This book addresses the two major issues faced by the modern steel industry: CO2 emissions and energy consumption. The steel industry accounts for 6.7% of the anthropogenic CO2 emissions and consumes 6% of the total energy consumed in manufacturing. In response to these critical issues, a new technology called flash ironmaking has been developed, aimed at producing iron directly from iron ore concentrate using gaseous reductants/fuels such as natural gas or hydrogen. This ironmaking technology takes advantage of the rapid reaction rate of fine particles and bypasses the palletization process. This book discusses the principles of flash ironmaking, laboratory experiments, and design and operation of a prototype flash reactor.
• Provides theories and principles of ironmaking and a novel ironmaking technology.
• Includes laboratory experiments to establish the kinetic feasibility of flash ironmaking.
• Covers the design and operation of a prototype flash reactor as well as the design of industrial-size flash ironmaking reactors.
• Describes various cases of flow sheet development, which forms the basis for process analysis and simulation
• Presents economic analysis case studies.
Presenting a novel technology that addresses contemporary issues facing one of the largest manufacturing industries, this book is aimed at professionals and researchers in metallurgy, materials engineering, manufacturing engineering, and related disciplines.
Author(s): H. Y. Sohn
Publisher: CRC Press
Year: 2023
Language: English
Pages: 296
City: Boca Raton
Cover
Half Title
Title Page
Copyright Page
Dedication
Table of Contents
Abbreviations
Nomenclature
Preface
Acknowledgments
Author
Chapter 1 Introduction
Chapter 2 Current Technologies for Ironmaking
2.1 Blast Furnace Process
2.2 Direct Reduction Processes
2.3 Smelting Reduction Processes
2.3.1 Advantages
2.3.2 Disadvantages
Chapter 3 Issues Facing the Steel Industry
3.1 Raw Materials
3.2 Greenhouse Gas Emissions
3.3 Energy Consumption
Chapter 4 Flash Ironmaking Technology – Concept Development
Chapter 5 Basic Properties and Sources of Magnetite Concentrate
Chapter 6 Principles Related to Iron Oxide Reduction
6.1 Thermochemistry
6.1.1 The First Law of Thermodynamics – Heat and Heat Capacity
6.1.2 Physical Changes and Heat Content
6.1.3 Chemical Changes and Standard State
6.1.4 Standard Heat of Formation or Standard Enthalpy of Formation
6.1.5 Standard Heat of Combustion
6.1.6 Hess' Law
6.1.7 Heat of Chemical Reaction
6.1.8 Heat of Reaction at Different Temperatures
6.1.9 Adiabatic Reaction Temperature
6.1.10 Heat of Mixing
6.1.11 The Second Law of Thermodynamics
6.1.12 Activity and Activity Coefficient
6.1.13 Chemical Equilibrium
6.1.14 Calculation of Equilibrium Composition
6.1.15 Ellingham Diagram – ΔG° – T Diagram
6.1.16 Gibbs' Phase Rule
6.1.17 Stability Diagram
6.2 Reaction Kinetics of Fine Solid Particles with a Gas
6.2.1 Introduction
6.2.2 Chemically Controlled Shrinking-Core Kinetics
6.2.3 Nucleation and Growth Kinetics – Avrami–Erofeev Equation
6.2.4 Nucleation and Growth Kinetics – Prout–Tompkins Model (Also Called the Autocatalytic Model)
6.2.5 Solid-State Diffusion Model
6.2.6 Summary of Various Solid-State Reaction Kinetics Models
6.2.7 Analysis of Rate Data
6.2.7.1 The Isothermal Method
6.2.7.2 The Direct Differential Method – Linear T-t Program
6.2.7.3 Coats–Redfern Integral Method – Linear T-t Program
6.2.7.4 Iso-Conversional Methods
6.2.7.5 Sohn's Non-Linear Temperature–Time Program
Chapter 7 Development of Flash Ironmaking Technology – Reduction Kinetics of Magnetite Concentrate Particles
7.1 Materials
7.2 Experimental Apparatus
7.3 Experimental Procedure
7.4 Formulation of Reduction Kinetics Equation
7.4.1 Definitions of Parameters
7.4.1.1 Reduction Degree
7.4.1.2 The Amount of Excess Reducing Gas
7.4.1.3 Excess Driving Force
7.4.1.4 Particle Residence Time
7.4.2 Selection of Rate Equation
7.4.3 Determination of the Reaction Order with Respect to Gas Partial Pressures
7.4.4 Effect of Particle Size
7.4.5 Determination of the Activation Energy
7.4.6 Verification of the Absence of the Effects of Mass Transfer and Pore Diffusion
7.5 Results of Rate Measurements and Rate Equations
7.5.1 Reduction by Hydrogen: Temperature Range of 1,150°C–1,350°C
7.5.2 Reduction by Hydrogen: Temperature Range of 1,350°C–1,600°C
7.5.3 Reduction by Carbon Monoxide: Temperature Range of 1,150°C–1,350°C
7.5.4 Reduction by Carbon Monoxide: Temperature Range of 1,350°C–1,600°C
7.5.5 Reduction by H[sub(2)] + CO Mixtures: Temperature Range of 1,150°C–1,350°C
7.5.6 Reduction by H[sub(2)] + CO Mixtures: Temperature Range of 1,350°C–1,600°C
7.5.7 Summary on the Reduction Kinetics of Magnetite Concentrate Particles
7.6 Refinements of the Rate Equations for the Reduction of Concentrate Particles Through Computational Fluid Dynamics Modeling
7.6.1 Approach and Methodology
7.6.2 Numerical Procedure
7.6.3 Modeling Results
7.6.4 Kinetics Analysis Procedure
7.6.5 Complete Rate Equations
7.6.5.1 Reduction by Hydrogen: Temperature Range of 1,150°C–1,350°C
7.6.5.2 Reduction by Hydrogen: Temperature Range of 1,350°C–1,600°C
7.6.5.3 Reduction by Carbon Monoxide: Temperature Range of 1,150°C–1,350°C
7.6.5.4 Reduction by Carbon Monoxide: Temperature Range of 1,350°C–1,600°C
7.6.5.5 Reduction of Hematite Concentrate by H[sub(2)] or CO
7.6.5.6 Derivation for Comparison of X-vs-t of a Compound with That of an Intermediate Phase as a Separate Reactant
7.6.6 Reduction by H[sub(2)] + CO Mixtures
7.6.7 Summary and Concluding Remarks
Chapter 8 Development of Flash Ironmaking Technology – Tests in a Laboratory Flash Reactor
8.1 Laboratory Flash Reactor
8.1.1 Importance of Testing in Laboratory Flash Reactor
8.1.2 Apparatus
8.1.3 Experimental Procedure
8.2 Factors Affecting the Extent of Reduction
8.2.1 Particle Feeding Modes
8.2.2 Flame Configuration
8.2.3 Excess Driving Force – for H[sub(2)] + CO mixtures
8.2.4 Nominal Particle Residence Time
8.3 Experiments with Hydrogen
8.4 Experiments with Methane
8.5 Concluding Remarks
Chapter 9 Development of Flash Ironmaking Technology – Operation of a Pilot-Plant-Scale Flash Reactor
9.1 Introduction
9.2 Facility
9.2.1 Reactor Vessel and Roof
9.2.2 Burners
9.2.3 Quench Tank
9.2.4 Flare Stack
9.2.5 Gas Valve Train
9.2.6 Off-Gas Analyzer
9.2.7 Water-Cooling System
9.2.8 Concentrate Feeding System
9.2.9 Gas Leak Detectors
9.2.10 Human–Machine Interface
9.3 Operation of the Mini-Pilot Flash Reactor
9.4 Results from Mini-Pilot Flash Reactor Runs
9.5 Difficulties During Operation
9.5.1 Water-Cooling System
9.5.2 Embedded Thermocouples in Reactor Vessel
9.5.3 Quench Tank Cracking
9.5.4 Sample Collection
9.6 Concluding Remarks
Chapter 10 Development of Flash Ironmaking Technology – Computational Fluid Dynamics Design of Flash Ironmaking Reactors
10.1 Computational Fluid Dynamics Modeling of the Utah Laboratory Flash Reactor
10.1.1 Fluid Flow
10.1.2 Heat Transfer
10.1.3 Species Transport
10.1.4 Particle Tracking
10.1.5 Boundary Conditions
10.1.6 Numerical Details
10.1.7 Laboratory Flash Reactor Runs – with Hydrogen
10.1.7.1 Combustion Mechanism Validation
10.1.7.2 Temperature Validation
10.1.7.3 Reduction Degree
10.1.7.4 Velocity Field
10.1.7.5 Temperature Distribution
10.1.7.6 Species Distribution
10.1.7.7 Particle Residence Time
10.1.7.8 Concluding Remarks on Runs with Hydrogen
10.1.8 Laboratory Flash Reactor Runs – with Methane
10.1.8.1 Definition of Parameters
10.1.8.2 Governing Equations
10.1.8.3 Combustion Mechanism
10.1.8.4 Experimental Results
10.1.8.5 CFD Simulation Results
10.1.9 Concluding Remarks
10.2 Computational Fluid Dynamics Modeling of the Pilot-Plant-Scale Flash Reactor
10.2.1 Introduction
10.2.2 CFD Simulation
10.2.2.1 Incorporation of Natural Gas Combustion
10.2.3 Results and Discussion
10.2.4 Concluding Remarks
10.3 Optimization of Mini-Pilot Flash Reactor Operating Conditions with CFD
10.3.1 Realistic Boundary Conditions
10.3.2 Effect of the Inlet Oxygen to Natural Gas Ratio with the Same Total Gas Flow Rate
10.3.3 Effect of Total Gas Flow Rate with Constant Oxygen/Natural Gas Ratio
10.3.4 Comparison of the Simulated and the Equilibrium Gas Compositions
10.3.5 Profiles of Metallization Degree
10.3.6 Heat Loss to the Surroundings
10.4 Computational Fluid Dynamics Modeling – Design of Intermediate-Size Flash Ironmaking Reactors
10.4.1 Introduction
10.4.2 Geometries and Dimensions
10.4.3 Operating Conditions
10.4.4 Meshing and Mathematical Model
10.4.5 One-Burner Design
10.4.6 Four-Burner Design
10.4.7 Summary
10.5 Computational Fluid Dynamics Modeling – Design of Full-Scale Industrial Flash Ironmaking Reactors
10.5.1 Introduction
10.5.2 Model
10.5.3 Dimensions and Operating Conditions
10.5.4 Meshing
10.5.5 Mass-Weighted Average Gas Composition and Product Metallization at the Outlet
10.5.6 Profiles of Metallization Degree
10.5.7 Heat Loss
10.5.8 Concluding Remarks
Chapter 11 Flash Ironmaking Flow Sheet Development and Process Analysis
11.1 Hydrogen-Based Flash Ironmaking Technology
11.1.1 Introduction
11.1.2 Flow Sheet Development and Process Simulation
11.1.3 Simulation Results
11.1.3.1 Material and Energy Balances
11.1.4 Summary on Hydrogen-Based Flash Ironmaking
11.2 Natural-Gas-Based Flash Ironmaking Technology – Reformerless Process
11.2.1 Introduction
11.2.2 Flow Sheet Development and Process Simulation
11.2.3 Material and Energy Balances
11.2.4 Summary on Reformerless Natural-Gas-Based Flash Ironmaking Technology
11.3 Natural-Gas-Based Flash Ironmaking Technology–Ironmaking Combined with Steam-Methane Reforming
11.3.1 Introduction
11.3.2 Flow Sheet Development and Process Simulation
11.3.2.1 Ironmaking Section
11.3.2.2 Steam-Methane Reforming Section
11.3.3 Material and Energy Balances
11.3.4 Summary on Natural-Gas-Based Flash Ironmaking Technology – Combined with Steam-Methane Reforming
Chapter 12 Economic Analysis of Flash Ironmaking Technology
12.1 Introduction
12.2 Methods of Estimation for Economic Feasibility Analysis
12.2.1 Capital Cost Estimation
12.2.2 Operating Cost Estimation
12.2.2.1 Estimation Procedure of Net Present Value
12.2.2.2 Carbon Dioxide Emission Credit
12.3 Net Present Value Results and Sensitivity Analysis – Hydrogen-Based Flash Ironmaking
12.4 Net Present Value Results and Sensitivity Analysis – Natural-Gas-Based Flash Ironmaking
12.4.1 Capital Cost Estimation
12.4.2 Operating Cost Estimation
12.4.3 Summary of Net Present Value Estimation
12.4.4 Conclusions on Natural-Gas-Based Flash Ironmaking
References
Index
