Cover
Half Title
Also of Interest
Off-Gas Purification: Basics, Exercises and Solver Strategies
Copyright
Preface
Contents
Symbols and abbreviations
Abbreviations
Symbols
Greek letters
Subscripts
Superscripts
Part I: Basic
1. Do we need off-gas purification?
1.1 Pollutants
1.2 Effects of air pollutants
1.3 How can we get it done?
1.4 Our job
2. The basics (for successful design work)
2.1 Volume
2.1.1 Standard volume, dry (in m3 stp,dry)
2.1.2 Standard volume, humid (in m3 stp,hymid)
2.1.3 Actual volume (in am3)
2.2 Concentration units
2.2.1 Volume fraction
2.2.2 ppm
2.3 Conversion from ppm into mg mโ3 stp
2.4 Reference oxygen value (ROV)
2.5 Gas velocity
2.6 Dew point, cooling limit, adiabatic cooling limit and sulfuric acid dew point
2.6.1 Definition
2.6.2 Vapor pressure of water (Antoine equation)
2.6.3 The specific water load and the partial pressure of water vapor
2.6.4 The adiabatic cooling limit
2.6.5 The cooling limit (or โthe correct engineerโ approach)
2.6.6 Estimation of the sulfuric acid dew point of SO2-laden off-gas
3. Specification of solid/gas and liquid/gas dispersions: properties
3.1 Optical properties of dispersions
3.2 Particle size distribution (PSD)
3.3 Particle size distribution (PSD) equations
4. Legislative framework and dispersion modeling
4.1 Meteorology
4.2 Pollutant dispersion modeling
4.3 Smog: photochemical smog
4.4 Particulate matter: dispersion and deposition
4.5 Pollutant accumulation
4.6 Odor and odor dispersion
5. Summary
Part II: Technologies
6. Particulate matter precipitation
6.1 Performance of particle separation devices
6.2 Outlook
6.3 Equipment
6.3.1 Gravity settler
6.3.1.1 Summary
6.3.2 Cyclone separators
6.3.2.1 Applications
6.3.2.2 Flow pattern and mode of action
6.3.2.3 Pressure drop
6.3.2.4 Apparatus design and prediction of the separation efficiency
6.3.2.5 Summary
6.3.3 Electrostatic precipitators
6.3.3.1 Electrical properties of gases and specification of corona discharge
6.3.3.2 Industrial ESPs and requirements for successful particle precipitation
6.3.3.3 Corona discharge and design basics
6.3.3.4 Separation efficiency
6.3.3.5 Theoretical energy consumption
6.3.3.6 Summary
6.3.4 Scrubbers
6.3.4.1 Mechanism of dust precipitation by scrubbing
6.3.4.1.1 Inertial impaction
6.3.4.1.2 Direct interception
6.3.4.1.3 Diffusion
6.3.4.1.4 Other mechanisms: diffusiophoresis, thermophoresis and condensation
6.3.4.2 Separation efficiency of scrubbers
6.3.4.2.1 Semrau model
6.3.4.2.2 Barth model
6.3.4.2.3 Calvert model
6.3.4.2.4 Pressure drop
6.3.4.3 Industrial scrubbers
6.3.4.3.1 Scrubbing tower
6.3.4.3.2 Ejector spray scrubbers (jet scrubber)
6.3.4.3.3 Self-induced spray scrubbers (orifice scrubbers)
6.3.4.3.4 Rotary scrubber
6.3.4.3.5 Venturi scrubbers
6.3.4.4 Scrubber design
6.3.4.5 Summary
6.3.5 Dust precipitation by filtration
6.3.5.1 Deep bed filters
6.3.5.1.1 Pressure drop of fiber layer
6.3.5.2 Cleanable filters (fabric filters)
6.3.5.2.1 Precipitation characteristics and separation efficiency
6.3.5.2.2 Pressure drop
6.3.5.2.3 Cleaning mechanism and filter designs
6.3.5.2.4 Design of cleanable filters
6.3.5.2.5 Filter material and standards
6.3.5.2.6 Fiber materials
6.3.5.3 Granular bed filters
6.3.5.4 Summary
6.4 Conclusion
7. Thermal and catalytic off-gas purification
7.1 Introduction to thermal and catalytic off-gas purification
7.2 Chemical reaction engineering fundamentals
7.2.1 Chemical thermodynamics
7.2.1.1 Enthalpy of reaction
7.2.1.2 Gibbs free enthalpy of reaction
7.2.1.3 Principle of Le Chatelier
7.2.2 Reaction kinetics
7.2.2.1 Rate laws
7.2.2.2 Temperature dependence
7.2.2.3 Summary
7.2.3 Types of reaction
7.2.3.1 Homogeneous gas-phase reactions
7.2.3.2 Heterogeneous catalytic gas-phase reactions
7.2.4 Heterogeneous catalysis
7.2.4.1 Selectivity and yield of a chemical reaction
7.2.4.2 Heterogeneous catalysts in off-gas purification
7.2.4.3 Catalyst requirements
7.2.4.4 Summary
7.2.5 Reactor design
7.2.5.1 Material balance for an ideal reactor
7.2.5.2 Design of ideal tubular reactors (PFR)
7.2.6 Process selection
7.3 Off-gas purification by oxidation in the gas phase: combustion
7.3.1 Combustion fundamentals
7.3.1.1 Complete versus incomplete combustion
7.3.1.2 Specification of combustibles
7.3.1.3 Combustion mechanism and procedure
7.3.1.4 Technical considerations for pollutant combustion
7.3.1.5 Summary
7.3.2 Thermal combustion
7.3.2.1 Combustion in flares
7.3.2.2 Thermal combustion in combustion chambers
7.3.2.3 Design of combustion chambers for thermal combustion
7.3.3 Catalytic combustion
7.3.3.1 Reactor design
7.3.3.2 Summary
7.3.4 Combination of thermal and catalytic combustion
7.4 Off-gas purification by reduction in the gas phase
7.4.1 Nitrogen oxides
7.4.1.1 Formation of nitrogen oxides
7.4.1.2 NOx emission mitigation measures
7.4.1.2.1 Primary measures โ prevention of NOx formation (emission prevention)
7.4.1.2.2 Secondary measures โ off-gas purification through NOx reduction (emission control)
7.4.1.3 Catalytic reduction of NOx
7.4.1.3.1 Catalyst specification
7.4.1.3.2 Application
7.4.1.3.3 SCR of NOx: reactor design
8. Absorptive off-gas purification
8.1 Physiochemical basics
8.1.1 Physiosorption
8.1.2 Chemisorption
8.1.3 Absorbent selection
8.1.4 Gasโliquid partition
8.2 Technologies, processes, their thermodynamics and kinetics
8.2.1 NaOH
8.2.2 MgO
8.2.3 ZnO, NiO and FeO
8.2.4 CaCO3
8.2.5 Ca(OH)2 (slaked lime)
8.2.6 Activity: the link between energy and the ability to โoffer workโ
8.2.7 Double-alkali processes
8.2.8 Oxidation of sulfite and hydrogen sulfite
8.3 Design of absorption processes
8.3.1 Mass balances
8.3.2 Selection of equipment
8.4 Apparatus design for absorption towers with stage-wise phase contact: apparatus diameter and apparatus height
8.4.1 The hydraulics of stage-wise phase contact
8.4.2 The theory of separation stages for determining Nth
8.4.3 Overall mass transfer efficiency of staged phase contactors
8.5 Apparatus design for absorption towers with continuous phase contact: apparatus diameter and apparatus height
8.5.1 The film theory
8.5.2 The HTU-NTU concept
8.5.3 Mass transfer
8.5.4 Hydraulic design of packed bed absorption towers
8.5.5 Design of spray scrubbers
8.5.5.1 Summary
9. Adsorption
9.1 Basics
9.2 Adsorbents
9.2.1 Activated carbon
9.2.2 Silica and alumina
9.2.2.1 Silica gel
9.2.2.2 Active alumina
9.2.3 Zeolite
9.2.4 Adsorbent selection
9.2.5 Evaluation of pore-related properties
9.2.5.1 Porosity
9.2.5.2 Pore size distribution and surface area
9.3 Adsorption equilibrium
9.3.1 Isotherm classification
9.3.2 Isotherm equations
9.3.2.1 Langmuir isotherm
9.3.2.2 Henry isotherm
9.3.2.3 Freundlich isotherm
9.3.2.4 BrunauerโEmmetโTeller (BET) isotherm
9.3.2.5 Fowler and Guggenheim isotherm
9.3.3 Micropore adsorption
9.4 Transport and dispersion mechanism
9.4.1 Pore diffusion
9.4.2 Surface diffusion
9.4.3 Film diffusion
9.5 Heat of adsorption
9.6 Multicomponent adsorption
9.7 Mass balances in adsorption towers
9.7.1 Type I isotherm systems
9.7.1.1 Adsorption
9.7.1.2 Desorption
9.7.2 Type III isotherm systems
10. Some final remarks
Bibliography
Index