 | Ambedkar B. Ultrasonic coal-wash for de-ashing and de-sulfurization: experimental investigation and mechanistic modeling, doctoral thesis accepted by Indian Institute of Technology Madras, Chennai, India. - Berlin: Springer, 2012. - xviii, 125 p. - (Springer theses). - ISBN 978-3-642-25016-3
|
1 Introduction ................................................. 1
1.1 Importance of Coal Washing .............................. 1
1.2 Ultrasound-Assisted Process Intensification ............. 3
1.2.1 Basic Mechanism of Ultrasound .................... 3
1.3 Outline of Thesis ....................................... 6
References ................................................... 6
2 Literature Review ............................................ 7
2.1 General ................................................. 7
2.2 Effect of Burning High-Ash and High-Sulfur Coal ......... 7
2.2.1 Boiler Equipment ................................. 7
2.2.2 Environmental and Health Hazards of Coal
Burning Power Plants ............................ 11
2.3 Conventional Methods for De-Ashing and
De-Sulfurization ....................................... 12
2.4 Ultrasound-Assisted Coal Particle Breakage and
Application of Ultrasound in Various Fields ............ 16
2.4.1 Ultrasound-Assisted Coal Particle Breakage ...... 16
2.4.2 Application of Ultrasonic Process ............... 18
2.4.3 Patented Ultrasonic Coal-Wash Process for
De-Ashing ....................................... 19
2.4.4 Ultrasound in Aqueous Medium .................... 20
2.5 Ultrasonic Process for De-Ashing and
De-Sulfurization ....................................... 22
2.6 Scope and Objectives for the Present Work .............. 24
References .................................................. 25
3 Assessment of Fly-Ash Erosion Potential of Indian Coals ..... 29
3.1 Introduction ........................................... 29
3.2 Experimental Details ................................... 30
3.2.1 Materials Used and Their Properties ............. 30
3.2.2 Test Equipment and Procedure .................... 32
3.3 Results and Discussion ................................. 34
3.3.1 Effect of Process Parameters on Erosion Mass
Loss ............................................ 34
3.3.2 Effect of Surface Roughness on Erosion Mass
Loss ............................................ 34
3.3.3 Effect of Ash and Substrate Alloy Properties
on Erosion Mass Loss ............................ 37
3.3.4 Predictive Model for Ash-Impact Erosion ......... 37
3.4 Summary ................................................ 40
References .................................................. 40
4 Experimental Studies on Ultrasonic Coal Beneficiation ....... 41
4.1 Overview ............................................... 41
4.2 Materials, Methods and Equipment Used .................. 41
4.2.1 Materials ....................................... 41
4.2.2 Methods ......................................... 42
4.2.3 Equipment Used .................................. 44
4.3 Experimental Procedure ................................. 47
4.3.1 Aqueous-Based De-Ashing Experiments ............. 47
4.3.2 Aqueous-Based De-Sulfurization Experiments ...... 47
4.3.3 Solvent-Based De-Ashing Experiments ............. 48
4.3.4 Reagent-Based De-Sulfurization Experiments ...... 49
4.4 Results for Aqueous-Based Coal Beneficiation ........... 51
4.4.1 Motivation ...................................... 51
4.4.2 De-Ashing ....................................... 51
4.4.3 De-Sulfurization ................................ 59
4.5 Results for Solvent-Based Coal Beneficiation ........... 62
4.5.1 Introduction .................................... 62
4.5.2 De-Ashing ....................................... 62
4.5.3 De-Sulfurization Studies ........................ 68
References .................................................. 71
5 Experimental Studies and Mechanistic Modeling of Reagent-
Based Ultrasonic Coal De-Sulfurization ...................... 73
5.1 Motivation ............................................. 73
5.2 Experimental ........................................... 73
5.2.1 Materials ....................................... 73
5.2.2 Experimental Design ............................. 74
5.2.3 Experimental Procedure .......................... 74
5.2.4 Reaction Mechanism .............................. 74
5.3 Results and Discussion ................................. 76
5.3.1 Effect of Ultrasonic Frequency on Total Sulfur
Removal ......................................... 76
5.3.2 Effect of Reagent Concentration on Total
Sulfur Removal .................................. 77
5.3.3 Effect of Sonication Time on Total Sulfur
Removal ......................................... 78
5.3.4 Effect of Coal Particle Size on Total Sulfur
Removal ......................................... 79
5.3.5 Effect of Reagent Volume on Total Sulfur
Removal ......................................... 79
5.3.6 Statistical Validation of Results ............... 80
5.4 Optimum Conditions and Validation ...................... 81
5.5 Mechanistic Modeling of Ultrasound Assisted Reagent-
Based Coal De-Sulfurization ............................ 82
5.6 Scale-Up of Ultrasonic Reagent-Based Coal
De-Sulfurization ....................................... 86
5.7 Summary ................................................ 87
References .................................................. 88
6 Assessment of Benefits from Ultrasonic Coal-Wash (USCW) ..... 89
6.1 Introduction ........................................... 89
6.2 Proposed Flow Chart for USCW on Industrial Scale ....... 89
6.3 Effect of USCW on Metal Erosion and Corrosion Due
to Burning of High-Ash and Sulfur Coal ................. 91
6.4 Particulate and SOx Emission ........................... 92
Reference ................................................... 93
7 Summary, Conclusions and Recommendations .................... 95
7.1 Recommendations for Future Work ........................ 95
Appendix I ..................................................... 97
Appendix II .................................................... 99
Appendix III .................................................. 101
Appendix IV.................................................... 105
Appendix V .................................................... 109
Appendix VI ................................................... 113
Appendix VII .................................................. 117
Appendix VIII.................................................. 121
Curriculum Vitae .............................................. 125
|
|
