UNIVERSIDAD DE CANTABRIA PROGRAMA DE DOCTORADO EN INGENIERÍA QUÍMICA, DE LA ENERGÍA Y DE PROCESOS TESIS DOCTORAL Optimización del ciclo de vida para el diseño sostenible de sistemas circulares de gestión de residuos municipales PhD THESIS A life cycle optimization framework for the sustainable design of circular municipal solid waste management systems Selene Cobo Gutiérrez Directores: Prof. Dr. Ángel Irabien Gulías y Dr. Antonio Domínguez Ramos Escuela de Doctorado de la Universidad de Cantabria Santander 2019 “We do not inherit the Earth from our ancestors; we borrow it from our children.” Proverb CONTENTS PREFACE..................................................................................................................... 1 AGRADECIMIENTOS/ACKNOWLEDGEMENTS ................................................................ 3 RESUMEN ................................................................................................................... 5 ABSTRACT .................................................................................................................. 7 CHAPTER 1. GOALS AND SCOPE ................................................................................... 9 Revisiting the sustainability concept ................................................................................................. 11 The coordinated management of waste and resources..................................................................... 12 Monitoring the circular economy ...................................................................................................... 15 Policy development for the management of municipal solid waste .................................................. 17 State-of-the-art processes for bio-waste recycling ............................................................................ 21 The potential of nutrient recovery .................................................................................................... 23 THE CONTRIBUTIONS OF PROCESS SYSTEMS ENGINEERING TO SUSTAINABILITY .................................. 25 OBJECTIVES OF THE THESIS .................................................................................................................... 27 REFERENCES ........................................................................................................................................... 29 CHAPTER 2. METHODOLOGY AND FUNDAMENTALS ................................................... 37 MATHEMATICAL PROGRAMMING ......................................................................................................... 37 Multi-objective optimization ............................................................................................................. 39 LIFE CYCLE THINKING ............................................................................................................................. 40 BIOGEOCHEMICAL MODELING ............................................................................................................... 42 METHODOLOGICAL SEQUENCE .............................................................................................................. 45 REFERENCES ........................................................................................................................................... 46 CHAPTER 3. RESULTS AND DISCUSSION...................................................................... 48 REFERENCES ........................................................................................................................................... 50 CHAPTER 3.1. CIRCULAR INTEGRATED WASTE MANAGEMENT SYSTEMS ..................... 51 METHOD ................................................................................................................................................ 53 TECHNOLOGICAL BACKGROUND ............................................................................................................ 54 Quality and value of recycled materials ............................................................................................ 54 State-of-the-art technologies and processes for IWMSs ................................................................... 56 Materials recycling or energy recovery? ............................................................................................ 57 FRAMEWORK FOR THE ANALYSIS OF CIWMSs ....................................................................................... 60 Previous application of the circular economy approach to the design of IWMSs .............................. 60 Proposed definition of CIWMSs ......................................................................................................... 60 Configuration and boundaries of a CIWMS ....................................................................................... 62 Link between industrial symbiosis and CIWMSs ................................................................................ 64 Recommended tools for the analysis of CIWMSs .............................................................................. 65 METHODOLOGIES APPLIED IN THE LITERATURE .................................................................................... 65 HOT TOPICS ............................................................................................................................................ 67 Accounting for waste prevention ...................................................................................................... 67 Quantifying biogenic carbon.............................................................................................................. 69 Accounting for uncertainty ................................................................................................................ 71 Dynamic modeling ............................................................................................................................. 74 APPLICATION OF THE CRADLE-TO-CRADLE APPROACH.......................................................................... 76 Goal and scope definition .................................................................................................................. 76 Multi-functionality problem .............................................................................................................. 76 Functions of a CIWMS ................................................................................................................... 77 System expansion approach .......................................................................................................... 77 Allocation approach ...................................................................................................................... 78 Summary of approaches to solve the multi-functionality problem ............................................... 81 Functional unit ................................................................................................................................... 81 CONCLUSIONS ........................................................................................................................................ 83 REFERENCES ........................................................................................................................................... 86 CHAPTER 3.2. RESOURCE USE AND CARBON EMISSIONS........................................... 100 SYSTEM DESCRIPTION .......................................................................................................................... 102 METHODS ............................................................................................................................................ 105 LIFE CYCLE MODEL ............................................................................................................................... 106 PROBLEM FORMULATION .................................................................................................................... 107 PERFORMANCE INDICATORS ............................................................................................................... 108 DEFINITION OF SCENARIOS .................................................................................................................. 109 RESULTS AND DISCUSSION .................................................................................................................. 109 Research relevance and shortcomings ............................................................................................ 114 REFERENCES ......................................................................................................................................... 116 CHAPTER 3.3. CIRCULARITY AND ENVIRONMENTAL ASSESSMENT ............................. 120 METHODOLOGY ................................................................................................................................... 123 Superstructure description .............................................................................................................. 123 Data flow ......................................................................................................................................... 125 DEFINITION OF THE CIRCULARITY INDICATORS ................................................................................... 126 Nutrient circularity indicators.......................................................................................................... 128 PROBLEM FORMULATION