While there are technological hurdles still to overcome, the hydrogen fuel cell remains an attractive source of electricity generation, particularly for the heavy-duty transport sector currently dominated by diesel power. Daimler and the Volvo Group entered a joint venture to produce fuel cells systems last year. Toyota and PACCAR are collaborating. General Motors and Stellantis each are launching production fuel-cell-powered delivery vans and many other truck OEMs are involved in programs to develop the technology further for commercial transport applications.
Refueling with pressurized gaseous hydrogen is one of the issues that would need to be resolved, requiring a distribution and storage infrastructure that might need building from the ground up. One possible alternative would be to use methanol (CH3OH) as the source fuel. Using a reformer, liquid methanol could be split into a hydrogen-rich gas that would feed the fuel cell.
The reforming process would release greenhouse gas (GHG) emissions, but if the methanol is produced from renewable sources – renewable electricity with atmospheric carbon dioxide, or carbon dioxide from biomass, or landfill sites for instance – the well-to-wheel cycle should be carbon-neutral.
Methanol is already produced, stored and transported in industrial quantities and its handling requirements are widely understood. As a liquid, it could be readily distributed through the current diesel and gasoline road-fuel infrastructure, assuming a gradual transition away from fossil fuels. This would solve one of the big problems facing fueling with hydrogen gas. It could also address the infrastructure challenges, requiring no significant additional infrastructure, with just the modifications required for handling methanol at current gasoline and diesel refueling and storage sites.
This is loosely the strategy being pursued by the Danish company Blue World Technologies. The company’s senior management has been involved in fuel cell research for more than 20 years.
Newfound efficiency gains
Commercial, military and aerospace fuel cells have been around for many decades and have been explored in various ways, Blue World Technologies co-founder and CEO Anders Korsgaard told SAE Media. “We also worked with conventional hydrogen fuel cells for the first five years of our professional career, back in the late ‘90s and early 2000s. But we decided to focus our attention on e-fuels, and basically liquid e-fuels that would all solve the market barriers associated with a gaseous fuel,” he said.
The technology associated with fuel cells dating back to the 1990s was the low-temperature Proton Exchange Membrane (PEM) ‘stack.’ “The problem with that technology is that it is very sensitive to any impurity,” Korsgaard noted. “Basically, what you do to overcome that is to increase the temperature from typically 70° to 80° C [158° to 176° F] to 160° C [320° F] and above. Anything above let’s say 150° C [302°F] to 160° C and it would be pretty tolerant to most impurities generated by the reformer. We are focused on that temperature window of about 160C/170 deg C, because this is where most of the problems disappear in supporting liquid fuels.”
There also are efficiency gains generated by the thermal integration between the reformer reaction and the fuel cell, he added. “And in that way, you can say for a conventional hydrogen fuel cell, taking hydrogen in and converting it into power, when we look at the combined system with the methanol reformer and the fuel cell itself, we are looking into pretty much the same peak efficiency as working with hydrogen.”
The high-temperature PEM fuel cell technology that Blue World Technologies is working on was invented in the mid-1990s. According to Korsgaard, the technology now is approaching the same power density as low-temperature PEM fuel cells. The objective is to improve the high-temperature PEM fuel cell to make it more efficient than the low-temperature designs.
Cost parity with ICEs
Critics of the methanol fuel cell system highlight the fact that the system does emit GHGs. Korsgaard contented that “clean methanol” is often manufactured from biogas. “In that sense, it has potential” as a “stepping stone,” he said, explaining that “it’s a cheaper version of getting bio-methanol than just going directly to getting carbon dioxide from air capture.”
Among the “concentrated carbon dioxide sources” is biogas, which contains roughly the same amount of methane as already exists in CO2, Korsgaard noted. “If you take the methane out and put it into the grid or whatever you use it for, you are making a lot of carbon dioxide. You can do it because it is basically just re-cycling, going back to the farmlands and so on. But alternatively, you can capture it there, because you have a very concentrated carbon dioxide source.” Combining the CO2 with hydrogen from electrolysis, as in conventional hydrogen production, produces methanol.
“Then you have something liquid and you don’t need to pressurize it,” he said. “You can distribute it exactly like you do today. One of the benefits is that you can also put it into combustion engines – just mixing it with gasoline. We don’t need to roll out hundreds of gigawatts of fuel cells before you can actually enable a take-up of bio-methanol, because you can also use it in combustion engines.”
Improving the cost-efficiency of the system will take time, however. Korsgaard believes that in time, the methanol fuel cell will be on a par, in cost terms, with IC engines. “We can see how solar technology and battery technology have decreased by 15, 20, or 25 percent, depending on which time you are looking at, per year,” he said. “This will be at similar levels to ours – and at some point, we predict that probably even the capital expenditure will be comparable to internal combustion engines.”
The bottleneck in commercializing the methanol fuel cell has been the industrialization of the manufacturing process, according to Korsgaard. He said Blue World Technologies is building the largest fuel cell factory in Europe, with production scheduled to start in the latter half of 2022. “That’s really our focus, it is actually to make sure that we can drive down the cost to a certain level where basically we can begin the commercial rollout,” Korsgaard said.Continue reading »