Jet Fuel From Sugarcane? It’s No Flight of Fancy
By Deepak Kumar, Stephen P. Long and Vijay Singh
The aviation industry produces two percent of global human-induced carbon dioxide emissions. This share may seem relatively small—for perspective, electricity generation and home heating account for more than 40 percent—but aviation is one of the world's fastest-growing greenhouse gas sources. Demand for air travel is projected to double in the next 20 years.
Airlines are under pressure to reduce their carbon emissions, and are highly vulnerable to global oil price fluctuations. These challenges have spurred strong interest in biomass-derived jet fuels. Bio-jet fuel can be produced from various plant materials, including oil crops, sugar crops, starchy plants and lignocellulosic biomass, through various chemical and biological routes. However, the technologies to convert oil to jet fuel are at a more advanced stage of development and yield higher energy efficiency than other sources.
We are engineering sugarcane, the most productive plant in the world, to produce oil that can be turned into bio-jet fuel. In a recent study, we found that use of this engineered sugarcane could yield more than 2,500 liters of bio-jet fuel per acre of land. In simple terms, this means that a Boeing 747 could fly for 10 hours on bio-jet fuel produced on just 54 acres of land. Compared to two competing plant sources, soybeans and jatropha, lipidcane would produce about 15 and 13 times as much jet fuel per unit of land, respectively.
Creating dual-purpose sugarcane
Bio-jet fuels derived from oil-rich feedstocks, such as camelina and algae, have been successfully tested in proof of concept flights. The American Society for Testing and Materials has approved a 50:50 blend of petroleum-based jet fuel and hydroprocessed renewable jet fuel for commercial and military flights.
However, even after significant research and commercialization efforts, current production volumes of bio-jet fuel are very small. Making these products on a larger scale will require further technology improvements and abundant low-cost feedstocks (crops used to make the fuel).
Sugarcane is a well-known biofuel source: Brazil has been fermenting sugarcane juice to make alcohol-based fuel for decades. Ethanol from sugarcane yields 25 percent more energy than the amount used during the production process, and reduces greenhouse gas emissions by 12 percent compared to fossil fuels.
We wondered whether we could increase the plant's natural oil production and use the oil to produce biodiesel, which provides even greater environmental benefits. Biodiesel yields 93 percent more energy than is required to make it and reduces emissions by 41 percent compared to fossil fuels. Ethanol and biodiesel can both be used in bio-jet fuel, but the technologies to convert plant-derived oil to jet fuel are at an advanced stage of development, yield high energy efficiency and are ready for large-scale deployment.
When we first proposed engineering sugarcane to produce more oil, some of our colleagues thought we were crazy. Sugarcane plants contain just 0.05 percent oil, which is far too little to convert to biodiesel. Many plant scientists theorized that increasing the amount of oil to one percent would be toxic to the plant, but our computer models predicted that we could increase oil production to 20 percent.
With support from the Department of Energy's Advanced Research Projects Agency-Energy, we launched a research project called Plants Engineered to Replace Oil in Sugarcane and Sorghum, or PETROSS, in 2012. Since then, through genetic engineering we've increased production of oil and fatty acids to achieve 12 percent oil in the leaves of sugarcane.
Now we are working to achieve 20 percent oil—the theoretical limit, according to our computer models—and targeting this oil accumulation to the stem of the plant, where it is more accessible than in the leaves. Our preliminary research has shown that even as the engineered plants produce more oil, they continue to produce sugar. We call these engineered plants lipidcane.
Multiple products from lipidcane
Lipidcane offers many advantages for farmers and the environment. We calculate that growing lipidcane containing 20 percent oil would be five times more profitable per acre than soybeans, the main feedstock currently used to make biodiesel in the U.S., and twice as profitable per acre as corn.
To be sustainable, bio-jet fuel must also be economical to process and have high production yields that minimize use of arable land. We estimate that compared to soybeans, lipidcane containing five percent oil could produce four times more jet fuel per acre of land. Lipidcane with 20 percent oil could produce more than 15 times more jet fuel per acre.
And lipidcane offers other energy benefits. The plant parts left over after juice extraction, known as bagasse, can be burned to produce steam and electricity. According to our analysis, this would generate more than enough electricity to power the biorefinery, so surplus power could be sold back to the grid, displacing electricity produced from fossil fuels—a practice already used in some plants in Brazil to produce ethanol from sugarcane.
A potential U.S. bioenergy crop
Sugarcane thrives on marginal land that is not suited to many food crops. Currently it is grown mainly in Brazil, India and China. We are also engineering lipidcane to be more cold-tolerant so that it can be raised more widely, particularly in the southeastern U.S. on underutilized land.
A map of the growing region of cold-tolerant lipidcanePETROSS
If we devoted 23 million acres in the southeastern U.S. to lipidcane with 20 percent oil, we estimate that this crop could produce 65 percent of the U.S. jet fuel supply. Presently, in current dollars, that fuel would cost airlines $5.31 per gallon, which is less than bio-jet fuel produced from algae or other oil crops such as soybeans, canola or palm oil.
Lipidcane could also be grown in Brazil and other tropical areas. As we recently reported in Nature Climate Change, significantly expanding sugarcane or lipidcane production in Brazil could reduce current global carbon dioxide emissions by up to 5.6 percent. This could be accomplished without impinging on areas that the Brazilian government has designated as environmentally sensitive, such as rainforest.
In pursuit of 'energycane'
Our lipidcane research also includes genetically engineering the plant to make it photosynthesize more efficiently, which translates into more growth. In a 2016 article in Science, one of us (Stephen Long) and colleagues at other institutions demonstrated that improving the efficiency of photosynthesis in lipidcane increased its growth by 20 percent. Preliminary research and side-by-side field trials suggest that we have improved the photosynthetic efficiency of sugarcane by 20 percent, and by nearly 70 percent in cool conditions.
Normal sugarcane (left) growing beside engineered PETROSS sugarcane, which is visibly taller and bushier, in field trials at the University of FloridaFredy Altpeter / University of Florida, CC BY-ND
Now our team is beginning work to engineer a higher-yielding variety of sugarcane that we call "energycane" to achieve more oil production per acre. We have more ground to cover before it can be commercialized, but developing a viable plant with enough oil to economically produce biodiesel and bio-jet fuel is a major first step.
Reposted with permission from our media associate The Conversation.
Many people shop online for everything from clothes to appliances. If they do not like the product, they simply return it. But there's an environmental cost to returns.
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EcoWatch Daily Newsletter
By Dolf Gielen and Morgan Bazilian
John Kerry helped bring the world into the Paris climate agreement and expanded America's reputation as a climate leader. That reputation is now in tatters, and President-elect Joe Biden is asking Kerry to rebuild it again – this time as U.S. climate envoy.
Energy Is at the Center of the Climate Challenge<p>The <a href="https://science2017.globalchange.gov/chapter/1/" target="_blank">effects of climate change</a> are already evident across the globe, from <a href="https://theconversation.com/100-degrees-in-siberia-5-ways-the-extreme-arctic-heat-wave-follows-a-disturbing-pattern-141442" target="_blank">extreme heat waves</a> to <a href="https://science2017.globalchange.gov/chapter/12/" target="_blank">sea level rise</a>. But while the challenge is daunting, there is hope. Solar and wind power have become the <a href="https://www.irena.org/publications/2020/Jun/Renewable-Power-Costs-in-2019" target="_blank">cheapest forms of power generation globally</a>, and technology progress and innovation continue apace to support a transition to clean energy.</p><p>In the U.S. under a Biden administration, long-term national climate legislation will depend on who controls the Senate, and that won't be clear until after two run-off elections in Georgia in January.</p><p>But there is no shortage of <a href="https://www.bloomberg.com/features/2020-biden-climate-change-advice/" target="_blank">ideas for ways Biden</a> could still take action even if his proposals are blocked in Congress. For example, he could use executive orders and direct government agencies to tighten regulations on greenhouse gas emissions; increase research and development in clean energy technologies; and empower states to exceed national standards, <a href="https://www.reuters.com/article/us-autos-emissions-california/defying-trump-california-locks-in-vehicle-emission-deals-with-major-automakers-idUSKCN25D2CH" target="_blank" rel="noopener noreferrer">as California did in the past with auto emission standards</a>. A focus on a just and equitable transition for communities and people affected by the decline of fossil fuels will also be key to creating a sustainable transition.</p><p>The U.S. position as the world's largest oil and gas producer and consumer creates political challenges for any administration. U.S. forays into European energy security are often treated with suspicion. Recently, France blocked <a href="https://www.wsj.com/articles/frances-engie-backs-out-of-u-s-lng-deal-11604435609" target="_blank">a multi-billion dollar contract</a> to buy U.S. liquefied natural gas because of concerns about limited emissions regulations in Texas.</p><p>Strengthening cooperation and partnerships with like-minded countries will be critical to bring about a transition to cleaner energy as well as sustainability in agriculture, forestry, water and other sectors of the global economy.</p>
Creating a Global Sustainable Transition<p>How the world recovers from COVID-19's economic damage could help drive a lasting shift in the global energy mix.</p><p>Nearly one-third of Europe's US$2 trillion economic relief package <a href="https://www.bloomberg.com/news/articles/2020-07-21/eu-approves-biggest-green-stimulus-in-history-with-572-billion-plan" target="_blank" rel="noopener noreferrer">involves investments that are also good for the climate</a>. The European Union is also strengthening its 2030 climate targets, though each country's energy and climate plans will be critical for successfully implementing them. The <a href="https://joebiden.com/clean-energy/" target="_blank" rel="noopener noreferrer">Biden plan</a> – including a $2 trillion commitment to developing sustainable energy and infrastructure – is aligned with a global energy transition, but its implementation is also uncertain.</p><p>Once Biden takes office, Kerry will be joining ongoing <a href="https://www.un.org/en/conferences/energy2021/about#:%7E:text=The%20overarching%20goal%20of%20the,2030%20Agenda%20for%20Sustainable%20Development.&text=Accelerate%20delivery%20of%20United%20Nations,related%20issues%20at%20all%20levels." target="_blank" rel="noopener noreferrer">high-level discussions on the energy transition</a> at the U.N. General Assembly and other gatherings of international leaders. With the U.S. no longer obstructing work on climate issues, the G-7 and G-20 have more potential for progress on energy and climate.</p><p>Lots of technical details still need to be worked out, including international trade frameworks and standards that can help countries lower greenhouse gas emissions enough to keep global warming in check. <a href="https://www.carbonpricingleadership.org/what" target="_blank" rel="noopener noreferrer">Carbon pricing</a> and <a href="https://www.csis.org/analysis/how-can-europe-get-carbon-border-adjustment-right" target="_blank" rel="noopener noreferrer">carbon border adjustment taxes</a>, which create incentive for companies to reduce emissions, may be part of it. A consistent and comprehensive set of national energy transition plans will also be needed.</p><p>The global shift to <a href="https://www.irena.org/publications/2019/Jan/A-New-World-The-Geopolitics-of-the-Energy-Transformation" target="_blank">clean energy will also have geopolitical implications for countries and regions</a>, and this will have a profound impact on wider international relations. Kerry, with his experience as secretary of state in the Obama administration, and Biden's plan to make the climate envoy position part of the National Security Council, may help mend these relations. In doing so, the U.S. may again join the wider community of countries willing to lead.</p>
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By Maria Caffrey
As we approach the holidays I, like most people, have been reflecting on everything 2020 has given us (or taken away) while starting to look ahead to 2021.
We Need More Than Listening<p>By now we have all become sadly accustomed to the current administration sidelining scientists, most prominently Dr. Anthony Fauci, because the facts they provide do not fit with the political rhetoric of the moment.</p><p>I have <a href="https://www.csldf.org/2019/08/22/csldf-helps-climate-scientist-maria-caffrey-fight-for-scientific-integrity/" target="_blank">my own history</a> of filing a scientific integrity complaint with the National Park Service (which falls under the Department of the Interior) after senior ranking employees attempted to censor one of my scientific reports. I know all too well the damage and pain that these actions cause, not just for the individual scientist, but also because these <a href="https://www.ucsusa.org/resources/attacks-on-science" target="_blank" rel="noopener noreferrer">attacks on science</a> over the last few years have undermined sound, evidence-based decision making.</p><p>President-elect Biden has repeatedly said that he will <a href="https://thehill.com/homenews/521638-trump-biden-will-listen-to-the-scientists-if-elected" target="_blank" rel="noopener noreferrer">listen to the scientists</a>. While this is certainly a welcome change, listening can only take us so far. This past week Lauren Kurtz from the <a href="https://www.csldf.org/" target="_blank" rel="noopener noreferrer">Climate Science Legal Defense Fund</a> and my colleague <a href="https://www.ucsusa.org/about/people/gretchen-goldman" target="_blank" rel="noopener noreferrer">Gretchen Goldman</a> published <a href="https://www.scientificamerican.com/article/ten-steps-that-can-restore-scientific-integrity-in-government/" target="_blank" rel="noopener noreferrer">an article</a> listing 10 actions the new administration should implement to show their commitment to strengthening government science:</p><ol><li>Clearly prohibit political interference and censorship.</li><li>Protect scientists' communication rights.</li><li>Acknowledge that attempts to violate scientific integrity, even if ultimately not fruitful, are still violations.</li><li>Protect federal scientists' right to provide information to Congress and other lawmakers.</li><li>Commit to incorporating the best science as part of agency decisions.</li><li>Elevate agency scientific integrity policies to have the full force of law.</li><li>Publicly release anonymized information about scientific integrity complaints and their resolutions at every agency.</li><li>Institute an intra-agency workforce, potentially under the White House <a href="https://www.ucsusa.org/sites/default/files/2020-09/strengthening-science-and-si-at-ostp.pdf" target="_blank" rel="noopener noreferrer">Office of Science and Technology Policy</a>, to coordinate scientific integrity efforts across agencies, foster discussion of policy improvements, and standardize criteria for policies across agencies.</li><li>Strengthen whistleblower protections.</li><li>Ensure that policies cover all actors who will be dealing with science.</li></ol>
Time for Action<p>I have spoken to many scientists, particularly federal scientists, who are eager to turn the page so they can hurry back to the work they had been doing before this administration, but I urge caution in assuming that things can be "normal" again.</p><p>Before Trump, I naively thought the scientific integrity policies established during the <a href="https://obamawhitehouse.archives.gov/blog/2016/12/19/scientific-integrity-policies-update" target="_blank">Obama administration</a> would be sufficient. I never imagined that any administration could so willfully ignore and attack expert advice and evidence that is intended to protect us and our public lands.</p><p>I have personally witnessed how hard our federal scientists work. They put in long hours with minimal pay (far less that what they could get if they worked in private industry) to pursue one simple goal: to make things better for the nation.</p><p>We need stronger scientific integrity policies to protect these people and their work. But more than that, we need stronger scientific integrity laws because they also benefit society.</p>
By Andrea Germanos
Environmental campaigners stressed the need for the incoming Biden White House to put in place permanent protections for Alaska's Bristol Bay after the Trump administration on Wednesday denied a permit for the proposed Pebble Mine that threatened "lasting harm to this phenomenally productive ecosystem" and death to the area's Indigenous culture.
<div id="da98c" class="rm-shortcode" data-rm-shortcode-id="478a197b7c59c92787c92bec92f1ac39"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1331662923710693376" data-partner="rebelmouse"><div style="margin:1em 0">Bristol Bay forever, Pebble mine never. #NoPebbleMine #SaveBristolBay https://t.co/CBQ9zuy8A5</div> — Save Bristol Bay (@Save Bristol Bay)<a href="https://twitter.com/SaveBristolBay/statuses/1331662923710693376">1606328156.0</a></blockquote></div>
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By Gwen Ranniger
In the midst of a pandemic, sales of cleaning products have skyrocketed, and many feel a need to clean more often. Knowing what to look for when purchasing cleaning supplies can help prevent unwanted and dangerous toxics from entering your home.