Although pressure for decarbonization remains unrelenting, this investment approach has clear limitations for commercial aviation – the business of flying aircraft with more than 100 seats. Battery-electric aviation and hydrogen propulsion remain long-term propositions unlikely to replace conventional propulsion at scale for decades in commercial aviation. Large-scale SAF implementations look like they will have serious economic and scalability challenges. Air New Zealand, for example, recently walked back from its commitment to cut emissions 29% by 2030 due to challenges in fleet availability and SAF capacity constraints.

Perhaps more alarming, airlines are starting to price in the costs of SAF policies. Lufthansa recently announced surcharges of up to €72 per ticket to cover part of the costs of increasing environmental requirements. The policies driving these price hikes are just getting started. Today, France mandates 1% SAF and EU ETS allowances trade at €65 a ton. By 2030, France’s SAF mandate will grow tenfold and EU ETS allowances are expected to more than double to €150 a ton. Expect more, larger price increases if the current policy trajectory continues.

All of this belies the underlying reality that commercial aviation’s medium-term future won’t scale or pencil out financially to “Net Zero 2050” (the goal to have all aviation emissions directly or indirectly mitigated by 2050). The airlines don’t control the most important levers and real progress will require dramatic changes to how aerospace dollars get invested. To get those dollars invested, policymakers need to change gears and focus on promoting the development of new aircraft with radically better fuel efficiency.

Aviation’s Current Sustainability Route

Commercial aviation realized a 52% decline in fuel burn per passenger mile (and therefore emissions) between 1980 and 2012 – much faster than the auto sector, where fuel burn only dropped 26%. These steady efficiency gains have made commercial aviation far more efficient than ground transportation in terms of both cost and carbon produced, with aviation moving people at the equivalent of 90-120 miles per gallon – the equivalent of electric cars. These advantages and others contributed to a more rapid rate of growth for aviation than ground transportation over the last 40 years.

The industry challenge looks different by type of aircraft. Small aircraft that serve mostly regional routes generate less than 10% of the industry’s emissions. It should benefit from the widespread adoption of hybrid-electric propulsion, which has the potential to reduce fuel burn and costs by up to 50% on regional routes. Although they will take longer to get into service, hydrogen and battery-powered aircraft developed could also eventually contribute to improved efficiency and reduced fuel burn.

Larger aircraft that serve primarily commercial aviation routes over 500 miles generate 90% or more of total emissions of the sector and have seen less innovation. Based on historical rates of improvement as depicted in the chart below, traditional tube and wing airframes using turbo-fan engines cannot meet the challenge of full decarbonization by 2050. Fuel represents around 25% of the typical airline’s cost bar and the industry consumes vast amounts of it. Unfortunately, the promising clean technologies for smaller aircraft—hybrid electric, electric, and hydrogen—do not scale easily to larger commercial aircraft.

In the absence of those new solutions for commercial aviation, policy support and investment have overwhelmingly favored the development of synthetic hydrocarbons, also called sustainable aviation fuels (SAF). These fuels promise to address all aviation emissions, not just those from regional flying. Commitments from airlines, including some of the world’s largest carriers, have led to global SAF offtakes to date totaling 14BN gallons. Figure 2 represents the typical plan you would see published by major airlines or industry groups (FAA, IATA) to reach NetZero 2050 for commercial aviation. Most of the projected carbon savings relevant to commercial aviation come from SAF assuming equipment-based improvements consistent with traditional rates of performance improvement. Yet, as we will see, without new equipment solutions, SAF solutions themselves become far less attractive and potentially unviable.

The Uncomfortable Economic Realities

SAF won’t come cheap. The World Economic Forum (WEF) estimates the total cost of the industry’s projected Net-Zero 2050 route at $4.6T (the route illustrated above). Nearly 95% of that incremental cost will come from SAF and most of the cost will accrue to commercial aviation. The WEF doesn’t expect these new fuels will reach price parity to jet fuel. The remaining ~5% will come from investment in battery electric and hydrogen aircraft that address primarily the regional aviation markets. The $184BN of new investment per year for this route represents six times the industry’s expected profits of $30.5BN in 2024.

These challenges will impact the regional market differently than commercial aviation. The former should benefit from the widespread, medium-term adoption of hybrid-electric propulsion, which has the potential to reduce fuel burn and costs by up to 50% on regional routes. Hydrogen and battery-powered aircraft developments could also contribute to improved efficiency and reduced fuel burn in the long-term. The negative abatement costs (i.e., operators are accruing cost savings for every ton of CO2 they avoid) associated with these new equipment solutions and the reduction in need for fuel overall should help the regional segment of the aviation industry grow even as it pays for increased SAF penetration and radically reduces emissions.

Commercial aviation poses a much greater challenge. Theoretically, hydrogen, hybrid-electric and battery electric could contribute to more carbon efficient commercial aircraft. Practically, these technologies won’t have the weight, power or volume profiles to meet commercial aviation’s on-wing power needs in the medium term. The aerospace industry is making insufficient progress to manage this problem for larger commercial aircraft.

Yet, SAF programs will struggle to succeed without more fuel, and therefore carbon, efficient commercial aircraft. To understand why, look at the scale of the need, how SAF will increase airline costs and how higher costs will influence demand for air services. Commercial aviation uses about 100 billion gallons of fuel per year. Given the scale of the need, SAF will likely come from several different technologies, cost profiles, and feedstocks as seen below. These technologies are expected to cost 2-3 times their traditional substitutes.

These estimates may understate the impact on prices. Many SAF technologies rely on electricity for cost-efficient production. However, the electrification of the economy will likely dramatically accelerate the demand for power and put strains on existing transmission infrastructure. Many expect electricity prices to increase at the point of use over the next decade even if prices for some types of power fall at the point of generation. Indeed, recent reports say Microsoft has contracted green power at $0.10 to $0.14 cents per kwh. Not a problem for high value added data centers that sell Nvidia processing time to AI companies, but perhaps more challenging for synthetic fuel plants that sell to a price sensitive industry.

How high AI demand will push electricity prices remains unclear. The optimistic end of the range for 2050 SAF production assumes unprecedented breakthroughs in energy production efficiency: $0.02 per KwH production cost. This price is nearly two-thirds the cost of today's lowest-cost energy projects, a much lower fraction of the cost of renewable energy available today at scale and 20% or less of Microsoft’s contracted price noted above.

Prices will become increasingly challenging for airlines and governments to manage as volumes increase. Prices typically get set by costs of the marginal producer/technology. The higher SAF penetrates into aviation fuel markets, the more SAF production will need to rely on less attractive, higher cost technologies. This will push up the prices for key feedstocks and ultimately the price of SAF.

For governments, the size and cost of the subsidies required to support a mostly SAF led transition could cost hundreds of billions of dollars per year. If governments impose mandates, forcing airlines and consumers to pay the cost of increased prices, they could unravel the global economy by creating economic dislocation in the tourism industry, which contributes $8.8 trillion to world GDP (10.4% of the global economy), and other aviation dependent sectors. Combine this with the fact that higher fares disproportionately impact the least expensive seats on the aircraft, and you have a recipe for significant backlash from the traveling public.

Traditional airline economic modeling tells us that cost increases at this scale will lead to unprecedented demand destruction. Historically, about 25% of airline costs come from fuel. If SAF were to replace jet fuel at the prices above, fuel costs would increase to 40-50% of airline costs. The resulting increase in ticket costs means the industry could lose 9 trillion revenue passenger kilometers (RPKs) in 2050—about the same total as all industry RPKs flown in 2019. In addition to the direct loss of revenue, this unprecedented cost pressure could cut industry margins by a third as airlines manage the transfer of SAF premiums to passengers. Higher exposure to fuel prices would also increase the volatility of cash flows forcing airlines to increase working capital to mitigate risk.

This scenario would cripple the investment case for the aviation industry AND the SAF industry lowering the amount of capital available to both sectors from investors and taxpayers needed to drive decarbonization. An impoverished aviation industry would have little capital to invest in the new, fuel-efficient aircraft already in production. As some government’s push back their climate goals and others do not, the commercial aviation industry could balkanize with different variants of aircraft for each region further increasing costs. SAF plants could become difficult to finance given this economic uncertainty and an unstable customer base.

In short, Net Zero 2050 looks upside down at the moment. The relatively small, regional sector should have good prospects for dramatic GHG reductions and growth based on significant innovation in multiple break-through, negative-abatement-cost technologies that should also make using SAF attractive. The larger commercial aviation sector, where most of the fuel is burned, has fewer prospects for breakthrough technologies and limited ability to absorb the economic premium associated with SAF as a result.

The Great Misallocation

How did the industry get itself into this position? The flow of capital should have followed the biggest financial opportunities with the biggest carbon footprint and prioritized projects with medium term payoffs while seeding longer-term opportunities. So far, that isn’t what has happened.

Nearly all “sustainable aviation” investment from private capital markets and airlines has been put toward SAF or short-haul aircraft technologies. Over the last eight years, nearly 70% of total venture investment in the sector has gone to electric, hybrid electric or hydrogen technologies that will help decarbonize regional aviation. Oddly, most of that investment has gone into battery electric or hydrogen technologies with longer-term payoff cycles, limited impact on industry passenger growth and limited reduction in medium-term GHG production. About 30% has gone into SAF investments that could help decarbonize both regional and commercial aviation.

Commercial aviation CVCs have a similar profile, with a higher emphasis on SAF, which reflects a pragmatic response to the pressure investors have put on airlines for sustainable flying. Surprisingly, investments in new commercial aircraft that could help solve the biggest part of the Net Zero challenge and unlock the value of existing SAF investments received almost no investment at all.

Given the scale of the crisis, it seems remarkable that Airbus and Boeing have no breakthrough airframe programs underway that will solve the industry’s sustainability and demand destruction issues. The last generation of narrowbody aircraft, the A320neo and 737MAX families, realized ~20% fuel savings largely based on advances in turbo-fan technology. However, the difficulties the LEAP and GTF engines have experienced demonstrate how challenging the OEMs will find it to maintain historical rates of improvement without changing the tube-and-wing airframe model they have relied on for the last six decades. Nevertheless, both have publicly stated their intention to release new narrowbody or widebody class aircraft based on tube and wing designs in the mid 2030s. Nearly all publicized Net Zero 2050 plans including those outlined in the charts above take for granted the OEMs will realize an additional 20% in efficiency improvements per historical trends, leaving unsolved the industry’s sustainability and demand destruction issues.

The OEM’s have begun exploration of more transformational concepts. Take Boeing’s advanced development program, the X66 Truss Braced Wing concept. It targets up to a 30% fuel efficiency improvement from airframe advancements, propulsion and materials, with additional efficiency coming mostly from open rotor engine technology. This reliance on engine efficiency is consistent with the industry’s strategy to date and may face challenges in implementation.

The sluggish response of the airframe OEMs to commercial aviation’s challenges has its roots in the complexity of designing and building new aircraft and the regulatory framework for certification that supports safety and other social objectives. Designing and manufacturing new passenger aircraft can require $10B or more of capital to develop and deep expertise to start and scale. Exacting safety standards and the complex nature of aerospace systems creates high capital and time requirements. (E.g., even a small aircraft like Joby’s eVTOL has taken years, $3.5B of invested capital and has yet to be certified to fly passengers.) The regulatory system demands manufacturers to complete nearly all capital investment in its manufacturing and engineering before their aircraft is certified for operation. Together, these factors mean airframe OEMs can release derivatives of existing aircraft for a much lower cost than developing a clean sheet aircraft.

These structural elements incent the current OEMs to limit product line breadth and create derivatives that stretch existing product lines across multiple use cases. In effect, this creates a financial bias towards product line consolidations and against airframe innovation. Mid-market aircraft represent a good example of how these incentives operate. Narrowbody aircraft typically have up to 200 seats and up to 3,000 miles of range powered by lighter engines with up to 34,000 pounds of thrust. Widebody aircraft typically have many more seats and often have a range of over 9,000 miles and heavy engines with 80,000 pounds of thrust or more. A mid-market aircraft would have more seats than a narrowbody and a range of 5,000 to 6,000 miles to fly over the Atlantic. This type of aircraft would save fuel, even if configured in a tube-and-wing design, for North Atlantic flights and other mid-range flying. However, OEMs could understandably find it hard to make the capital economics for developing a new, more efficient aircraft for the mid-range use case pencil out. That aircraft would cannibalize existing product lines and result in significantly higher capital costs than creating a new derivative of an existing aircraft. This puts into perspective why David Calhoun’s may have canceled Boeing’s New Midmarket Airplane project in 2020 and why the last mid-market aircraft, the Boeing 757, was launched over 40 years ago. Today, the existing OEM’s face an innovator’s dilemma accentuated by a set of regulatory incentives unique to aviation.

Given the limited support from the financial community and the OEMs, the aviation industry’s focus on SAF allows it to manage the risks of the transition without over-extending itself. Decades of crises, narrow margins, and an over-consolidated supply chain have made airlines cautious with respect to capital outlays. SAF investments allow the industry to trade capex for operating expense (opex) with the option to avoid that opex if the technology doesn’t pan-out. When that opex is low, airlines can experiment and innovate with smaller-scale partnerships and agreements with SAF companies or find the customer segments willing to fund the premium. These investments in SAF create signaling value that can facilitate larger investments from financial investors. If airlines want to make their CVC investments in SAF relevant they need to do the same with breakthrough commercial aircraft that make SAF economically affordable.

A New Policy Emphasis

Airlines’ primary mission remains safe, low cost transportation. That mission requires the industry to cut fuel consumption to reduce costs and thereby cut emissions. Yet, without more efficient commercial aircraft, SAF will increase fuel costs, shrink the market, undermine public support for decarbonization and kill off the investments that will make SAF available.

Creating policies that open up commercial aerospace to innovation via new competition would help. The military has done some of this in regional aviation with its Stratfi contract with Electra and its tanker contract with JetZero. (My venture capital firm DiamondStream is an investor in JetZero and I sit on the board.) However, military contracts, though helpful, can’t take the place of a broader commercial aerospace policy.

Policy needs to address competition and innovation at the same time. For example, accelerated depreciation on new, fuel efficient aircraft could increase demand for new aircraft. Without competition, existing competitors would benefit by increasing prices as demand increases whereas a competitive market might lead to larger supply increases. Similarly, providing research funding to established competitors can result in interesting findings that don’t turn into deployed products. Boeing and NASA spent close to 20 years and hundreds of millions of dollars researching blended wing body aircraft before Boeing dropped the concept. Whatever the financial merits of the decision, Boeing clearly faced significant disincentives to introduce a BWB aircraft given the potential for cannibalization of its existing wide-body offering. In addition to airframes, the current regulatory environment also protects current competitors at the expense of innovation at the supply chain level. An airframes policy could be the first step to a broader policy that helps mitigate some of the anti-competitive impact that regulatory policy has created within the commercial aerospace overall.

Ideas for radical improvements of airframes are available. Otto Aerospace claims a 60% reduction in fuel consumption from its airframe design that promotes laminar flow and Boeing’s Truss Wing aircraft has already been mentioned. Start-ups have launched multiple blended wing body (BWB) aircraft projects with similar step change improvements to fuel efficiency including: JetZero, Natilus and Outbound. At the higher end of the regional business, aircraft powered by hybrid electric systems could see deployment in the next decade.

Governments have helped make aviation the world’s safest business — they should make sure that stifling innovation is not its price. Catalyzing the development of 4-5 fuel-efficient, next generation aircraft projects with negative abatement costs with the goal of 1-2 successes might cost $50-100B. That looks cheap compared to $4-5T of SAF investments and like a bargain compared to the economic costs of shrinking the aviation industry and other related sectors like tourism.

Importantly, the negative abatement costs of these new aircraft don’t compete with SAF projects, they enable them. Investment cases for high capital cost technologies like SAF that depend on government mandates for adoption instead of core economics often struggle to raise funding. As noted above, the negative abatement costs new airframes provide can make SAF affordable and make investment in SAF facilities more financially rational. For example, hybrid-electric powered aircraft running all SAF can operate inter-island routes more cheaply than a turbo-prop version of the same aircraft using JetA.

As highly visible consumer businesses, airlines tend to take the heat for the lack of commercial aerospace innovation and occupy the best position to explain these issues to the public. Explaining the realities of decarbonizing to less expert audiences with strongly held views takes determination, patience and leadership. Many have and will continue to demonize the industry for speaking forthrightly on this issue.

Yet the airlines have little choice. Airbus and Boeing will develop SAF enabled, traditional aircraft with evolutionary improvements that don’t solve the problem. In doing so and consistent with their financial incentives, they will push de facto responsibility for decarbonization issues back to the airlines. It also will saddle governments and airlines with a choice between undermining the financial stability of the air transportation system by aggressively switching to SAF or slowing progress on climate goals. Airlines need to explain to their airframe partners, policymakers and the public the best path to solving these issues in the medium term are better airspace utilization, fleet renewal and policies that facilitate accelerated commercial aerospace innovation, even while they continue to seed and explore longer term solutions like SAF and hydrogen.

After all, what is the alternative? Massive capital investment in a SAF industry that will cause the core market for that technology to shrink dramatically and shrink tourism, one of the world’s largest sectors? An inconsistent regulatory regime around mandates that creates geographic aerospace silos out of a global industry and makes it less efficient? Do nothing and watch emissions grow?

The time to take action is now before policy drift creates a policy mess.

Enhanced Geothermal Systems (EGS) are quietly transforming how we think about renewable energy, turning one of the Earth's most underutilized resources—its internal heat—into a reliable and sustainable power source. The DOE Department of Energy (DOE) has estimated that there is approximately 100,000 megawatts of clean, baseload power possible through EGS technology in the United States

The beauty of this technology, which extracts thermal energy from deep beneath the surface, is that it is widely applicable, and may be of particular interest in regions where wind and solar face limitations.

Harnessing Earth's Internal Heat

EGS operates by drilling deep into the Earth's crust to access hot, dry rock formations. By injecting water into these formations and creating fractures, a closed-loop system is established. The water circulates through the hot rock, absorbing thermal energy and transforming into steam. This steam is brought to the surface to drive turbines, generating electricity. The cooled fluid is reinjected underground, minimizing environmental impact and sustaining the process.

Reliable Baseload Power

One of EGS's standout features is its ability to provide baseload power. Unlike wind and solar, which are intermittent and depend on weather conditions, EGS generates firm power, producing electricity around the clock.

Companies and institutions are demonstrating the potential of EGS to reshape the energy landscape.

Fervo Energy is pioneering advanced techniques adapted from the oil and gas industry, including horizontal drilling and well stimulation. Its Utah project, set to produce 320 megawatts of electricity by 2028, is a landmark in renewable energy innovation. This project has already attracted attention from Southern California Edison, which has committed to integrating Fervo's geothermal energy into its grid.

The project builds on Ormat's previous EGS work, including a demonstration at the Desert Peak geothermal power plant, which is set to be the first application of EGS technology to supply a producing power project in the U.S. Ormat's air-cooled power plants are particularly well-suited for EGS developments due to their compatibility with typical production temperatures and their water-conserving design, which re-injects all geothermal fluid back into the ground.

Cornell University is exploring EGS for district heating with its Earth Source Heat Project. This initiative aims to provide carbon-neutral thermal energy to the university’s campus, demonstrating how EGS can serve localized heating needs while supporting decarbonization goals.

Advancements and Opportunities

Recent advancements in drilling technology have significantly reduced the costs associated with EGS, making it more competitive with other renewable energy sources. Innovations like synthetic diamond drill bits and horizontal well systems have enhanced efficiency, enabling faster project development.

Additionally, federal and state policies promoting renewable energy integration are creating opportunities for EGS expansion. Enhanced mapping of geothermal potential by agencies like the National Renewable Energy Laboratory (NREL) has revealed viable sites across much of the U.S., further broadening EGS's appeal.

A Critical Component for the Future of Energy

Enhanced Geothermal Systems represent a potentially intriguing component of future clean energy production. Their scalability, reliability, and minimal environmental footprint make them a valuable addition to the renewable energy mix.

As technology continues to advance and costs decline, EGS has the potential to play a leading role in the global shift toward sustainable energy, providing solutions that meet both electricity and heating needs while combating climate change.

• Farmers often carry the heaviest burden to access the capital, technology and knowledge needed for the climate transition.
• All actors in the value chain, from brand owners to retailers to distributors to consumers, have a role in supporting farmers with this transition.
• Through initiatives like the First Movers Coalition for Food, companies and countries are coming together to show demand for sustainably produced foods and giving farmers the market confidence to transition.

• The complex interrelationships between climate and nature are recognized by scientists but are still being insufficiently prioritized by policymakers and businesses.
• With the right strategies, prioritizing nature and climate can be compatible with economic growth and value creation.
• This coming season of UN Conference of the Parties (COP) meetings and other sustainable development gatherings offers an unprecedented opportunity to accelerate integrated action for nature, climate and land.
  

• The energy-efficiency retrofit market is expected to grow by 8% year over year from 2024 to 2050, from $500 billion to $3.9 trillion.
• The built environment ecosystem must recirculate materials and reduce virgin material extraction before this extensive wave of energy-efficiency retrofits.
• There are four circular ecosystem actions that materials and parts manufacturers can take to capture more value in this growing market.

• Two years after the landmark UN Biodiversity Plan was adopted in 2022, biodiversity loss continues unabated on an unprecedented scale.
• Governments are revising their national biodiversity strategies and action plans as the 16th UN Biodiversity Conference (COP16) in Colombia approaches, providing opportunities to take a whole-of-government approach.
• Effective implementation of biodiversity commitments requires coherent policies and a connection between biodiversity commitments and green jobs, climate transition, sustainable production, plastics and more.

In an era defined by globalization and the pursuit of efficiency, supply chains have become essential yet vulnerable networks within the global economy.

The 5 Rs of the circular economy: recycling, remanufacturing, repair, refurbishment and recommerce.Image: DXC Technology

Lignin is a class of complex structural molecules that give plants their woody characteristics, making them rigid and resistant to degradation. It is derived from agricultural byproducts such as corn stover—the stalks, cobs, and leaves left after harvest—and is considered a waste product in many agricultural processes.

According to Professor Bin Yang, the lead researcher and a professor in WSU’s Department of Biological Systems Engineering, this development represents a critical step forward in utilizing agricultural waste to create renewable aviation fuel.

The aviation industry has significantly contributed to greenhouse gas emissions, consuming nearly 100 billion gallons of fuel in 2019. As global fuel demand is expected to increase by 32% by 2030 and potentially more than double by 2050, the need for alternative fuels is more pressing than ever.

In response, the aviation sector has focused on sustainable aviation fuels (SAFs) derived from renewable resources like plant-based biomass. However, despite the progress made in biofuels, current technologies still face challenges in meeting the aviation industry’s strict performance and volume requirements.

Lignin, often discarded or underutilized in biorefining processes, presents a promising new pathway for sustainable fuel production. It is produced in large quantities—about 300 million tons annually—and its aromatic structure makes it a viable candidate for jet fuel. However, converting lignin into fuel continuously has been a challenge until now. The WSU team’s research builds on this potential by demonstrating a novel process that could overcome many technical hurdles.

Innovative Technology: Simultaneous Depolymerization and Hydrodeoxygenation

The WSU researchers developed "simultaneous depolymerization and hydrodeoxygenation" (SDHDO), which breaks down the lignin polymer into smaller molecules while simultaneously removing oxygen. This process converts lignin into hydrocarbons, which can be used to produce lignin-based jet fuel.

The key innovation in this research is the ability to perform this conversion continuously, making it more feasible for commercial-scale production. The industry prefers Continuous processes because they can operate without interruptions, increasing efficiency and reducing costs.

The research was conducted at WSU’s facility in Richland, Washington, where the scientists introduced dissolved lignin polymers into a hydrotreating reactor to produce jet fuel. This continuous process contrasts with previous research that used batch processing, which is less efficient for large-scale production. The WSU team’s success in creating a continuous process marks a significant milestone toward commercializing lignin-based aviation fuel.

“This achievement takes this technology one step closer to real-world use by providing data that lets us better gauge its feasibility for commercial aviation,” said Professor Yang. “We now have a clearer understanding of how this process can be scaled up, making it a strong candidate for sustainable aviation fuel production.”

The Potential of Lignin-Based Jet Fuel in Aviation

Aviation is a notoriously difficult sector to decarbonize due to its heavy reliance on energy-dense liquid fuels and the challenges of electrifying aircraft. Sustainable aviation fuels are a key solution to reducing the industry’s environmental impact, and lignin-based fuels offer several advantages.

One of the primary benefits is that lignin-derived hydrocarbons can replace aromatics. These fossil fuel-derived compounds enhance fuel density and contribute to contrail formation and other environmental impacts. Aromatics are still widely used in jet fuel because they help swell O-rings in metal-to-metal joints, making them critical to fuel system performance. However, they are also a significant soot source, which has environmental and health consequences.

Lignin-based fuels could offer a cleaner alternative to fossil fuel-derived aromatics, helping to reduce the formation of contrails and improve fuel performance. In addition, the hydrocarbons produced from lignin are dense, efficient, and compatible with existing aviation infrastructure. These characteristics make lignin-based jet fuel a strong contender for use in commercial aviation, as it can be blended with conventional jet fuels to increase the renewable content while maintaining the performance characteristics required by airlines.

Overcoming Challenges for Commercialization

One of the most significant challenges facing the aviation industry is the need for “drop-in” fuels—fuels that can be used without modifying existing aircraft engines or fueling infrastructure. Lignin-based jet fuels have the potential to meet this requirement, as they offer sealing properties, energy density, and emissions profiles similar to conventional jet fuel. The WSU team’s research demonstrated that lignin-based jet fuel could be blended with conventional fuels to create a drop-in solution, moving the industry closer to producing 100% renewable aviation fuels.

The research also addressed another critical challenge: the cost and complexity of producing sustainable fuels. Using a less processed form of lignin, known as “technical lignin,” the team could reduce the cost and energy input required to produce the fuel. This contrasts with other studies that used highly processed lignin bio-oils, which are more expensive and energy-intensive.

The continuous process developed by WSU also used engineered catalysts, including a ruthenium-based catalyst (Ru-HY-60-MI), which proved effective in converting lignin into jet fuel range hydrocarbons. The researchers were able to achieve a carbon yield of 17.9%, producing a fuel rich in mono cycloalkanes and poly cycloalkanes, which are critical components for aviation fuel performance.

A Sustainable Path Forward for Aviation

The WSU team’s research represents a critical step toward making sustainable aviation fuels commercially viable. The successful demonstration of a continuous process for producing lignin-based jet fuel shows that agricultural waste can be transformed into a valuable resource for the aviation industry. By utilizing lignin, which is often discarded or burned, this technology not only provides a renewable alternative to fossil fuels but also contributes to waste reduction and more efficient resource use.

In the broader context of global sustainability goals, the aviation industry has set ambitious targets to reduce its carbon footprint. The International Air Transport Association (IATA) has committed to achieving net-zero carbon emissions by 2050, and sustainable aviation fuels will play a crucial role in meeting this goal. Lignin-based jet fuel offers a promising pathway to achieving these targets by reducing emissions, improving fuel efficiency, and providing a renewable alternative to fossil fuels.

The research was supported by several prominent organizations, including the U.S. Department of Energy’s Bioenergy Technologies Office, the Pacific Northwest National Laboratory (PNNL), the National Renewable Energy Laboratory (NREL), and Advanced Refining Technologies LLC.

With continued support and further refinement of the technology, lignin-based jet fuel could become a vital component of the aviation industry’s efforts to reduce its environmental impact and transition to a more sustainable future.

The battery operates by encapsulating carbon-14, a radioactive isotope of carbon, within a synthetic diamond structure. This encapsulation not only prevents radioactive leakage but also utilizes the betavoltaic effect, where the diamond converts the emitted electrons from the carbon-14 decay into electricity. The battery is the size of a conventional wristwatch battery, measuring 10mm across and just 0.5mm thick.

The Telegraph, Bild, IFLScience, BBC, Newsweek, PCWorld, TechCity, O Globo, TheNextWeb, and News18 reported on the new technology, among other outlets.

Sarah Clark, Director of Tritium Fuel Cycle at UKAEA, highlighted the innovative approach behind the technology. “Diamond batteries provide a safe and sustainable way to provide continuous power levels in the microwatt range. They are an emerging technology that uses manufactured diamond to safely encapsulate small amounts of carbon-14,” she stated, according to Newsweek.

The half-life of carbon-14 is 5,730 years, meaning the battery could potentially provide energy for thousands of years without the need for replacement. News18 reported that this longevity makes it especially useful for devices where durability and reliability are crucial, such as pacemakers, hearing aids, and other implantable medical devices. Patients would not need to undergo battery replacements throughout their lifetime, significantly simplifying their lives and reducing stress.

“Our micro-power technology can support a wide range of important applications, from space technologies and security devices to medical implants. We are excited to explore all these possibilities, collaborating with partners in industry and research in the coming years,” said Professor Tom Scott from the University of Bristol, as reported by The Telegraph.

The diamond battery also offers a solution for managing nuclear waste. The carbon-14 used in the batteries is extracted from graphite blocks, which are waste products in nuclear power stations. By extracting carbon-14 from the graphite, the radioactivity decreases, alleviating costs and challenges for the safe storage of nuclear waste.

The battery's potential extends beyond medical applications. TechCity highlighted its suitability for powering devices in extreme environments, such as space exploration and deep-sea missions, where conventional batteries are not viable due to the difficulty of replacement or maintenance. The stable and long-lasting energy source could keep systems and instruments operating for extended periods without the need for maintenance.

"The diamond battery would revolutionize the battery industry," said Fatimah Sannie, a senior process engineer at UKAEA who worked on the project, "We can use it in small satellites, in computer chips, and remote control wrist watches," she added.

Newsweek reported that the radioactive carbon-14 is securely encased within the diamond structure, ensuring safety for humans and the environment. The diamond casing not only prevents radioactive leakage but also helps increase the durability of the battery.

"Carbon-14 was chosen as the starting material because it emits short-range radiation, which is quickly absorbed by any solid material. This would make it dangerous to ingest or touch with bare skin, but if kept safely inside the diamond, no short-range radiation can escape," said Neil Fox from the School of Chemistry at the University of Bristol.

The Telegraph reports that work is underway to upscale production and improve power performance.