Biowaste-to-biomethane or biowaste-to-energy? An LCA study on anaerobic digestion of organic waste. (10th February 2018)

• Record Type: Journal Article
• Authors: Ardolino, Filomena; Parrillo, Francesco; Arena, Umberto
• Is Part Of: Journal of cleaner production. Volume 174(2018)
• Page Start: 462
• Page End: 476
• Publication Date: 2018-02-10
• Subjects: Biomethane -- Biowaste -- Anaerobic digestion -- Biogas upgrading -- Life cycle assessment -- Biofuels; AD Anaerobic Digestion -- CHP Combined Heat and Power -- EWC European Waste Catalogue -- GHG Greenhouse Gas -- GWP Global Warming Potential -- ISO International Organisation for Standardisation -- LCA Life Cycle Assessment -- LCI Life Cycle Inventory -- LCIA Life Cycle Impact Assessment -- LOP Land Occupation Potential -- MFA Material Flow Analysis -- MSW Municipal Solid Waste -- NCP Non Carcinogens Potential -- NREP Non-Renewable Energy Potential -- OECD Organisation for Economic Co-operation and Development -- OFMSW Organic Fraction of Municipal Solid Waste -- PSA Pressure Swing Adsorption -- RINP Respiratory INorganics Potential -- SFA Substance Flow Analysis -- SR Sensitivity Ratio -- TECP Terrestrial ECotoxicity Potential -- VF Variation Factor -- WWTP Waste Water Treatment Process; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2017.10.320
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: The study aims to demonstrate the overall environmental sustainability of biomethane production by anaerobic digestion of the separately collected organic fraction of municipal solid waste. There is a great interest in the utilisation of biofuels produced from biowaste in the transport sector, due to the benefits of reduced pollutant emissions and diversified transport fuel supplies. An attributional, process-based life cycle assessment study quantifies and compares the potential environmental impacts of an anaerobic digestion plant, where the produced biogas is upgraded to biomethane for the transport sector instead that directly burned in a combined heat and power unit. The avoided impacts related to the utilisation of biomethane instead of diesel, petrol or natural gas have been evaluated with reference to a vehicle fleet made of passenger cars and small rigid trucks. They appear large enough to make the biomethane production the cleanest option for the management of biowaste. The global warming and non-renewable energy potentials of the Biowaste-to-Biomethane scenario improve of 79% and 36%, respectively, with reference to the Biowaste-to-Energy scenario. A sensitivity analysis evaluates the effect of several key parameters. Some of them are peculiar for the analysed application, such as the composition of the vehicle fleet, specific biomethane consumptions of these vehicles, and methane slip in the biogas upgrading unit. Some other parameters are more general, such as the final destination of solid digestate, gas engine efficiency, national electric energy mix. The results of the analysis provide data and information to policy-makers, planners and operators that would like or have to approach the management of the separately collected organic fraction of municipal solid waste. They also inform on the environmental advantages connected with the utilisation for road transportation of biomethane produced from this waste fraction. Highlights: An attributional LCA is utilised to quantify environmental burdens and potential impacts. The biogas upgrading unit utilises a membrane separation unit made of polyimide hollow fibres. Reliable data provide an exhaustive LCI table for all the configurations and sub-units. Production of biomethane for road transport is always cleaner than the production of energy. Biomethane as transport fuel reduces GHG emissions and non-renewable energy consumptions.