Nissan Announces Major Investment in Bioethanol Fuel Cell Technology, Claims Massive Benefits Over Hydrogen

Unlike its rivals Toyota and Honda, Japanese automaker Nissan has to date steered clear of hydrogen fuel cell technology. Citing concerns over economic viability, technical challenges such as power density and carbon-intensive way in which most commercial hydrogen is produced today, Nissan has instead focused on battery electric vehicles in the form of its Nissan LEAF electric hatchback and e-NV200 electric minivan.

To date, that policy has paid off: the Nissan LEAF is still the world’s best-selling electric car and Nissan, working alongside its alliance partner Renault have sold more than 200,000 electric vehicles around the world to date. Together, the two firms have also invested millions of dollars in public charging infrastructure worldwide, making it easier than ever before to make long-distance trips in any short-range but rapid charging-capable electric car.

The new Solid Oxide Fuel Cell is more efficient than existing PEM fuel cells.

The new Solid Oxide Fuel Cell is more efficient than existing PEM fuel cells.

Given its massive multi-billion dollar investment in electric vehicles and electric vehicle infrastructure, Nissan isn’t about to dump the electric car any time soon and has massive electric vehicle plans stretching more than a decade into the future which include both fully autonomous vehicle technologies and advanced, wirelessly-charging long-range electric cars.

But this morning it also announced a new research and development program in which it intends to commercialize a Solid Oxide Fuel Cell (SOFC) for use as an alternative power source for zero emission vehicles. Unlike hydrogen fuel cell vehicles which require compressed hydrogen to operate, Nissan’s new SOFC fuel cell can be powered by either natural gas or bioethanol. While the former is neither renewable nor carbon neutral, the latter can be produced in a carbon neutral way.

The extra heat from the SOFC can be used to steam reform hydrogen from bioethanol.

The extra heat from the SOFC can be used to steam reform hydrogen from bioethanol.

In a conventional hydrogen fuel cell vehicle stack, hydrogen is fed into the anode side of the fuel cell stack and passed over a platinum-rich proton-exchange membrane while at the same time, oxygen is fed into the other (cathode) side of the proton-exchange membrane. The platinum in the proton-exchange membrane acts as a catalyst, encouraging the positively charged hydrogen ions and negatively charged electrons in the hydrogen gas to separate. The electrons travel to the cathode, via whatever circuit you use (in fuel cell vehicles, via the motor). This, then, is the electrical current between the anode and cathode. The hydrogen protons themselves migrate through the exchange membrane and the electrolyte to combine with the oxygen and the returning electrons from the electrical circuit on the other side of the fuel cell, producing water (and heat) as the only byproduct of the process.

Inside Nissan’s SOFC, things are a little different. While hydrogen is still fed into the fuel cell on the anode side, it’s actually the oxygen entering into the fuel cell on the cathode side which passes through the fuel cell exchange membrane and through the electrolyte to the other side of the fuel cell. The oxygen combines with the hydrogen to produce water, electricity and heat.

Unlike proton exchange membrane (PEM) hydrogen fuel cells, which use high-cost platinum on both sides of the fuel cell, Nissan’s SOFC doesn’t require such expensive or rare materials to function, lowering build costs. And while Nissan hasn’t confirmed efficiency of its SOFC, SOFC technology is generally around ten to fifteen percent more efficient than a comparable PEM fuel cell.

Nissan wants SOFC to be part of its future zero emission drivetrain portfolio.

Nissan wants SOFC to be part of its future drivetrain portfolio.

Sadly there’s a setback: temperature. An SOFC operates at a far higher temperature (around 1,000 degrees Celsius) than a PEM fuel cell (80 degrees Celsius), meaning more heat is produced as a byproduct. But that, says Nissan, is one of the reasons it can use bioethanol as the fuel source.

With so much heat on tap, Nissan’s SOFC technology includes a steam reformer upstream of the fuel cell which combines the heat from the fuel cell exhaust with water to steam reform the bioethanol into carbon dioxide and hydrogen. The hydrogen is then used to directly power the fuel cell.

Nissan says the water needed to carry out steam reforming of the bioethanol (or natural gas) can either come from the fuel cell exhaust, combining inside the reformer with 100 percent bioethanol, or by using ethanol mixed with water as the fuel source.

Since Nissan’s SOFC technology doesn’t require hydrogen to be stored on the vehicle in either liquid or gaseous form, it has some major advantages over PEM fuel cell technology. For a start, bioethanol is far easier and safer to store, dispense, and use. Secondly, since SOFC systems are more efficient than PEM fuel cells, a car using an SOFC should demonstrate longer range than a PEM counterpart.

Nissan says the process of making biofuels is almost carbon neutral.

Nissan says the process of making biofuels is almost carbon neutral.

Finally, there’s the claim of better emissions. Unlike a hydrogen fuel cell car using compressed hydrogen, Nissan’s system does have tailpipe emissions in the form of carbon dioxide given off as part of the steam reforming process. However, since growing crops for biofuel captures carbon dioxide, Nissan claims these emissions are offset, making its technology carbon neutral.

Nissan says it plans to perfect its SOFC technology and bring it to market at some point in the future, but for now, the technology is still very much in a research and development phase.

Does this mean Nissan is switching its attention away from electric cars? No. For the foreseeable future, electricity appears to be Nissan’s number one future fuel source. But while electric cars can satisfy the needs of large swathes of the population, Nissan’s SOFC technology could find a home powering its larger commercial vehicles and full-size pickups. Like the Mercedes-Benz GLC F-Class plug-in hybrid fuel cell SUV we covered yesterday, Nissan’s SOFC technology could become a viable range-extending alternative to an internal combustion engine.

But there’s one fly in the ointment: biofuels. While biofuels have been touted for many years as a viable, lower-carbon alternative to fossil fuels, producing them requires a significant amount of land to be set aside, land which then cannot be used for food.

To date, the lure of biofuels has caused many hundreds of thousands of square miles of rainforests to be illegally felled, not only threatening the natural habitat of thousands of species of flora and fauna but also commandeering precious water supplies.

In a world where food and water supplies are becoming increasingly strained as the effects of climate change and population growth are felt, setting aside crops for biofuel rather than food is not sustainable. And while there are ways to produce bioethanol and biofuels from the byproducts of food production (the stuff you wouldn’t want to eat), or via developing algae based systems, we suspect it’s going to take some time before bioethanol fuel cells and bioethanol mass production reaches market readiness.

Do you think Nissan’s new investment in Solid Oxide Fuel Cells is a smart move? Or does it distract from Nissan’s already extensive work with electric cars?

Leave your thoughts in the Comments below.


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  • vdiv

    Just can’t see myself using fuel for my car ever again. It feels archaic and pointless. We have a rather urgent problem on this planet and we have the existing technology to solve it on the transportation and energy supply sides. Everything else is at best an intriguing experiment and at worse a diversion and a lapse of responsibility.

    • Martin Lacey

      I guess zero emissions in use justifies polluting at source?

      Are Nissan struggling to maintain the lead they had in BEV’s?

      • vdiv

        No idea what either of your questions mean. The first one makes no sense, the second doesn’t either, Nissan still has a commendable lead.

        • Electric Bill

          Vdiv: his comment is not easy to understand, but is not nonsensical. EVs produce no emissions while being driven, but there are some persistent EV haters that are always ready to claim that EVs simply shift the emissions from the tailpipe to the generating station.

          There is plenty of truth in the claim that it is far better to produce the emissions at the generating plant than on the road. For one, having the luxury of as much space as you need to kill emissions at a generating plant is certainly helpful. If that emission equipment is big and heavy is of little consequence.

          Also, stationary generators have the luxury of being able to use two or even three stages or systems to extract energy, such as a turbine in the first stage, and some form of thermocouple to, extract electrical every directly,, and, even a third stage that relies on valuable gases for use in an industrial process, such as producing plastics or solvents.

          So Martin was apparently reflecting on being able to counter criticisms of EV trolls, which I still see a lot of these days, although their numbers have diminished and will probably die away soon enough, as such curmudgeons see the futility of trying to discourage progress with electric transport. .

  • Joe Viocoe

    It’s R&D. I have no problem with private companies researching all day long.

    • vdiv

      Unless that research is in the way of providing real solutions. Also Nissan is a publicly owned company that receives gov’t grants to make ZEVs.

  • windsorsean

    Don’t discount natural gas. If you use renewable natural gas (e.g. methane from water treatment plants), you end up with a carbon negative situation. Methane going into the atmosphere is a much more potent greenhouse gas than the CO2 it creates when used as fuel. Unintuitively it can be better even than solar electric from an environmental perspective.

    I’m still a BEV fan for the simplicity and ease of it but this is an interesting development and could be great for long distance commercial transportation.

    • vdiv

      Yes, we have that, it’s called trains, they haul significant loads very efficiently and they can run on renewable grid power.

    • Electric Bill

      I still am not fond of any fueled vehicle for several reasons, but there is one reason for which EVs will be more convenient: you can, harvest electrons to run an EV anywhere, even on the wings of, an, EV aircraft high overhead, or on chilly but very well – lit activities on summer forays on the North and, South poles (sunlight is 24 hours for about six months… the sun, simply circles around you on the horizon rather than setting every day as it does closer to the Equator.)

      I doubt fueled vehicles will ever be quite as safe in a collision as an EV would be. Hundreds of people die horrendous fiery deaths in fueled vehicles every year; there has never been anyone yet to die from a fire that was started in an EV, although there have been a few fires which took a half an hour or so to get started,, which is usually plenty of time to extract an accident victim from a serious collision in an EV, or at least enough time to use a fire suppressant.

      • windsorsean

        Absolutely and like I said I agree BEVs have a number of advantages for consumer vehicles. Long range commercial transportation is where a renewable natural gas fuel cell could be a good fit. Similar idea to the Nikola One truck which uses natural gas as fuel for an electric turbine generator. By using methane from waste as the natural gas fuel source you remove greenhouse gas from the atmosphere with every mile/km driven. The same is true if waste methane is used in a power generator to provide electricity for BEVs. My point is to not discount natural gas as not being environmentally beneficial, the source is key.

  • vdiv

    Two separate problems, both solvable right now.

  • I will not drive any car that emits CO2 directly. First generation biofuels are a joke “Renewable transport goal has encouraged biofuels including those from palm oil and soybean, which are found to be worse than diesel oil for emissions”

    If Nissan bring this to market I will no longer consider the MK2 Leaf as a possible alternative to the Tesla model 3 and use my reservation. I will not support a company that does not have an environmentally sustainable business model.

  • Chris O

    Batteries are steadily improving and prices are dropping quickly so Nissan is aiming at a moving target while it’s trying to sort out the problems with this technology. I could see it work in vehicles with the sort of energy use that make batteries impractical like large SUVs, vans and trucks. Bio ethanol is carbon neutral and despite clever campaigns funded by Koch brothers& co is not the threat to food production it’s made out to be so I do like that aspect of it. Also it should make for a fuel that unlike hydrogen is really cost efficient to produce and distribute so unlike HFCVs there may be a substantial market potential here.