Explain the origin of Equation (e) in Example 5.7. What information in the problem statement was used in writing this relationship? What does rconsumption, butene represent physically?

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EXAMPLE 5.7 (continued) Ethylene balance: form..eth. = neth.,e.rich + neth.b.rich or * form..eth. = Yeth.,e.richnerich + Ceth.b.richVb.rich (b) From the balances (2 equations), we identify five unknowns: Ybu..e.rich, Chu ,b.rich, Icons. but.. form.,eth.. Ceth. b.rich. Therefore, we need three more equations. Mole fractions: Yeth.e.rich + Vbut.,e.rich = 1.0 Stoichiometry: Conversion: From Equation (e): From Equation (d): cons..but = 0.84nbut..feed 0.84 mbut..feed (MW) but. We now have five equations and five unknowns and can solve those equations: From Equation (c): From Equation (b): From Equation (a): 11 Y but..e.rich == 865 lbm/hr 56 lbm/lbmol rform..eth. 2 Icons.,but. cons..but.= = Chut..brich = = 1.0 - Yah.,e.rich = 1.0 -0.92 = 0.08 (0.84) (865 lbm/hr) 56lbm/lbmol rform.,eth. = 2(rcons.but.) = 26.01bmol/hr form..eth. - Yeth..e.richne.rich Vb.rich Ceth.b.rich = = = 26.0lbmol/hr-0.92(25.5 lbmol/hr) 240 ft³/hr mbut..feed (MW) but. = Ibmol hr 13. -0.0106 lbmol/ft³ Ybut.,e.richhe.rich - I'cons..but. Vb.rich -0.08(25.5 lbmol/hr) - 13.0 lbmol/hr 240 ft³/hr = 0.0017 lbmol/ft³ (c) (d) (e)