Ammonia + Light = Hydrogen

Hydrogen continues on its course of always being five to ten years away as a cheap, viable storage mechanism for energy.  The ideal of driving a car that emits only water vapor (or flying an airplane that zooms about on a few pounds of H2) seems like an ever-distant dream.

Tina Casey, writing for reports on Rice University solution using stinky ammonia that might clear the air for hydrogen, though.  She explains that the October 8th celebration of the fourth annual Hydrogen and Fuel Cell Day was great for natural gas stakeholders, since the gas is the primary source today for hydrogen.  Her headline indicates this could become a leading way to store and extract H2: “Forget the Hydrogen Economy, Here Comes the Ammonia Economy.”

So Desirable.  So Hard to Get.

Casey explains the big drawbacks to this market – fugitive greenhouse gas emissions and natural gas’s non-sustainable nature.  Another factor, the often high cost of producing H2, adds to the difficulties facing its ready availability.  She notes, “Renewable hydrogen is not a particularly new thing. The real challenge is getting the cost of renewable hydrogen down to parity with fossil-sourced H2.”

The Houston Chronicle reported on another Rice hydrogen researcher, James M. Tour, whose laboratory pursues different means of obtaining cheap hydrogen.  “’How do you store electricity? You have to make it into a fuel – something you can put into a bottle and ship around,’ Tour said. ‘Hydrogen is a great way to store electricity.’”

The Chronicle adds another concern that Tour expressed: “The cheapest and most common way to produce hydrogen is to use heat, steam and a nickel catalyst to split methane into hydrogen and carbon dioxide. But generating one carbon dioxide molecule for every two hydrogen molecules makes little environmental sense if the goal is to cut greenhouse gas emissions.”  Methane is indeed problematic, with its release during fracking for natural gas not uncommon.  Clouds of escaping methane caused the Aliso Canyon evacuation in 2015, displacing 25,000 residents for over four months and costing over a billion dollars in damage settlements.

Global mean CFC-11 (CFCl3) tropospheric abundance (ppt) from 1950 to 1998 based on smoothed measurements and emission models. CFC-11’s radiative forcing is shown on the right axis.  Source: IPCC

Global mean CFC-11 (CFCl3) tropospheric abundance (ppt) from 1950 to 1998 based on smoothed measurements and emission models. CFC-11’s radiative forcing is shown on the right axis.

Environmental issues aside, the U. S. Department of Energy looks for cost parity with gasoline, Casey adds.  “In order for fuel cell electric vehicles to be competitive, the total untaxed, delivered and dispensed, cost of hydrogen needs to be less than $4/gge. A gge, or gasoline gallon equivalent, is the amount of fuel that has the same amount of energy as a gallon of gasoline. One kilogram of hydrogen is equivalent to one gallon of gasoline.”

The Ammonia Economy?

Casey dispenses with several ways of producing renewable H2, including pulling it from landfill and wastewater gas, biomass gasification, and splitting water with an electrical current, and turns to Rice University’s potential offering, hydrogen from ammonia.

The counter-intuitive approach seems more reasonable the more it is explained.  Question: Why produce renewable hydrogen to make renewable ammonia, and then turn around and pull the hydrogen back out?  Answer: You can transport renewable ammonia fairly easily and reduce the “delivered and dispensed” part of your fuel costs.  She suggests that we “Think of ammonia as an energy storage system and you get to the “Neighborhood Energy Station” concept, in which a facility the size of a conventional gas station provides for local energy needs.

Your editor thought of the dangers of a tanker-size load of ammonia cracking open after a collision on the freeway, and thought that would be a good time to be elsewhere.  Fortunately, the Ammonia Energy Association (there is such a thing), cites two reports from Rise National Laboratory and Quest Consultants, Inc. that, “Ammonia risk levels are acceptable and similar to current fuels.”

How to Make Cheap Hydrogen?

Getting that renewable hydrogen, according to one Rice University research team, uses a new catalyst, heat, and light to extract the desirable element.  According to their paper in the journal Science, their catalysts rely on “the new catalytic nanoparticles, which are made mostly of copper with trace amounts of ruthenium* metal. Tests showed the catalyst benefited from a light-induced electronic process that significantly lowered the “activation barrier,” or minimum energy needed, for the ruthenium to break apart ammonia molecules.”  Not only does this budget approach work for breaking up ammonia molecules, but it may find applications in “commercial ammonia-based systems that generate hydrogen fuel on demand.”

“Scientists with Rice’s Laboratory for Nanophotonics have shown how a light-driven plasmonic effect allows catalysts of copper and ruthenium to more efficiently break apart ammonia molecules, which each contain one nitrogen and three hydrogen atoms. When the catalyst is exposed to light (right), resonant plasmonic effects produce high-energy “hot carrier” electrons that become localized at ruthenium reaction sites and speed up desorption of nitrogen compared with reactions conducted in the dark with heat (left)” by LANP/Rice University.

Heating the catalyst and shining light on it makes all the activation barriers fall more easily, apparently.  Still, the question remains – are we able to make enough hydrogen this way, and in turning it into ammonia for transport, able to extract it in such an efficient way that we get the benefits we seek?

More on Plasmonics

Namoi Hala, Stanley C. Moore Professor of Electrical and Computer Engineering at Rice and director of the school’s Laboratory for Nanophotonics, has an interesting blog on her laboratory’s many specialties, featuring “A Plethora of Plasmonics from the Laboratory for Nanophotonics at Rice University.”  The blog includes explanations of the science of plasmonics, active plasmonics, Single Nanoparticle and Single Molecule Spectroscopy, Line Shape Engineering, and Theranostics** and Biomedical Applications.  These areas of research are almost as obscure as quantum physics, and this definition of plasmonics probably yields meaning only after lengthy and deep reflection.

A kinder, gentler definition might help.  “Plasmonics is the name given (in 2000) to a discipline for exploiting the resonant interaction obtained under certain conditions between electromagnetic radiation… and free electrons at the interface between a metal and a dielectric material (e.g. air or glass). This interaction generates electron density waves called plasmons or surface plasmons.”

For more details check out the article “Quantifying hot carrier and thermal contributions in plasmonic photocatalysis” in the journal Science.

*Ruthenium is a chemical element with symbol Ru and atomic number 44.  A rare transition metal, it belongs to the platinum group of the periodic table.

**Theranostics is a new field of medicine which combines specific targeted therapy based on specific targeted diagnostic tests. With a key focus on patient centred care, theranostics provides a transition from conventional medicine to a contemporary personalized and precision medicine approach. The theranostics paradigm involves using nanoscience to unite diagnostic and therapeutic applications to form a single agent, allowing for diagnosis, drug delivery and treatment response monitoring.


Volocopters to Hover Over Singapore

Helena Treeck from Volocopter sent the following message this morning:

“Bruchsal/Paris/Singapore, October 2018 – Volocopter, the pioneer in urban air mobility, announced today during Autonomy – the Summit of Urban Mobility in Paris, that they will perform a next set of inner urban flight tests in Singapore. The series of test that are scheduled to take place in the second half of 2019 are supported by the Ministry of Transport (MOT), Civil Aviation Authority of Singapore (CAAS), and Economic Development Board (EDB).”

Singapore’s spectacular architecture forms a stunning backdrop for Volocopter’s vision of urban aerial transport

Already undergoing testing in Germany and Dubai, Volocopter’s 2X appears to be the company’s flagship for continuing development.  The following video (in French) intercuts a representative explaining the benefits of the Volocopter with images of its public flight testing in Dubai.  There are apparently less well-publicized tests in the nearby desert and ongoing development in Germany.

Ms. Treeck’s press released provides more goals.  “These flight tests are designed to validate and verify the ability of Volocopter’s eVTOL vehicles to operate in Singapore’s urban environment and will culminate in public demo flights. Volocopter and CAAS will work together to establish the scope of the flight trials and ensure that the necessary requirements are met before flight tests are allowed to commence. In addition to the flight tests, Volocopter will be setting up a product design and engineering team in Singapore to support its expansion plans. They are also looking for real-estate developers, mobility providers and businesses ready to join their quest to enable air taxis in Singapore.”

Architects will take on providing spaces for Volocopters, ala Uber’s recent competition

Volocopter promotes its emission-free flight, with nine battery packs powering 18 motor/rotor combinations.  For safety’s sake, the 2X has “Multiple redundancy in all critical components such as propellers, motors, power source, electronics, flight control, displays.”  Its communications network between devices through a “meshed polymer optic fiber network (´fly-by-light´).”

Vision of future includes air-conditioned comfort while getting a ride home

With a safe range “just under” 30 kilometers (18.6 miles), the Volocopter is well-suited to inner-city flights.  Worries about micro turbulence around tall buildings can be offset because of its drone-like ability to handle gusts “thus offering a smooth ride for passengers.”  Since Singapore is an island about 16 by 27 miles, it’s sized right for such testing, too.

Its data sheet shows a noise level of 65 dB (A) at 75 meters (246 feet), less than the typical background noise of a city.  Usually, Volocopters will fly at 100 meters (328 feet) or more, eliminating their aural presence.  The visual aspects will be more spectacular as the 2X’s wend their way through Singapore’s towering architecture.

One person who will oversee these flights has a positive outlook already.  Mr. Ho Yuen Sang, Director  for the Aviation Industry, CAAS, says, “There is potential for air taxis, or eVTOLs, to transform mobility and logistics in urban cities. Volocopter is at the forefront of such new and innovative technology in the aviation industry. CAAS is pleased to work together with Volocopter to study the technical capabilities and develop appropriate operational guidelines to facilitate such trials in Singapore.”

Volocopter envisions launch platforms on large buildings. Will this be plausible or problematic?

Mr. Tan Kong Hwee, Executive Director of the Economic Development Board (EDB) of  Singapore adds, “Volocopter’s decision to set up a local product design and engineering team in Singapore is a testament to Singapore’s aerospace engineering talent, as well as our prime position for industry players. We are excited to welcome Volocopter to Singapore and look forward to our future partnerships.”

Florian Reuter, CEO of Volocopter explains, “We are getting ready to start implementing the first fixed routes in cities.  Singapore is a logical partner: The city is a true pioneer in technology and city development. We are confident this is another exciting step to make air taxi services a reality.”

With a preliminary permit to fly in Germany since 2016, Volocopter is cooperating with the European Aviation Safety Authority (EASA) to receive a full commercial license.  Various Volocopter models have flown both indoors and out in its home country, and with public flights there and in Dubai, are competing with eHang and others to be the first sky taxis in several locations worldwide.  This could become a thing, as the young are apt to say.


Promising 3D Printed Microlattice Battery

The three biggest words in battery structures are “Area, Area, Area.”  The more anode and cathode area a battery can expose to the electrolyte that carries ions and electrons between the positive and negative ends of the battery, the better.  Most battery configurations, according to researchers at Carnegie Mellon University and Missouri University of Science and Technology, block a great deal of interaction between these elements.  Their solution is to go porous in a microlattice battery, thanks to 3D printing.

Lattice architecture can provide channels for effective transportation of electrolyte inside the volume of material, while for the cube electrode, most of the material will not be exposed to the electrolyte. Source: Additive Manufacturing 23 (2018) 70-78

Electrodes present some surface area to the electrolyte, which can only interact with the surface area presented.  Rahul Panat at Carnegie Mellon and Jonghyun Park at Missouri S & T have created a cube-shaped battery composed of microlattice electrodes which present significantly greater amounts of surface area to the electrolyte.

The title of their paper (with co-author Mohammad Sadeq Saleh) brings out this “area rule”: “3D printed hierarchically-porous microlattice electrode materials for exceptionally high specific capacity and areal capacity lithium ion batteries.”   The abstract explains, “This work reports a major advance in 3D batteries, where highly complex and controlled 3D electrode architectures with a lattice structure and a hierarchical porosity are realized by 3D printing. Microlattice electrodes with porous solid truss members (silver – Ag) are fabricated by Aerosol Jet 3D printing (AJP) that leads to an unprecedented improvement in the battery performance such as 400% increase in specific capacity, 100% increase in areal capacity, and a high electrode volume utilization when compared to a thin solid Ag block electrode.”

Lattice battery features microscopic “hierarchical porosity” and high performance

The microlattice structure proved to be mechanically robust, not losing its minuscule shape after 40 charge-discharge cycles, and managed to retain its electrical capacities.  The authors note that the technology can be applied to a wide range of electrochemical energy storage systems.

Panat, an Associate Professor in Mechanical Engineering at Carnegie Mellon, reflects, “I don’t believe anybody until now has used 3D printing to create these kinds of complex structures.  Since this work was done at the laboratory scale, it’s a bit surprising to see that the researchers think it can be “Ready to translate to industrial applications in about two to three years.”  As a droplet-based deposition technology, AJP is one of the only means of creating such precise and complex geometries. Panat asserts, “If this was a single stream of material, [as in FDM (Fused Deposition Modeling)/FFF (Fused Filament Fabrication) technology] as in the case of extrusion printing, we wouldn’t be able to make them.”

Fabrication process melds dots of silver in intricate maze to form structural, electrical cube.  Like other 3D processes, fine thread of silver becomes heated, deposited in precise arrays

As noted by the researchers, batteries can be lighter for the same capacity as current storage devices – or more powerful for the same weight.  The microlattice’s strength, electrical performance, and potential design flexibility could lead to uses in medical devices, drones and even full-size aircraft.  “For example, a part of a drone can act as a wing, a structural material, while simultaneously acting as a functional material such as a battery.”  This would bring one of your editor’s dreams closer to reality – the Grand Unified Airplane, in which the structure stores energy while collecting it from the act of flight itself.  Sunlight, even the wind itself, could power the aircraft.  With materials like the microlattice battery, this dream could be realized in at least some components of future aircraft.


UAVOS Flies ApusDuo HAPS

UAVOS, located in the midst of surrounding Google properties in Mountain View, California, sells a wide variety of goods and services related to the unpiloted aircraft world.  One of their biggest creations so far, the ApusDuo High Altitude Psuedo Satellite (HAPS) ran through a full series of tests.  The 10-meter span prototype vehicle will test control algorithms, including takeoffs and landings and verify HAPS aerodynamics.  According to UAVOS “Test flights fully confirmed the flight characteristics of the UAV.”   This is good news, since their next step will be to make at least a 15-meter wing (49.2 feet) wingspan version.  That will rely even more on “Control of roll, pitch, v-shape and slip…due to a controlled change in the angle of attack in particular sections of the wings” employed by the designers.  Note the flexibility of the entire airframe during launch and flight.

These controls include the visibly tricky interactions of the two slender wings, a rare pair in tandem designed to allow their reactions to the air around them to maintain stability and structural reliability.  Weighing a maximum of 23 kilograms (50.6 pounds), the ApusDuo stays within the FAA’s 55-pound limit for drones, but will occupy airspace between almost 40,000 and 65,000 feet.  Plans seem to include a 28-meter (91.8 feet) version.

The company makes a full array of automated control systems and control stations for aerial vehicles from under 15 kilograms (33 pounds) to over 1,500 kilograms (3,300 pounds).  They produce UAVs from 15 kilogram fixed wing craft to their Pipistrel conversion, and a range of rotary-wing vehicles up to 107 kilograms (235.4 pounds) takeoff weight.

UAVOS recently flew another of their creations, a Pipistrel Sinus (pronounced see-nus) under full autonomous control of their on-board systems.  A Light Sport Aircraft such as the Sinus can carry a payload of 200 kilograms (441 pounds) for up to five hours, making it a useful tool for many applications.  With a payload of only 40 kilograms (88 pounds), the Pipistrel can carry more fuel and stay airborne for up to 20 hours.  The flight included a fully autonomous takeoff, navigation to a selected destination and back and a fully-autonomous landing.

As UAVOS continues its flight tests on a growing number of vehicles, the company’s leading statement, “Beyond human capacity, under machine control,” will probably become even more apparent.  Civilian and military uses for their aircraft and systems are well defined on their website.


Communicating Between Ducted Fans and the Wing

Aircraft quite often seem to get designed as an assembly of separate components, wings an entity unto themselves, engines or motors something attached to the fuselage or wings, and not always seen as a set of matched components until final assembly.  Quite often, different components are compromised from their optimal shape or structure because of the need to integrate them with other parts of the craft.  One group of researchers is finding ways to even cause components to begin communicating among themselves.

Some parts, such as engines or motors, are hung on the wing or fuselage as replacements for earlier design variants.  The new powerplants may provide additional power, but they may also interfere with the overall performance and handling of the airplane.

Dr. Phillip Ansell of the University of Illinois

University of Illinois researchers led by Dr. Phillip Ansell, assistant professor in the Department of Aerospace Engineering in the College of Engineering has explored this subset of aeronautics and come to the conclusion that wings and propulsion need to be an integrated whole.  “If we allow those two systems to talk to each other, there is a lot of increased complexity in the flow field over the wing and into the propulsor – which also substantially alters the performance.  We’ve taken two subsystems – propulsion and aerodynamics – and we’ve said that these are not isolated subsystems. These are now one thing.”

Very much like experiments performed by Dr. David Ullman in his home wind tunnel in Independence, Oregon, Dr. Ansell’s work involved, “Using a 3D printed model of an airfoil, which is a cross-section of a wing, mounted inside a subsonic wind tunnel.  We had a model with ducted fans mounted over the trailing edge of the airfoil. The flow goes across the upper surface and then into the fan.”

Ansell’s team’s research might lead to aircraft such as the French ONERA Ampere

With graduate student Aaron Perry of the U of I and Michael Kerho from the Rolling Hills Research Corporation, Ansell attempted to understand the coupling between ducted fan systems and wing sections and how their interactions can modify overall aerodynamics of the total flight system.

Ansell explains, “If we integrate the propulsors, which in this case are fans, into the wing, we can improve the aircraft’s propulsive efficiency by ingesting the low-speed air across wing surface into the propulsor.  But it’s challenging to figure out how to do it in a smart way.”

Another possibility would be use of integrated ducted fans as in the Lilium VTOL machine

Seeing that a ducted fan on top of the wing changed the aerodynamic behavior of the airfoil when fan’s throttle setting was changed, he explained, “We can adjust the throttle to make the fan spin faster or slower, so that I now have a high-speed jet that’s coming out the back end and acts to substantially lift the aircraft through a phenomenon known as supercirculation. It also changes the flow across the surface.  I have little regions of the flow on the surface called boundary layers. Whenever I ramp up the throttle and start pulling air into that propulsor, it thins out the boundary layer. It modifies the distribution of the pressure across the airfoil itself. There are some complex things happening. That fan RPM talking to the aerodynamics of the larger airfoil is substantial.”

We can’t just think of increasing the throttle and adding thrust as an isolated function any more, he added.  “It’s not that simple because it also changes the air flow over the wing. The different orientations of the end of the fan changes the performance of the wing section as well as the pressure distribution because it changes the local flow quality characteristics. We have now quantified that and can understand some aspects of what that looks like.

“We were able to take measurements to better understand what those variations in coupling characteristics are. Previously we knew that if we ramp up the throttle on this fan, the result is a thrust vector pointed in a certain direction. Now we know that it will also modify my local wing aerodynamics.”

The team’s findings were published in a paper, “Aero-Propulsive and Propulsor Cross-Coupling Effects on a Distributed Propulsion System,” in the Journal of Aircraft, and as part of the 2018 AIAA Aerospace Sciences Meeting, AIAA SciTech Forum, (AIAA 2018-2051)

Dr. Ansell’s airfoil integrated with a “crossflow fan” would extend laminar flow and provide added thrust with reduced drag

Part of Dr. Ansell’s current research may be a call-back to recent investigations on National Aeronautics and Space Administration (NASA)-related studies on reducing skin friction.  His prospective new propulsion system would stretch the extent of laminar flow across the top surface of an airfoil and reduce the extent of turbulent flow.

He explains his design: “Propulsion is built into the airfoil so that the intake sucks in the flow across the upper surface (of the wing), and exhausts the air out the trailing edge. This provides us new ways to tailor the way the pressure is distributed across the airfoil surface and also employ our propulsion system directly at the location of the wing wake. Both of these effects offer distinct benefits within an aircraft design.”


A Triple-Redundant Powerplant

Your editor saw this Tweet from Frank Anton, head of Siemens eAircraft:

FrankAnton @Frank_E_Anton Oct 9

Hybrid-electric with multiple redundancy: three independent drive units in one engine block. Should a module fail, flight can continue with two remaining components. Scalewings engine exists as concept, development work expected to take three years.

This caused your editor to go quickly to the ScaleWings home page, where a beautiful P-51 Mustang in 70-percent scale dazzles.  The airplane is available in Ultralight, Light Sport Aircraft, and Experimental configurations using engines from the UL and Rotax lines up to a Chevrolet LS300, with a supercharged variant offering up to 600 horsepower.  Their brochure, in German or English gives a great overview of the features of this carbon-fiber replica.

Scalewings has an even more exciting powerplant on the way, especially for those of us who value our own hides.  Their triple-redundant engine/motor combines a naturally-aspirated four-stroke engine, a turbocharged four-stroke engine, and an electric motor.  If any one unit fails, the plane can fly the other two.

One V-twin engine is naturally-aspirated, one is turbocharged, and they both share their shaft with an electric motor

Flyer Magazine quotes Hans Schwöller, described as a “mastermind” on the company’s website  and managing director of the ScaleWings group, explaining his “secret recipe”:

“’The ground-breaking concept of the multiple-redundant aircraft engine consists, in its standard configuration, of three interlocking engines of which two work on the basis of efficient two-cylinder 4-stroke injection engines.

“’The third drive in the form of a high-performance, state of the art electric motor, delivers enormous additional performance, as required, or can also be used for noise protection for accelerating, take-off and climbing to cruising altitude.’”

The integration of all these units in the same casing and using the same crankshaft is a bit of magic, and the sharing of support mechanisms is even more intriguing.

Compact dimensions of what is essentially two V-twin engines, one electric motor

Schwöller continues, ““It is irrelevant if the oil or water cooling system fails or important engine components such as engine control, injection, ignition, crankshaft, connecting rods or valves fail. The drive even continues to work if engine components become fully blocked. Flight can even continue with just one single functioning module.’”

Other firms’ projects to create redundant internal combustion/electric hybrid motors have not been this elaborate.  Flight Design and Rotax collaborated on a system originally intended to power that company’s CT Light Sport Aircraft, but which ended up powering Embry Riddle’s EcoEagle in the 2011 Green Flight Challenge.  Another product, Axter’s electric motor mounted on the nose of a Rotax engine, was originally designed to allow 20 minutes of flight on battery power if the engine failed.  They now have a newer version but don’t show specifications for that option.

Scalewing’s engine comprises these modules, which can be assembled in a variety of way, apparently:

  • 2 x 2 cylinder naturally aspirated engine with 180hp (132kW)
  • Electric engine unit with 77.7 hp (58kW) plus 2 x 2-cylinder naturally aspirated engine = 260hp (190kW)
  • 2 x 2-cylinder turbo engine + electric engine unit = 350hp (257kW).

Since the Mustang can manage something as powerful as a 600-horsepower LS300 engine, it will manage the hybrid with ease.  The engine itself gives hopes that it will be available to other designers who see merit in the reliability it should provide.  Your editor thinks it may derive great interest from the eVTOL market, especially.


DHL Parcelcopter Delivers the (Medical) Goods

Vertical Daily News this morning reports on the DHL Parcelcopter 4.0 as it delivers medicines to an island in Lake Victoria on the northern tip of Tanzania.  The Parcelcopter is a fourth generation design from Wingcopter, a German drone manufacturer.  It’s found delivering packages autonomously in German mountain demonstrations and now in differently rugged terrain, flying life-saving packages to a remote island.

With financial help from the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ – The German Society for International Cooperation ) GmbH ( on behalf of the German Federal Ministry for Economic Cooperation and Development (BMZ), DHL and Wingcopter have flown a total of 1,367 miles (2,200 kilometers) and about 2,000 flight minutes in a six-month trial.  The 37-mile (60-kilometer) flights averaged about 40 minutes.

Parcelcopter on delivery mission somewhere over Tanzania

Compare such speedy deliveries to the time, personnel, and energy required on the six-hour overland route of 150 miles (240 kilometers).  ).  As Vertical Daily News notes, “That makes it nearly impossible to provide emergency medication or to quickly refill cool chain commodities that are out of stock.”  Medicines and blood or tissue samples require refrigeration, and time in transit can often ruin precious commodities.  To prevent spoilage, the DHL machine has an insulated cargo compartment.

Wingcopter’s founders and designers, Darmstadt University students Jonathan Hesselbarth and Tom Plümmer, developed their project with support from the Technical University of Darmstadt’s Highest innovation and start-up center.  Combining helicopter and conventional aircraft features, their design shows flexibility and multiple possibilities for different applications.  The video gives an on-board view of how an earlier iteration fo the machine functions.

Operators see new opportunities for addressing logistic challenges in the public health sector in many parts of Africa, especially supplying hospitals and pharmacies, according to Vertical Daily News.  “Medical care for the roughly 400,000 residents of the Ukerewe island district of Lake Victoria, for instance, is severely limited. This is partly due to the poor infrastructure and difficult terrain.”

Luckily, Parcelcopters require very little infrastructure to carry out their missions since they take off and land vertically.  “After delivering its cargo, it can easily be loaded with blood and laboratory samples to take back to the mainland.”  This versatility and speed could help quell epidemics or pandemics, “allowing an early response to slow the spread of viral diseases like Ebola.”

A More Sophisticated Infrastructure

Other groups such as Matternet, Zipline, and Flying Donkeys have worked in Africa to deliver medical supplies. DHL has joined them and has a history in Bavaria, testing a more sophisticated form of delivery using drones.  The video shows the evolution of the DHL Parcelcopter, but since it was completed in 2016, misses the fourth iteration of the drone.

DHL customers in Reit im Winkl and Winklmoosalm plateau were able to sample aerial deliveries at specially-developed Packstations, “dubbed the Parcelcopter Skyport.” 130 autonomous loading and offloading cycles were ultimately performed.

Whether delivering parcels in the Alps or critical medical supplies in the veldt, DHL’s Parcelcopters show that their approach to “last-mile” delivery is an increasingly useful one.


Biofuels from Many Sources

We’ve looked at an array of different biofuel sources ranging from used cooking oil and algae to farm and municipal waste.  This is essential as the percentage of airline emissions becomes a bigger part of our overall greenhouse gas situation.   The Guardian reports, “A 2017 estimate said air travel accounted for 2.5% of all carbon dioxide emissions, with the total emissions expected to quadruple by 2050.”We’ll look here at how some of the early efforts have panned out and examine a late-breaking surprise or two.

Mustard Seeds?

According to the Guardian, “A Qantas plane powered partly by mustard seeds has become the world’s first biofuel flight between Australia and the United States, after landing in Melbourne on [January 30, 2018].”

A Qantas 787-9 Dreamliner made the journey from Los Angeles to Melbourne using a a blended fuel 10% derived from the brassica carinata, an industrial type of mustard seed that functions as a fallow crop. Photograph: Brent Winstone/PR IMAGE

A major test, the 15-hour flight used a blended fuel 10-percent of which came from the brassica carinata, a mustard seed used as a fallow crop between regular crop cycles.

Qantas’ Boeing Dreamliner 787-9 “Reduced carbon emissions by 7 percent compared with the airline’s usual flight over the same LA to Melbourne route. Compared pound for pound with jet fuel, carinata biofuel reduces emissions by 80% over the fuel’s life cycle,” according to the Guardian.  Qantas has flown with biofuels since its first trials in 2012, using a 50-percent blend of used cooking oil.

Daniel Tan, an agriculture expert from the University of Sydney, said mustard seed could double as a valuable crop and a source of sustainable fuel for farmers.

“Almost within a day after harvesting, they can press the oil out in their own shed and use it straight into their tractors,” he said.  “Basically it’s good for growing, and also farmers can also use it. If they grow wheat every year it’s not good for the soil. They can grow mustard seed in between the wheat crops, every second or third year, press the oil and use it locally or export it for use in aviation fuel.  One hectare (about 2.5 acres) of the crop can be used to produce 400 liters of aviation fuel or 1,400 liters of renewable diesel.

“A lot of the biodiesel now being processed is actually from waste oil from places like fish and chip shops. A lot of these oils can be processed, but the problem is that they can’t get consistent supply. The big problem with the biodiesel industry in Australia is mainly the continuity of supply.”  Qantas hopes to use biofuels, supplied by U. S. company SG Preston, on all Los Angeles-based flights by 2020.

Other Airlines, Other Approaches

Other airlines, perhaps with less faith in the power of mustard seeds to move large jets, are using a wide array of plant and waste materials to produce jet fuel.

An Alaska Airlines Cooperative

Alaska Airlines, Boeing and SeaTac Airport have been cooperating on using farm and municipal waste to produce renewable jet fuel, but Boeing’s efforts have stretched as far as the United Arab Emirates, where a plan to develop halophyte plants (which can thrive in salt water) continues with the Khalifa University.  Boeing also works with partners in biofuel development on six continents, a sign of deep involvement and earnest commitment.

A letter from Paul McElroy, with Boeing Commercial Airplanes Environment Communications, explains the company, “led the approval of the first pathway and that fuel has been flown successfully on thousands of commercial flights. Boeing continues to work tirelessly within ASTM, the international standards body… develop and commercialize new sources of aviation biofuel.”

His letter notes, “Boeing is now partnering with the U.S. Federal Aviation Administration and other stakeholders to gain approval for a biofuel called HF-HEFA (high freeze-point-hydrotreated esters and fatty acids), which is produced from fats, oils and greases.  Known as ‘green diesel’ when used in ground transport, global production capacity exceeds 1 billion gallons annually. To verify this fuel’s performance and characteristics, Boeing tested two blends of HFHEFA on its ecoDemonstrator program’s 787 and 757 flight test airplanes. Approval of this fuel would make a price-competitive sustainable biofuel available that could meet more than 1 percent of global aviation fuel supply needs.”

Alaska Airlines, Boeing, and SeaTac have partnered to provide an infrastructure to supply biofuels to all airlines flying from Seattle

Alaska Airlines wants to lead in these ambitions.  “As an airline, we require large volumes of fuel to run our business. While technology and operational flying efficiencies have reduced the amount of fuel we use and the associated emissions, they are not enough to lower emissions to achieve industry-wide goals of carbon neutral grown by 2020, and a 50% reduction in emissions by 2050, compared to a 2005 baseline.  In 2016, They partnered with Gevo on three commercial flights using alcohol-to-jet fuels, completed two

“Alaska was the first domestic airline to fly multiple scheduled flights using aviation biofuel, and we have committed to use only aviation biofuels that meet stringent sustainability criteria.”  Alaska’s 2020 goal of using sustainable aviation biofuel in at least one airport is a work in progress, with several mileposts showing the airline’s progress.  In 2016, Alaska partnered with Gevo and completed three biofuel flights using fuel produced by the alcohol-to-jet (ATJ) process.  They flew twice on biofuel that used corn as a feedstock, and that November, flew from Seattle to Washington, D. C. on ATJ made from post-harvest forest residues.

Alaska also partnered with Boeing and the Port of Seattle to conduct a $250,000 biofuel infrastructure feasibility study, a major step towards bringing biofuels to all air carriers at Sea-Tac Airport.

The Port of Seattle encourages further development of SAF, with a goal of having all commercial flights powered by sustainable fuels by 2028.  The Port sees its roles in providing infrastructure, financing, land use, advocacy and partnerships as crucial to the plan’s success.  A note on financing shows assistance from some heavy hitters in the environmental world.    The Port reports, “In 2017, Carbon War Room/Rocky Mountain Institute and SkyNRG investigated the feasibility of using different airport revenue streams at Sea-Tac to help bring down the cost to all airlines compared to petroleum jet fuel, as well as support the build-out of fueling infrastructure.  The report identified a range of funding sources, and included ways an airport could be involved without directly paying for fuel.”

United’s Far-Flung Suppliers

Other airlines have similar goals and timelines.  United Airlines, in a letter expressing its goals, claims to have improved its fuel efficiency by 45 percent since 1990, “but that’s only the first step.”  United is working toward “a collective industry goal of 1.5 percent average improvement of annual fuel efficiency through 2020, carbon neutral growth beginning in 2020 and a 50 percent reduction airline CO2 emissions by 2050.  United hopes not only to be a good corporate citizen but to guard against oil price instability.  Its efforts led the Natural Resources Defense Council (NRDC) to name United a “Leading Airline for having a strong range of commitments and supply chain implementation.”

AltAir Fuels

United became the first airline globally on SAF on an ongoing daily basis.  AltAir Fuels in Los Angeles supplies fuels made from agricultural wastes and non-edible natural oils.  AltAir fuels lower greenhouse gas (GHG) emissions more than 60 percent compared to petroleum-based products.  AltAir’s fuels are certified for sustainability by the Roundtable for Sustainable Biomaterials.

Fulcrum BioEnergy

Since 2015, United partnered with Fulcrum BioEnergy, a company pioneering conversion of waste and household trash into low-cost, sustainable aviation fuel.  United will have Fulcrum SAF refineries near all its U. S. hubs, producing nearly one-billion gallons in their first ten years of operation, nearly three times the amount United uses yearly.  This will keep trash out of landfills, lower United’s emissions, and probably power other operation’s fuel needs.

A Worldwide Organization Promotes SAF

Irina Slav, writing for the industry watchdog, tells us, “The International Air Transport Association has set an ambitious goal for its members: transporting a billion passengers on flights using biofuel by 2025. The goal is a demonstration of IATA’s efforts to help cut carbon dioxide emissions. The aviation industry is a major source of these, after all.”

She goes on to explain that although biofuels might cut into Big Oil’s profit margins, such alternatives will not grow big enough to be a major threat to the oil business.   More expensive than regular jet fuel, some biofuels price themselves out of a very competitive market.

The International Air Transit Association (IATA) backs the drive to promote biofuels.  Chief Executive and Managing Director Alexandre de Juniac says, “We want 1 billion passengers to have flown on a SAF (Sustainable Aviation Fuel)-blend flight by 2025. That won’t be easy to achieve. We need governments to set a framework to incentivize production of SAF and ensure it is as attractive to produce as automotive biofuels.”  IATA estimates, though, that only half a billion passengers might fly on “biofueled” flights by the target date.   You can see the organization’s biofuel report here.

Ms. Slav explains that loan guarantees and capital grants might help if sometimes skeptical banks will cooperate.  The industry hopes to trend toward carbon neutral growth and reduce net emissions.  Currently, emissions average between 114 grams of CO2 per kilometer on long-haul flights and 260 grams per kilometer for shorter flights.  IATA suggests biofuels could cut this by as much a 80 percent.  Ms. Slav concludes that the economics will be the tricky part, with producers concentrating on reducing costs and governments providing incentives and probably regulation.  Look for higher fares and greater Big Oil activity in biofuels, she cautions.

More to Come

With Zunum and Airbus coming forward with medium-size, medium-range single-aisle airliners, and Pipistrel and the MAHEPA organization coming forward with hybrid small aircraft, biofuels will have a promising place in near-future aviation.  We have only shown a few players here, with much more to come on the national and international front in the near future.


Zunum Picks Safran Helicopter Engine for ZA10

Ashish Kumar, CEO of Zunum Aero, announced that his firm will partner with Safran Helicopter Engines to use that firm’s Ardiden 3Z engine as the powerplant for Zunum’s 10-passenger regional airliner.  He lists the advantages this installation will provide.

Safran (formerly Turbomeca) Ardiden 3Z turbine engine will power generator on Zunum ZA10 regional airliner

“Our ZA10 aircraft, under development for entry in the early 2020s, will be powered by dual power sources: propulsion batteries, and a Safran turboshaft in the 1,700 to 2,000 shaft horsepower (shp) Ardiden range.  This new model, the Ardiden 3Z, will be used as a hybrid power source achieving demanding cost, efficiency and uptime requirements.  It will be coupled with an electric generator, and the integrated turbo-generator will deliver 500 [kilowatts] of electric power to supplement propulsion batteries on key stages of flight and over long ranges.  Upgrades such as advanced materials and integrated lifecycle management for hybrid service will dramatically reduce operating costs of the engine by extending the life of critical components.”

Florent Chauvancy, Safran Helicopter Engines EVP OEM Sales, added: “The Ardiden 3Z represents a very powerful complement to the ZA10 because of its exceptional performance, along with low operating and maintenance costs. This announcement marks a new step forward in demonstrating Safran ability to offer hybrid propulsive solutions for tomorrow’s mobility solutions.”

Zunum ZA10 in currently depicted configuration. Underwing pods are new addition and batteries in wings are smaller than previous illustrations

Kumar claims the ZA10 will operate at costs around $250 per hour.  For comparison, a local flight school near your editor rents an instrument flight equipped Piper Geronimo Apache for $255 per hour cash – $265 credit card.  Kumar claims operating costs are 60- to 80-percent lower for the Zunum craft than “comparable conventional aircraft.”  According to Wikipedia, these costs are based on using power grid electricity instead of exclusively jet fuel and include “replacing the rechargeable battery packs every six months after 1,000-1,500 cycles.”

Ground testing in Chicago area facilities has been ongoing, with flight tests originally scheduled for 2019.  Through the fourth quarter of this year and into early 2019, the total power system will be upgraded and tested in stages.  The Ardiden 3Z engine will be tested in France and the U. S., then integrated with a modified Rockwell Turbo Commander test vehicle in 2019.  With similar weights and performance to the ZA10, the Rockwell will provide valuable data as testing progresses.  The powerplant package and batteries will be well tested before they are integrated in to the first Zunums.

Rockwell Turbo Commander will take on lop-sided look with conventional turboprop on one wing and electric ducted fan on the other

Zunum expects to deliver its first ZA10’s in “the early 2020s,” with upgrades to successive prototypes until the start of certification in 2020 to 2021.

Dominic Gates, writing for the Seattle Times, explains the “evolution of Tesla-style lithium ion battery technology” is crucial to the project, “Yet the rapid changes to that technology are complicating the effort.”  Batteries will change a great deal between now and the ZA10’s first flight, and even more by the time the airplane is certified for passenger service.  Zunum engineers, “Anticipate having to redo the battery certification process multiple times even after that, as the technology improves.”

Zunum’s chief technical officer, Matt Knapp, said the uncertainty about the shape, size, or weight of the battery pack is, “Driving my mechanical engineers nuts.  They are having to figure out how to accommodate a changing energy source and size over the lifetime of the aircraft… We don’t have a crystal ball to lock down a (battery) production partner for 2022,” when Zunum wants to start final Federal Aviation Administration (FAA) certification of the airplane.  Knapp explains this means recertification and requalification as new batteries become available.

To avoid issues such as battery overheating that grounded early 787 Dreamliners,  “Knapp said the fundamental design requirement for Zunum’s battery system is that two or more cells can overheat without spreading to the entire pack and creating a fire, according to the Times… How to do this is pretty well known.  It’s a matter of doing it in a lightweight and consistent manner.“


Oxis Energy Hits a Lithium-Sulfur Battery High

That near-mythical 10X  (of current lithium cells’ energy density) battery hangs out there on the distant horizon, promising automobiles that can exceed 1,000 miles range, or light aircraft that can carry four at Cessna-like distances.  Right now, we have two-place trainers good for an hour’s laps around the circuit, and the hope for improvements soon.  OXIS Energy, a UK-based company, has achieved 425 Watt-hours per kilogram at the cell level, and looks to go higher in the near future.

Lithium-Sulfur – A Worthy Alternative?

Promoters of lithium-sulfur batteries suggest their products have several desirable characteristics and performance boosts that may transcend the limits of lithium-ion cells.  Sion Power, for instance, claims availability of their Licerion battery with an even better 500 Watt-hours per kilogram and 1,000 Watt-hours per liter.

OXIS Energy’s graph of current and future performance for their lithium-sulfur batteries

On the same track, OXIS Energy has announced they have a demonstrated 425 Wh/kg cell, expected to rise to 450 Wh/kg by the end of the year and to 500 by the end of 2019.  These numbers, as those for Sion’s cells, are about double or greater those for the best lithium-ion batteries now being sold.  Inside EVs reports, “On the module level, energy densities now stand at 300 Wh/kg, but by the end of 2019, OXIS Energy hopes to reach 400 Wh/kg.” (Their bolding)

OXIS’ 16-Amp-hour pouch cells are currently available for High-Altitude Pseudo Satellite use and Sion’s batteries have been used in Airbus’ Zephyr HAPS program.

OXIS works along several development lines, and CEO Huw W. Hampson-Jones explains their direction and future.

Note that battery management systems, packing, and wiring for these cells will reduce the total capacity per kilogram, although they should still be more potent per pound than their lithium-ion competitors.  Several other factors come into play that add to lithium-sulfur cells’ attractiveness.  The cells can be fully discharged without damage, for instance, something that would shorten the life of a lithium-ion battery significantly.  They have a broader temperature tolerance range than lithium-ion.  And they can withstand nail penetration without bursting into flames while continuing to deliver their rated voltage.

An even more brutal test pits an OXIS battery pack against a NATO 5.56 mm round (roughly equivalent to a .22 caliber long rifle shell).

Kokam managed such a demonstration in 2016 with their lithium NANO battery, showing their ability to withstand military use – something also aimed for by the OXIS pack.

OXIS is working on packs to HALE aircraft and other drone use, and on a 30 kW-hr battery pack for a two-seat light aircraft under development.  All this bodes well for future light aircraft and larger electric airframes.