Dry Scrubbing Technologies for Flue Gas Desulfurization

1 Flue Gas Desulfurization for Acid Rain Control.- Abstract.- Background.- General Discussion of Current FGD Technology.- Overview.- Process Research Studies.- Wet/Wet Systems.- Dry/Dry Systems.- Wet/Dry Systems.- In-Fumace Injection.- Fundamentals.- Sulfur Evolution.- Modeling of Sorbent Reaction.- Technology.- Scope.- Economizer Zone Injection, 900–1200°F.- Injection of Hydrated Lime Downstream of the Air Preheater.- Fundamental Studies.- Dry/Dry Systems.- Wet/Dry Systems.- Spray Drying Absorption.- Description of the Spray Drying FGD Process.- Reagent Preparation.- Dryer Configuration.- Waste Disposal.- Process Chemistry.- Particulate Control.- Electrostatic Precipitator (ESP).- Fundamentals and Operating Parameters.- Operating Conditions.- ESP Design Considerations.- Fabric Filters (Baghouse).- Wet Scrubber.- Mechanical Particulate Control Devices.- Comparison of SO2 Removal in Fabric Filter (Baghouse) and ESPs.- Scope.- Sorbent Forms and Additives.- Calcium-Based Sorbents.- Chemical Form.- Calcium/Magnesium Ratio.- Morphology.- Preparation by Aqueous Hydration.- The Use of Additives to Enhance Reactivity.- Deliquescents, Buffers, and Sodium Additives.- Alcohol and Sucrose Hydration.- Silicate Additives.- Miscellaneous Additives - High Temperature Applications.- Contacting Flow Patterns and Multiphase Flows.- Contacting Flow Patterns and Some Novel Techniques.- Novel Techniques with FGD Applications.- Circulating Fluidized Bed Absorber.- Limestone Emission Control (LEC) System.- Novel Impeller Fluidizer.- Acoustic and Other Techniques.- Fundamental Fluid Mechanics, Mass and Heat Transfer Consideration in FGD Processes Involving Multiphase Flows.- Transport Properties of Dry Sorbent and Sorbent Slurries.- Conclusions.- In-Furnace Injection.- Economizer Zone Injection.- Injection of Hydrated Lime Downstream of the Air Preheater.- Spray Drying Absorption.- Particulate Control.- Future Research Needs.- Reaction Mechanisms and Sorbent Material.- Transport Effects and Modeling.- Process Development.- References.- 2 New Calcium-Based Sorbents for Flue Gas Desulfurization.- Abstract.- Properties of SO2.- Properties of CO2.- Properties Required in Sorbents.- Previously Considered Sorbents.- Techniques and Apparatus.- Infrared Spectroscopy.- X-Ray Powder Diffractometry.- BET Nitrogen Adsorption Surface Area Determinations.- Scanning Electron Microscopy.- SO2 Uptake Measurements.- Milling.- Shaking.- Survey of Calcium Silicates.- Tabulation of Known Calcium Silicates.- Further Description of C-S-H.- Conclusions.- Pure Calcium Silicate Sorbents.- Experimental.- Results and Discussion.- Conclusions.- SiO2-Modified Ca(OH)2 Sorbents.- Experimental.- Results and Discussion.- Conclusions.- Hydrated Ca3SiO5 AND ?-Ca2SiO4 Sorbents.- Experimental.- Results And Discussion.- Conclusions.- Hydrated Portland Cement Sorbents.- Experimental.- Results and Discussion.- Conclusions.- Summary.- List of Symbols and Abbreviations.- Notes and References.- 3 Fundamental Studies Concerning Calcium-Based Sorbents.- Abstract.- Literature.- Background.- Sorbent Preparation.- Limestone/Lime Characterization Study.- Limestone/Lime Samples.- Calcine Preparation.- Hydrate Preparation.- Sorbent Characterization.- Effect of Chemical Additives on Duct Injection/Spray Drying Performance.- Introduction/General Description.- Chemical Effects of Additives.- Model Comparisons.- Conclusions.- Recommendations.- Nomenclature.- References.- 4 Sorbent Transport and Dispersion.- Abstract.- Powder Characterization.- General Theory of Interparticle Forces.- Results of Powder Characterization.- Mechanical Properties.- Powder Dispersion.- Experimental.- Simulation of the Gas Flow Field in the Entrances.- Results and Discussion.- Modeling.- A Stochastic Model for Attrition of Sorbent Particles.- Integral Model for Powder Dispersion.- Nomenclature.- References.- 5 Transport Processes Involved in FGD.- Abstract.- Issues Regarding Transfer Processes for FGD Processes.- Literature Review.- Single Phase Flow Confined Ducted Jets.- Free Coaxial Jets.- Confined Jet Flow with Sudden Expansion.- Particle-Laden Flows, Turbulent Free Jet.- Concentric Jet Flows.- Pipe Flow.- Modeling.- Conclusions.- The Objectives of Investigation of Transport Processes in FGD.- Design Consideration for the Sorbent Injection Facility.- Geometric Similarity.- Particle-Laden Jet-to-Stream Momentum Flux Ratio.- Reynolds Number.- Stokes Number.- Froude Number.- Particle Loading and Particle-to-Fluid Density Ratio.- Sorbent Injection Facility.- Sorbent Injection (Particle-Laden Jet Test Facility).- Characteristics of Particle Phase (Glass Particles, Lime).- Glass Particles.- Lime Particles.- Laser Based Optical Measurement systems.- Calibration Tests.- Test Results and Discussion.- Axial Velocity Profile Across the Jet.- Particle-Laden Flow Measurements.- Axial Development Along the Centerline.- Axial Velocity Profile Across the Jet.- Jet Spreading Rate and Entrainment.- Measurement of Mean Particle Diameter and Particle Concentration.- Conclusions.- Single-Phase Flow.- Particle-Laden Flows.- Investigation of Spray-Concurrent Flow.- Experimental Setup.- Experimental Procedure.- Experimental Results.- Experimental Velocity Profiles and Prediction.- Flow Reversal.- Development of Criterion for Prediction of Flow Reversal.- Conclusions.- Particle-Laden Jet Reversal in Cocurrent Flow.- Summary.- Nomenclature.- References.- 6 High Temperature Desulfurization of Flue Gas Using Calcium-Based Sorbents.- Abstract.- Furnace Sorbent Injection (FSI).- High Temperature Phenomena: Calcination, Sintering and Sulfation.- Role of Surface Area and Porosity of the Calcines.- Role of Particle Size.- Roleof Sorbent Type.- Role of Temperature.- High-Temperature Entrained Flow Reactor Setup.- Entrained Flow Reactor System.- The Powder Feed System.- The High-Temperature Reactor.- The Probe System.- Particle Collection/Classification System.- Data Acquisition System.- Experimental Approach.- Operating Conditions.- On-Line Estimation of Particle Residence Time.- Post-Reaction Analyses of Data on Reaction Kinetics.- Ca-Based Sorbents Used in High-Temperature Flue Gas Desulfurization.- Experimental Results and Discussion: Calcination of Calcium Based Sorbents.- Effect of Temperature on Calcination.- Internal Surface Area Development with Calcination.- Effect of Particle Size on Calcination.- Development of Porosity and Pore Size Distribution of Calcined Sorbent Particles.- Experimental Results and Discussion: Sulfation of Calcium-Based Sorbents.- Effect of Temperature on the Sulfation of CaO and Ca(OH)2.- Effect of Initial Surface Area and Porosity on CaO Sulfation.- Effect of Particle Size on Sulfation.- Development of Internal Structural Properties During Sulfation.- Reaction Modeling for High-Temperature SO2 Sorption.- Calcination Modeling.- Sintering Modeling.- Comprehensive Sulfation Modeling.- Comparison of Experimental Data and Model Predictions.- Modified Calcium-Based Sorbent.- Surfactant Modifiers.- Lignosulfonate Modified Calcium Hydroxide.- Experimental Results and Discussion: Comparison Between Modified and Pure Calcium Hydroxide.- Conclusions.- Nomenclature.- Greek Letters.- Reference.- 7 Kinetic Studies on the Medium Temperature Ca(OH)2 Sorbent Injection FGD Process.- Abstract.- Background.- Entrained Flow Reactor.- Entrained Flow Reactor Construction and Operation.- Entrained Flow Reactor II.- Particle Heat Transfer Rate Determination.- Particle Residence Time Determination.- Dehydration Reaction of Ca(OH)2.- Literature Review.- Equilibrium of the Dehydration Reaction.- Dehydration Kinetics in the Entrained Flow Reactor.- Dehydration Model.- The Pseudohomogeneous Model.- Conclusions.- Carbonation Reaction.- Literature Review.- Carbonation ofCa(OH)2 in Entrained Flow Reactors.- Reactivity of CaO with CO2.- First-Order Deactivation Model.- Third-Older Deactivation Model.- General dth-Order Deactivation Model.- Model Application and Results.- Conclusions.- Sulfation Reaction.- Sulfation in an Entrained Flow Reactor.- Reactivity of CaO with SO2.- Sulfation Model.- Model Application and Results.- Conclusions.- Simultaneous Sulfation and Carbonation Reaction.- Literature Review.- Simultaneous Dehydration, Sulfation and Carbonation in the Entrained Flow Reactor.- Kinetic Model for Simultaneous Dehydration, Sulfation and Carbonation.- Reaction with Nascent CaCO3.- Activity.- Model Application.- Conclusions.- Recommendations.- References.- 8 Advances in Spray Drying Desulfurization for High-Sulfur Coals.- Abstract.- Literature Review.- General Spray Dryer Operations for Desulfurization.- Reagent Properties and Preparations.- Spray Drying Desulftirization.- Particulate Collection.- Recycle, Solid Waste Treatment and Disposal.- Methods of Increasing SO2 Removal and Sorbent Utilization.- Previous Lime and Limestone Dissolution Rate Studies.- Spray Dryer FGD Models.- Lime Dissolution Rate Studies.- Experimental Approach and Limestone Test Results.- Rotating Disk Technique and Lime Dissolution Rate Experimental Studies.- Pilot Spray Dryer Experimental Approach and Results.- Spray Dryer and Sampling System.- Baseline Test and Parameters that Affect Spray Dryer Desulrurization Processes.- Additives to Increase Ca(OH)2 Utilization.- Hydration of Fly Ash with Ca(OH)2 to Increase Sorbent Reactivity and Utilization.- Spray Dryer Modeling.- to “SPRAYMOD” and its Application to Baseline Test Results.- SO2 Absorption Process.- Modification of the Model by Hygroscopic Additive Effects: The Mechanism of Hygroscopicity.- Conclusions.- Nomenclature.- Greek Letters.- References.- 9 Low Temperature Dry Scrubbing/LEC Process Support.- Abstract.- Literature Review.- General Background.- Fixed-Bed Limestone Emission Control.- Moving-Bed Limestone Emission Control.- Limestone Solubilities and Dissolution Rates.- Process Theory and Model Development.- Assumptions.- Removal Rate of Sulfur Dioxide.- Interfacial Concentrations.- Reaction Site and Determination of Control.- Fixed-Bed Process Model.- Mass and Enthalpy Balances.- Model Simulations.- Moving-Bed Reactor Process Model.- Model Development.- Model Simulations.- Limestone Solubilities and Rates of Solubilization.- Theory.- Experimental.- Results and Discussion.- Conclusions and Recommendations: Solubilities and Rates of Dissolution.- Nomenclature.- References.- 10 Simulation and Optimization of a Granular Limestone Flue Gas Desulfurization Process.- Abstract.- Literature Review.- Transport and Reaction.- Economics.- Process Model.- Reactor Model.- Sorbent Blinding.- Dry Capture Model.- Differential Equations.- Solution Algorithm for Partial Differential Equations.- Calculation Speed Enhancement.- Cost Model.- Plant Simulation Model.- Optimization Algorithm.- Design Cases.- Computer Code.- Results.- Discussion of Results.- Conclusions.- Nomenclature.- References.- Appendix A-Governing Differential Equations.- Material and Enthalpy Balances.- Gas Phase Material Balances.- Solid Phase Material Balances.- Liquid Phase Material Balances.- Detailed Enthalpy Balances.- Appendix B Transport and Physical Property Correlations.- Sulfur (Dioxide) Transport Rate (gS).- Water Transport Rate (gW).- Gas/Liquid Heat Transport Rate (gg).- Gas/Liquid Heat Transfer Coefficient (hg).- Calcium Pseudo-Mass Transfer Coefficient (kmC).- Water Vapor Mass Transfer Coefficient (kmS).- Colbum j Factor for Heat and Mass Transfer in the Gas Phase (Jg).- Appendix C - Plant Simulation and Cost Model.- Mass Balance Equations.- Equipment Size Parameters.