Material Recovery Processes Research Articles

Sustainable management of family life and finance in the context of digital capabilities - data flow dynamics

In recent years, biorefining Municipal Solid Waste (MSW) has gained attention as a promising solution to the challenges of waste management and resource shortages, while also advancing sustainability goals. This research focuses on the European Union, analyzing the material flow and sustainability of biorefining systems and evaluating their impact on society, the economy, and the natural environment. The final products of the integrated material recovery processes, including recycling (18.3 %), heavy metals (3.6 %), fiber (1.4 %), hydrogen sulfate (7.4 %), recoverable water (14.8 %), fertilizer (8.4 %), and electric power (0.126 MWH/t MSW), are derived from the combined operations of material recovery facilities, pulverization, chemical conversion, wastewater treatment plants (WWTP), and combined heat and power (CHP) systems. The CHP system recovers energy from sources such as refuse-derived fuel (RDF), other disposable waste, charcoal, and natural gas produced by material recovery facilities, chemical conversion, and anaerobic digestion (AD) systems. Levulinic acid (LA), priced at 52 Euro/t, generates a profit of 220 Euro/t, excluding any subsidies. Potential reductions in carbon dioxide emissions are estimated at 2.5 and 1.4 kg CO2 equivalents per kilogram of levulinic acid (LA) and fertilizer, respectively, and 0.18 kg CO2 equivalents per megajoule of electrical power. This study underscores the importance of sustainable management practices in the context of digital capabilities, emphasizing the data flow dynamics essential for optimizing family life and finance in achieving sustainability.

“A global perspective on building material recovery incorporating the impact of regional factors”

Recovery of buildings through the extraction of building materials at the end of the building life can contribute to the reduction of construction material consumption and waste generation. The viability of recovering in-situ building materials when they reach the end of their lifespan depends on regional factors such as construction and demolition norms, labour costs, secondary material markets, and general perceptions and culture toward material recovery processes. The objective of this study is to analyze the impact of regional factors on building end-of-life strategies. For this study, five different buildings with similar general characteristics from globally distributed locations are selected as case studies. To analyze the impact of regional factors, a previously developed decision-support optimization tool is used that intakes regionally dependent factor data and generates optimal end-of-life options for each building component that reflect market-based practices based on the regional factor data. The study takes a comparative approach to analyze the recovery potential of the chosen building case studies. The results of the study highlight the importance of social economic factors in the decision-making of building component end-of-life strategies alongside material recovery-related policies, incentives, and waste disposal regulations. Labour costs are found to be less impactful than regulations and cultural norms on materials recovery decisions. The findings of this study have important implications for the construction industry, policymakers, and researchers. Construction stakeholders can better assess the feasibility and potential benefits of recovering building components based on each region's specific conditions and consequently develop regionally focused policies and regulations that can more effectively reduce waste generation.

Environmental and Technological Assessment of Operations for Extraction and Concentration of Metals in Electronic Waste

The exponential growth in the consumption of electronics, in combination with the reduction in their useful life, has led to a significant increase in the volume of electronic materials which are discarded. Printed Circuit Boards (PCBs) are modules composed of ceramic, polymer, and metallic materials of high economic value and with a great potential for damage to biotic and anthropic environments when inadequately discarded. The aims of this work were to study the main environmental impacts and the efficiency of mechanical operations in the electronic waste recycling process in optimizing the concentration of metallic copper. For this, the samples obtained were characterized according to their morphology and chemical composition, and subjected to physical and mechanical treatments: dismantling, grinding, separation by granulometry, density, and magnetic property. The environment impacts were estimated by the Life Cycle Assessment of the pre-treatment processes, associated with copper extraction operations in Waste Printed Circuit Boards (WPCBs). According to the results obtained, it is possible to infer that the NM + 1 mm Concentrated product presents in its metallic composition around 78% copper, which contributes to the efficiency of the hydrometallurgical extraction processes. It is noteworthy that the Concentrated class represents about 14% of copper (wt) taking into account the amount of 3.789 kg of PCB waste input material. The potential for reinsertion of the dust in the material recovery process is highlighted, given that the chemical composition of this particulate has a significant presence of metals. In general, it was found that due to the higher concentration (wt%) of the sample being allocated in the range of −0.15 mm + 0.05 mm, the elements Fe (18.30%), Si (10.73%), Ca (9.21%), and Cu (8.89%) stand out regarding the participation of the elemental composition of this fraction and also regarding the general composition of the sample. Furthermore, the generation of dust during the fragmentation process can be associated with occupational respiratory diseases when not managed. About the Life Cycle Assessment, in seven of the nine categories evaluated, crushing and screening activities accounted for more than 90% of the recorded impact values. In general, it is estimated that in the pre-treatment phase it generated 15.4 kg CO2 eq.

From excavated waste to hydrogen: Life cycle techno-environmental-economic comparison between plasma-gasification-based water gas shift and sorption enhanced water gas shift routes

The mismanagement of excavated waste (EW) is leading to serious land occupancy and greenhouse gases leakage problems globally. This study explores the possibility to realize utilization of EW and satisfaction of the hydrogen fuel demand at the same time. Based on plasma gasification (PG), the excavated waste has shown its potential to act as a sustainable source of hydrogen. In this study, the techno-environmental-economic performance of the EWtH (excavated waste to hydrogen) process based on PG-WGS-AGR (water gas shift-acid gas removal) and PG-SEWGS (sorption enhanced water gas shift) routes are investigated. The results demonstrate that the EWtH process based on the PG-SEWGS route has higher exergy efficiency, better environmental performance, and more promising economic feasibility. The EWtH process can maintain profitable when resisting the fluctuation of EW treatment subsidy, selling price of CO2 and carbon tax (±75%), with the biggest LPEW (levelized profit of excavated waste) drop of 19.22%. However, as the selling of H2 is the largest income, the LPEW has decreased to a negative value within the fluctuation of the selling price of H2 in ± 55%, which suggests that the selling price of H2 is the decisive factor in the economic feasibility of the EWtH process. Also, the EW with fewer landfill years brings higher profit, and the material recovery process plays a more significant role in the treatment of EW with longer landfill years. The highest exergy efficiency (57.79%) and the most environmentally friendly performance (-70.84 mPE) locates in the 05-EWtH process applying SEWGS, and the 15-EWtH process based on PG-SEWGS route has the highest LPEW of 185.78 $/tonEW.

CONSIDERING ENGINEERING ACTIVITIES AND PRODUCT CHARACTERISTICS TO ACHIEVE MATERIAL CIRCULARITY BY DESIGN

AbstractTo select design guidelines engineers have to identify relevant from a bewildering amount of design guidelines. In this paper, a rule-based method for selecting design guidelines for material circularity selection is presented. For this purpose, a generic Product Life Cycle model is detailed with regard to Multi Material cycles (gPLC-MM). The presented method is divided into four steps. Core of the presented method is the comparison of circular product strategies with product life phases and material recovery processes. Engineering activities and increments of the product architecture are used to identify design guidelines. The results show that through the material circularity-oriented design guideline identification method, the product architecture is designed for different processes and technologies, to recover materials. The method allows engineers to select guidelines in a more targeted and consolidated way in sustainability-friendly product engineering.

Consecutive recovery of recovered carbon black and limonene from waste tyres by thermal pyrolysis in a rotary kiln

End of life tyres are one of the most abundant and least recycled waste streams. Material recovery processes that accommodate for the complexity and heterogeneity of waste tyres, such as pyrolysis, require urgent development. Examples of recycled tyre pyrolysis products include recovered carbon black (RCb), a recycled filler, and limonene, a solvent, although investigations reporting the recovery of both are limited. In this study the pyrolysis of waste tyres was investigated in a batch rotary kiln under varying conditions (temperature, gas flow, sample mass). Characterisation analysis was then applied to selected samples of RCb (BET surface area, transmissibility of toluene extract, proximate analysis) and tyre pyrolysis oil (yield, limonene content, FTIR). The best RCb (77.7 m2/g, 0.2% volatile matter, 17.0% ash, 94.8% transmissibility of toluene extract) was produced at 550 °C with a high ratio of purge gas flow (2000 mL/min) to rubber sample mass pyrolysed (100 g), minimising the recondensation of tarry volatiles on the RCb. The highest oil and limonene yield (38.4% and 17.4 g/kg waste tyres respectively) was produced at a temperature of 550 °C with a low ratio of purge gas (400 mL/min) to rubber sample pyrolysed (200 g), as these conditions prevented the decomposition of limonene to less valuable products and improved the oil trap condensation efficiency. These findings demonstrate the importance of pyrolysis processing conditions when considering the consecutive production of RCb and solvents from waste tyre pyrolysis, which shows significant future potential to valorise waste tyres, incentivising recycling.

Peroxymonosulfate activation by β-cyclodextrin modified amorphous manganese oxides for a high-efficiency bisphenol A degradation

Manganese oxide activated peroxymonosulfate (PMS) has gradually become one of the research focuses in the field of advanced oxidation. In this work, β-cyclodextrin (β-CD) modified amorphous manganese oxide (CD-AM) catalyst was obtained from a mild reaction condition (80 °C oil bath), high temperature crystallization is avoided in the synthesis process, which reduces the difficulty of catalyst preparation process and energy consumption. β-CD is involved in the formation of manganese oxides. Amorphous manganese oxides have larger specific surface area and better PMS activation effect than crystalline manganese oxides, which is different from previous studies. The enrichment of cyclodextrin on BPA can improve the removal activity of amorphous manganese oxide/PMS system on BPA. The introduction of β-CD increased the bisphenol A (BPA) degradation efficiency from 33.1% to 99.4%, and brought the kinetic constant to its 14.9 times. The 94% BPA degradation efficiency was obtained under neutral conditions that is more favorable for the actual process. During the degradation process, 1O2 and ·OH were the main ROS in CD-AM/PMS system, and O·- 2 not only promoted the conversion of O·- 2 to 1O2 but also accelerated the cycle of Mn (III)/Mn (IV). In addition, a simpler material recovery process for application was achieved by transforming CD-AM into the “supported membrane” (AMSM), and better performance and lower Mn ion leaching concentration were accessible. With the utilization of AMSM, Mn ion concentration in the filtrate after first filtration was about 1.2 mg/L, which was only 37% of the Mn ion concentration firstly detected in CD-AM. And after four cycles, the BPA degradation efficiency was 96.9%. When AMSM/PMS system was used to treat BPA in river water, the final degradation efficiency reached 94.8%. CD-AM as a catalyst for activating PMS shows great application potential in actual water.

Circular economy adoption barriers in built environment- a case of emerging economy

Built environment consumes vast volumes of natural resources and also poses several environmental threats owing to mining, construction emissions, and waste disposal processes. Thus, it is imperative that the principles of circular economy (CE) be adopted to enable the recirculation of resources back to the construction system. However, in the emerging economies, owing to numerous barriers, the momentum for achieving accountable progress towards CE adoption in the construction sector has not been adequate. This research article aims to understand & examine the factors that obstruct the incorporation of CE in the built environment or the construction sector in India. A total of sixteen barriers hampering the adoption of CE in built environment are identified and categorised under six categories of economic, environmental, technical, societal, governmental, and behavioral barriers. The research uses Decision-Making Trial and Evaluation Laboratory (DEMATEL) method to analyse the barriers and develop a cause-effect relationship among them. This study reveals that the most predominant barrier to adopting CE in the Indian construction sector is an environmental barrier. The lack of environmentally safe material recovery processes and high operating costs for running a circular supply chain are other significant barriers. Authors further stress on the interdependence of factors and propose appropriate enablers to facilitate CE in built environment. The study's findings are intended to enable policy and decision-makers of the built environment to implement CE effectively.

Analysis of the Past Seven Years of Waste-Related Doctoral Dissertations: A Digitalization and Consumer e-Waste Studies Mystery

Solving global sustainability challenges is based on a well-researched understanding of the corresponding underlying problems, key contributing factors, and current state-of-the-art. Utilizing the scope of recent doctoral studies is one potent way to map current young researchers nowadays and near future research focus areas and directions. Here, the authors focused on waste management, especially, mapping dissertations on the grooving global challenge of electronic waste. Currently, this is the first scoping study of its kind, about e-waste -related trends within the circle of waste management-related doctoral studies. Apparently, in a waste-related context, dissertations have a low interest in directly focusing on the topic of consumable e-waste, even though this waste stream is the world’s fastest-growing domestic waste stream. Only a handful of doctoral dissertations, related to e-waste management, were found in the study. In a more general waste-related benchmarking/comparing mapping search, the ProQuest Digital Dissertations database was found to contain 201 dissertations between the years 2015 and 2022, covering waste matters in general. E-waste was covered in six of these 201 dissertations. These six did not have any real overlapping between each other and their research areas. Further thesis content analysis revealed e-waste topics to be currently addressed through consumer behavior, material recovery processes, forecasting, and robotics. The need for future research in the areas of consumable e-waste management is also widely discussed.

Circular Economy of Construction and Demolition Waste: A Literature Review on Lessons, Challenges, and Benefits.

Conventionally, in a linear economy, C&D (Construction and Demolition) waste was considered as zero value materials, and, as a result of that, most C&D waste materials ended up in landfills. In recent years, with the increase in the awareness around sustainability and resource management, various countries have started to explore new models to minimize the use of limited resources which are currently overused, mismanaged, or quickly depleting. In this regard, the implementation of CE (Circular Economy) has emerged as a potential model to minimize the negative impact of C&D wastes on the environment. However, there are some challenges hindering a full transition to CE in the construction and demolition sectors. Therefore, this review paper aims to critically scrutinize different aspects of C&D waste and how CE can be integrated into construction projects. Reviewing of the literature revealed that the barriers in the implementation of CE in C&D waste sectors fall in five main domains, namely legal, technical, social, behavioral, and economic aspects. In this context, it was found that policy and governance, permits and specifications, technological limitation, quality and performance, knowledge and information, and, finally, the costs associated with the implementation of CE model at the early stage are the main barriers. In addition to these, from the contractors’ perspective, C&D waste dismantling, segregation, and on-site sorting, transportation, and local recovery processes are the main challenges at the start point for small-scale companies. To address the abovementioned challenges, and also to minimize the ambiguity of resulting outcomes by implementing CE in C&D waste sectors, there is an urgent need to introduce a global framework and a practicable pathway to allow companies to implement such models, regardless of their scale and location. Additionally, in this paper, recommendations on the direction for areas of future studies for a reduction in the environmental impacts have been provided. To structure an effective model approach, the future direction should be more focused on dismantling practices, hazardous material handling, quality control on waste acceptance, and material recovery processes, as well as a incentivization mechanism to promote ecological, economic, and social benefits of the CE for C&D sectors.

Variation in chemical composition of MSWI fly ash and dry scrubber residues

Our society generates extensive amounts of municipal solid waste (MSW), which are mainly incinerated for volume reduction and energy recovery. Though, MSW incineration generates hazardous air pollution control (APC) residues that must be treated and deposited in appropriate landfills. An alternative to landfilling is material recovery, leading to regeneration of valuable products and reducing hazardous waste amounts. The chemical composition of APC residues, stemming from MSW, makes the waste attractive for metal and salt recovery, but its variation makes the development of material recovery processes challenging. This study investigates results from 895 X-ray fluorescence analyses of fly ash and dry scrubber residue samples originating from Norway and Sweden between 2006 and 2020 to explore variation in chemical composition within and between different incineration plants. The average relative standard deviation of elemental concentration in APC residue was estimated to 30% within plants. The variation in elemental concentration between grate fired incineration plants is about half of the average variation within the plants. The study also clarifies compositional differences from APC residues originating from fluidized bed incinerators and grate incinerators. Also, reported concentrations of APC residues from other countries than Sweden and Norway showed significant differences in chemical composition. The presented variations clarifies the importance of holistic approaches for waste valorization processes which can substitute stabilization processes for landfilling.

Effect of Copper-Doping on LiNiO2 Positive Electrode for Lithium-Ion Batteries

LiNiO2 (LNO) is one of the most potential alternatives to LiCoO2 in Li ion batteries (LIBs). However, it still suffers from poor cyclability. Meanwhile, the recycling processes of LIBs are widely investigated to enable effective recycling for the growing amounts of LIB waste. Cu is one of the dominating impurities in LIB recycling fractions. In this work, LNO and 0.2 mol% Cu-doped LNO are studied. Cu-doping is demonstrated to stabilize the LNO lattice structure, reduce cation mixing and improve the reversibility of phase transitions during electrochemical processes. Consequently, the rate capability of LNO is improved by Cu-doping, especially at high C-rates. The Cu-doped LNO shows much higher capacity retention of 85% than that of 66% for the undoped LNO at the current density of 100 mA·g−1 after 100 cycles in a voltage window of 2.5–4.5 V. Our results show that a possible Cu contamination in the Ni fraction of the LIB material recovery process can be used to enhance the electrochemical properties of newly synthetized Ni-based positive electrode materials.

Environment-friendly technology for recovering cathode materials from spent lithium iron phosphate batteries.

The consumption of lithium iron phosphate (LFP)-type lithium-ion batteries (LIBs) is rising sharply with the increasing use of electric vehicles (EVs) worldwide. Hence, a large number of retired LFP batteries from EVs are generated annually. A recovery technology for spent LFP batteries is urgently required. Compared with pyrometallurgical, hydrometallurgical and biometallurgical recycling technologies, physical separating technology has not yet formed a systematic theory and efficient sorting technology. Strengthening the research and development of physical separating technology is an important issue for the efficient use of retired LFP batteries. In this study, spent LFP batteries were discharged in 5 wt% sodium chloride solution for approximately three hours. A specially designed machine was developed to dismantle spent LFP batteries. Extending heat treatment time exerted minimal effect on quality loss. Within the temperature range of 240°C-300°C, temperature change during heat treatment slightly affected mass loss. The change in heat treatment temperature also had negligible effect on the shedding quality of LFP materials. The cathode material and the aluminium foil current collector accounted for a certain proportion in a sieve with a particle size of -1.25 + 0.40 mm. Corona electrostatic separation was performed to separate the metallic particles (with a size range of -1.5 + 0.2 mm) from the nonmetallic particles of crushed spent LFP batteries. No additional reagent was used in the process, and no toxic gases, hazardous solid waste or wastewater were produced. This study provides a complete material recovery process for spent LFP batteries.

Integracja procesów odzysku/przekształcenia energetycznego i materiałowego odpadów tworzyw sztucznych pochodzenia komunalnego w krajowym systemie gospodarki odpadami

Integracja procesów odzysku/przekształcenia energetycznego i materiałowego odpadów tworzyw sztucznych pochodzenia komunalnego w krajowym systemie gospodarki odpadami

Sustainable E-waste supply chain management with price/sustainability-sensitive demand and government intervention

The impact of appropriate E-waste management practices on the environment, human health, and natural resources has made E-waste management an interesting research topic in recent decades. Research also shows that government intervention is an important factor in controlling the emission volume produced by waste management systems. This study considers a base E-waste supply chain in which a collection center is responsible for collecting E-waste and delivering it to a recycling center. The recycling center recovers valuable material and sells it to electronic device manufacturing companies using a price/sustainability-sensitive demand. E-waste material recovery generates emissions that are undesirable for manufacturing companies. Two extended cases regarding the base supply chain are studied, as well: (1) the recycling center is also active in E-waste collection. (2) There are two active recycling centers. Although the sustainability-sensitive demand is a controlling factor for material recovery emissions, government interferences through tariff and emission penalties make sure that sustainable issues are considered in the material recovery process. Each plant in this study makes a marginal profit by processing E-waste; therefore, it is important to know which plant is the primary decision-maker when it comes to price. Because of its capability in terms of solving interactive decision-making problems, game theory is used to model different scenarios in our problem. Equilibrium values are derived, and a numerical example with parameter sensitivity analysis is provided to show the applicability of the proposed models. The results show that the E-waste supply chain makes more profit and selects a higher level of material recovery sustainability if the plants work under a centralized decision-making framework. Moreover, it is more profitable for the entire E-waste supply chain if the recycling center undertakes a portion of the E-waste collection activity.

Eddy current separation for recovering aluminium and lithium-iron phosphate components of spent lithium-iron phosphate batteries.

With the rapid development of the electric vehicle market since 2012, lithium-iron phosphate (LFP) batteries face retirement intensively. Numerous LFP batteries have been generated given their short service life. Thus, recycling spent LFP batteries is crucial. However, published information on the recovery technology of spent LFP batteries is minimal. Traditional separators and separation theories of recovering technologies were unsuitable for guiding the separation process of recovering metals from spent LFP batteries. The separation rate of the current method for recovering spent LFP batteries was rather low. Furthermore, some wastewater was produced. In this study, spent LFP batteries were dismantled into individual parts of aluminium shells, cathode slices, polymer diaphragms and anode slices. The anode pieces were scraped to separate copper foil and anode powder. The cathode pieces were thermally treated to reduce adhesion between the cathode powder and the aluminium foil. The dissociation rate of the cathode slices reached 100% after crushing when the temperature and time reached 300℃ and 120 min, respectively. Eddy current separation was performed to separate nonferrous metals (aluminium) from aluminium and LFP mixture. The optimized operation parameters for the eddy current separation were feeding speed of 1 m/s and magnetic field rotation speed of 4 m/s. The separation rate of the eddy current separation reached 100%. Mass balance of the recovered materials was conducted. Results showed that the recovery rate of spent LFP can reach 92.52%. This study established a green and full material recovery process for spent LFP batteries.

Recycle of End-of-Life NMC 111 Cathodes By Electrochemical Relithiation

Recycling end-of-life (EoL) lithium ion batteries (LIBs) is of great significance to provide additional transition metal resources and alleviate environmental pollution from batteries wastes, but lags far behind compared with that of lead-acid batteries in the recycling industry. Conventional LIBs recycling methods including pyrometallurgy and hydrometallurgy processes have limitations with regard to energy inefficiency, extensive gas treatment, as well as complex chemical reactions and purification steps for leaching and separating metals. This project is part of ReCell which is a collaborative effort to develop efficient and economical recycle and reuse methods for EoL battery cathodes. The objective of this work is to recover the EoL cathode performance and structure by electrochemical relithiation using a Li metal sacrificial anode since Li ion (Li+) inventory loss plays a significant role for the cathode degradation. The morphology, composition and structure of the initial NMC 111 pristine and chemically delithiated powders used for the ReCell project were characterized through Raman spectroscopy, FIB SEM and TGA. Chemically Delithiated NMC 111 anodes have been prepared and relithiated using a range of temperatures and currents in order to optimize the electrochemical relithiation for application in a roll to roll process. Initial results indicate that elevated temperatures will be necessary to facilitate fast relithiation of the NMC 111 cathodes with the addition of more thermally stable electrolytes. Analysis and characterization of aged NMC 111 anodes in pouch cells is applied to verify the effectiveness of electrochemically relithiated anodes and to compare to the chemically delithiated NMC 111 model material. This study provides more understanding towards developing a battery material recovery process that will potentially recover specialized material morphology and help to minimize energy use and emissions. Figure 1

Analysis on adsorbent for spent solvent treatment by micro-PIXE and EXAFS

The spent PUREX solvent containing U and Pu is generated from the reprocessing process of spent nuclear fuel. The nuclear material removal is important for the safe storage or disposal of the spent solvent. Our previous study revealed that the adsorbent with the iminodiacetic acid (IDA) functional group is one of the most promising materials for designing the nuclear material recovery process. Accordingly, an IDA-type adsorbent was synthesized by using graft polymerization technology or a chemical reaction to improve the adsorption rate and capacity. The synthesized IDA-type adsorbent was characterized by micro particle-induced X-ray emission (PIXE) and extended X-ray absorption fine structure (EXAFS) analyses. The micro-PIXE analysis revealed that Zr was adsorbed on the whole synthesized adsorbents and quantified the microamount of adsorbed Zr. Moreover, EXAFS suggested that Zr in the aqueous solution and solvent can be trapped by the IDA group with different mechanisms.

Critical Analysis of Material and Energy Recovery Processes of Municipal Solid Waste in Satu Mare County

Critical Analysis of Material and Energy Recovery Processes of Municipal Solid Waste in Satu Mare County

Evaluating carbon footprint of municipal solid waste treatment: Methodological proposal and application to a case study

This paper applies the Life Cycle Assessment methodology to develop a simple method to calculate the carbon footprint of the municipal solid waste treatment stage. This simple and structured methodological procedure takes into account: i) direct greenhouse gas emissions produced in waste treatment, taking place within the city boundary (scope 1 of international carbon footprint standards); ii) indirect greenhouse gas emissions related to the use of grid-supplied electricity, as well as fuel production and distribution (scopes 2 and 3 emissions as per international carbon footprint standards); and iii) avoided greenhouse gas emissions as a result of the products obtained (if any) that can replace other products or the raw materials used to produce them. Madrid City (a representative European city), the capital of Spain, was used as a case study to prove the validity and usefulness of the proposed methodology. In this city, 344 kg of municipal solid wastes were produced per inhabitant in 2013. These wastes were collected separately in different fractions (packaging, glass, paper/cardboard and mixed waste, including organic material). Mixed waste and packaging fractions were processed at the Valdemingómez Technology Park. The current treatment stage was compared with several alternative scenarios which describe hypothetical management routes for the different waste fractions. The carbon footprint for the current situation is equal to 224 kg CO2 eq/twaste. In comparison to the worst situation, corresponding to the scenario in which municipal wastes were landfilled without energy recovery, the current scenario reduces its carbon footprint by 1597 kg CO2 eq/twaste (a reduction of 88%). Improvements in the material separation and recovery processes, along with the implementation of biological treatments for the organic fraction, clearly contribute to reducing the carbon footprint of the municipal solid wastes handled in the city of Madrid.According to the obtained results, the scenarios based on a total recovery of valuable materials and waste-to-energy or anaerobic digestion treatments present the lowest carbon footprint because burden avoided is more important than direct and indirect emissions from treatments. In addition, the consumption of electricity and the emissions derived from its generation (mix of generation), can increase the carbon footprint of power-intensive treatments.