{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 8: Multiphase Reactors" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 8.1: Gas_absorption_coefficient_and_fraction_of_overall_resistance.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-8 Ex8.1 Pg No. 323\n", "//Title:Gas absorption coefficient and fraction of overall resistance\n", "//============================================================================================================\n", "clear\n", "clc\n", "//INPUT\n", "rho_oil=0.8;//Density of oil (g/cm3)\n", "IV_init=130;//Iodine Value initial\n", "IV_final=80;//Iodine Value final\n", "P=45;//Pressure of system (psig)\n", "T_C=204;// Temperature of system (°C)\n", "t_run=[26 17];//Time required for hydrogenation run 2;\n", "frac_Ni=[0.005 0.0125]//Fraction of Nickel used for different run\n", "\n", "//CALCULATION\n", "r_ave=((IV_init -IV_final))*(0.039*rho_oil)*(1/60).*(t_run.^(-1));//Relationship between Iodine value and Hydrogen consumption (mol- H2/ L sec)\n", "H_H2= 4*10^(-3);//Solubility of H2 from Fig8.4 Pg No.322\n", "P_H2=(P/14.7)+1;//Absolute Pressure in (atm)\n", "C_H2=P_H2 *H_H2;\n", "Ci_by_r=C_H2.*(r_ave.^(-1));\n", "Coeff_R_cat=frac_Ni.^(-1);\n", "equation=[ones(1,2);Coeff_R_cat]//Simultaneous Equation\n", "Resistance= Ci_by_r*inv(equation);\n", "Gas_abs_resistance=(Resistance(1)*100 ).*(Ci_by_r.^(-1));\n", "Gas_abs_coefficient=(1/Resistance(1));\n", "\n", "//OUTPUT\n", "mprintf('\nThe Gas absorption coefficient is %f sec-1',Gas_abs_coefficient);\n", "mprintf('\n The Fraction of overall resistance due to gas absorption\n Run 1 %0.0f%% \n Run 2 %0.0f%%',Gas_abs_resistance(1),Gas_abs_resistance(2));\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter8-Ex1-Output.txt','w');\n", "mfprintf(fid,'\nThe Gas absorption coefficient is %f sec-1',Gas_abs_coefficient);\n", "mfprintf(fid,'\n The Fraction of overall resistance due to gas absorption\n Run 1 %0.0f%% \n Run 2 %0.0f%%',Gas_abs_resistance(1),Gas_abs_resistance(2));\n", "mclose(fid);\n", "//=======================================================END OF PROGRAM=================================================" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 8.2: External_Mass_Transfer_resistance.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-8 Ex8.2 Pg No. 329\n", "//Title:External Mass Transfer resistance\n", "//===========================================================================================================\n", "\n", "clear\n", "clc\n", "//INPUT\n", "Chi=1.9;\n", "M_A=2;//Molecular weight of Hydrogen\n", "M_B=32;//Molecular weight of methanol\n", "rho=0.79;//Density of methanol\n", "myu=0.52;//Viscosity of methanol (cP)\n", "V_A=14.3//Molar volume H2\n", "T_C=30;//Operating Temperature(°C)\n", "T_K=273+T_C//Temperature (K)\n", "Epsilon=0.4;//Porosity\n", "rho_cat_dry=1.2;//Density of dry catalyst (g/cm3)\n", "rho_s=2;//Solid density\n", "g=9.8// Acceleration due to gravity(m/s2)\n", "d_p=10^(-3);//Size of catalyst (cm)\n", "lambda=1.3;//From equation 8.4 Pg. No. 317\n", "r_vol=2.4;//Measured rate (L/min)\n", "V_mol=22.4;//(L/mol) assuming ideal gas\n", "C_H2=4.1*10^(-3);//From Figure 8.3 (mol/L) Pg. No. 321\n", "\n", "\n", "//CALCULATION\n", "//Assume D_H2 is three times the value given by the Wilke–Chang Equation\n", "D_H2=3*(7.4*(10^(-8))*(Chi*M_B)^(0.5)*T_K)/(myu*(V_A)^0.6)\n", "Sc=myu*10^-2/(rho*D_H2);\n", "rho_cat_methanol=(1-Epsilon)*rho_s+Epsilon*rho;\n", "delta_rho=rho_cat_methanol-rho;\n", "v_t=(g*10*(d_p)^2*delta_rho)/(18*myu*10^-2);// From Stoke's Law\n", "Re=rho*v_t*d_p/(myu*10^-2);\n", "Sh_star=2+0.6*(Re)^(0.5)*(Sc^(1/3));//Refer equation 8.9 Pg.No.325\n", "kc_star=Sh_star*D_H2/d_p;\n", "kc=2*kc_star;//With vigorous agitation\n", "a_c=6*lambda/(d_p*rho_cat_dry);//From Equation 8.4 Pg. No. 317 \n", "r_mol=r_vol/(22.4*60);//\n", "delta_C_ext=r_mol*10^3/(kc*a_c);\n", "percent_ext_resistance=(delta_C_ext/C_H2)*100;\n", "\n", "//OUTPUT\n", "mprintf('\nThe external mass transfer resistance is about %0.0f%% of overall resistance',percent_ext_resistance);\n", "mprintf('\n The external mass transfer resistance is barely significant');\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter8-Ex2-Output.txt','w');\n", "mfprintf(fid,'\nThe external mass transfer resistance is about %0.0f%% of overall resistance',percent_ext_resistance);\n", "mfprintf(fid,'\n The external mass transfer resistance is barely significant');\n", "mclose(fid);\n", "//=====================================================END OF PROGRAM=========================================\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "\n", "" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 8.3: Apparent_rate_constant_and_consistency.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436.\n", "//Chapter-8 Ex8.3 Pg No.\n", "//Title:Apparent rate constant and consistency\n", "//===========================================================================================================\n", "\n", "clear\n", "clc\n", "// COMMON INPUT\n", "LHSV_inv=[0.75 1.39];//Refer table 8.2 Test Results (Liquid Hourly Space Velocity)\n", "X_S=[0.77 0.83];//Refer table 8.2 Percentage Sulphur removal\n", "T_C=365;//Operating Temperature (°C)\n", "rho=0.64;//Density of Sulphur Compounds (g/cm3)\n", "myu=0.5;//Viscosity(cP)\n", "T_K=273+T_C;//Temperature (K)\n", "M_B=374;//For CHS compounds(Refer table8.1)\n", "V_A=M_B/0.6;//Molar volume\n", "Chi=1;\n", "Epsilon_by_tau=0.1;\n", "D_pore_by_D_bulk=0.5;//Hinderance due to large molecules\n", "epsilon_holdup=0.6;// Assuming bed consists 60% catalyst\n", "k_app_rhob=1.96//Refer Ex8.3.a Run 1\n", "eta=0.74;\n", "R=0.095;//Size of particle\n", "C_H2_incorrect=0.48;//Solubility of H2 at 56 atm\n", "P_incorrect=56;//Incorrect Pressure\n", "P_correct=65;//Correct Pressure\n", "m_feed=640;// Concentration of Feed (g/L);\n", "percent_S=2.04;//Percentage of Sulphur\n", "MW_S=32;//Molecular weight of Sulphur\n", "N_H2=1.5;//Moles of H2\n", "V_H2=14.3;//Solubility of Hydrogen\n", "\n", "//CALCULATION (Ex8.3.a)\n", "for i=1:2\n", " kapp_rhob(i)=log((1/(1-X_S(i))))*(1/LHSV_inv(i));//Refer Equation 8.21\n", " \n", "end\n", "L=LHSV_inv(2)/LHSV_inv(1);\n", "kapp_ratio=kapp_rhob(1)/kapp_rhob(2);\n", "n=log10(kapp_ratio)/log10(L);\n", "\n", "//CALCULATION (Ex8.3.b)\n", "//FOR SULPHUR\n", "D_CHS=(7.4*(10^(-8))*(Chi*M_B)^(0.5)*T_K)/(myu*(V_A)^0.6);\n", "D_e_S=Epsilon_by_tau*D_pore_by_D_bulk*D_CHS;\n", "epsilon_holdup=0.6;// Assuming bed consists 60% catalyst\n", "k_app_S=k_app_rhob/(3600*epsilon_holdup);//Refer Ex8.3.a\n", "phi_app_S=R*(k_app_S/D_e_S)^(0.5);\n", "//FOR H2\n", "C_H2_corrected=C_H2_incorrect*(P_correct/P_incorrect);\n", "C_S_initial=m_feed*percent_S*10^(-2)/MW_S;\n", "Initial_rate=k_app_rhob*C_S_initial;\n", "k_app_H2=N_H2*Initial_rate/(3600*epsilon_holdup*C_H2_corrected);\n", "//Assume D_H2 is three times the value given by the Wilke–Chang Equation\n", "D_H2=3*(7.4*(10^(-8))*(Chi*M_B)^(0.5)*T_K)/(myu*(V_H2)^0.6);\n", "D_e_H2=Epsilon_by_tau*D_H2;\n", "phi_app_H2=R*(k_app_H2/D_e_H2)^(0.5);\n", "\n", "//OUTPUT (Ex8.3.a)\n", "mprintf('\n OUTPUT Ex8.3.a');\n", "mprintf('\n==========================================================');\n", "mprintf('\n\tThe Apparent rate constants are \n\t Run1 %0.2f hr-1 \n\t Run2 %0.2f hr-1 ',kapp_rhob(1),kapp_rhob(2))\n", "mprintf('\n\tThe exponent value = %0.1f hence the difference is not consistent with repect to equations (8.23) and (8.24) for the apparent rate constants obtained',n); \n", "mprintf('\n\tThe error may be due to error in assuming a first order reaction');\n", "\n", "//OUTPUT (Ex8.3.b)\n", "mprintf('\n\n\n OUTPUT Ex8.3.b');\n", "mprintf('\n==========================================================');\n", "mprintf('\n\tThe internal effectiveness factor based on Sulphur and Hydrogen diffusion are %0.2f and %0.2f respectively',phi_app_S,phi_app_H2);\n", "mprintf('\n\tThe internal effectiveness factor based on Hydrogen is negligible');\n", "\n", "//FILE OUTPUT\n", "fid= mopen('.\Chapter8-Ex3-Output.txt','w');\n", "mfprintf(fid,'\n OUTPUT Ex8.3.a');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n\tThe Apparent rate constants are \n\t Run1 %0.2f hr-1 \n\t Run2 %0.2f hr-1 ',kapp_rhob(1),kapp_rhob(2))\n", "mfprintf(fid,'\n\tThe exponent value = %0.1f hence the difference is not consistent with repect to equations (8.23) and (8.24)for the apparent rate constants obtained',n); \n", "mfprintf(fid,'\n\tThe error may be due to error in assuming a first order reaction');\n", "mfprintf(fid,'\n\n\n OUTPUT Ex8.3.b');\n", "mfprintf(fid,'\n==========================================================');\n", "mfprintf(fid,'\n\tThe internal effectiveness factor based on Sulphur and Hydrogen diffusion are %0.2f and %0.2f respectively',phi_app_S,phi_app_H2);\n", "mfprintf(fid,'\n\tThe internal effectiveness factor based on Hydrogen is negligible');\n", "mclose(fid);\n", "//============================================END OF PROGRAM=================================================\n", "" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }