We’ve spilled plenty of ink on the idea that some day, fuel cell electric vehicles could run on “clean” hydrogen made with solar energy, instead of that nasty stuff produced from natural gas. Now let’s check out another angle on clean hydrogen, in which researchers have combed the waters of Soap Lake, Washington, in search of a little bug that burps out hydrogen without even thinking about it.
To be clear, this bug — the bacterium Halanaerobium hydrogeninformans — is very small, so you’d need to string together a massive number of tiny little burps just to roll your fuel cell EV out of the driveway, but like they say, you gotta start somewhere.
Clean Hydrogen… Or Not
There are already ways to source hydrogen from biomass, but when you get into non-food, woody biomass like switchgrass, you’re also talking about a conventional steam-blasting pretreatment step that depends on fossil fuels. You’d hardly call it clean hydrogen.
The steam blast is also highly inefficient. It produces weak acids and other toxins that have to be separated out, further complicating the whole process.
As described in a 2012 paper, there’s a better way to do it. Halanaerobium hydrogeninformans offers a microbial fermentation pathway to produce biohydrogen more efficiently. Think beermaking and you’re on the right track in terms of generating gas from microorganisms as they chomp happily away on whatever food you give them.
The research team described a process that involves relatively benign, low-temperature pretreatment of woody biomass, and minimal reliance on fossil fuels.
As an added bonus, the team found that H. hydrogeninformans will produce acetate and formate in addition to hydrogen.
The research team did hedge a bit regarding the marketability of hydrogen for fuel cell EVs, but the results were promising enough to produce this observation regarding the commercial prospects for industrial uses (break added):
As the price of natural gas continues to increase, demand is likely to increase for an economically and environmentally sustainable means of H2 [hydrogen gas] production that can fit into the current on-site production model.
The further development of biological H2 generation derived from plant biomass could be used to meet the demands of these industries while decreasing their reliance on fossil fuels.
The research team included the University of Wisconsin-Madison, Missouri University of Science and Technology, and the University of Missouri. You can find the paper at the journal Frontiers in Microbiology under the title, “A streamlined strategy for biohydrogen production with Halanaerobium hydrogeniformans, an alkaliphilic bacterium.”
An Extreme Bacteria For Clean Hydrogen
The key to the whole thing is that H. hydrogeninformans is an “extreme” bacteria that can survive in high-alkaline, hypersaline conditions.
That brings us to the mineral-rich waters of Soap Lake. Due to its unusual characteristics, the lake is home to a host of “extreme” bacteria that could be used for cleaning up polluted soil or, for that matter, powering up microbial fuel cells.
Biology professor Dr. Mealnie Mormile of Missouri University of Science and Technology, who also co-authored the earlier study, was digging around in Soap Lake in search of pollution-fighting bacteria when she came across H. hydrogeninformans.
In her study, published last fall at Frontiers in Microbiology, Mormile found that in addition to hydrogen, the bacterium can produce the organic compound 1,3-propanediol, a precursor for adhesives, solvents, and other products.
This naturally occurring bacterium is so efficient that it is comparable to genetically modified bacteria, leading Mormile to foresee its use in commercial-scale, clean-hydrogen production.
Perhaps in anticipation, Mormile and her team hold patents relating to clean hydrogen production by H. hydrogeninformans.
Don’t Hold Your Breath For Biohydrogen
It will be quite a while before microbe-generated clean hydrogen makes it out of the lab and into your hydrogen fuel cell filling station (if that ever happens), but keep in mind that woody biomass is just one possible source for biohydrogen. Besides, when you consider that battery electric vehicles still haven’t broken into the mainstream, despite coming on the automotive scene more than 100 years ago, sometimes these things take a while.
Meanwhile, solar-generated hydrogen is already starting to edge into the marketplace, so all you fuel cell EV fans out there might have some options, hopefully sooner rather than later.
Readers please note: If you’ve noted some inconsistency in the spelling of that bacterium, the 2012 paper has it as “hydrogeniformans” in the title and “hydrogenoformans” in the abstract, as well as in the caption for the image above. The more recent paper uses “hydrogeninformans.”
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