) Calculate the mol% purities of each of the products and summarize your results in a table similar to Table 1.7, but without the specifications, which are not givenhere.

Transcribed Image Text:

Column 1 Column 2 Column 3 ic, Deethanized feed C1 Component Ibmol/h C,He C,H iC,He nCHya iC,H12 nC,H12 0.60 57.00 171.80 227.30 40.00 33.60 205.30 735.70 nC, sich Ibmol/h in Stream Feed to C3 iC4 Ce-rich Feed to C1 C3 Component C;t-rich Feed to C2 0.00 0.00 0.00 С-На C,H. iC.Hie CaH10 iC,H12 0.60 0.60 0.00 0.60 0.00 2.20 2.20 54.80 57.00 0.00 57.00 162.50 8.60 0.60 171.10 171.80 0.10 171.70 0.00 0.00 0.00 10.80 215.80 226.60 227.30 226.60 0.70 28.10 0.00 28.10 28.10 40.00 11.90 17.50 17.50 0.00 17.50 16.10 33.60 0.00 0.00 0.00 0.00 0.00 205.30 205.30 56.00 445.50 175.50 270.00 Total 234,10 501.50 735.60 mol% in Product Propane Isobutane Normal Butane Data Spec Data Spec Data Spec Component 5 max 1.07 C;H, 97.86 93 min 1.25 3 max I max iCHi0 1.07 2 min 92.60 92 min | 83.11 80 min 6.15 7 max 16.89 20 max 100.00 100.00 Total 100.00