Agricultural and forestry residues, animal manure and municipal solid waste are replenishable and widely available. However, harnessing these heterogeneous and diffuse resources for energy requires a holistic assessment of alternative conversion pathways, taking into account spatial factors. Here, we analyse, from a life-cycle assessment perspective, the potential renewable energy production, net energy gain and greenhouse gas (GHG) emission reduction for each distinct type of waste feedstock under different conversion technology pathways. The utilization of all available wastes and residues in the contiguous United States can generate 3.1–3.8 exajoules (EJ) of renewable energy, but only deliver 2.4–3.2 EJ of net energy gain, and displace 103–178 million tonnes of CO2-equivalent GHG emissions. For any given waste feedstock, looking across all US counties where it is available, except in rare instances, no single conversion pathway simultaneously maximizes renewable energy production, net energy gain and GHG mitigation.
Subscribe to Journal
Get full journal access for 1 year
only $4.92 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the findings of this study are available at https://github.com/labyseson/Waste-LCA
Codes for energy and emission accounting as well as data visualization are available at https://github.com/labyseson/Waste-LCA
The State of Food and Agriculture 2008. Biofuels: Prospects, Risks and Opportunities (FAO, 2008).
Renewables 2017: Global Status Report (REN21, 2017).
de Gorter, H., Drabik, D. & Just, D. R. How biofuels policies affect the level of grains and oilseed prices: theory, models and evidence. Glob. Food Secur. 2, 82–88 (2013).
To, H. & Grafton, R. Q. Oil prices, biofuels production and food security: past trends and future challenges. Food Secur. 7, 323–336 (2015).
Tadasse, G., Algieri, B., Kalkuhl, M. & Von Braun, J. in Food Price Volatility and its Implications for Food Security and Policy 59–82 (Springer, 2016).
Hochman, G., Rajagopal, D., Timilsina, G. & Zilberman, D. Quantifying the causes of the global food commodity price crisis. Biomass Bioenerg. 68, 106–114 (2014).
Runge, C. F. & Senauer, B. How biofuels could starve the poor. Foreign Aff. 86, 41–53 (2007).
Lambin, E. F. & Meyfroidt, P. Global land use change, economic globalization, and the looming land scarcity. Proc. Natl Acad. Sci. USA 108, 3465–3472 (2011).
Melillo, J. M. et al. Indirect emissions from biofuels: how important? Science 326, 1397–1399 (2009).
Farrell, A. E. et al. Ethanol can contribute to energy and environmental goals. Science 311, 506–508 (2006).
Crutzen, P. J., Mosier, A. R., Smith, K. A. & Winiwarter, W. in Paul J. Crutzen: a Pioneer on Atmospheric Chemistry and Climate Change in the Anthropocene (eds Crutzen, P. J. & Brauch, H. G.) 227–238 (Springer, 2016).
Rajagopal, D. & Zilberman, D. Environmental, economic and policy aspects of biofuels. Found. Trends Microecon. 4, 353–468 (2008).
Whalen, J. et al. Sustainable biofuel production from forestry, agricultural and waste biomass feedstocks. Appl. Energy 198, 281–283 (2017).
Campbell, J. E. & Block, E. Land-use and alternative bioenergy pathways for waste biomass. Environ. Sci. Technol. 44, 8665–8669 (2010).
Tonini, D., Hamelin, L., Alvarado-Morales, M. & Astrup, T. F. GHG emission factors for bioelectricity, biomethane, and bioethanol quantified for 24 biomass substrates with consequential life-cycle assessment. Bioresour. Technol. 208, 123–133 (2016).
2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy, Volume 1: Economic Availability of Feedstocks ORNL/TM-2016/160 (US Department of Energy, 2016).
Carreras-Sospedra, M., Williams, R. & Dabdub, D. Assessment of the emissions and air quality impacts of biomass and biogas use in California. J. Air Waste Manag. Assoc. 66, 134–150 (2016).
Wang, W. & Tao, L. Bio-jet fuel conversion technologies. Renew. Sustain. Energy Rev. 53, 801–822 (2016).
de Jong, S. et al. The feasibility of short‐term production strategies for renewable jet fuels—a comprehensive techno‐economic comparison. Biofuels Bioprod. Bioref. 9, 778–800 (2015).
de Jong, S. et al. Life-cycle analysis of greenhouse gas emissions from renewable jet fuel production. Biotechnol. Biofuels 10, 64 (2017).
Staples, M. D., Malina, R. & Barrett, S. R. The limits of bioenergy for mitigating global life-cycle greenhouse gas emissions from fossil fuels. Nat. Energy 2, 16202 (2017).
Sustainable Development Goals: 17 Goals to Transform Our World. United Nations https://www.un.org/sustainabledevelopment (2018).
Geissdoerfer, M., Savaget, P., Bocken, N. M. & Hultink, E. J. The Circular Economy—a new sustainability paradigm? J. Clean. Prod. 143, 757–768 (2017).
Stahel, W. R. The circular economy. Nat. News 531, 435 (2016).
Liu, W. et al. Economic and life cycle assessments of biomass utilization for bioenergy products. Biofuels Bioprod. Bioref. 11, 633–647 (2017).
Laurent, A. & Espinosa, N. Environmental impacts of electricity generation at global, regional and national scales in 1980–2011: what can we learn for future energy planning? Energy Environ. Sci. 8, 689–701 (2015).
Aguirre-Villegas, H. A. & Larson, R. A. Evaluating greenhouse gas emissions from dairy manure management practices using survey data and life cycle tools. J. Clean. Prod. 143, 169–179 (2017).
Aguirre‐Villegas, H. A., Larson, R. & Reinemann, D. J. From waste‐to‐worth: energy, emissions, and nutrient implications of manure processing pathways. Biofuels Bioprod. Bioref. 8, 770–793 (2014).
Banks, C. J., Chesshire, M., Heaven, S. & Arnold, R. Anaerobic digestion of source-segregated domestic food waste: performance assessment by mass and energy balance. Bioresour. Technol. 102, 612–620 (2011).
Broun, R. & Sattler, M. A comparison of greenhouse gas emissions and potential electricity recovery from conventional and bioreactor landfills. J. Clean. Prod. 112, 2664–2673 (2016).
Macias-Corral, M. et al. Anaerobic digestion of municipal solid waste and agricultural waste and the effect of co-digestion with dairy cow manure. Bioresour. Technol. 99, 8288–8293 (2008).
Morris, J. Recycle, bury, or burn wood waste biomass? LCA answer depends on carbon accounting, emissions controls, displaced fuels, and impact costs. J. Ind. Ecol. 21, 844–856 (2017).
Nuss, P., Gardner, K. H. & Jambeck, J. R. Comparative life cycle assessment (LCA) of construction and demolition (C&D) derived biomass and US Northeast forest residuals gasification for electricity production. Environ. Sci. Technol. 47, 3463–3471 (2013).
Pressley, P. N. et al. Municipal solid waste conversion to transportation fuels: a life-cycle estimation of global warming potential and energy consumption. J. Clean. Prod. 70, 145–153 (2014).
Wang, H., Wang, L. & Shahbazi, A. Life cycle assessment of fast pyrolysis of municipal solid waste in North Carolina of USA. J. Clean. Prod. 87, 511–519 (2015).
Anex, R. P. et al. Techno-economic comparison of biomass-to-transportation fuels via pyrolysis, gasification, and biochemical pathways. Fuel 89, S35 (2010).
Iribarren, D., Peters, J. F. & Dufour, J. Life cycle assessment of transportation fuels from biomass pyrolysis. Fuel 97, 812–821 (2012).
Baral, A. & Malins, C. Assessing the Climate Mitigation Potential of Biofuels Derived from Residues and Wastes in the European Context (International Council on Clean Transportation, 2014).
Astrup, T., Møller, J. & Fruergaard, T. Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions. Waste Manag. Res. 27, 789–799 (2009).
Fruergaard, T. & Astrup, T. Optimal utilization of waste-to-energy in an LCA perspective. Waste Manag. 31, 572–582 (2011).
Gabra, M., Pettersson, E., Backman, R. & Kjellström, B. Evaluation of cyclone gasifier performance for gasification of sugar cane residue—Part 1: gasification of bagasse. Biomass Bioenerg. 21, 351–369 (2001).
Gabra, M., Pettersson, E., Backman, R. & Kjellström, B. Evaluation of cyclone gasifier performance for gasification of sugar cane residue—Part 2: gasification of cane trash. Biomass Bioenerg. 21, 371–380 (2001).
Møller, J., Boldrin, A. & Christensen, T. H. Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution. Waste Manag. Res. 27, 813–824 (2009).
Swanson, R. M., Platon, A., Satrio, J. A. & Brown, R. C. Techno-economic analysis of biomass-to-liquids production based on gasification. Fuel 89, S19 (2010).
Tews, I. J. et al. Biomass Direct Liquefaction Options: TechnoEconomic and Life Cycle Assessment (Pacific Northwest National Laboratory, 2014).
July 2017 Monthly Energy Review (US Energy Information Administration, 2017).
Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2016 (US Environmental Protection Agency (EPA), 2018).
Thornley, P., Gilbert, P., Shackley, S. & Hammond, J. Maximizing the greenhouse gas reductions from biomass: the role of life cycle assessment. Biomass Bioenerg. 81, 35–43 (2015).
Phyllis2 Database for Biomass and Waste (Energy Research Centre of the Netherlands, 2017); https://phyllis.nl/
The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model GREET_1_2016 (Argonne National Laboratory, 2016).
Williams, R. B., Jenkins, B. M. & Kaffka, S. An Assessment of Biomass Resources in California, 2013 (California Biomass Collaborative, University of California, Davis, 2015).
Waste Reduction Model (WARM) Tool User’s Guide version 14 (US EPA, 2016).
Cooney, G. et al. Updating the US life cycle GHG petroleum baseline to 2014 with projections to 2040 using open-source engineering-based models. Environ. Sci. Technol. 51, 977–987 (2016).
Lee, D., Elgowainy, A. & Dai, Q. Life cycle greenhouse gas emissions of hydrogen fuel production from chlor-alkali processes in the United States. Appl. Energy 217, 467–479 (2018).
Ecoinvent Database version 3 (Ecoinvent Centre, 2015); https://www.ecoinvent.org/database/database.html
Emissions and Generation Resource Integrated Database (eGRID2016) (US EPA, 2018); https://www.epa.gov/energy/emissions-generation-resource-integrated-database-egrid
The Life Cycle Assessment (LCA) Harmonization Project OpenEI Database (National Renewable Energy Laboratory, 2012); https://openei.org/apps/LCA/
Edenhofer, O. et al. (eds) Renewable Energy Sources and Climate Change Mitigation: Special Report of the Intergovernmental Panel on Climate Change (Cambridge Univ. Press, 2011).
Posen, I. D., Griffin, W. M., Matthews, H. S. & Azevedo, I. L. Changing the renewable fuel standard to a renewable material standard: bioethylene case study. Environ. Sci. Technol. 49, 93–102 (2014).
Environmental Management—Life Cycle Assessment—Principles and Framework ISO 14040:2006 (International Organization for Standardization, 2006).
Sikarwar, V. S. et al. An overview of advances in biomass gasification. Energy Environ. Sci. 9, 2939–2977 (2016).
Mu, D., Seager, T., Rao, P. S. & Zhao, F. Comparative life cycle assessment of lignocellulosic ethanol production: biochemical versus thermochemical conversion. Environ. Manag. 46, 565–578 (2010).
This study would not have been possible without financial support from the UCLA Grand Challenges—Sustainable LA programme.
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Liu, B., Rajagopal, D. Life-cycle energy and climate benefits of energy recovery from wastes and biomass residues in the United States. Nat Energy 4, 700–708 (2019). https://doi.org/10.1038/s41560-019-0430-2
Renewable Energy (2020)
Preparation of biochar catalyst from black liquor by spray drying and fluidized bed carbonation for biodiesel synthesis
Process Safety and Environmental Protection (2020)
Pretreatment methods of lignocellulosic wastes into value-added products: recent advances and possibilities
Biomass Conversion and Biorefinery (2020)
Harnessing Advances in Agricultural Technologies to Optimize Resource Utilization in the Food-Energy-Water Nexus
Annual Review of Resource Economics (2020)
Ambient-pressure and low-temperature upgrading of lignin bio-oil to hydrocarbons using a hydrogen buffer catalytic system
Nature Energy (2020)