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GC 11: Gas Purification

GC 11: Gas Purification
     Part 1: Introduction
     Part 2: Volatile Organic Compounds Abatement Technology
         1 INTRODUCTION
         2 LITERATURE REVIEW
             2.1 Definition of Volatile Organic Compound (VOC)
             2.2 Waste Minimisation
             2.3 Photochemical Potential of VOC
                 2.3.1 Chemistry of the Process
             2.4 Adsorption Systems
             2.5 Solvent Recycling
             2.6 Thermal Processes
             2.7 Thermal Separation
             2.8 Organic Sensors
             2.9 Biological Processes
             2.10 Absorption (Scrubbers)
             2.11 Sorbent Materials
         3 STATE OF THE SCIENCE ON VOC EMISSION CONTROL
             3.1 Adsorption
                 3.1.1 Adsorption Mechanisms
                 3.1.2 Equilibrium Relations
                 3.1.3 Shapes of Adsorption Isotherms
                 3.1.4 Examples of applicable equations.
                 3.1.5 Isotherms for Multicomponent Systems
                 3.1 6 Mechanism of Diffusion
                 3.1.7 Pore Diffusion
                 3.1.8 Surface Diffusion
                 3.1.9 Micropore Diffusion
                 3.1.10 Kinetics of Adsorption
                 3.1.11 Batch Adsorption (Constant Conc. of Fluid)
                 3.1.12 Vessel With Continuous Flow
                 3.1.13 Adsorber System Design Procedure
             3.2 Absorption (Scrubbing)
                 3.2.1 Liquid Scrubbing
                 3.2.2 Equilibrium Considerations
                 3.2.3 Contacting Schemes
                 3.2.4 Approach to Equilibrium
                 3.2.5 Prediction of Coefficients
                 3.2.6 Absorption With Chemical Reaction
                 3.2.7 Method of Contact and Types of Equipments
                 3.2.8 Capacity of System
                 3.2.9 Flooding
             3.3 Condensation
                 3.3.1 Physical Fundamentals
                 3.3.2 Practical Applications
                 3.3.3 Condensing Multicomponent Mixtures
             3.4 Membrane Gas Separation
                 3.4.1 Microporous Membrane
                 3.4.2 Homogeneous Membrane
                 3.4.3 Electrically Charged Membranes
                 3.4.4 Membrane Theory
                 3.4.5 Application to VOC Control
             3.5 Combustion
                 3.5.1 Combustion Fundamentals
                 3.5.2 Air-Fuel Ratio
                 3.5.3 Equilibrium Equation
                 3.5.4 Excess Air
                 3.5.5 Measurement of Excess Air
                 3.5.6 Waste Characterization for Combustion
                 3.5.7 Incineration of Gaseous Waste
                 3.5.8 Heat Recovery Methods
             3.6 Gas Incinerator Types
                 3.6.1 Flares
                 3.6.2 Thermal Oxidation (Direct Flame Incineration)
                 3.6.3 Catalytic Oxidation
             3.7 Processing with Plasma
                 3.7.1 Processes in Plasma VOC Destruction
                 3.7.2 Atmospheric Pressure Non-Thermal Plasma Production
                 3.7.3 Microwave and Radio Frequency Techniques
             3.8 Biological Processes
                 3.8.1 Application Difficulties
                 3.8.2 Theory of Operation
                 3.8.3 Process Modelling
                 3.8.4 Design and Operation
                 3.8.5 Micro-organisms
                 3.8.6 Filter Material
                 3.8.7 Raw-Gas Conditioning
                 3.8.8 Moisture Control
                 3.8.9 Control of pH
                 3.8.10 Back Pressure and Energy Consumption
         4 ODOUR
             4.1 Response to Odour
             4.2 Odour Interaction
             4.3 Adaptation
             4.4 Anosmia
             4.5 Odour Intensity
             4.6 Measurement of Odour
                 4.6.1 Threshold of Smell and Measurement
                 4.6.2 Analytical Approach
                 4.6.3 Sensory Approach
                 4.6.4 Olfactometry (Odour Assessment)
                 4.6.5 Sampling Odour
             4.7 Industrial Sources of Odour
             4.8 Odour Control Technologies
                 4.8.1 Chemical and Petroleum Industries
                 4.8.2 Pharmaceutical Industries
                 4.8.3 Sewage Treatment
         5 FUGITIVE EMISSIONS
             5.1 Introduction
             5.2 Estimate of Fugitive Emission (FE)
             5.3 SOCMI Emission Factors
             5.4 Leak/No-leak Factors
             5.5 Stratified Factors
             5.6 Correlation Curves
             5.7 Unit Specific Correlations
             5.8 Control of Fugitive Emissions from Pumps
             5.9 Minimizing Fugitive Emission by Better Valve Packing
         6 STATE OF THE ART ON VOC RECOVERY TECHNIQUES
             6.1 Abatement Selection Criteria
             6.2 Containment
             6.3 Equipment Selection Criteria
             6.4 Adsorption Processes
                 6.4.1 Desorption Processes
                 6.4.2 Adsorbents
                 6.4.3 Types of Adsorption Systems
                 6.4.4 Ventsorb
                 6.4.5 Fixed Bed Adsorber
                 6.4.6 Travelling Bed Adsorbers
                 6.4.7 Fluidized Bed Adsorber
                 6.4.8 Toyobo Adsorber Systems
                 6.4.9 Rekusorb Adsorber System
             6.5 Absorption
                 6.5.1 Methods of Application
                 6.5.2 Absorption Systems
                 6.5.3 Regeneration
                 6.5.4 QVF Absorber
             6.6 Thermal Combustion (Incineration)
                 6.6.1 High Temperature Incineration
                 6.6.2 Regenerative Thermal Oxidizer (CMB Engineering)
                 6.6.3 Recuperative Thermal Oxidizer (CMB Engineering)
                 6.6.4 ADTEC-5000
             6.7 Catalytic Incineration
                 6.7.1 Catalytic Selection Criteria
             6.8 Condensation
                 6.8.1 Direct Contact Condensers
                 6.8.2 Surface Condensers
                 6.8.3 Airco Solvent Recovery Systems
             6.9 Biofiltration
                 6.9.1 BIOTON
                 6.9.2 Bioscrubbers:
                 6.9.3 Trickling Filters
                 6.9.4 Biofilters
             6.10 Membrane Separation
                 6.10.1 Equipment
         7 INSTRUMENTATION AND CONTROL DEVICES
             7.1 Principle of Process Measurement
             7.2 Detection and Analysis of VOCs
                 7.2.1 Mass Spectrometer
                 7.2.2 UV Analyser
                 7.2.3 Infrared Process Analyzer
                 7.2.4 Gas Chromatography
             7.3 Data Transmission
             7.4 Control Systems
             7.5 Control of Adsorption Systems
             7.6 Control of Absorption Systems
             7.7 Biological Processes
             7.8 Thermal Processes
             7.9 Condensation
             7.10 Membrane Processes
         8 FUTURE ABATEMENT POLICIES
             8.1 CEC Reports
             8.2 Reduction Strategy
             8.3 First Step Solution
             8.4 Second Step Solution
         9 ECONOMICS OF EACH SOLVENT RECOVERY TECHNIQUE
             9.1 Adsorption
             9.2 Incinerators
             9.3 Absorption
             9.4 Condensation
             9.5 Membrane Gas Separation
             9.6 Cost Data for Odour Control
         10 CONCLUSIONS
         11 APPENDICES
             11.1 APPENDIX A
             11.2 APPENDIX B
             11.3 APPENDIX C
             11.4 APPENDIX D
             11.5 APPENDIX E
             11.6 APPENDIX F
             11.7 APPENDIX G
             11.8 APPENDIX H
         12 NOMENCLATURE
         13 REFERENCES
     Part 3: Chlorinated Dibenzodioxins and Dibenzofurans in Waste Combustion
         1 INTRODUCTION
             1.1 Objectives
             1.2 Report Structure
         2 BACKGROUND TO DIOXINS AND FURANS.
         3 CHEMICAL MECHANISMS OF PCDD/F FORMATION
             3.1 Heterogeneous Formation Reactions.
                 3.1.1 Formation from Volatile Organic Precursors
                 3.1.2 Formation from Residual Carbon in Fly-ash
             3.2 Homogeneous Reactions.
             3.3 Effects of Additives on PCDD/F Formation.
             3.4 Modelling of PCDD/F Reactions.
             3.5 Overview and Discussion of Formation Mechanisms.
         4 COLLATION AND ANALYSIS OF INCINERATOR DATA.
             4.1 Processes, Feedstocks, and the Available Data.
             4.2 Data Collation and Spreadsheeting.
         5 ANALYSIS OF PCDD/F ASSAYS WITH RESPECT TO PROCESS CONDITIONS.
             5.1 PCDD/F Distributions between Flue Gases and Ash Products.
             5.2 The Effects of Feedstock and Combustion Conditions on PCDD/F Totals and TEQs.
             5.3 PCDD/F Isomer Distributions.
             5.4 PCDD/F Formation in Particulate Removal Devices.
             5.5 PCDD/Fs Measured in Grit Ashes.
             5.6 PCDD/Fs Measured in Gaseous Emissions.
             5.7 Effects of Combustion Temperature and of Indicators of Combustion Efficiency.
             5.8 Effects of Heat Recovery Equipment and Boiler Exit Temperature.
         6 DISCUSSION.
         7 CONCLUSIONS.
         8 RECOMMENDATIONS.
         9 REFERENCES
         10 APPENDIX
     Part 4: The Selection of Adsorbents for the Removal of Contaminants from Gas Streams
         1. INTRODUCTION
             1.1 Objective
             1.2 Motives
             1.3 Choice of Adsorbent
             1.4 Contaminants Considered
             1.5 Adsorptive Separation
             1.6 Factors Excluded
             1.7. Procedure for the Choice of Adsorbent
                 1.7.2 Selection of Adsorbent Properties
                 1.7.3 Capacity of Adsorbents
                 1.7.4 Regeneration
                 1.7.5 Poisoning
         2. NATURE AND CLASSIFICATION OF ADSORBENTS
             2.1 Classical Adsorbents
                 2.1.1 Silica Gel
                 2.1.2 Activated Alumina
                 2.1.3 Activated Carbon
                 2.1.4 Charcoal Cloth
             2.2 Molecular Sieves
                 2.2.1 Carbon Molecular Sieves
                 2.2.2 Zeolites
             2.3 Alternative Adsorbents
         3. ADSORPTION SELECTIVITY
             3.1 Selectivity
             3.2 Deactivation
             3.3 Adsorption
         4. GAS FLOW IN PACKED BEDS
             4.1 Choice of Reactor
             4.2 Equilibrium Considerations
                 4.2.1 The Equilibrium Loaded Region
                 4.2.2 The Residually Loaded Part of the Bed
                 4.2.3 The Mass Transfer Zone (MTZ)
                 4.2.4 The Length of Unused Bed (LUB)
             4.3 Calculation of Adsorbent Bed Length
             4.4 General Points
         5. REGENERATION PROCESSES
             5.1 Thermal Swing
             5.2 Pressure Swing
                 5.2.1 Pressure Swing Adsorption (PSA)
             5.3 Purge Gas Stripping
             5.4 Displacement Desorption
             5.5 Selection of Regeneration Technique
         6. NATURE AND CLASSIFICATION OF CONTAMINANTS
             6.1 Molecular Size
             6.2 Molecular Shape
             6.3 Adsorption Considerations
         7. CONCLUSIONS
             7.1 Research Requirements
             7.2 Conclusions
         8. GLOSSARY OF TERMS
         9. COMPANIES CONSULTED
         10. REFERENCES
         11. APPENDIX 1: Adsorption Isotherms
         12. APPENDIX 2: Common Uses of Adsorbents
         13. APPENDIX 3: Information Required for the Decision Process
     Part 5: SOx and NOx Control Techniques
         1 INTRODUCTION
             1.1 Objectives
             1.2 Report Structure
         2 SO x CONTROL TECHNIQUES
             2.1 Introduction
                 2.1.1 Pre-combustion methods
                 2.1.2 Combustion technologies
                 2.1.3 Post combustion flue gas treatment
             2.2 Fuel desulphurisation
             2.3 Advanced combustion techniques
                 2.3.1 Shallow fluidised bed combustion
                 2.3.2 Circulating fluidised beds
                 2.3.3 Pressurised fluidised beds
                 2.3.4 Fluidised bed performance parameters
             2.4 Dry scrubbing FGD systems
                 2.4.1 In-furnace injection
                 2.4.2 In-duct Injection
                 2.4.3 In-furnace sorbent injection with water activation
             2.5 Semi-dry scrubbing techniques
             2.6 Regenerable wet scrubbing techniques
                 2.6.1 Wellman Lord Process
                 2.6.2 Activated Carbon Process
                 2.6.3 Magnesium Oxide Process
             2.7 Non-regenerable wet scrubbing techniques
                 2.7.1 Limestone/gypsum Process
                 2.7.2 Dual-alkali Process
                 2.7.3 Aqueous Ammonia Process (Walther)
                 2.7.4 Sea-water Scrubbing
                 2.7.5 Alkali Wet Scrubbing (Sodium hydroxide/sodium carbonate)
         3 NO x CONTROL TECHNIQUES
             3.1 Introduction
                 3.1.1 NO x formation
                 3.1.2 NO x control techniques
             3.2 Furnace Design
                 3.2.1 Firing type
                 3.2.2 Burner fired combustion
                 3.2.3 Low NO x burners
                 3.2.4 Burner orientation
                 3.2.5 Stoker fired and fluidised bed combustion
             3.3 Combustion Modification
                 3.3.1 Lower excess air
                 3.3.2 Plant de-rating
                 3.3.3 Combustion air vitiation
                 3.3.4 Combustion staging
             3.4 NO x Removal Processes
                 3.4.1 Selective catalytic reduction (SCR)
                 3.4.2 Selective non-catalytic reduction (SNCR)
             3.5 NO x control costs
         4 COMBINED SO x AND NO x CONTROL TECHNOLOGIES
             4.1 Introduction
             4.2 Activated carbon process
             4.3 Catalytic processes
                 4.3.1 SNOX process
                 4.3.2 NOXSO process
             4.4 Electron beam irradiation
         5 STATE OF THE SCIENCE
             5.1 General
             5.2 Combustion
                 5.2.1 The formation of SO 2 during coal combustion
                 5.2.2 NO x formation during coal combustion
             5.3 Gas absorption
                 5.3.1 Mass transfer
                 5.3.2 Absorption systems
             5.4 Adsorption
                 5.4.1 Adsorbent materials
                 5.4.2 Adsorption fundamentals
                 5.4.3 Adsorption Column Design
         6 REFERENCES
         7 BIBLIOGRAPHY
         8 APPENDIX A - SYSTEM SELECTION CRITERIA
     Part 6: Liquid Crystals for Molecular Separations
         1 LIQUID CRYSTALS
             1.1 Introduction
                 1.1.1 Definition of Liquid Crystalline Behaviour
                 1.1.2 Structural Concepts
             1.2 Liquid Crystal Molecules or Mesogens
                 1.2.1 Rod or Lathe Like Mesogens
                 1.2.2 Discotic Liquid Crystals
                 1.2.3 Liquid Crystal Polymers
                 1.2.4 Liquid Crystal Elastomers
             1.3 Composite Liquid Crystal Systems
             1.4 Lyotropic Systems
             1.5 Unusual Properties of Liquid Crystals
                 1.5.1 Electric Field Effects in Liquid Crystals
                 1.5.2 Magnetic Field Effects in Liquid Crystals
         2 MEMBRANE TECHNOLOGY
             2.1 Conventional Membrane Technology for Molecular Separations
                 2.1.1 Separation Properties and Membrane Structure
                 2.1.2 Gas Permeation and Separation
                 2.1.3 Membrane Design
                 2.1.4 Materials Used for Commercial Gas Separations
             2.2 Pervaporation
             2.3 Reverse Osmosis
             2.4 Nanofiltration Membranes
             2.5 Ultrafiltration Membranes
         3 NOVEL LIQUID CRYSTALLINE MEMBRANES FOR MOLECULAR SEPARATIONS
             3.1 Introduction
             3.2 Research of Liquid Crystalline Membranes
                 3.2.1 Liquid Crystalline Systems Studied
             3.3 Temperature Effects on Gas Sorption and Permeation Through Liquid Crystal Membranes
                 3.3.1 Mechanical Mediation of Gas Transport Through Liquid Crystalline Elastomers
                 3.3.2 The Effects of Electric and Magnetic Fields on Permeation Through Liquid Crystalline Membranes
                 3.3.3 Light Activated Transport of Molecules Across Liquid Crystalline Membranes
                 3.3.4 Species Specific Carriers Incorporated in Liquid Crystalline Membranes
         4 EXPERIMENTAL
             4.1 Overview of Experiment Design
                 4.1.1 Gas Permeation Cell and Mass Spectrometer
                 4.1.2 Materials
                 4.1.3 Membrane Design
             4.2 Experimental Results
                 4.2.1 The Effect of Voltage on Permeation and Selectivity
                 4.2.2 The Effect of Temperature on Permeation and Selectivity
             4.3 Discussion
                 4.3.1 Membrane Performance
                 4.3.2 Separation Mechanism
             4.4 Applications ofLiquid Crystal Membranes
             4.5 Conclusions
         5 ACKNOWLEDGEMENTS
         6 GLOSSARY OF TERMS USED
         7 NOMENCLATURE
         8 REFERENCES
     Terms and Conditions

Volume XI deals with the removal of gaseous contaminants from gas streams. Each part of the Manual deals with a specific topic area, and the Manual will be added to periodically as new topic areas are covered.

Part 1    Introduction
Part 2    Volatile organic compounds (VOC) abatement technology
Part 3    Dioxin and furan formation in waste combustion
Part 4    The selection of adsorbents for contaminant removal from gas stream
Part 5    SOx and NOx control techniques
Part 6    Controllable liquid crystal membranes for molecular separations

Volume GC XI Part 1  Introduction

Volume GC XI  Part 2 Volatile organic compounds (VOC) abatement technology.

This part provides an overview of the technology and an introduction to the procedures required for the correct selection of systems for the removal of organic vapours from process gas streams. It covers absorption, adsorption, biofiltration and incineration, and highlights future technologies which hold promise of economic treatment processes.


Volume GC XI  Part 3 Dioxin and furan formation in waste combustion.

This part of Volume XI reviews a large body of data and describes the formation mechanisms of Chlorinated Dibenzodioxins and Dibenzofurans in combustion processes. The main chemical interactions are described, and methods by which the formation of these highly toxic materials can be avoided are discussed together with a large body of data from on-site measurements.


Volume GC XI  Part 4 The selection of adsorbents for contaminant removal from gas streams.

This report, currently fills a gap in the existing literature on gas phase adsorption by providing recommendations on the procedures to use to select suitable materials for the removal of contaminants from gas streams. A selection procedure is proposed and the engineer is aided in the decision making process by a series of easy to use tables which summarise the important interactions involved. The available data on adsorption isotherms in a range of typical process conditions are assembled and prediction methods are also summarised.


Volume GC XI  Part 5 SOx and NOx control techniques. 

This part of the manual gives detailed descriptions of processes and equipment which may be applied to minimise and reduce emissions of oxides of sulphur and nitrogen to the atmosphere. It concentrates on reviewing available technology, giving details of process layout, efficiency, waste and by-product streams, energy consumption, operability and operating experience.


Volume GC XI  Part 6 Controllable liquid crystal membranes for molecular separations.

This part of the manual gives detailed descriptions of liquid crystals and how they may be used to create membranes for separating chemical species. It is shown that by applying an electric voltage across the liquid crystal membrane, the membrane can be controlled in terms of its permeability and selectivity to different chemical species thus providing a controllable membrane.