The DOI matches its Crossref record; 25 of the 27 references it cites were found in a registry or an index.
Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels
Open accessAbstract
Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Industrialized nations with biofuels targets, such as the United States and members of the European Union, are unlikely to have the land base needed to meet their growing demand for current-generation agricultural biofuels, which are largely produced from food and feed crops (e.g., maize, oil palm, rapeseed, soy)”
From Carbon payback times for crop-based biofuel expansion in the tropics: the effects of changing yield and technology (2008) · cites this paper as Hill et al 2006
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“However, including generalized estimates of upstream emissions to grow, produce and transport would decrease biofuel carbon offsets used here by ∼ 80% for cornethanol, ∼ 20% for cane-ethanol and ∼ 60% for soy-biodiesel (Hill et al 2006), thereby increasing the carbon payback time.”
From Carbon payback times for crop-based biofuel expansion in the tropics: the effects of changing yield and technology (2008) · cites this paper as Hill et al 2006
Experimental — accuracy not yet measuredThe cited source says what the claim attributes to it.
In the citing paper
“The concept of energy balance, or Net Energy Balance (NEB), evaluates the amount of energy from the biofuel to the fossil energy input necessary for feedstock cultivation and conversion; for instance, soybean biodiesel yields approximately 93% more energy than is invested in its production [103].”
From Biofuels, E-Fuels, and Waste-Derived Fuels: Advances, Challenges, and Future Directions (2025) · cites this paper as [103]
In the citing paper
“Currently, bioethanol is produced by fermentation of agricultural crops, mainly sugarcane in Brazil (Goldemberg 2007) and/or corn in the US (Hill et al. 2006).”
From Renewable energy from Cyanobacteria: energy production optimization by metabolic pathway engineering (2011) · cites this paper as Hill et al. 2006
In the citing paper
“biodiesel yields 93% more [99]”
From The potential of biofuels from first to fourth generation (2023) · cites this paper as [99]
In the citing paper
“ethanol yields 25% more energy than that invested in its production”
From The potential of biofuels from first to fourth generation (2023) · cites this paper as [99]
In the citing paper
“Advanced fuels share many advantages over first-generation biofuels, such as reduced land requirements and minimal fertilizer, pesticide, and fossil energy input [66].”
From Investigation of Biofuel as a Potential Renewable Energy Source (2021) · cites this paper as [66]
In the citing paper
“the indirect effects of bioenergy production on CO 2 emissions are also important concerns”
From Bioenergy production and environmental impacts (2018) · cites this paper as Hill et al. 2006
In the citing paper
“Review on environmental impacts suggested that substituting fossil fuels with biofuels could significantly reduce greenhouse gas emissions and air pollution (e.g., particulate matter).”
From Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment (2018) · cites this paper as [6]
In the citing paper
“Overall, biofuels from cellulosic feedstocks (e.g., corn residues, switchgrass) and certain non-grain conventional crops (e.g., cassava, Jatropha) have much less greenhouse gas (GHG) emissions and air pollutants than fossil fuels (e.g., gasoline, diesel) on an energy basis [6][7][8].”
From Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment (2018) · cites this paper as [6]
In the citing paper
“Most studies agreed that, without land use change impacts, biofuels release much less GHG emissions than their fossil fuel counterparts on a per unit energy basis [6,7,44].”
From Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment (2018) · cites this paper as [6]
In the citing paper
“Overall air quality can be improved if using biofuels in place of fossil fuels, however specific emission reduction still varies among different biofuel feedstocks, air quality species and biofuel pathways [6,77] (Table 2).”
From Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment (2018) · cites this paper as [6]
In the citing paper
“For example, biofuels can help reduce PM 2.5 and SO 2 but not nitrous oxide (N 2 O), a potent GHG emissions (Table 2).”
From Biomass and biofuels in China: Toward bioenergy resource potentials and their impacts on the environment (2018) · cites this paper as [6]
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen
Carpenter, S. R., Caraco, N. F., Correll, D. L., Howarth, R. W., Sharpley, A. N., & Smith, V. H. (1998) · Ecological Applications · doi:10.1890/1051-0761(1998)008[0559:nposww]2.0.co;2 · Cited by 6,099
Ethanol Can Contribute to Energy and Environmental Goals
Farrell, A. E., Plevin, R. J., Turner, B. T., Jones, A. D., O'Hare, M., & Kammen, D. M. (2006) · Science · doi:10.1126/science.1121416 · Cited by 2,823
Biodiversity and ecosystem stability in a decade-long grassland experiment
Tilman, D. G., Reich, P. B., & Knops, J. M. H. (2006) · Nature · doi:10.1038/nature04742 · Cited by 2,409
Self-citationDiversity and Productivity in a Long-Term Grassland Experiment
Tilman, D., Reich, P. B., Knops, J., Wedin, D., Mielke, T., & Lehman, C. (2001) · Science · doi:10.1126/science.1060391 · Cited by 2,373
Self-citationPerlack, R. D. (2005) · doi:10.2172/885984 · Cited by 2,087
Pimentel, D. M. D. S., & Patzek, T. W. (2005) · Natural Resources Research · doi:10.1007/s11053-005-4679-8 · Cited by 1,399
Robertson, G. P., Paul, E. A., & Harwood, R. R. (2000) · Science · doi:10.1126/science.289.5486.1922 · Cited by 1,358
US Department of Energy (USDOE), W., Perlack, R., USDOE Office of Energy Efficiency and Renewable Energy (EERE), O. O. S. T. B. T. O. (., Oak Ridge National Laboratory (ORNL), O. R., USDA, Wright, L., Turhollow, A., Graham, R., Stokes, B., & Erbach, D. (2005) · doi:10.2172/1216415 · Cited by 1,327
Aden, A., Ruth, M., Ibsen, K., Jechura, J., Neeves, K., Sheehan, J., Wallace, B., Montague, L., Slayton, A., & Lukas, J. (2002) · doi:10.2172/15001119 · Cited by 1,197
Technical Report: Human Alteration of the Global Nitrogen Cycle: Sources and Consequences
Vitousek, P. M., Aber, J. D., Howarth, R. W., Likens, G. E., Matson, P. A., Schindler, D. W., Schlesinger, W. H., & Tilman, D. G. (1997) · Ecological Applications · doi:10.2307/2269431 · Cited by 569
Self-citation
Research works printed but not linked: 12
- H. Shapouri, J. Duffield, A. McAloon, M. Wang The 2001 Net Energy Balance of Corn-Ethanol (U.S. Dept. of Agriculture, Washington, DC, 2004).
- P. M. Vitousek, J. D. Aber, R. W. Howarth, G. E. Likens, P. A. Matson, D. W. Schindler, W. H. Schlesinger, D. G. Tilman Ecol. Appl. 7, 737–750 (1997).
- Feed Grains Database (Dept. of Agriculture, Washington, DC, 2005).
- D. G. Tiffany, V. R. Eidman Agriculture as a Producer and Consumer of Agriculture, eds J. Outlaw, K. J. Collins, J. A. Duffield (CABI, Cambridge, MA, 2005).
- Natural Gas Monthly (Dept. of Energy, Washington, DCDOE Publ. No. EIA-0130(2006/04). (2006).
- Petroleum Marketing Monthly (Dept. of Energy, Washington, DCDOE Publ. No. EIA-0380(2005/06). (2006).
- USDA Agricultural Baseline Projections to 2015 (Dept. of Agriculture, Washington, DCDOE Publ. No. OCE-2006-1. (2006).
- Industry Statistics (Renewable Fuels Assoc, Washington, DC, 2006).
- Annual Energy Outlook 2006 With Projections to 2030 (Dept. of Energy, Washington, DCDOE Publ. No. EIA-0383(2006). (2006).
- How Much Biodiesel Has Been Sold in the U.S.? (Natl. Biodiesel Board, Jefferson City, MO, 2005).
- D. G. Tiffany, V. R. Eidman Food, Agriculture, and the Environment: Economic Issues, eds E. Defrancesco, L. Galletto, M. Thiene (FrancoAngeli, Milan), pp. 325–340 (2005).
- International Energy Outlook (Dept. of Energy, Washington, DCDOE Publ. No. EIA-0484 (2006). (2006).
Cited by
Sorted by citations
Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production
Schenk, P. M., Thomas‐Hall, S. R., Stephens, E., Marx, U. C., Mussgnug, J. H., Posten, C. H., Kruse, O., & Hankamer, B. D. (2008) · BioEnergy Research · doi:10.1007/s12155-008-9008-8 · Cited by 2,335
Catalytic conversion of biomass to biofuels
Alonso, D. M., Bond, J. Q., & Dumesic, J. A. (2010) · Green Chemistry · doi:10.1039/c004654j · Cited by 2,333
Global food security under climate change
Schmidhuber, J., & Tubiello, F. N. (2007) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.0701976104 · Cited by 2,128
The Future of Energy Supply: Challenges and Opportunities
Armaroli, N., & Balzani, V. (2006) · Angewandte Chemie International Edition · doi:10.1002/anie.200602373 · Cited by 1,964
Carbon-Negative Biofuels from Low-Input High-Diversity Grassland Biomass
Tilman, D., Hill, J., & Lehman, C. (2006) · Science · doi:10.1126/science.1133306 · Cited by 1,813
Self-citation
Metadata
- Authors
- Hill, J., Nelson, E., Tilman, D., Polasky, S., & Tiffany, D.
- Affiliations
- University of Minnesota (US)
- Corresponding author
- Tilman, David
- Venue
- Proceedings of the National Academy of Sciences
- Publisher
- National Academy of Sciences
- Published
- 2006-07-25
- Volume
- 103
- Issue
- 30
- Pages
- 11206-11210
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- PMC
- PMC1544066
- OpenAlex
- W2164449327
- Cited by
- 2,871
- References
- 27
- Citations by year
- 2026: 36 · 2025: 57 · 2024: 60 · 2023: 86 · 2022: 89 · 2021: 138 · 2020: 103 · 2019: 126 · 2018: 147 · 2017: 155 · 2016: 149 · 2015: 171 · 2014: 175 · 2013: 242 · 2012: 228
- FWCI
- 117.55
- Type
- journal article
- Language
- en
- Open access
- green
- europepmc.org
- Locations
- Proceedings of the National Academy of Sciences (publishedVersion)
- Europe PMC (PubMed Central) (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Bowdoin - Digital Commons (Bowdoin College) (submittedVersion)
- Funders
- National Science Foundation (0080382)
- Howard Hughes Medical Institute
- Bush Foundation
- Topics
- Physical Sciences › Engineering › Biomedical Engineering › Biofuel production and bioconversion
- Physical Sciences › Environmental Science › Environmental Engineering › Environmental Impact and Sustainability
- Life Sciences › Agricultural and Biological Sciences › Agronomy and Crop Science › Bioenergy crop production and management
- Keywords
- biodiesel, ethanol, corn ethanol, soybean biodiesel, net energy analysis, life cycle assessment, greenhouse gas emissions, air pollutants, pesticide use, biofuel subsidies, oil displacement, biofuel economics, cellulosic ethanol, biomass waste
- MeSH terms
- Agriculture, Air Pollutants, Air Pollution, Ethanol, Vehicle Emissions, Energy-Generating Resources, Environment, Fossil Fuels, Gasoline, Humans, Petroleum, Glycine max, Biomass
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
