Biofuels

Corn is an essential feedstock in ethanol fuel production (Benicia Independent) [23]

What are Biofuels?

Biofuels are a powerhouse when it comes to fuel in the transportation sector. Derived from biomass, these materials can be used as feedstocks and converted into a desired biofuel [1]. In the United States, a common biofuel we produce is ethanol, where feedstocks range from crops high in starch and sugar content such as corn and sugarcane [4]. A common method for ethanol production is by fermentation which utilizes yeast to ferment feedstock. An advantage for using ethanol fuels is that not only are its resources abundant and low cost, but it's identified as a negative-emissions technology (NET). Therefore, removal of CO2 emissions that target the limit of the average temperature rise of 2 degrees C can be achieved.

Will Biofuels make an impact on emissions?

By 2050, estimations for CO2 emissions removal was primarily determined by accounting for biofuel emissions savings (2.6 million tons CO2) and barrels per day consumed in the US which was 1.09 million [7-8]. After additional considerations for biofuel density (1 barrel = 42 gal) and its mass per gallon (1 gal = 2661 grams), our calculations result in a CO2 removal of 0.78 GtCO2/year when reaching year 2050 [10]. Thus, this removal rate can contribute to the overall reduction goal of 3 GtCO2/year in the US by 2050.

In May 2020, U.S. Department of Agriculture announced $100 million to expand US biofuels infrastructure [11].

How much resources does biofuel production need?

Two factors that play an important role in biofuel production are land and water usage. Projected estimates for the US in 2015 determined that 5.25 billion of bushels of corn were used in ethanol production with a harvest yield of 379.8 bushels per hectare [5]. Therefore, these estimates result in 13,823,965 total hectares of land where corn was grown. In addition, the UN Food and Agriculture Organization estimated in 2016 that production consumption reached 216 billion cubic meters of water [6].

Cycle of Biofuel Production (Journal Star) [22]

Are biofuels easily implementable in the US?

From assessing the Technology Readiness Level (TRL) of biofuel plants, TRL ranges from 8-9 so from early deployment to commercial with support [13]. Also, there are around 100 well established plants in the US. Especially with ethanol production, the US mostly uses gasoline-ethanol blends such as E85 and reports by the US Department of Energy estimated that over 2300 E85 fueling stations are located across the US. The prevalent number of biofuel plants and funding valued at 136 billion dollars shows that we are capable of implementation but, scaling up these plants to achieve the removal of 0.78 GtCO2/year by 2050 would take time and more funding.

What are some potential risks and issues with the public?

Risks of biofuel production include land use competition, higher food prices, and increased use of polluting inputs. Changing land use patterns increases GHG emissions due to the release of carbon stocks. For land use competition with food, the National Research Council reported that an increase of 20% to 40% of corn prices occurred in 2007 to 2009 [14]. With production of biofuel feedstocks, land becomes susceptible to water pollution due to pesticides and sediment formation. Financial competition between biofuels and other renewables can cause capital constraints. Lastly, while it’ll take time to shift from fossil fuel to biofuel fueling for transportation, using biofuels for vehicles previously reliant on gasoline wouldn’t damage the engine due to its higher cetane number which means that it improves lubricity and causes less wear of moving parts.

Graph of Corn Prices and % Corn Production used for Ethanol (EPA) [21]

Are there proposed policies used today?

The first proposed policy passed in the US was in 2005 called the Renewable Fuels Standard (RFS). Essentially, this policy requires that a certain volume of renewable fuel must be used to reduce petroleum based fuels [16]. By the enactment of the 2007 Energy Independence and Security Act, this also aimed for a renewable fuel usage of 36 billion gallon and an extension of volume standards by year 2022. Specifically looking at California, California’s Air Resources Board adopted the Low Carbon Fuel Standard in 2009 and was made effective in 2011 [17]. LCFS addresses ways of cutting GHG emissions by improving vehicle technology and providing renewable energy alternatives [18]. Some policy suggestions we propose would be increasing the strictness of the RFS standards and incentivize using different fueling alternatives by using tax credits.

References

1. Environmental; Energy Study Institute (EESI). Biofuels versus gasoline: The emissions gap is widening https://www.eesi.org/articles/view/biofuels-versus-gasoline-the-emissions-gap-is-widening (accessed Dec 5, 2020).

2. Biofuels Basics https://www.energy.gov/eere/bioenergy/biofuels-basics (accessed Dec 5, 2020).

3. New study: Biofuel use saved 589.3 million tons of carbon emissions over the past decade https://archive.bio.org/media/press-release/new-study-biofuel-use-saved-5893-million-tons-carbon-emissions-over-past-decade (accessed Dec 5, 2020).

4. Ethanol explained - U.S. Energy Information Administration (EIA) https://www.eia.gov/energyexplained/biofuels/ethanol.php (accessed Dec 5, 2020).

5. Feeding a potential Mars Colony: protein and B-12 https://hungermath.wordpress.com/2015/10/29/how-much-farmland-is-used-for-biofuel/f (accessed Dec 5, 2020).

6. Biofuels lead to increasing competition for land and water, study warns https://www.globalagriculture.org/whats-new/news/en/31803.html (accessed Dec 5, 2020).

7. BLE - Homepage - Biofuels reduce greenhouse gas emissions by 84 percent https://www.ble.de/SharedDocs/Meldungen/EN/2019/191213_biofuel.html (accessed Dec 5, 2020).

8. EIA projects U.S. biofuel production to slowly increase through 2050 - Today in Energy - U.S. Energy Information Administration (EIA) https://www.eia.gov/todayinenergy/detail.php?id=43096 (accessed Dec 5, 2020).

9. https://afdc.energy.gov/files/pdfs/30882.pdf (accessed Dec 5, 2020).

10. Ethanol Measurement - OnlineConversion Forums https://onlineconversion.vbulletin.net/forum/main-forums/convert-and-calculate/7123-ethanol-measurement (accessed Dec 5, 2020).

11. USDA announces $100 million for American biofuels infrastructure https://www.usda.gov/media/press-releases/2020/05/04/usda-announces-100-million-american-biofuels-infrastructure (accessed Dec 5, 2020).

12. Biodiesel laws and incentives in federal https://afdc.energy.gov/fuels/laws/BIOD?state=US (accessed Dec 5, 2020).

13. https://www.researchgate.net/publication/277928846_Investing_in_negative_emissions/figures?lo=1 (accessed Dec 5, 2020).

14. Epa, U. S.; OP. Economics of Biofuels. 2014.

15. Biodiesel Magazine - the latest news and data about biodiesel production http://www.biodieselmagazine.com/plants/listplants/USA/ (accessed Dec 5, 2020).

16. History of ethanol production and policy — energy https://www.ag.ndsu.edu/energy/biofuels/energy-briefs/history-of-ethanol-production-and-policy (accessed Dec 5, 2020).

17. Epa, U. S.; OAR. Overview for Renewable Fuel Standard. 2015.

18. Low Carbon Fuel Standard https://ww2.arb.ca.gov/our-work/programs/low-carbon-fuel-standard/about (accessed Dec 5, 2020).

19. Popp, J.; Lakner, Z.; Harangi-Rákos, M.; Fári, M. The Effect of Bioenergy Expansion: Food, Energy, and Environment. Renew. Sustain. Energy Rev.2014, 32, 559–578.

20. Diesel Vehicles Using Biodiesel https://afdc.energy.gov/vehicles/diesel.html (accessed Dec 5, 2020).

21. October, R. Working Paper Series https://www.epa.gov/sites/production/files/2014-12/documents/impacts_of_ethanol_policy_on_corn_prices.pdf (accessed Dec 5, 2020).

22. Blue Sky Science: Could the Biofuel Cycle Be Made More Efficient?; 2019.

23. Straw, R. Renewable diesel – The Benicia Independent ~ Eyes on the Environment / Benicia news & views http://beniciaindependent.com/topics/renewable-diesel/ (accessed Dec 5, 2020).