{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12 : Recycle Bypass Purge and the Industrial Application of Material Balance" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.1 Page No.349\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from numpy import matrix\n", "\t\t\t\n", "# Variables \n", "F = 10000. ;\t\t\t#[lb/hr]\n", "\t\t\t\n", "NaOH_F = 40./100 ;\t \t\t#[wt. fraction]\n", "NaOH_P1 = 95./100 ;\t \t\t#[wt. fraction of NaOH filter cake]\n", "NaOH_P2 = (0.05 * 45)/100 ;\t\t\t#[wt. fraction of NaOH in NaOH soln.]\n", "H2O_P2 = (0.05 * 55)/100 ;\t\t\t#[wt. fraction of H2O in NaOH soln.]\n", "NaOH_R = 45./100;\t\t\t#[wt. fraction]\n", "NaOH_G = 50./100;\t\t\t#[wt. fraction]\n", "\t\t\t\n", "P = (NaOH_F * F)/(NaOH_P1 + NaOH_P2) ;\t\t\t#[lb/hr]\n", "\t\t\t\n", "W = F-P ;\t\t\t# [lb/hr]\n", "\n", "# Calculations & Results\t\n", "a = matrix([[NaOH_G,-NaOH_R],[1,-1]]) \t\t\t# matrix formed of coefficients of unknown\n", "b = matrix([[F*NaOH_F],[P]]);\t\t\t# matrix formed by constant\n", "a = a.I\n", "x = a*b ;\t\t\t# matrix of solutions . x(1) = G, x(2) = R\n", "G = x[0] ;\t\t\t# [lb/hr]\n", "R = x[1] ;\t\t\t# [lb/hr]\n", " \n", "print '(a) Flow rate of water removed by evaporator is %.1f lb/hr'%W\n", "print 'The recycle rate of the process is %.1f lb/hr'%R\n", "\n", "\t\t\t\n", "NaOH_H = 45./100 ;\t\t\t#[wt fraction]\n", "H2O_H = 55./100 ;\t\t\t#[wt fraction]\n", "\n", "a1 = matrix([[NaOH_G,-NaOH_H],[NaOH_G,-H2O_H]]) ;\t\t\t# matrix formed of coefficients of unknown\n", "b1 = matrix([[((NaOH_P1+NaOH_P2)* P)],[(H2O_P2) * P]]);\t\t\t# matrix formed by constant\n", "x1 = a1**-1\n", "x1 = x1*b1 ;\t\t\t# matrix of solutions nw_G = x1(1);H = x1(2)\n", "nw_G1 = x1[0] ;\t\t\t# [lb/hr]\n", "H = x1[1];\t\t\t# [lb/hr]\n", "\n", "nw_F = (NaOH_H * H + (NaOH_P1 + NaOH_P2) * P)/NaOH_F ;\t\t\t#[lb/hr]\n", "print ' (b) Total feed rate when filterate is not recycled is %.1f lb/hr'%nw_F\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) Flow rate of water removed by evaporator is 5886.9 lb/hr\n", "The recycle rate of the process is 38868.9 lb/hr\n", " (b) Total feed rate when filterate is not recycled is 53727.5 lb/hr\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.2 Page No.357\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "F_Bz = 100. ;\t\t\t# Fresh benzene feed / basis - [mol]\n", "con_Bz = .95 ;\t\t\t# Fraction of conversion of benzene\n", "sp_con = .20 ;\t\t\t# Fraction of single pass conversion\n", "ex_H2 = .20 ;\t\t\t# Fraction of exces H2 used in fresh feed\n", "R_Bz = 22.74 ;\t\t\t# Benzene in Recycle stream - [mol %]\n", "R_H2 = 78.26 ;\t\t\t# H2 in Recycle stream - [mol %]\n", "TLV_Bz = 0.5 ;\t\t\t# TLV value of benzene -[ppm]\n", "TLV_C6H12 = 300. ;\t\t\t# TLV value of cyclohexane -[ppm]\n", "TLV_H2 = 1000. ;\t\t\t# TLV value of H2 -[ppm]\n", "\n", "# Calculations\n", "F_H2 = F_Bz*3*(1+ex_H2) ;\t\t\t# H2 in Feed - [mol]\n", "F = F_Bz + F_H2 ;\t\t\t# Total feed - [mol] \n", "\n", "ex_r = con_Bz*F_Bz/(-(-1)) ;\t\t\t# Extent of reaction\n", "\n", "P_Bz = F_Bz -1*(ex_r) ;\t\t\t# Benzene in P ,by benzene balance - [mol]\n", "P_H2 = F_H2 + -3*(ex_r) ;\t\t\t# H2 in P ,by H2 balance - [mol]\n", "P_C6H12 = 0 + 1*(ex_r) ;\t\t\t# Cyclohexane in P ,by cyclohexane balance - [mol]\n", "P = P_Bz + P_H2 + P_C6H12 ;\t\t\t# Total Product - [ mol]\n", "\n", "R = ((-(-ex_r))/(sp_con) - F_Bz)/(R_Bz/100.) ;\t\t\t# Recycle stream - [mol]\n", "R_by_F = R/F ;\t\t\t# Ratio of R to F \n", "\n", "TLV = (P_Bz/P)*(1/TLV_Bz) + (P_H2/P)*(1./TLV_H2) + (P_C6H12/P)*(1/TLV_C6H12) ;\t\t\t# TLV (environmental index) \n", "\n", "# Results\n", "print 'Ratio of R to F is %.2f .'%R_by_F\n", "print ' TLV (environmental index) is %.3f .'%TLV\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio of R to F is 3.58 .\n", " TLV (environmental index) is 0.059 .\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.3 Page No.359\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "RR = 8.33 ;\t\t\t# Recycle ratio\n", "F = 100. ;\t\t\t# Overall feed/basis - [lb]\n", "F_g = 0.40 ;\t\t\t# Fraction of glucose in overall feed \n", "F_w = 0.60 ;\t\t\t# Fraction of water in overall feed \n", "F_dash_f = 0.04 ; \t\t\t# Fraction of fructose in feed to reactor\n", "P = F \t\t\t# By overall balance -[lb]\n", "R = P/RR ;\t\t\t# Recycle stream - [lb]\n", "P_w = (F_w * F)/ P ;\t\t\t# Fraction of water in product(P), by overall water balance\n", "R_w = P_w ;\t\t\t#Fraction of water in recycle (R), since both R and P has same composition\n", "\n", "# Calculations\t\t\n", "F_dash = F +R ;\t\t\t# Feed to reactor ,by total balance -[lb]\n", "R_f = (F_dash*F_dash_f)/R ;\t\t\t# Fraction of fructose in recycle stream \n", "R_g = 1 - (R_f + R_w) ;\t\t\t# Fraction of glucose in recycle stream\n", "F_dash_g = (F*F_g + R*R_g)/F_dash ;\t\t\t# Fraction of glucose i feed to reactor\n", "\n", "f_con = ((F_dash*F_dash_g) - (R + P)*R_g)/(F_dash*F_dash_g) ;\t\t\t# Fraction of conversion of glucose in reactor\n", "\n", "# Results\n", "print 'Fraction of conversion of glucose in reactor is %.2f .'%f_con\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Fraction of conversion of glucose in reactor is 0.93 .\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.4 Page No.362\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "F = 100. ;\t\t\t# Overall feed/basis - [kg]\n", "F_com = 0.10 ;\t\t\t# Mass fraction of component in fresh feed \n", "F_w = 0.90 ;\t\t\t# Mass fraction of water in fresh feed \n", "P_w = 0.10 ;\t\t\t# Mass fraction of water in product\n", "P_com = 0.90 ;\t\t\t#Mass fraction of component in product\n", "F_dash_com = 0.03 ;\t\t\t#Mass fraction of component in feed to reactor\n", "W_w = 1. ;\t\t\t# Mass fraction of water in W(waste)\n", "C_con = .40 ;\t\t\t# Fraction of conversion of component in reactor\n", "\n", "# Calculations\n", "P = F_com*F/P_com ;\t\t\t#By component balance- Product - [kg]\n", "W = F - P ;\t\t\t# By overall balance - waste(W)- [kg]\n", "\n", "Rw = (F*F_com - F*F_com*C_con)/C_con ;\t\t\t# Mass of component in recycle(R) - [kg]\n", "F_dash = ( F*F_com + Rw )/F_dash_com ;\t\t\t# By component balance - feed to reactor(F') -[kg]\n", "R = F_dash - F ;\t\t\t # Recycle(R) - By total balance -[kg]\n", "w = Rw/R ;\t\t\t # Mass fraction of component in recycle(R) \n", "\n", "# Results\n", "print 'Recycle(R) stream- %.0f kg '%R\n", "print ' Mass fraction of component in recycle(R)- %.4f .'%w\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Recycle(R) stream- 733 kg \n", " Mass fraction of component in recycle(R)- 0.0205 .\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.5 Page No.367\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "F = 100. \t\t\t# Overall feed/basis - [kg]\n", "F_n_C5H12 = 0.80 ;\t\t\t# Fraction of n_C5H12 in overall feed \n", "F_i_C5H12 = 0.20 ;\t\t\t# Fraction of i_C5H12in overall feed \n", "S_i_C5H12 = 1. ;\t\t\t# Fraction of i_C5H12 in isopentane stream\n", "P_n_C5H12 = .90 ;\t\t\t# Fraction of n_C5H12 in overall product\n", "P_i_C5H12 = .10 ;\t\t\t# Fraction of i_C5H12 in overall product\n", "\n", "# Calculations\n", "P = (F*F_n_C5H12)/P_n_C5H12 ;\t\t\t#Product Material Balance of n_C5H12 -[kg]\n", "S = F - P ;\t\t\t# Isopentane stream (S) from overall material balance - [kg]\n", "\n", "from numpy import matrix\n", "a = matrix([[1,-1],[F_n_C5H12,-1]]) ;\t\t\t# Matrix of coefficients of unknown \n", "b = matrix([[S],[0]]) ;\t\t\t# Matrix of constants\n", "a = a.I\n", "x = a*b \t\t\t# Matrix of solutions, x(1) = x , x(2) = y\n", "\n", "xf = x[0]/F ;\t \t\t# Fraction of butane-free gas going to isopentane tower \n", "\n", "# Results\n", "print 'Fraction of butane-free gas going to isopentane tower is %.3f .'%xf\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Fraction of butane-free gas going to isopentane tower is 0.556 .\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ " Example 12.6 Page No.369\n" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Variables\n", "F = 100. ;\t\t\t# Overall feed/basis - [mole]\n", "F_H2 = 0.673 ;\t\t\t# Mole fraction of H2 in overall feed \n", "F_CO = 0.325 ;\t\t\t# Mole fraction of i_C5H12in overall feed \n", "F_CH4 = .002 ;\t\t\t# Mole fraction of CH4 in overall feed \n", "E_CH3OH = 1. ;\t\t\t# Mole fraction of CH3OH in Exit(E)\n", "\t\n", "z = .032 ;\n", "CO_con = .18 ;\t\t\t# Fraction of conversion of CO in reactor\n", "\n", "# Calculations\n", "#By using eqn.(c) and (d)\n", "P = F_CH4*F/z ;\t\t\t# Purge stream - [mole]\n", "\n", "# Using eqn.(a) , (b) and (c)\n", "x_plus_y = 1 - z ;\t\t\t# x + y \n", "E = (F_H2*F + F_CO*F + 3*F_CH4*F - P*(x_plus_y + 3*z ))/3 ;\t\t\t# Exit stream - [mole]\n", "\n", "# By using eqn. (d)\n", "y = ( F_CO*F - E )/P ;\t\t\t# Mole fraction of CO \n", "\n", "# By using eqn. (a)\n", "x = 1 - z - y ;\t\t\t# Mole fraction of H2 \n", "\n", "# Lastly by using eqn.(e)\n", "R = ( F_CO*F - P*y - F_CO*F*CO_con )/(y*CO_con) ;\t\t\t# Recycle steam - [mole]\n", "\n", "# Results\n", "print 'Moles of recycle(R) per mole of feed(F) - %.4f '%(R/F)\n", "print ' Moles of CH3OH(E) per mole of feed(F) - %.4f '%(E/F)\n", "print ' Moles of Purge(P) per mole of feed(F) - %.4f '%(P/F);\n", "print ' Composition of Purge '\n", "print ' Component Mole fraction '\n", "print ' H2 %.3f '%x\n", "print ' CO %.3f '%y\n", "print ' CH4 %.3f '%z\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moles of recycle(R) per mole of feed(F) - 7.0556 \n", " Moles of CH3OH(E) per mole of feed(F) - 0.3125 \n", " Moles of Purge(P) per mole of feed(F) - 0.0625 \n", " Composition of Purge \n", " Component Mole fraction \n", " H2 0.768 \n", " CO 0.200 \n", " CH4 0.032 \n" ] } ], "prompt_number": 6 }, { "cell_type": "code", "collapsed": true, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }