Reducing carbon emissions in order to prevent climate change requires developing new technologies for sustainable and renewable fuel production to replace fossil fuels. Today, in labs around the world, scientists are making discoveries that will lead to the advanced zero-carbon fuels of the future.

Only more research and development will show which of these promising discoveries will survive the rigorous tests of time and travel.



1 - Pulling Fuel Out of Thin Air


Someday soon, the gasoline we buy might come from carbon dioxide (CO2) pulled out of the air rather than from oil pumped from the ground.


By removing emitted CO2 from the atmosphere and turning it into fresh fuels, engineers have demonstrated a scalable, cost-effective way to make deep cuts in the carbon footprint of transportation with minimal disruption to existing vehicles.


It's not just theory - Carbon Engineering's facility in British Columbia, Canada is already achieving both CO2 capture and fuel generation.


Carbon Engineering has developed an industrially scalable Direct Air Capture technology, which can remove CO2 directly from the atmosphere at an affordable price.



A diagram of how Carbon Engineering's Direct Air Capture technology works.
(Graphic courtesy Carbon Engineering)


This is done in a closed loop where the only major inputs are water and clean electricity, and the output is a stream of pure, compressed CO2.


This CO2 can either be stored underground or converted into fuels using Carbon Engineering's Air to Fuels™ technology.


Centuries of unchecked human carbon emissions mean that atmospheric carbon dioxide is a virtually unlimited feedstock for transformation into new fuels.


"We are not going to run out of air anytime soon," says Steve Oldham, CEO of Carbon Engineering. "We can keep collecting carbon dioxide with direct air capture, keep adding hydrogen generation and fuel synthesis, and keep reducing emissions through this AIR TO FUELS pathway."


“It sounds like spinning straw into gold: suck carbon dioxide from the air where it’s contributing to climate change and turn it into fuel for cars, trucks, and jets,” the Canadian Press reported June 10.

But in an article published days later in the peer-reviewed journal "Joule," Carbon Engineering outlined what it calls direct air capture, in which CO2 is removed from the atmosphere through a chemical process, then combined with hydrogen and oxygen to create fuel.


CE says individual Direct Air Capture facilities can be built to capture one million tons of CO2 per year each - equivalent to the annual emissions of 250,000 average cars.


2 - Turning Power Plant Emissions Into Automotive Fuel


Massachusetts Institute of Technology (MIT) researchers have developed a new system that could be used for converting power plant emissions of CO2 into useful fuels for cars, trucks, and planes, as well as into chemical feedstocks for a wide variety of products.


The new membrane-based system was created by MIT postdoctoral scholar Xiao-Yu Wu and professor of mechanical engineering Ahmed Ghoniem, and is described in a paper in the journal "ChemSusChem."


The membrane, made of a compound of lanthanum, calcium, and iron oxide, allows oxygen from a stream of carbon dioxide to migrate through to the other side, leaving carbon monoxide behind.


The membrane, with a structure known as perovskite, is "100 percent selective for oxygen," allowing only those atoms to pass, Wu explains.


Carbon monoxide produced during this process can be used as a fuel by itself or combined with hydrogen and/or water to make many other liquid hydrocarbon fuels as well as chemicals, including syngas and methanol, an automotive fuel, and syngas, a mixture of hydrogen and carbon monoxide, a widely used industrial fuel and feedstock.


The method may thus not only cut greenhouse emissions; it could also produce another potential revenue stream to help defray its costs.


The process can work with any level of carbon dioxide concentration. Wu says they have tested it all the way from two percent to 99 percent, but the higher the concentration, the more efficient the process.


So, it is well-suited to the concentrated output stream from conventional fossil-fuel-burning power plants or those designed for carbon capture such as oxy-combustion plants.


The research was funded by Shell Oil and the King Abdullah University of Science and Technology in Thuwal, Saudi Arabia.


3 - Making Hydrogen Anywhere


As the race to find energy sources to replace dwindling fossil fuel supplies continues, hydrogen is likely to play a crucial role, scientists and technicians agree.


Japan has already announced its intention to become the world's first "hydrogen society," aiming to open 35 hydrogen fueling stations by 2020. Japanese auto Toyota projects that 30 percent of its vehicles will be powered by hydrogen by 2050.


3.1 - Fuel cells are currently used as a low carbon energy technology for electricity generation in transportation and stationary applications, but the use of precious-metal-based catalysts, especially platinum, makes the technology expensive.


Scientists from the University of Surrey in the UK say they have produced non-metal electro-catalysts for fuel cells that could pave the way for production of low-cost, environmentally friendly energy generation.


3.2 Fuel Cell Cars Enter the market at last. Fuel cell cars entered the retail market in 2015, but how quickly the market will grow remains uncertain.


Degradation and durability of components remain a concern. The relatively high cost keeps hydrogen fuel cell cars out of reach for many consumers. And, there are currently only 29 retail hydrogen filling stations in the United States, and they're all in California. But researchers are continuing to search for ways to lower costs and make improvements, betting that more and more private motorists will want to own one of these vehicles in the future.


3.3 - Hydrogen fuel anywhere, anytime. One of the biggest hurdles to the widespread use of hydrogen fuel is making the hydrogen efficiently and cleanly.

Now a team of researchers in Australia have created an experimental paint that attracts water molecules from the air and dissects them to produce hydrogen, a clean-burning fuel.



Distinguished Professor Kourosh Kalantar-zadeh, left, and Dr. Torben Daeneke

with a pot of solar paint and a piece of glass with the paint applied.
(Photo courtesy Royal Melbourne Institute of Technology School of Engineering)



“Our new development has a big range of advantages,” Dr. Torben Daeneke, a research fellow at Royal Melbourne Institute of Technology School of Engineering in Melbourne and leader of the team, said in a statement. “There’s no need for clean or filtered water to feed the system. Any place that has water vapor in the air, even remote areas far from water, can produce fuel.”


Traditionally, hydrogen for industrial use has come from fossil fuels. But this approach creates carbon byproducts and other pollutants. In search of a cleaner source, the researchers developed a photocatalyst to generate hydrogen from water vapor using porous, sulfur-rich molybdenum sulfide, a highly conductive efficient water-splitting catalyst. Testing shows the sulfide strongly absorbs moisture from the air.


Then, combining the sulfide with titanium dioxide nanoparticles, the researchers created an ink that can be coated onto surfaces, such as glass.


Films printed with this ink produce hydrogen without electrolytes or external power sources at a relatively high rate.


The moisture-absorbing photocatalytic paint can be applied to any surface such as building facades, introducing the novel capability of generating hydrogen fuel just about anywhere.


Daeneke's colleague, Distinguished Professor Kourosh Kalantar-zadeh, said hydrogen is the cleanest source of energy and can be used in fuel cells as well as conventional combustion engines as an alternative to fossil fuels.


“This system can also be used in very dry but hot climates near oceans. The sea water is evaporated by the hot sunlight and the vapour can then be absorbed to produce fuel," said Kalantar-zadeh. "This is an extraordinary concept – making fuel from the sun and water vapor in the air."


Their research is published as “Surface Water Dependent Properties of Sulfur Rich Molybdenum Sulphides – Electrolyteless Gas Phase Water Splitting” in "ACS Nano," a journal of the American Chemical Society.


3.4 - Nanoalloys 10X Better Then Pure Platinum in Fuel Cells


A new type of nanocatalyst can result in the long-awaited commercial breakthrough for fuel cell cars, Danish researchers say.


Research results from Chalmers University of Technology and Technical University of Denmark show it is possible to cut the need for platinum, a precious, rare and costly metal, by creating a nanoalloy using a new production technique.


"A nano solution is needed to mass-produce resource-efficient catalysts for fuel cells. With our method, only one tenth as much platinum is needed for the most demanding reactions. This can reduce the amount of platinum required for a fuel cell by about 70 percent," says Björn Wickman, researcher at the Department of Physics at Chalmers.


If this level of efficiency is possible to achieve in a fuel cell, the amount of required platinum would be comparable to what is used in an ordinary car catalytic converter.


"Hopefully, this will allow fuel cells to replace fossil fuels and also be a complement to battery-powered cars," says Björn Wickman.


Previous research has shown that it is possible to mix platinum with other metals, such as yttrium, to reduce the amount of platinum in a fuel cell. Yet no one has managed to create alloys with these metals in nanoparticle form in a manner that can be used for large-scale production. The major problem has been that yttrium oxidizes instead of forming an alloy with the platinum.


This problem has now been solved by Chalmers researchers who combined the metals in a vacuum chamber using a technique called sputtering. The result is a nanometer-thin film of the new alloy that allows mass-produced platinum and yttrium fuel cell catalysts.


To use the new material, today's fuel cells need to change slightly, but doing so creates incredible opportunities.


"When we can use our resources better, we save both the environment and lower costs," says Niklas Lindahl, researcher at the Department of Physics at Chalmers. "Fuel cells convert chemical energy into electrical energy using hydrogen and oxygen - with water as the only product. They have huge potential for sustainable energy solutions in transport, portable electronics and energy."


The research results are published in the journal "Advanced Materials Interfaces," as "High Specific and Mass Activity for the Oxygen Reduction Reaction for Thin Film Catalysts of Sputtered Pt3Y"


4 - Solar Microbial Fuel Cells


The U.S. Naval Research Laboratory Center for Biomolecular Science and Engineering in Washington, DC in June 2017 received a U.S. patent for a self-assembling, self-repairing, and self-contained microbial photoelectrochemical solar cell driven entirely by sunlight and microorganisms.


This non-semiconductor-based system employs microorganisms to generate electric power by photosynthetically replenishing reactants of a sealed microbial fuel cell using sunlight.


The sealed microbial fuel cell reactants, glucose and oxygen, are internally regenerated by a group of photosynthetic microbes whose reactants, carbon dioxide and water, are the products of the microbial fuel cell.


This interdependency results in many thousands of hours of long-term electricity generation from sunlight without replenishment of the microbial fuel cell reactants.


Dr. Lenny Tender, a microbial electro-chemist at the U.S. Naval Research Laboratory,
wades in a mesocosm he used to develop his Benthic Microbial Fuel Cell.
(Photo by Jamie Hartman, U.S. Naval Research Laboratory)


"Natural photosynthetic systems, such as trees and algae blooms, self-repair, a property that makes them highly durable," said Dr. Lenny Tender, research chemist, Center for Bio/Molecular Science and Engineering. "Here, we incorporate photosynthetic organisms with the self-assembling and self-maintaining benthic microbial fuel cell  to enable durable land-based photoelectrochemical solar cells."


5 - Hydrogen Sponges Look Promising


Finding practical hydrogen storage technologies for vehicles powered by fuel cells is the point of a $682,000 grant from the U.S. Department of Energy, awarded to Mike Chung professor of materials science and engineering at Pennsylvania State University.


Chung's recent research on superabsorbent polymers, which show potential to aid in oil spill recovery and cleanup, may also be a storage vehicle for hydrogen fuel cells.


"My group developed hydrocarbon polymers with a high oil absorption capacity," Chung said. "The polymers provide an efficient way to separate and store the hydrocarbon molecules - oils - from water during spills."


He hopes to apply similar technology to create a hydrogen adsorbent, which happens when thin layers of molecules adhere to the surface of solids or liquids.


Chung said the difficulties faced in storing the hydrogen could be overcome with the adsorbent, which would condense the gas into supercritical liquid form.


A liquid turns supercritical at the point when distinct liquid and gas phases do not exist. Hydrogen can then be stored in pores within the adsorbent at ambient temperature and low-pressure conditions. The pores naturally form in the spaces between the polymer's molecules.


"The polymer would act as a 'hydrogen sponge' in the storage tanks," Chung said.


"We face many difficulties with hydrogen storage technology," Chung said. "The technology isn't as well established yet as other alternative fuel sources, such as solar and wind power."


His research could be critical given the challenges that researchers face in storing and using hydrogen fuel safely and efficiently.


6 - Solid Oxide Fuel Cells Offer Something New


Using advanced computational methods, University of Wisconsin-Madison scientists have discovered new materials that could bring widespread commercial use of solid oxide fuel cells closer to reality.


These fuel cells burn their fuel electrochemically instead of by combustion, and are more efficient than any practical combustion engine.



University of Wisconsin Madison scientist Dane Morgan
(Photo courtesy UW Madison)



Solid oxide fuel cells could be used in a variety of applications, from serving as a power supply for buildings to increasing fuel efficiency in vehicles.


But solid oxide fuel cells are more costly than conventional energy technologies, and that has limited their adoption.


"Better cathode catalysts can allow lower-temperature operation, which can increase stability and reduce costs, potentially allowing you to take your building off the electrical grid and instead power it with a solid oxide fuel cell running on natural gas," says Dane Morgan, a materials science and engineering professor at UW-Madison.


The team of UW-Madison engineers harnessed quantum mechanics-based computational techniques to search for promising new candidate materials that could enable solid oxide fuel cells to operate at lower temperatures, with higher efficiency and longer lifetimes.


Their computational screening of more than 2,000 candidate materials from a broad class of compounds called perovskites yielded a list of 52 potential new cathode materials for solid oxide fuel cells.


The researchers published details of their advance in the journal "Advanced Energy Materials."


"With this research, we've provided specific recommendations of promising compounds that should be explored further," said Morgan, whose work is supported by the U.S. Air Force and the National Science Foundation. "Some of the new candidate cathode materials we identified could be transformative for solid oxide fuel cells for reducing costs."


7 - Making Fuel From Coal Waste


Coal waste fuel may reduce human emissions, a Tomsk Polytechnic University study reveals. The use of liquid fuel from this waste could save resources and reduce the damage to the ozone layer.

Russian scientists from Tomsk Polytechnic are developing a technology for obtaining liquid fuel from coal wastes for thermal power stations.


The research team of the Department of Automation of Thermal Power Processes is led by Professor Pavel Strizhak.


Their fuel will make it possible to resolve two problems at once: to reduce the amount of anthropogenic emissions of TPS and efficiently dispose wastes from coal processing.


"We use four groups of substances as major components: solid combustible components out of low-rank coals and coal-processing wastes, liquid combustible components, water, and plasticizers. The resulting fuel is a viscous mass which will further be burnt in boiler units," said Strizhak.


None of the four components can be used as fuel, but together they form fuel that is not worse than traditional coal.


The outcomes of the study have been published in the "Journal of Hazardous Materials."


The technology has been already tested at one coal production enterprise of the Kemerovo Region, the biggest coal producing region of Russia.


8 - Fireworks! A Zero-Carbon Fuel


In search of an alternative fuel type, some researchers are turning to the stuff of fireworks and explosives - metal powders.


Fireworks November 4, 2017 (Photo by Andrew Sweeney)



Metal powders, which can contain large amounts of energy, have long been used as a fuel in explosives, propellants and pyrotechnics. It might seem counterintuitive to develop them as a fuel for vehicles, but some researchers have proposed to do just that.


One team is reporting a method to produce a metal nanopowder fuel with high energy content that is stable in air and doesn't go boom until ignited.


"This idea of burning metals as a fuel sounds pretty far out there, but this is something that has been done in rockets forever," says Jeffrey Bergthorson, an aeronautics engineer at McGill University in Montreal, Canada.


He and colleagues at McGill and at the European Space Agency published in "Applied Energy" in 2015 a study outlining how metal powder could serve as a zero-carbon fuel to power transportation and the grid.


"Aluminum powder has long been known to be a very energetic material," says Bergthorson. But other metals such as magnesium and even lithium and silicon could do as well.  


Bergthorson and his colleagues' idea is not to use metal powders as a primary energy source, but as a way to store, transport and trade it as a zero-carbon fuel.


If this sounds similar to the idea of a hydrogen economy, it is. In the hydrogen economy the gas is manufactured by solar or other renewable forms of energy and then distributed as a fuel that can drive cars and other transport systems.


Bergthorson proposes that instead iron powder would be distributed as a means to drive cars, power plants, ships and locomotives.


"Storing energy will be an important part of the green-energy equation," says Bergthorson. "And for this purpose, metal powders have an advantage over hydrogen and batteries. Metals have a much higher energy density, specifically the energy density by volume, than other materials proposed in low-carbon schemes, including hydrogen.


Compared to hydrogen, where storage and transport are still a major problem, metal powder is easy.


"If you think about shipping energy by ships, as we do today, we have a much higher energy density as biomass," says Bergthorson. "We ship wood chips all over the globe as one of the ways to trade clean energy, but we can do this with metal fuels on a much larger scale."


9 - The Promise of Biohydrogen


Molecular hydrogen is regarded as one of the most promising energy carriers due to its high energy density and clean, carbon-free use.


A research group from the University of Turku, Finland, has discovered an efficient way for transforming solar energy into the chemical energy of biohydrogen through the photosynthesis of green algae that function as cell factories.


During photosynthesis, green algae utilize harvested solar energy to split water, release oxygen into the atmosphere and produce biomass that functions as a feed-stock in the blue biorefinery.


The University of Turku researchers decided to apply the knowledge retrieved from the basic research on the photosynthesis of algae and established a new method for producing hydrogen.


The researchers showed that the production of hydrogen could be greatly extended by exposing the anaerobic algal cultures to a train of strong yet short light pulses, which are interrupted by longer dark periods.


The process lasts for at least several days, and the maximum rate of the production of hydrogen occurs during the first eight hours, says senior researcher Sergey Kosourov.


The study opens up new possibilities for the construction of efficient living cell factories for the production of biofuels and different chemicals directly from sunlight, carbon dioxide and water.


The research provides important information on how to avoid wasting solar-driven energy in biomass production and how to apply this energy directly for the production of useful bio-products, says research group leader, Yagut Allahverdiyeva-Rinne, associate professor of molecular plant biology at the University of Turku.


The research was funded by Kone Foundation and the NordAqua Nordic Centre of Excellence of NordForsk Bioeconomy program.


This new method is valuable both for the basic research of the photosynthesis of algae and for the research and development work of the industrial sector when producing new technologies for the large-scale production of carbon neutral biofuels.


By Sunny Lewis

Environment News Service (ENS)

July 7, 2018