//Harriot P., 2003, Chemical Reactor Design (I-Edition), Marcel Dekker, Inc., USA, pp 436. //Chapter-8 Ex8.3 Pg No. //Title:Apparent rate constant and consistency //=========================================================================================================== clear clc // COMMON INPUT LHSV_inv=[0.75 1.39];//Refer table 8.2 Test Results (Liquid Hourly Space Velocity) X_S=[0.77 0.83];//Refer table 8.2 Percentage Sulphur removal T_C=365;//Operating Temperature (°C) rho=0.64;//Density of Sulphur Compounds (g/cm3) myu=0.5;//Viscosity(cP) T_K=273+T_C;//Temperature (K) M_B=374;//For CHS compounds(Refer table8.1) V_A=M_B/0.6;//Molar volume Chi=1; Epsilon_by_tau=0.1; D_pore_by_D_bulk=0.5;//Hinderance due to large molecules epsilon_holdup=0.6;// Assuming bed consists 60% catalyst k_app_rhob=1.96//Refer Ex8.3.a Run 1 eta=0.74; R=0.095;//Size of particle C_H2_incorrect=0.48;//Solubility of H2 at 56 atm P_incorrect=56;//Incorrect Pressure P_correct=65;//Correct Pressure m_feed=640;// Concentration of Feed (g/L); percent_S=2.04;//Percentage of Sulphur MW_S=32;//Molecular weight of Sulphur N_H2=1.5;//Moles of H2 V_H2=14.3;//Solubility of Hydrogen //CALCULATION (Ex8.3.a) for i=1:2 kapp_rhob(i)=log((1/(1-X_S(i))))*(1/LHSV_inv(i));//Refer Equation 8.21 end L=LHSV_inv(2)/LHSV_inv(1); kapp_ratio=kapp_rhob(1)/kapp_rhob(2); n=log10(kapp_ratio)/log10(L); //CALCULATION (Ex8.3.b) //FOR SULPHUR D_CHS=(7.4*(10^(-8))*(Chi*M_B)^(0.5)*T_K)/(myu*(V_A)^0.6); D_e_S=Epsilon_by_tau*D_pore_by_D_bulk*D_CHS; epsilon_holdup=0.6;// Assuming bed consists 60% catalyst k_app_S=k_app_rhob/(3600*epsilon_holdup);//Refer Ex8.3.a phi_app_S=R*(k_app_S/D_e_S)^(0.5); //FOR H2 C_H2_corrected=C_H2_incorrect*(P_correct/P_incorrect); C_S_initial=m_feed*percent_S*10^(-2)/MW_S; Initial_rate=k_app_rhob*C_S_initial; k_app_H2=N_H2*Initial_rate/(3600*epsilon_holdup*C_H2_corrected); //Assume D_H2 is three times the value given by the Wilke–Chang Equation D_H2=3*(7.4*(10^(-8))*(Chi*M_B)^(0.5)*T_K)/(myu*(V_H2)^0.6); D_e_H2=Epsilon_by_tau*D_H2; phi_app_H2=R*(k_app_H2/D_e_H2)^(0.5); //OUTPUT (Ex8.3.a) mprintf('\n OUTPUT Ex8.3.a'); mprintf('\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)) 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); mprintf('\n\tThe error may be due to error in assuming a first order reaction'); //OUTPUT (Ex8.3.b) mprintf('\n\n\n OUTPUT Ex8.3.b'); mprintf('\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); mprintf('\n\tThe internal effectiveness factor based on Hydrogen is negligible'); //FILE OUTPUT fid= mopen('.\Chapter8-Ex3-Output.txt','w'); mfprintf(fid,'\n OUTPUT Ex8.3.a'); mfprintf(fid,'\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)) 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); mfprintf(fid,'\n\tThe error may be due to error in assuming a first order reaction'); mfprintf(fid,'\n\n\n OUTPUT Ex8.3.b'); mfprintf(fid,'\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); mfprintf(fid,'\n\tThe internal effectiveness factor based on Hydrogen is negligible'); mclose(fid); //============================================END OF PROGRAM=================================================