Contents
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iii Contents Tables ............................................................................................................................... viii Figures .............................................................................................................................. xii Nomenclature ................................................................................................................... xx Acknowledgment .......................................................................................................... xxvi 1. Motivation ................................................................................................................... 1 2. Objectives .................................................................................................................... 4 3. Background ................................................................................................................. 5 3.1 Review of Previous Kinetic Studies .................................................................. 5 3.2 Discussion of Previous Kinetic Studies ........................................................... 17 3.3 Reaction System for Photo Chlorination of Toluene ...................................... 36 4. Reaction Model for Photo Chlorination of Toluene in a Bubble Column/Sparged Reactor ........................................................................................ 40 4.1 Model equations for chlorination of toluene in the bubble column/sparged reactors ............................................................................................................ 42 4.2 Evaluation of Concentration of Chlorine Free Radicals.................................. 50 4.3 Performance of Photo Bubble Column Reactors............................................. 58 5. Photo Chlorination of Toluene in a Reactive Distillation Column ...................... 65 iv 5.1 Experimental Studies ....................................................................................... 67 5.1.1 Experimental Apparatus ............................................................................... 67 5.1.2 Experimental Procedures .............................................................................. 72 5.1.3 Rotameter Calibration .................................................................................. 73 5.1.4 Measurement of Reflux Rates from the Condenser ..................................... 73 5.1.5 Evaluation of the Reboiler Heat Duty .......................................................... 75 5.1.6 Calibration for the Power Supply to the Heating Wire ................................ 75 5.1.7 Analysis Method for Reaction Products ....................................................... 77 5.1.8 Measurement of Voidage in the Distillation Column................................... 79 5.1.9 Holdup Measurement in the Distillation Column ........................................ 82 5.1.9.1 Direct measurement ....................................................................... 82 5.1.9.2 Indirect Measurement .................................................................... 83 5.1.10 Radiation Field inside a Reflector with Elliptical Cross-Section ............... 87 5.1.10.1 Photo Radiation Flux inside the Elliptical Reflector ................... 88 5.1.10.2 Photo Transmission Rates to the Distillation Column ................ 97 5.1.11 Experimental Results and Discussion ...................................................... 102 5.1.11.1 Photo Reactive Distillation in the Presence of UV light ........... 102 5.1.11.2 Photo Reactive Distillation in the Presence of Visible Light .... 120 5.1.11.3 Reactive Distillation in the Absence of Light ........................... 128 5.2 Dynamic Simulation of the Photo Reactive Distillation Process .................. 132 5.2.1 Reaction Model for a Batch Reactive Distillation Process ........................ 132 5.2.2 Numerical Method for Solution of the Model Equations ........................... 137 5.2.3 Simulation of the Semi-Batch Photo Reactive Distillation ........................ 142 6. v Conclusions and Future Work .............................................................................. 171 6.1 Conclusions ................................................................................................... 171 6.2 Future Work................................................................................................... 172 Appendix A - Data Compilation and Estimation for the Toluene Photo Chlorination System ..................................................................................................... 175 A.1 Physical Properties ....................................................................................... 175 A.2 Evaluation of Enthalpies of Gas Components .............................................. 179 A.3 Evaluation of Enthalpies of Liquid Components ......................................... 181 A.4 Henry’s Constants of Chlorine in Toluene and in Chlorinated Products ..... 182 A.5 Henry’s Constants for Hydrogen Chloride in Toluene and in Chlorinated Products ......................................................................................................... 183 A.6 Diffusivity Estimation .................................................................................. 189 A.6.1 Diffusivity of Binary Gas at Low Pressure ............................................... 189 A.6.2 Diffusivity of a Component in a Multicomponent Gas Mixture ............... 190 A.6.3 Diffusivity of a Dilute Dissolved Gas in a Liquid ..................................... 191 A.6.4 Diffusivity of Dilute Solute in a Nonaqueous Solvent .............................. 191 A.7 Kinetic Data .................................................................................................. 192 A.7.1 Reaction Rate Constants for Side-Chain Chlorination of Toluene............ 192 A.7.2 Reaction Rate Constant for Nuclear Chlorination of Toluene .................. 199 Appendix B - Derivation of Rate Expressions for Free Radical Side-Chain Chlorination of Toluene ......................................................................... 201 Appendix C - Estimation of Mass Transfer Coefficient and Gas Holdup in Bubble Column ................................................................................................... 203 vi C-1. Mass Transfer Coefficient of Gas Species in Liquid Phase ........................ 203 C-2. Estimation of Gas Holdup in Bubble Column ............................................. 204 Appendix D - Algorithm to Solve Model Equations for Bubble Column/Sparged Reactor.................................................................................................... 206 D-1 Solving Model equations for Plug Flow of Gas Phase and Wellmixedness of the Liquid Phase (m1) ................................................................................ 207 D-2 Solving Model Equations for both Gas and Liquid Phases are Wellmixed (m2) ................................................................................................................ 211 D-3 Solving Model equations for Cocurrent Plug Flow of Gas Phase and Liquid Phase (m3)...................................................................................................... 212 Appendix E - Derivation of Local Volumetric Rate of Energy Absorbed by Chlorine in Bubble Column Reactor .................................................... 215 Appendix F - Radiation in a Cylindrical Reflector with Elliptical Cross Section ... 217 F-1. Direct Radiation Flux ................................................................................... 217 F-2. Reflected Radiation Flux ............................................................................. 218 F-3. Photon Transmission Rates to the Distillation Column ............................... 221 Appendix G - HETP Estimation in the Packed Distillation Column ........................ 226 Appendix H - Estimation of Pressure Drop in the Packed Distillation Column ..... 232 Appendix I - Estimation of Conversion of Chlorine in the Reactive Distillation Column .................................................................................................... 234 Appendix J - Estimation of Local Over-Chlorination near the Gas Inlet in Reactive Distillation Column ................................................................................ 237 Appendix K - The Algorithm for Solution of Model Equations for Batch Reactive vii Distillation .............................................................................................. 239 References ...................................................................................................................... 243 Vita .................................................................................................................................. 249 viii Tables 3 - 1. Consecutive reaction rate constants for the side-chain chlorination of toluene, at two temperature levels, and with different light source (Haring and Knol 1964). . 12 3 - 2. Pseudo first order rate constants measured by Font and Ratcliffe ........................... 13 3 - 3. Rate constants determined by André et al (1983) at 50 C and 313 nm................... 17 3 - 4. Diffusion Coefficients of Chlorine free radical and Rate Constants at Various Temperatures........................................................................................................... 20 3 - 5. Activation energies difference of the consecutive reactions .................................... 27 4 - 1. Dimension of annular model reactor ........................................................................ 59 4 - 2. Dimension of the UV lamp and its emission rates at 313 nm .................................. 59 4 - 3. Operating Conditions and Parameters Used in Reaction Model for Chlorination of Toluene in Bubble Column Reactor ........................................................................ 60 4 - 4. Absorption Coefficients of Chlorine at Various Wavelengths. ............................... 60 5 - 1. Determination of drop volume ................................................................................. 74 5 - 2. Response Factors of Toluene and its Chlorinated Products ..................................... 79 5 - 3. Values used in Determining Voidage of the Distillation Column ........................... 80 5 - 4. Dimensions,Weight, and Density of Quartz Raschig Rings .................................... 81 5 - 5. Holdup in the Packed Column ................................................................................. 83 5 - 6. Liquid Volume and Compositions in the Reboiler .................................................. 85 ix 5 - 7. Surface Area and Active Volume in the Distillation Column.................................. 86 5 - 8. Holdups in the Distillation Column Determined by Indirect Method...................... 86 5 - 9. Comparison of Holdup Measurement by the Direct and the Indirect Methods ....... 87 5 - 10. Reaction conditions for the photo chlorination of toluene in the reactive distillation column in the presence of UV lamp. ................................................. 105 5 - 11. Temperature Rise in One Hour of Reaction at Gas Inlet in Reactive Distillation Column .................................................................................................................... 116 5 - 12. Conversion of Chlorine After 4 Hours of Reaction in the Distillation Column. . 126 5 - 13. Comparison of reactor performance by using UV and visible light. ................... 128 5 - 14. Comparison of Column Performance in One Hour of Reactions ........................ 129 5 - 15. Unknown Variables in Model Equations for Reactive Distillation ..................... 141 5 - 16. Heat Duties to the Compartment within the Packed Zone. .................................. 146 A - 1. Basic Physical Data for Reaction Components (Daubert and Danner 1993; AIChE 1994) ......................................................................................................... 175 A - 2. Parameters for Determination of Density.............................................................. 176 A - 3. Parameters for Determination of Vapor Pressure ................................................. 177 A - 4. Parameters for Determination of Ideal Gas Heat Capacity ................................... 177 A - 5. Parameters for Determination of Liquid Heat Capacity........................................ 178 A - 6. Parameters for Determination of Gas Viscosity .................................................... 178 A - 7. Parameters for Determination of Liquid Viscosity ............................................... 179 A - 8. Parameters for Determination of Heat of Vaporization ........................................ 179 A - 9. Parameters of Henry's constant of chlorine. .......................................................... 183 A - 10. Parameters of Henry's constant of hydrogen chloride ......................................... 186 x A - 11. Diffusional Volumes for Equation (A-14) .......................................................... 190 A - 12. Kinetic parameters estimated from Haring et al and Font et al’s experimental data ...................................................................................................................... 195 A - 13. Estimated frequency factors and activation energies of side-chain chlorination of toluene ............................................................................................................. 197 A - 14. Estimated frequency factors and activation energies of side-chain chlorination of toluene by choosing lower value of activation energy, Ea1............................. 198 A - 15. Estimated frequency factors and activation energies of side-chain chlorination of toluene based on Haring and Knol's studies. ................................................... 199 A - 16. Composition of Liquid Products in Reboiler from Dark Reaction. .................... 200 C - 1. Properties of toluene and mass transfer coefficients of chlorine and hydrogen chloride at 80 C. .................................................................................................. 204 C - 2. Gas Holdup Correlations and Estimated Holdup in Bubble Column. ................... 205 D - 1. Nature of Model Equations of Photo Chlorination of Toluene in Bubble Column .................................................................................................................. 206 F - 1. Photon Transmission rates to the Packed zone in the Distillation Column. .......... 225 G - 1. Summary of HETP Estimation in the Packed Column. ........................................ 230 G - 2. Effect of liquid flow rates and molar fraction of benzyl chloride on the HETP and the number of the compartments in the packed zone. ........................................... 231 H - 1. Parameters for Determine Pressure Drop in the Packed Distillation Column. ..... 233 I - 1. Chlorine and liquid in the reactive distillation column in 4 hours.......................... 235 xi I - 2. Liquid composition and holdup in the reboiler, and conversion of chlorine in 4 hours of reaction in the reactive distillation column. ...................................................... 236 xii Figures 3 - 1. Glass reaction vessel used by Haring and Knol 1964. ............................................. 10 3 - 2. Schematic representation of Photo reactor used by Andre et al 1983...................... 15 3 - 3. Solubility of Chlorine in Toluene Liquid at Various Temperatures. ....................... 24 3 - 4. Plot of a selectivity parameter, S1, versus temperature from published data (Haring and Knol 1964; Ratcliffe 1966; Font and Ratcliffe 1972; Yang, Thomas and Cullinan 1975; André, Tournier and Deglise 1983). .......................................... 26 3 - 5. Plot of a selectivity parameter, S2, versus temperature from published data (Haring and Knol 1964; Ratcliffe 1966; Font and Ratcliffe 1972; Yang, Thomas and Cullinan 1975; André, Tournier and Deglise 1983). .......................................... 26 3 - 6. Absorption coefficients of chlorine gas as a function of wave length. Concentrations are expressed in mole per liter, distance in centimeters , and logarithms are on base ten. (Halban et al, 1922). ...................................................... 30 3 - 7. Characteristic diffusion and reaction time for chlorination of toluene to benzyl chloride versus photon flux rate at various wavelengths........................................... 31 3 - 8. Characteristic diffusion and reaction time for chlorination of benzyl chloride to benzal chloride versus photon flux rate at various wavelengths. .............................. 31 3 - 9. Characteristic diffusion and reaction time for chlorination of benzal chloride to benzotrichloride chloride versus photon flux rate at various wavelengths. .............. 32 xiii 3 - 10. Ratio of characteristic diffusion to reaction time for chlorination of toluene to benzyl chloride versus photon flux rate at various wavelengths. .............................. 34 3 - 11. Ratio of characteristic diffusion to reaction time for chlorination of benzyl chloride to benzal chloride versus photon flux rate at various wavelengths. ............ 34 3 - 12. Ratio of characteristic diffusion to reaction time for chlorination of benzal chloride to benzotrichloride versus photon flux rate at various wavelengths. .......... 35 3 - 13. The species distribution of toluene and side-chain chlorinated products with time. [reaction conditions: 80 C; uniform photon radiation of 313 nm with photon flux rate of 0.5 Einstein/m2.sec.; [Cl2] of 0.04 mol/m3; Kinetic data based on Font and Ratcliffe's (1972)] ............................................................................................... 37 3 - 14. The selectivity to benzyl chloride versus conversion of toluene [reaction conditions: 80 C; uniform photon radiation of 313 nm with photon flux rate of 0.5 Einstein/m2.sec.; [Cl2] of 0.04 mol/m3; Kinetic data based on Font and Ratcliffe's (1972)] ....................................................................................................................... 38 3 - 15. Schematic diagram of industrial process of photochlorination of toluene. ............ 39 4 - 1. Schematic diagram of industrial photo reactor. ....................................................... 41 4 - 2. Variables involved in the theoretical analysis on LVREA ...................................... 52 4 - 3. Spectral distribution of Hanovia 679A0100, medium-pressure, mercury arc lamp with 450 watts input power (Scaiano, 1989). ............................................................ 53 4 - 4. Photo reactor geometry near the lamp. .................................................................... 55 4 - 5. Illustration of mixing states ...................................................................................... 56 xiv 4 - 6. Selectivity to benzyl chloride versus overall conversion of toluene (reaction condition: superficial chlorine gas velocity, 10 cm/sec; superficial toluene velocity, 0.5 cm/sec; relative light intensity, 1)......................................................... 61 4 - 7. Molar fraction profile of chlorine in the liquid phase along the reactor length in the bubble column where gas and liquid are cocurrent plug flow. ............................ 63 4 - 8. Temperature profile along the reactor length in the bubble column where gas and liquid are cocurrent plug flow. .................................................................................. 63 4 - 9. Dimensionless superficial gas velocity profile along the column where the gas and liquid are in cocurrent plug flow. ....................................................................... 64 5 - 1. Schematic of the photo reactive distillation column operated in a batch mode. ...... 68 5 - 2. Front and top views of the reflector assembled with a light sheet. .......................... 70 5 - 3. Calibration curve for the rotameter. ......................................................................... 74 5 - 4. Calibration curve for power supply to the heating wire. .......................................... 76 5 - 5. Gas chromatogram of the mixture of toluene and chlorinated products. ................. 79 5 - 6. Normalized photon flux rate profile from the direct radiation around the focus of the elliptical cross section of the reflector. ................................................................ 91 5 - 7. Normalized Photon flux rate profile from reflected radiation around the focus of the elliptical cross-section of the reflector................................................................. 91 5 - 8. Normalized overall photon flux rate profile around the focus of the elliptical cross section of the reflector. .............................................................................................. 92 5 - 9. Two positions of the UV lamp are employed in evaluating the photon radiation inside the reflector with elliptical cross-section. ....................................................... 93 xv 5 - 10. Normalized photon flux rate along y-axis when the UV lamp is located at high position in the absence of light sheet. ........................................................................ 93 5 - 11. Normalized photon flux rate along y-axis when the UV lamp is located at low position in the absence of light sheet. ........................................................................ 94 5 - 12. Normalized photon flux rate profile from direct radiation around the focus of the elliptical cross section of the reflector in the presence of light sheet 50 mm wide. .. 95 5 - 13. Normalized photon flux rate profile from direct radiation around the focus of the elliptical cross section of the reflectorin the presence of light sheet 50 mm wide. ... 96 5 - 14. Normalized overall photon flux rate profile around the focus of the elliptical cross section of the reflector in the presence of light sheet 50 mm wide. ................. 96 5 - 15. Normalized photon transmission rates to the sections of the distillation column when the UV lamp is located at high position. .......................................................... 98 5 - 16. Normalized photon transmission rates to the sections of the distillation column when the UV lamp is located at low position. ........................................................... 98 5 - 17. Three configurations employed in conducting the chlorination of toluene in the reactive distillation column (all indicated lengths are in millimeters). ................... 105 5 - 18. Selectivity to benzyl chloride versus conversion of toluene in the presence of UV light. .................................................................................................................. 106 5 - 19. Reflux rates from the condenser to the distillation column for photo chlorination of toluene using UV lamp........................................................................................ 107 5 - 20. Typical efficiency characteristics of packed columns. ........................................ 108 5 - 21. Liquid spread profile in a packed column (20-in-ID column, packed with 6 ft of 2-in-Pall rings, water study) measured by Hoek in 1983. ....................................... 110 xvi 5 - 22. Fraction of flow in the wall region of a packed column (a) Effect of liquid rate and packing size. (20-in-ID column, water study) measured by Hoek (1983). 111 5 - 23. Fraction of flow in the wall region of a packed column. (b) Effect of packing type and size (20-in-ID column, water study) measured by Hoek (1983). ............. 112 5 - 24. Temperature profile along the distillation column after one hour of reaction (UV lamp as a radiation source). ..................................................................................... 114 5 - 25. Ratio of local over chlorination reaction rate of toluene to benzyl chloride to chlorine feeding rates as function of local temperature rise and local section height, Hs, in reactive distillation column. .............................................................. 116 5 - 26. Conversion of toluene with reaction time for the chlorination of toluene in the photo reactive distillation column by using UV lamp. ............................................ 119 5 - 27. Selectivity to benzyl chloride versus conversion of toluene in the photo reactive distillation column by using fluorescent lamp......................................................... 122 5 - 28. Reflux rates from the condenser with reaction time for the photo reactive distillation by using the fluorescent lamp. ............................................................... 122 5 - 29. Temperature profile along the distillation column after one hour of reaction by using the fluorescent lamp. ...................................................................................... 124 5 - 30. Conversion of toluene with reaction time in the photo reactive distillation column by using the fluorescent lamp. .................................................................... 124 5 - 31. Column schematic diagram .................................................................................. 133 5 - 32. Selectivity to benzyl chloride versus conversion of toluene, experimental and simulation results. .................................................................................................... 147 5 - 33. Conversion of toluene versus reaction time, experimental and simulation results.148 xvii 5 - 34. Molar fraction profile of toluene in the liquid phase along the column obtained from simulation. ........................................................................................ 150 5 - 35. Molar fraction profile of toluene in the vapor phase along the column obtained from simulation. ...................................................................................................... 151 5 - 36. Molar fraction profile of benzyl chlorine in liquid phase along the column obtained from simulation. ........................................................................................ 152 5 - 37. Molar fraction profile of benzyl chlorine in vapor phase along the column obtained from simulation. ........................................................................................ 153 5 - 38. Molar fraction profile of chlorine in liquid phase along the column obtained from simulation. ...................................................................................................... 154 5 - 39. Molar fraction profile of chlorine in vapor phase along the column obtained from simulation. ...................................................................................................... 155 5 - 40. Production rate profile of benzyl chloride along the column obtained from simulation. ............................................................................................................... 156 5 - 41. Production rate profile of benzal chloride along the column obtained from simulation. ............................................................................................................... 157 5 - 42. Effect of reflux rates on reactor performance for chlorination of toluene in reactive distillation column based on simulation results. ........................................ 159 5 - 43. Effect of number of theoretical plates on reactor performance for chlorination of toluene in reactive distillation column based on simulation results. ....................... 160 5 - 44. The effect of light intensity on the reactor performance for photo chlorination of toluene in the reactive distillation column based on simulation results. ................. 162 xviii 5 - 45. Selectivity to benzyl chloride versus conversion of toluene at various Murphree efficiencies in compartments 2 to 4 in configuration 1. ......................... 164 5 - 46. Comparison of temperature profile along the column between the experimental and the simulation results. ....................................................................................... 166 5 - 47. Liquid flow rate profile along the column obtained from simulation. ................. 167 5 - 48. Vapor flow rate profile along the column obtained from simulation................... 168 5 - 49. Selectivity to benzyl chloride versus conversion of toluene in semi-batch photo reactive distillation column, simulation results by using different kinetic parameters and experimental results in configuration 3. ......................................... 169 A - 1. Thermodynamic paths to evaluate enthalpy of gas components (Sandler 1989). . 180 A - 2. Thermodynamic path to evaluate enthalpy of liquid components (Sandler 1989).181 A - 3. Henry’s constant of chlorine in toluene as function of temperature. .................... 183 A - 4. Henry’s constant of Chlorine in o-chlorotoluene function of temperature. .......... 184 A - 5. Henry’s constant of chlorine in benzyl chloride as function of temperature. ....... 184 A - 6. Henry’s constant of chlorine in benzal chloride as function of temperature. ....... 185 A - 7. Henry’s constant of chlorine in benzotrichloride as a function of temperature. ... 185 A - 8. Henry’s constant of hydrogen chloride in toluene as function of temperature. .... 187 A - 9. Henry’s constant of hydrogen chloride in o-chlorotoluene as function of temperature. ............................................................................................................. 187 A - 10. Henry’s constant of hydrogen chloride in benzyl chloride as function of temperature. ............................................................................................................. 188 A - 11. Henry’s constant of hydrogen chloride in benzal chloride as function of temperature. ............................................................................................................. 188 xix A - 12. Henry’s constant of hydrogen chloride in benzotrichloride as function of temperature. ............................................................................................................. 189 A - 13. Plot of logarithm of selective parameters over reciprocal of temperature based on Haring and Knol’s experimental data (Haring and Knol 1964). ........................ 194 A - 14. Plot of logarithm of selective parameters over reciprocal of temperature based on Font and Ratcliffe’s experimental data ( Font and Ratcliffe 1972). ................... 194 A - 15. The effect of activation energy, Ea1, on the selectivity to benzyl chloride in the reactive distillation column. .................................................................................... 198 A - 16. Comparison of simulated column performances of the reactive distillation using the kinetic data estimated based on Font and Ratcliffe, and Haring and Knol's studies. ..................................................................................................................... 200 D - 1. Procedure to solve non-linear equations converted from differential-algebraicintegral equations in flow pattern m1 in bubble column. ........................................ 210 D - 2. Procedure to solve non-linear equations with flow pattern m2 in bubble column.211 D - 3. Procedure to solve model equations with flow pattern m3 in bubble column. ..... 213 F - 1. Coordinates employed for calculation of direct radiation. ..................................... 217 F - 2. Coordinate employed for calculation of reflected radiation. ................................. 219 F - 3. Geometry for determination of view angle, , and R,1 and R,2........................... 220 F - 4. Geometry for determination of photo radiation flux in the direction normal to the column wall. ............................................................................................................ 223 G - 1. Vapor-liquid equilibrium curve of toluene in toluene-benzyl chloride binary system. ..................................................................................................................... 230 xx xxi Nomenclature aB Specific interfacial area of gas and liquid, 1/m al Total inner surface area of the condenser, m2 aP Total surface area in the packed zone, m2 AjL Molar liquid holdup in compartment j in distillation column, kmol AjV Vapor holdup in compartment j in distillation column, kmol Aon Initial moles in the reboiler, kmol ci* Concentration of gas species i at the gas-liquid interface, kmol/m3 ci0 Concentration of species i in bulk of liquid, kmol/m3 cg,0 Molar density of gas at inlet, kmol/m3 cg,j Gas molar concentration in reactor j, kmol/m3 CL,j Liquid molar concentration in reactor j, kmol/m3 Cp Heat capacity of toluene, J/kmol K D Critical distance, m; Diffusivity, m2/s DB Mean bubble diameter, m ea Energy absorbed, J/m3 sec eig, j Enthalpy of gas species i, J/kmol xxii e Enthalpy of liquid species i, J/kmol Ea,i Activation energy of formation of species i, J/kmol EMV Murphree efficiency, dimensionless fj Fraction of the photon transmission rate to the compartment j, dimensionless h Planck constant, 6.62610-34 J s Ha Hatta number He Henry’s constant, Pa/molar fraction He0 Pre-exponential factor of Henry constant, Pa/molar fraction HjL Volumetric liquid holdup in compartment j, m3 HjV Volumetric vapor holdup in compartment j, m3 Ia The absorbed light intensity, K Einstein/m3 Ij Molar enthalpy of vapor in component j, J/kmol I Photo flux rate at a given frequency , K Einstein/m2 s Jj Molar enthalpy of liquid in compartment j, J/kmol k Boltzmann constant, 1.381x10-23 J/K KD Rate constant of diffusion, 1/s kl Mass transfer coefficient of gaseous species, m/s kt Rate constant of the termination of chlorine free radical, 1/s k0 Frequency factor, 1/s ki,pseu The pseudo first order rate constant for the formation of component i, 1/s Kji Phase equilibrium coefficient, dimensionless L Length of the reactor, m L i, j xxiii Lpacking Length of the packed zone, m Lj Liquid flow rate in compartment j, kmol/s m Amount of toluene charged in the reboiler, kmol Mi Molecular weight of component i, kg/kmol NA Avogadro constant, 6.0231023 molecules/mol Ne The numbers of emitters per unit of source, K Einstein/m3 s P System pressure, Pa Pj Partial pressure of species j, Pa P Probability of emission at a given frequency , dimensionless Q Power to the wire, J Qn Heat duty to the reboiler, J QR Heat duty, J rc Radius of the column, m rj i Reaction rate of species i in reactor j, kmol/m3s R Gas constant, 8314 J/kmol K RA* Reaction rate at the gas-liquid interface, kmol/m3 s Rt Rate of the termination, kmol/m3 s s Cross-section area, m2 t Time, s tD Characteristic time of diffusion, s tr Characteristic time of reaction, s tg Mean residence time of the gas phase, s xxiv tL Mean residence time of the liquid phase, s T Absolute temperature, K ug,0 Superficial gas velocity at inlet, m/s uL Superfacial liquid velocity, m/s Ug Dimensionless gas velocity ug/ug,0, dimensionless V Output voltage from the transformer, V Vj Vapor flow rate from compartment j, kmol/s VR Total volume of the reactor, m3 xji Molar fraction of liquid species i in reactor j, dimensionless xji* Molar fraction of gas species i at the gas-liquid interface, dimensionless y ij Molar fraction of gas species i in reactor j, dimensionless z Reactor coordinate, m Greek Voidage of packed column, dimensionless e Effective coefficient, dimensionless g Gas holdup, dimensionless g Mean gas holdup, dimensionless Adsorption coefficient of chlorine at the frequency m3/kmol m The quantum yield of photolysis Molecular size, m xxv Viscosity of liquid, Pa s Attenuation coefficient of absorption at frequency, , 1/m Molar density, kmol/m3 Wavelength, nm Photon flux rate, K Einstein/m2 s Dimensionless length z/L, dimensionless i Group contribution values for diffusional volume of component i, m3 Hci Enthalpy change of condensation of species i at the standard state, J/kmol Hfi,0 Enthalpy of formation of gas species i at the standard state, J/kmol H2i Enthalpy change of the liquid species i at the standard state, J/kmol Hs Heat of solution, J/kmol Subscripts c component Cl2 chlorine F Feed I.D. Inner diameter j Index of reactor/compartment n Index of condenser xxvi O.D. Outer diameter Superscripts i Index of component i, i = 1 to 7 where 1,2,3,4,5,6, and 7 represent for toluene, benzyl chloride, benzal chloride, benzotrichloride, o-chlorotoluene, chlorine, hydrogen chloride, repsectively L Liquid phase V Vapor phase xxvii Acknowledgment I gratefully thank my advisor Professor Dudukovi for his valuable advise, encouragement, and constructive criticism. I have learned a lot from him how to deal with various chemical engineering problems. I want to express my thanks to Professor Ramanchandran, who gave me good suggestions on mathematical modeling and methodology. Many thanks to Professor Turner who helped me to test gas chromatography. I would also like to thank Professor Cassano. His wonderful lecture in our university introduced me to the field of photo radiation. Thanks Pat Harkin for helping me machine and fabricate the parts of my equipment. I also want to thank Dr. Mohan Khadilkar and Shantanu Roy for their kind help in improving my written English. Finally, I want to thank my parents, especially my father who encouraged me to continue with higher education.
