{ "metadata": { "name": "", "signature": "sha256:c896c859a24a6b70446a5e83cded412ac42718005bc7d2e546816e8274c18e21" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 19 : The Phase Rule and Vapor Liquid Equilibria" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 19.1 Page No. 563\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "N1 = 1.;\n", "P1 = 1. ;\t\t\t# Number of phases present\n", "C1 = 1. ;\t\t\t#Number of components present\n", "F1 = 2.-P1+C1 ;\t\t\t#Number of degree of freedom\n", "print ' (a) Number of degree of freedom of pure benzene is %i.\\n Therefore %i additional \\\n", "intensive variables must be specified to fix to fix the system.'%(F1,F1)\n", "\n", "\t\t\t# (b)\n", "N2 = 1.;\n", "P2 = 2. ;\t\t\t# Number of phases present\n", "C2 = 1. ;\t\t\t#Number of components present\n", "F2 = 2.-P2+C2 ;\t\t\t#Number of degree of freedom\n", "print '(b) Number of degree of freedom of a mixture of ice and water only is %i.\\\n", " \\nTherefore %i additional intensive variables must be specified to fix the system. '%(F2,F2)\n", "\n", "\t\t\t# (c)\n", "N3 = 2.;\n", "P3 = 2. ;\t\t\t# Number of phases present\n", "C3 = 2. ;\t\t\t#Number of components present\n", "F3 = 2.-P3+C3 ;\t\t\t#Number of degree of freedom\n", "print '(c) Number of degree of freedom of a mixture of liquid benzene,benzene vapour and\\\n", " helium gas is %i. \\nTherefore %i additional intensive variables must be specified to fix the system. '%(F3,F3)\n", "\n", "\t\t\t# (d)\n", "N4 = 2.;\n", "P4 = 2. ;\t\t\t# Number of phases present\n", "C4 = 2. ;\t\t\t#Number of components present\n", "F4 = 2.-P4+C4 ;\t\t\t#Number of degree of freedom\n", "print '(d) Number of degree of freedom of a mixture of salt and water designed to achieve\\\n", " a specific vapour pressure is %i. \\nTherefore %i additional intensive variables must be\\\n", " specified to fix the system. '%(F4,F4)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " (a) Number of degree of freedom of pure benzene is 2.\n", " Therefore 2 additional intensive variables must be specified to fix to fix the system.\n", "(b) Number of degree of freedom of a mixture of ice and water only is 1. \n", "Therefore 1 additional intensive variables must be specified to fix the system. \n", "(c) Number of degree of freedom of a mixture of liquid benzene,benzene vapour and helium gas is 2. \n", "Therefore 2 additional intensive variables must be specified to fix the system. \n", "(d) Number of degree of freedom of a mixture of salt and water designed to achieve a specific vapour pressure is 2. \n", "Therefore 2 additional intensive variables must be specified to fix the system. \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 19.2 Page No.564\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "N1 = 5.;\n", "P1 = 1.; \t\t\t# Number of phases present,here 1 gas \n", "C1 = 3. ;\t\t\t#Number of independent components present,here 3 because 3 elements(C,O and H)\n", "F1 = 2-P1+C1 ;\t\t\t#Number of degree of freedom\n", "print ' (a) Number of degree of gas composed of CO,CO2,H2,H2O and CH4 is %i. \\n \\\n", "Therefore %i additional intensive variables must be specified to fix the system. '%(F1,F1)\n", "\n", "# (b)\n", "N2 = 4.;\n", "P2 = 4. ;\t\t\t# Number of phases present,here 3 different solid phases and 1 gas phase\n", "C2 = 3. ;\t\t\t#Number of components present, here 3 because 3 elements(Zn,O and C) ,you can also use method explained \n", " #in Appendix L1\n", "F2 = 2.-P2+C2 ;\t\t#Number of degree of freedom\n", "print '(b) Number of degree of freedom of a mixture of ZnO(s), C(s) ,CO(g) and Zn(s) is %i. \\n \\\n", "Therefore %i additional intensive variables must be specified to fix the system. '%(F2,F2)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " (a) Number of degree of gas composed of CO,CO2,H2,H2O and CH4 is 4. \n", " Therefore 4 additional intensive variables must be specified to fix the system. \n", "(b) Number of degree of freedom of a mixture of ZnO(s), C(s) ,CO(g) and Zn(s) is 1. \n", " Therefore 1 additional intensive variables must be specified to fix the system. \n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 19.3 Page No :576" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "from scipy.optimize import fsolve\n", "import math\n", "\n", "# Variables\n", "P_atm = 1. ;\t\t\t#[atm]\n", "P = 760. ;\t\t\t#[mm of Hg]\n", "x_1 = 4./100 ;\t\t\t# Mole fraction of hexane in liquid phase\n", "# Constant A,B and C for Antoine eqn. of n_hexane \n", "A1 = 15.8366;\n", "B1 = 2697.55 ;\n", "C1 = -48.784;\n", "# Constant A,B and C for Antoine eqn. of n_octane\n", "A2 = 15.9798;\n", "B2 = 3127.60 ;\n", "C2 = -63.633;\n", "\n", "# Calculations\n", "# Solve for bubble point temperature by eqn. obtained by using Antoine equation\n", "def f(T):\n", " return math.exp(A1-(B1/(C1+T)))*x_1 + math.exp(A2-(B2/(C2+T)))*(1-x_1) - P\n", "T = fsolve(f,390)[0] ;\t\t\t# Bubble point temperature \n", "\n", "print 'Bubble point temperature is %.1f K'%T\n", "\n", "# Composition of first vapour\n", "# Get vapour pressure of hexane and octane from Perry, it is\n", "vp_1 = 3114. ;\t\t\t# vapour pressure of hexane-[mm of Hg]\n", "vp_2 = 661. ;\t\t\t# vapour pressure of octane-[mm of Hg]\n", "y_1 = vp_1*x_1/P ;\t\t\t# Mole fraction of hexane in vapour phase\n", "y_2 = 1- y_1 ;\t\t\t#Mole fraction of octane in vapour phase\n", "\n", "# Results\n", "print ' Composition of first vapour. '\n", "print 'Component Mole fraction. '\n", "print 'n_hexane %.3f'%y_1\n", "print ' n_octane %.3f'%y_2\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Bubble point temperature is 393.6 K\n", " Composition of first vapour. \n", "Component Mole fraction. \n", "n_hexane 0.164\n", " n_octane 0.836\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 19.4 Page no. 577" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "# Basis : 100 g solution\n", "F = 100. ;\t\t\t# Amount of solution-[g]\n", "P_atm = 1. ;\t\t\t#[atm]\n", "P = 760. ;\t\t\t# Total pressure -[mm of Hg]\n", "wf_hex = 68.6/100 ;\t\t\t#Weight fraction of hexane in mixture\n", "wf_tol = 31.4/100 ;\t\t\t#Weight fraction of toluene in mixture\n", "mw_hex = 86.17 ;\t\t\t# Mol.wt. of hexane-[g]\n", "mw_tol = 92.13 ;\t\t\t# Mol.wt. of toluene-[g]\n", "\n", "# Calculations\n", "mol_hex = wf_hex *F/mw_hex ;\t\t\t# moles of hexane-[g mol]\n", "mol_tol = wf_tol*F/mw_tol ;\t\t\t # moles of toluene-[g mol]\n", "mol_total = mol_hex + mol_tol ;\t\t\t# Total moles in mixture-[g mol]\n", "molf_hex = mol_hex/mol_total ;\t\t\t# Mole fraction of hexane \n", "molf_tol = mol_tol/mol_total ;\t\t\t# Mole fraction of toluene \n", "# Get vapour pressure of hexane and toluene at 80 deg. C from Perry, it is\n", "vp_hex = 1020. ;\t\t\t# vapour pressure of hexane-[mm of Hg]\n", "vp_tol = 290. ;\t\t\t# vapour pressure of toluene-[mm of Hg]\n", "K_hex = vp_hex/P ;\t\t\t# K-value of hexane\n", "K_tol = vp_tol/P ;\t\t\t# K-value of toluene\n", "rec_K_hex = 1/K_hex ;\t\t\t# Reciprocal of K-value of hexane\n", "rec_K_tol = 1/K_tol ;\t\t\t# Reciprocal of K-value of toluene\n", "\n", "# Let L/F = x, then use eqn. 19.11 to find x(L/F) \n", "def g(x):\n", " return (molf_hex)/(1-x*(1-rec_K_hex)) + (molf_tol)/(1-x*(1-rec_K_tol))-1\n", "\n", "x = fsolve(g,1)[0] ;\t\t\t# L/F value\n", "\n", "# Results\n", "print ' Fraction of liquid(L/F) that will remain at equilibrium after vaporization is %.3f. '%x\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Fraction of liquid(L/F) that will remain at equilibrium after vaporization is 0.744. \n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 19.5 Page no. 578\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variables\n", "Vo = 3.0 ;\t\t\t# Initial volume of the solution containing the culture and virus-[L]\n", "Vp = 0.1 ;\t\t\t# Volume of the polymer solution added to the vessel -[L]\n", "Kpc = 100. ;\t\t\t# Partition coefficient for virus(cp/cc) between two phases\n", "\n", "# Calculations\n", "Vc = Vo ;\t\t\t# At equilibrium -[L]\n", "cp_by_co = Vo/(Vp+(Vo/Kpc)) ;\t\t\t\n", "Fr_rec = cp_by_co*(Vp/Vo) ;\t\t\n", "\n", "# Results\n", "print ' Fraction of the initial virus in the culture phase that is recovered in the polymer phase is %.2f . '%Fr_rec\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " Fraction of the initial virus in the culture phase that is recovered in the polymer phase is 0.77 . \n" ] } ], "prompt_number": 15 }, { "cell_type": "code", "collapsed": true, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }