Process Chemistry of Coal Utilization

1. Scope of the Applications

1.1 Emissions (NOx, LOI/UBC), combustion efficiency, fuel quality impacts

1.2 PCC furnaces

1.2.1 Staging

1.2.2 Primary flow patterns and temperature fields

1.3 CFBC

1.4 Entrained flow gasification 

1.5 Exclude milling, fouling, ash deposition, flue gas cleaning

1.6 References 

2. Statistical Prediction Models

2.1 Definitions and Guidelines2-1

2.2 Using Standard Coal Properties to Interpret CQ Impacts2-5

2.3 Coals’ Constitution and Devolatilization Behavior As CQ Predictors 2-6

2.4 Neural Nets2-16

2.5 Summary2-20

2.6 Nomenclature2-21

2.7 References2-22 

3. Heuristic Prediction Schemes

3.1 NOX LOI Predictor3-1

3.2 Predicting CQ Impacts on NOX Emissions3-2

3.3 Predicting CQ Impacts on LOI Emissions3-11

3.3.1 Fuel Grinding Submodels3-12

3.3.2 Char Burnout Submodels3-13

3.3.3 Validating the LOI Predictions3-14

3.4 Novel Aspects and Generalizations3-17

3.5 Comprehensive Fuel Quality Management Tools3-22

3.6 Summary3-24

3.7 Nomenclature3-25

3.8 References3-25

4. Support for CFD and Process Simulation Applications 

4.1 Chemistry Submodels Accommodate Only A Handful of Chemical Species4-2

4.2 Support CFD From A Virtual Fuels Laboratory4-3

4.3 Fuel-Specific Input for CFD4-6

4.3.1 Thermophysical Properties and Drying Rates4-7

4.3.2 Primary Devolatilization Rates4-10

4.3.3 Volatiles Conversion4-15

4.3.4 Finite-Rate Tar Decomposition and Soot Production4-20

4.3.5 Oxidation of Char and Soot4-23

4.3.6 Gasification of Char and Soot4-32

4.3.7 An Important Omission4-41

4.4 Specifying Representative Operating Conditions4-42

4.5 Performance4-45

4.6 Summary4-47

4.7 Nomenclature4-51

4.8 References4-54 

5. Reactor Network Theory

5.1 Options for Simulations with Detailed Chemistry

5.2 Historical development 

5.3 Equivalent reactor networks 

5.3.1 CFD with particle tracking

5.3.2 Reactor network specifications

5.3.3 Mapping detailed operating conditions

5.3.4 Case study with a pilot-scale coal flame

5.4 Theory for reacting coal suspensions under inert atmospheres

5.5 Theory for burning coal suspensions 

5.5.1 Limiting volatiles mixing scenarios

5.5.2 Mixing length scales for dense coal suspensions

5.6 Theory for coal suspensions under reducing atmospheres

5.6.1 One dominant gasification agent 

5.6.2 Multiple gasification agents

5.7 References

6. Applications at Pilot- and Commercial Scale

6.1 Progression from lab- to pilot- to commercial-scale 

6.2 PCC furnaces 

6.2.1 Laboratory coal flow reactor at elevated pressure

6.2.2 Single-burner pilot-scale furnace with biomass co-firing

6.2.3 NOx emissions from a utility furnace with and without slagging 

6.2.4 Predicting VOC emissions from a utility furnace

6.2.5 Reactor network for a 55o MW T-fired furnace

6.3 CFBC combustion efficiency and LOI emissions

6.4 Coal gasification 

6.4.1 Interpreting lab-scale gasification test results

6.4.2 Predicting methane in syngas from a pilot scale coal gasifier

6.4.3 Interpreting syngas compositions from commercial gasifiers: Prenflo & Lurgi

6.5 Summary

6.6 References