Development of a weighting approach for the Environmental Footprint

In Life Cycle Assessment (LCA), according to ISO 14044 (ISO 2006), normalisation and weighting are optional steps of Life Cycle Impact Assessment (LCIA). Those steps allow expressing LCA results aggregating the results (up to a single score), giving different weight to the different environmental impacts. The step of prioritising and aggregating the results for the 16 environmental impact categories evaluated in the life cycle based Environmental Footprint (EF) - covering e.g. climate change, acid rain, human and eco-toxicity, particulate matter but also impacts due to the use of water, land and resources – has a high relevance. Weighting supports the identification of the most relevant impact categories, life cycle stages, process and resource consumptions or emissions to ensure that the focus is put on those aspects that matter the most and for communication purposes. Any weighting scheme is not mainly natural science based but inherently involves value choices that will depend on policy, cultural and other preferences and value systems. No “consensus” on weighting seems to be achievable. This situation does not apply only to weighting in a LCA or Environmental Footprint context, but seems inevitable for many multicriteria approaches. The objective of this work therefore was to find a convention suitable for the application in the EF context and to develop a method for weighting the Environmental Footprint Impact Categories according to their relevance for the overall environmental problems. A final recommendation is provided on a weighting set to be used for the EF that includes also aspects of the robustness of the results. This report includes, from page 46 onward, several annexes and the comments from a consultation of the Environmental Footprint Technical Advisory Board in June 2017.JRC.D.1-Bio-econom

CFD Analysis of NOx Emissions of a Natural Gas Lean Premixed Burner for Heavy Duty Gas Turbine

AbstractThe present work presents a numerical analysis of a low NOx partially premixed burner for heavy duty gas turbine. The first part of the paper is focused on the study of the premixing process inside the burner using standard RANS CFD approach. The resulting profiles at different test points have been used to perform reactive simulations of an experimental test rig, where exhaust NOx emissions were measured. A reliable numerical setup was found comparing predicted and measured NOx emissions at different operating conditions and split ratios between main and pilot fuel. The calibrated numerical setup was then employed to explore possible modifications to fuel injection criteria and fuel split, with the aim of minimizing exhaust NOx emissions. This preliminary numerical screening of new fuel injection strategies, allowed defining a set of advanced configurations to be investigated in future experimental tests

Numerical Analysis of a Low NOx Partially Premixed Burner for Industrial Gas Turbine Applications

Abstract A numerical analysis of a low NOx partially premixed burner for industrial gas turbine applications is presented. In the first part the mixing inside a double annular counter-rotating swirl nozzle where the fuel is injected in a transverse jet configuration is studied. Standard k – ∈ model and Two variable Schmidt number models were assessed in order to find a reliable configuration able to fit the available experimental profiles. Resulting profiles are used to perform reactive simulations of the experimental test rig, where NOx, CO measurement were available Results are compared in terms of NOx concentration at the outlet with experimental data

Structure and pattern of food consumption in Italian household: an analysis of impact on climate change and land use

The environmental impacts of food consumption of Italian households in 2011 have been calculated adopting an Environmentally Extended Input-Output Analysis, using EXIOBASE v3 as the underpinning database for the assessment. Because of the structure of such database, it is possible to divide domestic and imported final demand. Climate change and Land use related impacts are calculated then matched with household expenditures for the same year. The food consumption in an average Italian household for 2011 results in a total Climate change of 4237 kg CO2eq and in a total Land use impact of 10 kg Cdeficit. There are limitations due to a non-perfect match of food product groups in EXIOBASE and Italian National Statistics. Nevertheless, with this approach it is possible to investigate environmental impacts in relation to expenditure patterns of the families