L'analyse de cycle de vie appliquée aux biomasses énergie : Exemple de l'approvisionnement de la chaudière Lin 2000

oral communication abstract (french & english abstracts)absen

Life-cycle assessment of local feedstock supply scenarios to compare candidate biomass sources

The use of life cycle assessment (LCA) as a comprehensive tool to assess environmental impacts of bioenergies is recommended. Nevertheless, several methodological points remain under debate, particularly regarding the feedstock production step, which is a key stage of bioenergy chains. The present work focuses on field emissions during feedstock production, improving assessment methods by the use of process-based models. To do so, a real bioenergy chain, the local feedstock supply for a boiler located in northern France, was studied. The LCA compares flax shives, (the reference) with four other biomass sources: Miscanthus, cereal straw, linseed straw, and triticale as a whole plant. Six feedstock supply scenarios were also compared. The study aimed to test a new LCA methodology for agricultural chains by integrating local characteristics (such as climate, soil, and crop management data) and using models to estimate field dynamics of pesticide emissions and soil organic carbon (SOC). Results showed that flax shives and linseed straw had the lowest impacts, except for global warming: as a consequence, supply scenarios with the largest share of flax shives had the lowest impacts. For all selected impact categories, transportation and fertilization were the main contributors. SOC dynamics led to high C sequestration level (e.g. with Miscanthus) or to high CO 2 emissions level (e.g. with flax shives), thus significantly influencing the global warming impact. Sensitivity analysis showed a large influence of allocation method (economic or mass-based). This study demonstrated the relevance of integrating simulation models using local data in agricultural LCAs, especially for dynamics of SOC and pesticide from fields. Moreover, this work brought scientific elements to support the choice of flax shives as the main biomass feedstock, and the ranking of the other sources as alternative biomass supplies for the boiler

Life-cycle assessment of local feedstock supply scenarios to compare candidate biomass sources

(paper to appear in Global Change Biology Bioenergy)International audienceThe use of Life Cycle Assessment (LCA) as a comprehensive tool to assess environmental impacts of bioenergies is recommended. Nevertheless, several methodological points remain under debate, particularly regarding the feedstock production step, which is a key stage of bioenergy chains. The present work focuses on field emissions during feedstock production, improving assessment methods by the use of process-based models. To do so, a real bioenergy chain, the local feedstock supply for a boiler located in northern France, was studied. The LCA compares flax shives, (the reference) with four other biomass sources: Miscanthus, cereal straw, linseed straw and triticale as a whole plant. Six feedstock supply scenarios were also compared. The study aimed to test a new LCA methodology for agricultural chains by integrating local characteristics (such as climate, soil and crop management data) and using models to estimate field dynamics of pesticide emissions and soil organic carbon (SOC). Results showed flax shives and linseed straw had the lowest impacts, except for global warming: as a consequence, supply scenarios with the largest share of flax shives had the lowest impacts. For all selected impact categories, transportation and fertilization were the main contributors. SOC dynamics led to high C sequestration level (e.g.with Miscanthus) or to high CO2 emissions level (e.g. with flax shives), thus significantly influencing the global warming impact. Sensitivity analysis showed a large influence of allocation method (economic or mass-based). This study demonstrated the relevance of integrating simulation models using local data in agricultural LCAs, especially for dynamics of SOC and pesticide from fields. Moreover, this work brought scientific elements to support the choice of flax shives as the main biomass feedstock, and the ranking of the other sources as alternative biomass supplies for the boiler

Integrating diversity of smallholder coffee cropping systems in environmental analysis

Coffee represents an important trade asset internationally. Around 70% of global coffee production is provided by 25 million smallholders farmers. In recent decades, coffee systems have been transformed into more intensified systems of coffee monoculture. The general objectives of this paper are to provide a better picture of the traditional coffee cropping systems and postharvest processes on-farm and to assess the environmental impacts, integrating the diversity of smallholder cropping systems. A Life Cycle Assessment from cradle to farm gate was performed for three cropping systems representative of Colombian coffee cultivation according to the associated crops and shadow trees: coffee alone (CA), coffee with transition shade (CTS), and coffee with permanent shade (CPS). The system studied includes inputs, agricultural production and postharvest operations using the wet method. The final product of farms is parchment bean coffee at farm gate. The technology used is representative of the average practices of smallholder coffee growers in the region. To address multiple functions of coffee, three functional units (FU) were selected: area by time (ha*year−1 unit area), productivity (ton of parchment coffee) and farmers income (1000 USD$). Seven midpoint categories were selected: climate change, acidification, terrestrial eutrophication, freshwater eutrophication, marine eutrophication, freshwater ecotoxicity, and water resource depletion. We present the life cycle inventory and impact assessment results from three types of cropping systems CA, CTS and CPS. For all FU, the CPS system has the lowest potential impact, excepted for marine eutrophication. CPS also has the highest coffee yields, however it has also the highest costs. Even if cropping system diversification is only one of multiple factors that influence environmental performance, agroforestry seems to be a promising path to reduce and mitigate environmental impacts by decreasing off-fam contributions (input fabrication). Results show the possibility that diversified cropping systems have an influence when assessing potential environmental impacts of coffee at farm gate and differences found might be influenced by shading in traditional coffee systems. Future work is needed to consider the real potential of CTS cropping system including land use and carbon dynamics. Assessments including social indicators and the rest of the value chain in particular coffee industrial transformation and utilization are also needed since the consumption stages are also a key driver to reduce the environmental footprint of coffee

Report on the comparison of 3 carbon monitoring methods and on the implementation of the method (French case)

This report corresponds to the 2020 Output n° 5: “Improved method for soil carbon monitoring (French case)”. It concerns the Work Package 2 “Developing and implementing an action plan with demand owner 2, Nataïs, Gers, France” and to the Task 2.2. in which deployment of SAFYE-CO2 soil carbon method was continued and a comparison initiated with other carbon monitoring methods. The report will present the results obtained on one farm from the Nataïs network. First, we present the study area along with the primary objective of the task. Second, we describe the carbon monitoring methods as well as their differences and similarities. Third, we present the results for each carbon monitoring method outputs. Finally, we will discuss these results with respect to their differences and similarities

Report on the comparison of 3 carbon monitoring methods and on the implementation of the method (French case)

This report corresponds to the 2020 Output n° 5: “Improved method for soil carbon monitoring (French case)”. It concerns the Work Package 2 “Developing and implementing an action plan with demand owner 2, Nataïs, Gers, France” and to the Task 2.2. in which deployment of SAFYE-CO2 soil carbon method was continued and a comparison initiated with other carbon monitoring methods. The report will present the results obtained on one farm from the Nataïs network. First, we present the study area along with the primary objective of the task. Second, we describe the carbon monitoring methods as well as their differences and similarities. Third, we present the results for each carbon monitoring method outputs. Finally, we will discuss these results with respect to their differences and similarities

LCA of starch potato from field to starch production plant gate

Organisateurs INRA et AdemeLCA of starch potato from field to starch production plant gate. 8. International Conference on Life Cycle Assessment in the Agri Food Sector (LCA Food 2012