Contribution of plastic waste recovery to greenhouse gas (GHG) savings in Spain

This paper concentrates on the quantification of greenhouse gas (GHG) emissions of post-consumer plastic waste recovery (material or energy) by considering the influence of the plastic waste quality (high or low), the recycled plastic applications (virgin plastic substitution or non-plastic substitution) and the markets of recovered plastic (regional or global). The aim is to quantify the environmental consequences of different alternatives in order to evaluate opportunities and limitations to select the best and most feasible plastic waste recovery option to decrease the GHG emissions. The methodologies of material flow analysis (MFA) for a time period of thirteen years and consequential life cycle assessment (CLCA) have been integrated. The study focuses on Spain as a representative country for Europe. The results show that to improve resource efficiency and avoid more GHG emissions, the options for plastic waste management are dependent on the quality of the recovered plastic. The results also show that there is an increasing trend of exporting plastic waste for recycling, mainly to China, that reduces the GHG benefits from recycling, suggesting that a new focus should be introduced to take into account the split between local recycling and exporting

Floods and consequential life cycle assessment: integrating flood damage into the environmental assessment of stormwater Best Management Practices

Stormwater management is essential to reducing the occurrence of flooding events in urban areas and to adapting to climate change. The construction of stormwater Best Management Practices (BMPs) entails a series of life cycle environmental impacts but also implies avoided burdens, such as replacing urban infrastructure after flooding. The aim of this paper is to integrate flood damage prevention into the life cycle assessment (LCA) of BMPs for quantifying their net environmental impact (NEI) and environmental payback (EP) from a consequential LCA standpoint. As a case study, the application of a filter, swale and infiltration trench (FST) in a Brazilian neighborhood was assessed considering a high-intensity rainfall event. The potential avoided impacts were related to cars and sidewalks that were not destroyed due to flooding. In terms of CO2eq. emissions, the environmental investment related to the FST was recovered when the destruction of one car or 84 m2 of sidewalk was prevented. The NEI of the FSTs resulted in significant impact reductions (up to 700%) with respect to not accounting for the avoided products. This approach can be implemented to any type of BMP, and more accurate estimations can be made with data for different events and different types of material damage.Peer ReviewedPostprint (author's final draft

Energy balance and environmental impact analysis of marine microalgal biomass production for biodiesel generation in a photobioreactor pilot plant

A life cycle assessment (LCA) and an energy balance analysis of marine microalgal biomass production were conducted to determine the environmental impacts and the critical points of production for large scale planning. The artificial lighting and temperature conditions of an indoor bubble column photobioreactor (bcPBR) were compared to the natural conditions of an equivalent outdoor system. Marine microalgae, belonging to the dinoflagellate and raphidophyte groups, were cultured and the results were compared with published LCA data obtained from green microalgae (commonly freshwater algae). Among the species tested, Alexandrium minutum was chosen as the target marine microalgae for biomass production under outdoor conditions, although there were no substantial differences between any of the marine microalgae studied. Under indoor culture conditions, the total energy input for A. minutum was 923 MJ kg¯¹ vs. 139 MJ kg¯¹ for outdoor conditions. Therefore, a greater than 85% reduction in energy requirements was achieved using natural environmental conditions, demonstrating the feasibility of outdoor culture as an alternative method of bioenergy production from marine microalgae. The growth stage was identified as the principal source of energy consumption for all microalgae tested, due to the electricity requirements of the equipment, followed by the construction material of the bcPBR. The global warming category (GWP) was 6 times lower in outdoor than in indoor conditions. Although the energy balance was negative under both conditions, this study concludes with suggestions for improvements in the outdoor system that would allow upscaling of this biomass production technology for outdoor conditions in the Mediterranean

Potential savings of resources and greenhouse gas emissions from waste management: a case study of Spain in a global economy

Nuestras sociedades necesitan soluciones para reducir el consumo de recursos, así como de gases de efecto invernadero (GHG en inglés). La identificación de los residuos como un recurso valioso puede ayudar a reducir el consumo de recursos y en consecuencia las emisiones de GHG. Por lo tanto, el enfoque ha sido originalmente puesto en la recuperación y el reciclaje. Sin embargo, los gestores de residuos y los investigadores han destacado la reciente importancia de los residuos comercializados en mercados globales. Esta perspectiva global podría afectar los ahorros de emisiones de GHG atribuidas al reciclaje. Por lo tanto, el objetivo de esta tesis es en primer lugar calcular y evaluar las emisiones de GHG de la gestión en España de los residuos sólidos municipales (MSW, en inglés). En segundo lugar un enfoque especial se pone en las emisiones de GHG del reciclaje teniendo en cuenta el mercado y el comercio internacional, especialmente para los residuos de papel, aluminio y plástico. Una nueva herramienta llamada CO2ZW ®, el análisis de ciclo de vida consecuencial (CLCA en inglés) y el análisis del flujo de materiales (MFA en inglés) se aplicaron para las evaluaciones de GHG y de recursos. La aplicación de la CO2ZW ® para evaluar la gestión de los MSW confirmó que existe un alto potencial para la mitigación del cambio climático en España a través del aumento de la recuperación material junto con la reducción de la eliminación de los vertederos. La aplicación del MFA demostró que existe una considerable acumulación de productos de papel, aluminio y plástico que en los próximos años se convertirá en residuos pero el incremento de la oferta de residuo probablemente será exportado. Por otra parte, bajo el supuesto de que el reciclaje evita la producción de materia prima, se determinó también que el reciclaje evita emisiones de GHG. Sin embargo, los residuos pueden ser reciclados en España o en el extranjero, y el reciclaje puede sustituir la producción mundial o la española. Las emisiones de GHG varían en cada caso. Las producciones mundiales más competitivas de pulpa virgen, aluminio primario y plástico virgen fueron identificadas como los escenarios base bajo el CLCA. Las producciones nacionales españoles fueron evaluados como escenarios alternativos. Los resultados mostraron que los procesos más competitivos generan más emisiones de GHG, ya que son más ineficientes y a menudo se encuentran en países con alto contenido de carbón en su mix eléctrico Por lo tanto, si estos procesos se evitan mediante el reciclaje, más emisiones de GHG son mitigados que si se evitan los procesos españoles. Además, el aumento de la exportación de residuos disminuye los beneficios de GHG en todos los escenarios evaluados con excepción de la exportación de chatarra de aluminio. Los resultados no sólo pueden ayudar a los investigadores para evaluar las emisiones de GHG de la gestión de residuos, pero también pueden ser utilizados por los productores, gestores de residuos y los políticos de residuos para evaluar y proponer la mejor estrategia para reducir el consumo de recursos junto con las emisiones de GHG.Our societies need solutions to reduce resource consumption as well as greenhouse gas (GHG) emissions. Identifying waste as a valuable resource can help reduce resource consumption and consequently GHG emissions. Therefore, focus has originally been placed on recovery and recycling. However, waste managers and researchers have recently highlighted the importance of wastes traded in global markets. This global perspective could affect the savings of GHG emissions attributed to recycling. Thus, the goal of this thesis is firstly to calculate and evaluate the GHG emissions from municipal solid waste (MSW) management in Spain. Secondly a special focus is put on the GHG emissions of recycling considering the market and the international trade, specifically for waste paper, aluminium old scrap and plastic waste. A new tool called CO2ZW®, consequential life cycle assessment (CLCA) and material flow analysis (MFA) were applied for the GHG and resource assessments. The application of the CO2ZW® to evaluate the MSW management confirmed that there is a high potential for climate change mitigation in Spain through the increase of material recovery along with reducing disposal to landfills. The application of MFA showed that there is a considerable accumulation of paper, aluminium and plastics products which in coming years will become waste but the increase in waste supply will probably be exported. Moreover, under the assumption that recycling avoids raw material production, it was also determined that recycling avoids GHG emissions. However, waste can be recycled in Spain or abroad, and recycling can substituted global or Spanish raw material production. The GHG emissions varied in each case. The most competitive global productions of virgin pulp, primary aluminium and virgin plastic were identified as the base scenarios under CLCA. The Spanish national productions were assessed as alternative scenarios. Results showed that the most competitive processes generate more GHG emissions as they are more inefficient and they are often located in countries with high hard coal content in their electricity mixes. Therefore, if these processes are avoided by recycling, more GHG emissions are mitigated than if the Spanish processes are avoided. In addition, increasing the export of waste decreases the GHG benefits for all scenarios evaluated except for the aluminium old scrap export. The results not only help researchers to evaluate the GHG emissions from waste management but also can be used by producers, waste managers and waste politicians to evaluate and propose the best strategy to reduce the resource consumption and the GHG emissions

Contribution of plastic waste recovery to greenhouse gas (GHG) savings in Spain

This paper concentrates on the quantification of greenhouse gas (GHG) emissions of post-consumer plastic waste recovery (material or energy) by considering the influence of the plastic waste quality (high or low), the recycled plastic applications (virgin plastic substitution or non-plastic substitution) and the markets of recovered plastic (regional or global). The aim is to quantify the environmental consequences of different alternatives in order to evaluate opportunities and limitations to select the best and most feasible plastic waste recovery option to decrease the GHG emissions. The methodologies of material flow analysis (MFA) for a time period of thirteen years and consequential life cycle assessment (CLCA) have been integrated. The study focuses on Spain as a representative country for Europe. The results show that to improve resource efficiency and avoid more GHG emissions, the options for plastic waste management are dependent on the quality of the recovered plastic. The results also show that there is an increasing trend of exporting plastic waste for recycling, mainly to China, that reduces the GHG benefits from recycling, suggesting that a new focus should be introduced to take into account the split between local recycling and exporting

Deposition and residues of azoxystrobin and imidacloprid on greenhouse lettuce with implications for human consumption

Lettuce greenhouse experiments were carried out from March to June 2011 in order to analyze how pesticides behave from the time of application until their intake via human consumption taking into account the primary distribution of pesticides, field dissipation, and post-harvest processing. In addition, experimental conditions were used to evaluate a new dynamic plant uptake model comparing its results with the experimentally derived residues. One application of imidacloprid and two of azoxystrobin were conducted. For evaluating primary pesticide distribution, two approaches based on leaf area index and vegetation cover were used and results were compared with those obtained from a tracer test. High influence of lettuce density, growth stage and type of sprayer was observed in primary distribution showing that low densities or early growth stages implied high losses of pesticides on soil. Washed and unwashed samples of lettuce were taken and analyzed from application to harvest to evaluate removal of pesticides by food processing. Results show that residues found on the Spanish preharvest interval days were in all cases below officially set maximum residue limits, although it was observed that time between application and harvest is as important for residues as application amounts. An overall reduction of 40–60% of pesticides residues was obtained from washing lettuce. Experimentally derived residues were compared with modeled residues and deviate from 1.2 to 1.4 for imidacloprid and azoxystrobin, respectively, presenting good model predictions. Resulting human intake fractions range from... for imidacloprid to ... for azoxystrobin

Environmental consequences of recycling aluminum old scrap in a global market

Títol del pre-print: Global warming potential of the circular economy of aluminium: the role of old scrap recyclingFor decades, aluminium recycling was a regional concern traditionally concentrated in the regions with high aluminium demand and a well-organized aluminium recycling industry. Today, however, aluminium scrap is a global raw material commodity. This change has increased the need to analyze the flows of aluminium scrap, as well as to determine the environmental consequences from aluminium recycling. The objective of this work is to determine the environmental consequences of the old scrap aluminium collection for recycling, considering the market interactions. The study focused on Spain as a representative country for Europe. We integrate material flow analysis (MFA) with consequential life cycle assessment (CLCA) in order to determine the most likely destination for the old scrap and the most likely corresponding process affected. Based on this analysis, it is possible to project some scenarios and to quantify the environmental impacts (generated and avoided) associated with aluminium recycling within a global market. From the MFA results, we projected that the demand for aluminium products will be met mainly with an increase in primary aluminium imports, and the excess of old scrap not used in Spain will be exported in future years, mainly to Asia. Depending on the marginal source of primary aluminium considered, the greenhouse gases (GHG) emission estimates varied between -17,088 kg of CO2 eq. t-1 of old scrap collected to -10,305 of CO2 eq. t-1 of old scrap collected for the global or local scenario, respectively. More GHG emissions are avoided with an increase in export flows, but the export of old scrap should be considered as the loss of a key resource, and in the long term, it will also affect the semifinished products industry. Mapping the flows of raw materials and waste, as well as quantifying the environmental impacts derived from recycling, has become an essential prerequisite to consistent development from a linear towards a circular economy

A realistic material flow analysis for end-of-life plastic packaging management in Spain: Data gaps and suggestions for improvements towards effective recyclability

In this study we conducted a material flow analysis (MFA) of plastic packaging to determine the current state and performance of waste collection and recyclability with respect to the circularity objectives established by the European Union. In order to reach a recycling rate of 50% for plastic packaging waste and a recycled content rate of 25%, the material and packaging design system must be modified. Through the MFA we conducted in Spain, we observed that the figures published by official entities do not match the reality and it is not technically possible to achieve the objectives put in place due to the characteristics of the different parts of the materials. On the one hand, the official figures provided by the company in charge of packaging waste management range between a recycling rate of 48% to 70%. However, the data we obtained indicate an actual collection rate of 15% and a final recycling rate of 11%, figures that drastically differ from the European targets. On the other hand, we have observed that there is a very noticeable difference between the various types of plastic. For example, HDPE is recycled at a rate of 30% with almost no rejections at the plant. In contrast, only 3% of plastic film is recycled although it represents nearly half of the total plastic produced for packaging. With this in mind, unless an exclusive policy is created and focused entirely on this segment, it will be impossible to achieve the circularity objectives even if collection is increased to the highest levels possible. Establishing objectives that address administrative logic without taking into account the technical and scientific reality of the materials is impossible as we have illustrated with the indicators extracted from this MFA. In short, we have demonstrated a realistic scenario for transitioning towards a circular economy with regard to plastics in which the material uses are harmonized (whether for food contact or non-food contact), all film is diverted from the plastic fraction, and a possible path towards recyclability is taken into account considering the specific nature of the materials.Peer ReviewedPostprint (author's final draft

Energy balance and environmental impact analysis of marine microalgal biomass production for biodiesel generation in a photobioreactor pilot plant

A life cycle assessment (LCA) and an energy balance analysis of marine microalgal biomass production were conducted to determine the environmental impacts and the critical points of production for large scale planning. The artificial lighting and temperature conditions of an indoor bubble column photobioreactor (bcPBR) were compared to the natural conditions of an equivalent outdoor system. Marine microalgae, belonging to the dinoflagellate and raphidophyte groups, were cultured and the results were compared with published LCA data obtained from green microalgae (commonly freshwater algae). Among the species tested, Alexandrium minutum was chosen as the target marine microalgae for biomass production under outdoor conditions, although there were no substantial differences between any of the marine microalgae studied. Under indoor culture conditions, the total energy input for A. minutum was 923 MJ kg¯¹ vs. 139 MJ kg¯¹ for outdoor conditions. Therefore, a greater than 85% reduction in energy requirements was achieved using natural environmental conditions, demonstrating the feasibility of outdoor culture as an alternative method of bioenergy production from marine microalgae. The growth stage was identified as the principal source of energy consumption for all microalgae tested, due to the electricity requirements of the equipment, followed by the construction material of the bcPBR. The global warming category (GWP) was 6 times lower in outdoor than in indoor conditions. Although the energy balance was negative under both conditions, this study concludes with suggestions for improvements in the outdoor system that would allow upscaling of this biomass production technology for outdoor conditions in the Mediterranean

Potential savings of resources and greenhouse gas emissions from waste management : a case study of Spain in a global economy

Nuestras sociedades necesitan soluciones para reducir el consumo de recursos, así como de gases de efecto invernadero (GHG en inglés). La identificación de los residuos como un recurso valioso puede ayudar a reducir el consumo de recursos y en consecuencia las emisiones de GHG. Por lo tanto, el enfoque ha sido originalmente puesto en la recuperación y el reciclaje. Sin embargo, los gestores de residuos y los investigadores han destacado la reciente importancia de los residuos comercializados en mercados globales. Esta perspectiva global podría afectar los ahorros de emisiones de GHG atribuidas al reciclaje. Por lo tanto, el objetivo de esta tesis es en primer lugar calcular y evaluar las emisiones de GHG de la gestión en España de los residuos sólidos municipales (MSW, en inglés). En segundo lugar un enfoque especial se pone en las emisiones de GHG del reciclaje teniendo en cuenta el mercado y el comercio internacional, especialmente para los residuos de papel, aluminio y plástico. Una nueva herramienta llamada CO2ZW ®, el análisis de ciclo de vida consecuencial (CLCA en inglés) y el análisis del flujo de materiales (MFA en inglés) se aplicaron para las evaluaciones de GHG y de recursos. La aplicación de la CO2ZW ® para evaluar la gestión de los MSW confirmó que existe un alto potencial para la mitigación del cambio climático en España a través del aumento de la recuperación material junto con la reducción de la eliminación de los vertederos. La aplicación del MFA demostró que existe una considerable acumulación de productos de papel, aluminio y plástico que en los próximos años se convertirá en residuos pero el incremento de la oferta de residuo probablemente será exportado. Por otra parte, bajo el supuesto de que el reciclaje evita la producción de materia prima, se determinó también que el reciclaje evita emisiones de GHG. Sin embargo, los residuos pueden ser reciclados en España o en el extranjero, y el reciclaje puede sustituir la producción mundial o la española. Las emisiones de GHG varían en cada caso. Las producciones mundiales más competitivas de pulpa virgen, aluminio primario y plástico virgen fueron identificadas como los escenarios base bajo el CLCA. Las producciones nacionales españoles fueron evaluados como escenarios alternativos. Los resultados mostraron que los procesos más competitivos generan más emisiones de GHG, ya que son más ineficientes y a menudo se encuentran en países con alto contenido de carbón en su mix eléctrico Por lo tanto, si estos procesos se evitan mediante el reciclaje, más emisiones de GHG son mitigados que si se evitan los procesos españoles. Además, el aumento de la exportación de residuos disminuye los beneficios de GHG en todos los escenarios evaluados con excepción de la exportación de chatarra de aluminio. Los resultados no sólo pueden ayudar a los investigadores para evaluar las emisiones de GHG de la gestión de residuos, pero también pueden ser utilizados por los productores, gestores de residuos y los políticos de residuos para evaluar y proponer la mejor estrategia para reducir el consumo de recursos junto con las emisiones de GHG.Our societies need solutions to reduce resource consumption as well as greenhouse gas (GHG) emissions. Identifying waste as a valuable resource can help reduce resource consumption and consequently GHG emissions. Therefore, focus has originally been placed on recovery and recycling. However, waste managers and researchers have recently highlighted the importance of wastes traded in global markets. This global perspective could affect the savings of GHG emissions attributed to recycling. Thus, the goal of this thesis is firstly to calculate and evaluate the GHG emissions from municipal solid waste (MSW) management in Spain. Secondly a special focus is put on the GHG emissions of recycling considering the market and the international trade, specifically for waste paper, aluminium old scrap and plastic waste. A new tool called CO2ZW®, consequential life cycle assessment (CLCA) and material flow analysis (MFA) were applied for the GHG and resource assessments. The application of the CO2ZW® to evaluate the MSW management confirmed that there is a high potential for climate change mitigation in Spain through the increase of material recovery along with reducing disposal to landfills. The application of MFA showed that there is a considerable accumulation of paper, aluminium and plastics products which in coming years will become waste but the increase in waste supply will probably be exported. Moreover, under the assumption that recycling avoids raw material production, it was also determined that recycling avoids GHG emissions. However, waste can be recycled in Spain or abroad, and recycling can substituted global or Spanish raw material production. The GHG emissions varied in each case. The most competitive global productions of virgin pulp, primary aluminium and virgin plastic were identified as the base scenarios under CLCA. The Spanish national productions were assessed as alternative scenarios. Results showed that the most competitive processes generate more GHG emissions as they are more inefficient and they are often located in countries with high hard coal content in their electricity mixes. Therefore, if these processes are avoided by recycling, more GHG emissions are mitigated than if the Spanish processes are avoided. In addition, increasing the export of waste decreases the GHG benefits for all scenarios evaluated except for the aluminium old scrap export. The results not only help researchers to evaluate the GHG emissions from waste management but also can be used by producers, waste managers and waste politicians to evaluate and propose the best strategy to reduce the resource consumption and the GHG emissions