Sustainable Materialization of Residues from Thermal Processes into Carbon Sinks

Two of the largest and most important waste products from industrial the rmal processes are carbon dioxide gas and waste solid residues. Given th e high financial and environmental burden caused by these waste products , it is urgently desirable to industry and society alike to find a susta inable manner for managing them. The objective of this research project is the production of a carbon sink based on the process of mineral carbo n sequestration that provides a responsible and economical outlet for th ese waste products. Thermal processes are commonly applied in the production and refinement of metals, in waste incineration, energy generation, among other areas. The solid waste products typically produced include slag and fly ash, wh ich are composed primarily of oxides of silicon, calcium, magnesium, alu minum and iron, along other components such as heavy metals, chlorides a nd sulfates. Recently, due to rising production costs, increased regulat ory pressures and growing awareness towards environmental issues, there has been a change in the perception of these materials. It has been real ized that they can be regarded as potential products rather than simply as waste. This shift, however, still faces numerous challenges: unavaila bility of reliable low-cost technologies, variability of material qualit y, lack of legislation, underdeveloped markets for the resulting product s, and poor societal experience with closing material cycles. Thermal processes also generate a vast amount of carbon dioxide, which i s invariably emitted to the atmosphere. Concern regarding the role of ca rbon dioxide as a greenhouse gas in climate change is evolving rapidly, and it is evident that these emissions will become ever more regulated i n the future. In this regard, it will be of financial benefit to industr y to limit its net carbon dioxide emissions. Methods to sequester carbon dioxide gas currently being investigated included mineral carbon seques tration, which uses materials such as olivine and serpentine that must b e mined for use, and subsurface injection, which requires extensive geol ogical study and stewardship. An alternative method, sequestration in al kaline waste materials, is interesting due to the high reactivity of the material and the ease of on-site production, and is seen as potentially a low cost option. Further benefits include that fact that reaction of the alkaline waste with carbon dioxide stabilizes the material and often improves its environmental properties for disposal. This research project aims to investigate the use of alkaline waste mate rials in carbon dioxide sequestration and identify process properties su ch as sequestration load and yield efficiency, reaction kinetics, and li miting rate conditions. An optimized carbon sink should sequester a maxi mum amount of carbon dioxide without loss of reaction rate over time. Ai ming at the production of an improved carbon sink, two potential areas o f waste product improvement will be investigated: the first is to steer the functional properties of the cooled waste products during hot-stage residue processing; the second is to use physical-chemical methods for i mproving cold-product properties. Several carbonation strategies will be studied to overcome current process barriers and for optimization of th e concept, such as liquid-film carbonation and suspension carbonation. F or further sequestration process enhancement, a new approach will be int roduced by using localized energy for abrasion of the particles to obtai n new reaction surfaces and for enhanced diffusion.FOREWORD I ABSTRACT III SAMENVATTING V LIST OF ABBREVIATIONS AND SYMBOLS VII LIST OF PUBLICATIONS IX TABLE OF CONTENTS XIII 1. INTRODUCTION, SCOPE AND OUTLINE 1 1.1. INTRODUCTION 1 1.2. SCOPE 5 1.3. OUTLINE 8 2. RECENT DEVELOPMENTS AND PERSPECTIVES ON THE TREATMENT OF INDUSTRIAL WASTES BY MINERAL CARBONATION – A REVIEW 11 2.1. INTRODUCTION 12 2.2. MINERAL CARBONATION APPROACHES 13 2.2.1. Direct mineral carbonation 13 2.2.2. Indirect mineral carbonation 15 2.3. TREATMENT OF INDUSTRIAL ALKALINE WASTES BY MINERAL CARBONATION 16 2.3.1. Metallurgical slags 16 2.3.2. Incineration ashes 19 2.3.3. Mining tailings and asbestos containing materials 20 2.3.4. Red mud 22 2.3.5. Oil-shale processing residues 23 2.4. VALORIZATION OF TREATED INDUSTRIAL WASTES 24 2.5. CONCLUSIONS 26 2.6. REFERENCES 27 3. PROCESS INTENSIFICATION ROUTES FOR MINERAL CARBONATION 35 3.1. INTRODUCTION 36 3.2. BASICS OF PROCESS INTENSIFICATION AND PROCESS INTEGRATION 37 3.3. CASE STUDIES 39 3.3.1. Ultrasound assisted mineral carbonation 39 3.3.2. Intensified carbonation of stainless steel slag 41 3.3.3. Intensified carbonation of carbon steel slag 42 3.4. CONCLUSIONS 43 3.5. REFERENCES 43 4. ULTRASOUND-INTENSIFIED MINERAL CARBONATION 45 4.1. INTRODUCTION 46 4.2. BACKGROUND 46 4.2.1. Mineral carbonation 46 4.2.2. Ultrasound 47 4.2.3. Stainless steel slag 48 4.3. OBJECTIVES 49 4.4. MATERIALS AND METHODS 49 4.5. RESULTS AND DISCUSSION 51 4.5.1. Optimization of horn sonication by calorimetry 51 4.5.2. Effect of sonication on particle size 53 4.5.3. Effect of sonication on carbonation 55 4.5.4. Energy efficiency and scale-up considerations 61 4.6. CONCLUSIONS 62 4.7. REFERENCES 63 5. SYNTHESIS OF PURE ARAGONITE BY SONOCHEMICAL MINERAL CARBONATION 67 5.1. INTRODUCTION 68 5.2. EXPERIMENTAL SECTION 70 5.3. RESULTS AND DISCUSSION 72 5.3.1. Influence of stirring mode and temperature 72 5.3.2. Influence of MCR 75 5.3.3. Influence of ultrasound parameters 76 5.3.4. Influence of other process parameters 77 5.3.5. Synthesis at optimized conditions and lowest temperature 80 5.3.6. Fed-batch process 82 5.3.7. Precipitate powder characterization by laser diffraction 83 5.4. CONCLUSIONS 84 5.5. REFERENCES 85 6. MAGNESIUM CHLORIDE AS A LEACHING AND ARAGONITE-PROMOTING SELF-REGENERATIVE ADDITIVE FOR THE MINERAL CARBONATION OF CALCIUM-RICH MATERIALS 89 6.1. INTRODUCTION 90 6.2. METHODOLOGY 92 6.2.1. Alkaline materials 92 6.2.2. Leaching tests 94 6.2.3. Carbonation tests 95 6.2.4. Analytical methods 95 6.3. RESULTS AND DISCUSSION 96 6.3.1 Leaching results 96 6.3.2. Carbonation results 103 6.4. CONCLUSIONS 108 6.5. REFERENCES 109 7. STABILIZATION OF BASIC OXYGEN FURNACE SLAG BY HOT-STAGE CARBONATION TREATMENT 113 7.1. INTRODUCTION 114 7.2. MATERIALS AND METHODS 115 7.2.1. BOF slag 115 7.2.2. High temperature carbonation methodology 116 7.2.3. Basicity and leaching tests 118 7.3. RESULTS AND DISCUSSION 118 7.3.1. Characterization of BOF slags 118 7.3.2. High temperature carbonation 121 7.3.3. Basicity and heavy metal leaching 133 7.4. CONCLUSIONS 136 7.5. REFERENCES 137 7.6. SUPPLEMENTARY CONTENT 140 8. SUSCEPTIBILITY OF MINERAL PHASES OF STEEL SLAGS TOWARDS MINERAL CARBONATION: MINERALOGICAL, MORPHOLOGICAL AND CHEMICAL ASSESSMENT 147 8.1. INTRODUCTION 148 8.2. MATERIALS AND METHODS 149 8.2.1. Steel slags 149 8.2.2. Synthetic minerals 152 8.2.3. Pressurized slurry carbonation 154 8.2.4. Incubator carbonation 154 8.2.5. Analytical tests 154 8.3. RESULTS AND DISCUSSION 155 8.3.1 CO2 uptake of carbonated materials 155 8.3.2. Carbonation conversion of individual mineral phases 157 8.3.3. Steel slags carbonation results 159 8.3.4. Carbonate mineral phases 162 8.3.5. Non-carbonate mineral phases 164 8.3.6. Carbonated particle and crystal morphology 165 8.3.7. Basicity 167 8.4. CONCLUSIONS 169 8.5. REFERENCES 170 8.6. SUPPLEMENTARY MATERIAL 173 9. ACCELERATED MINERAL CARBONATION OF STAINLESS STEEL SLAGS FOR CO2 STORAGE AND WASTE VALORIZATION: EFFECT OF PROCESS PARAMETERS ON GEOCHEMICAL PROPERTIES 179 9.1. INTRODUCTION 180 9.2. MATERIALS AND METHODS 181 9.2.1. Materials characterization methodologies 181 9.2.2. Stainless steel slags 182 9.2.3. Thin-film carbonation methodology 184 9.2.4. Slurry carbonation methodology 185 9.2.5. Batch leaching test methodology 185 9.3. RESULTS 186 9.3.1. CO2 uptake 186 9.3.2. Mineralogy 192 9.3.3. Heavy metal leaching 198 9.4. DISCUSSION 202 9.5. CONCLUSION 203 9.6. REFERENCES 204 9.7. SUPPLEMENTARY CONTENT 207 9.8. ADDENDUM 218 9.8.1. Thin-film carbonation preliminary data 218 9.8.2. Theoretical analysis of carbonated shell effect on passivation 219 10. CONCLUSIONS AND FUTURE PERSPECTIVES 223 10.1. GENERAL CONCLUSIONS AND FINDINGS 223 10.2. RELATED AND ONGOING WORKS 233 10.2.1. Remediation of municipal solid waste incineration bottom ashes 234 10.2.2. Bioleaching of natural and waste-derived alkaline materials 236 10.2.3. Integrated mineral carbonation reactor technology: the gravity pressure vessel 237 10.2.4. Two-way valorization of blast furnace slag 238 10.2.5. In-situ high-pressure X-ray diffraction investigation of mineral carbonation kinetics of steel slags and synthetic constituent phases 240 10.3. FUTURE PERSPECTIVES 242 CURRICULUM VITAE 247nrpages: 266status: publishe