Energy

Genetic modification gives major boost to algal hydrogen production

Using genetic modification, researchers have boosted the hydrogen output of algae
Using genetic modification, researchers have boosted the hydrogen output of algae

Hydrogen has the potential to be a clean and sustainable fuel, but realizing that potential relies of clean and sustainable methods to produce it. Algae might fit the bill, but it only produces hydrogen in small amounts. Now, using genetic engineering, researchers at Tel Aviv University (TAU) have modified the organism, which could enable it to be used to mass-produce hydrogen on an industrial scale.

Hydrogen might burn clean, producing only water as a by-product, but currently over 90 percent of the hydrogen produced in the United States comes from fossil fuels. Although algae can produce hydrogen using photosynthesis, it was believed that this only occurred for a few minutes at dawn, resulting in limited amounts of the gas. But tests by a team led by Dr. Iftach Yacoby, the head of TAU's renewable energy laboratory, have revealed that algae actually produces hydrogen throughout the day.

Further tests revealed that the enzyme hydrogenase, which breaks down in the presence of oxygen, was integral to algae's hydrogen production. Through genetic modification the team was able to remove the oxygen so the hydrogenase is able to keep producing hydrogen, resulting in a boost in hydrogen production of 400 percent.

"The discovery of the mechanisms makes it clear that algae have a huge underutilized potential for the production of hydrogen fuel," says Dr. Yacoby. "The next question is how to beef up production for industrial purposes – to get the algae to overproduce the enzyme."

Dr. Yacoby is now hunting synthetic enzymes that can do just that. If he and his team prove successful, algae could soon be pumping out mass quantities of the clean-burning fuel.

"I grew up on a farm, dreaming of hydrogen," continues Dr. Yacoby. "Since the beginning of time, we have been using agriculture to make our own food. But when it comes to energy, we are still hunter-gatherers. Cultivating energy from agriculture is really the next revolution. There may be other ways to produce hydrogen, but this is the greenest and the only agricultural one."

The team's research appears in back-to-back studies published in Plant Physiology and Biotechnology for Biofuels.

Source: American Friends of TAU

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9 comments
michael_dowling
So they have given up on producing fuel oils from algae? That seems more practical to me,as hydrogen is difficult to store for any length of time,and tends to escape easily,whereas liquid fuels are easy and convenient to store.
guzmanchinky
These kinds of breakthroughs make me realize that technology will be the key to saving the world.
CraigAllenCorson
Liquid fuels are also polluting, michael. What makes hydrogen a dream fuel is that when it is burned, all you get is water, no CO2 or unburned hydrocarbons.
George Kafantaris
Well done.
Mark Uzick
When this algae gets loose, will it thrive in the wild? Will there be any dangers if the hydrogen level of the atmosphere rises?
El Bonko
@michael_dowling: What "they" are you talking about? I doubt this particular team has been working on oil-producing algae. The scientific community is not some monolithic structure that's only capable of focusing on one thing at a time, you know.
VirtualGathis
This is interesting, but seems kind of problematic to me. Algae is only about 15% efficient at converting sunlight to energy; hydrogen will only be a few percent of that energy release. So this will end up converting 1% or less of the insolation. Hydrogen is also not as energy dense as hydrocarbon fuels which means there would need to be more of it to replace hydrocarbon fuels.
Our hydrocarbon fuel economy is a very hungry beast consuming billions of gallons of fuel per year, just here in the US. This would require a comparably huge area to "grow" the hydrogen to replace them. This is even before the problem of there not being an existing infrastructure to transport and store the produced hydrogen...
Liquid Fluorine Thorium reactors on the other hand burn a fuel that is almost as common as dirt, do so cleanly in a very compact system, and are capable of breaking the hydrogen oxygen bond thermally at 90%+ efficiency. Thermal hydrogen production could therefore take place very near the point of consumption minimizing required transport and storage infrastructure. Not to mention they could replace the vast majority of hydrocarbon power generation thus dramatically lowering the requirement for hydrocarbon fuels.
As far as the question I've seen in this forum: Producing liquid fuels via algal production has not been abandoned, but the drop in fossil fuel prices has made the economics less attractive for a startup using existing or near term technology. As for it being CO2 polluting, that is not true. Burning the hydrocarbon oils produced by algae doesn't produce as much CO2 as the algae consume making it. So long as the power to operate the algae production comes from a clean solar, or nuclear source the CO2 emissions are negative. Liquid fuels also enjoy the benefit of an extant distribution and storage system, so make more sense than hydrogen.
So I'd conclude this is an interesting research project and could possibly replace hydrogen production in a niche market, but will not change the transport industry as claimed.
michael_dowling
I agree with the comments from VirtualGathis. I thought it would be unnecessary to say algae liquid fuels are carbon neutral,but some other commenters obviously haven't gotten the memo. And by "they" I meant the research community as a whole,not the Tel Aviv University group. Sorry if I was unclear.
StWils
VirtualG makes an excellent point but I think the better and greater use of this and similar research is to devise a more complete system geared to consume municipal sewage. The first and most important goal is to process sewage as completely and efficiently as possible and the second goal is to extract any and all useful materials as well as possible. Producing energy as oils or hydrogen or directly as electricity or heat, or any combination as well as at any suitable scale meets a collection of important objectives such that any individual piece is far less important than the whole system. While producing hydrogen from waste benefits society across a range of scales the most important element is the first, processing municipal sewage. While not a very attractive stylish topic, sewage, and recovering useful materials or energy efficiently can have a far larger benefit for society than just hydrogen, or electricity, or whatever. Along the way if some materials such as phosphorus can be captured and recycled into next years fertilizer then this completes a very desirable cycle for all of society. Also, it is important to think of a mix of solutions and not just a one-size-must-fit-all-situations. We should be open to tailoring a mix of components across a range of scale for everywhere. And, yes VirtualG is correct about Thorium. Thorium research got left by the side of the road in the 1930s because Uranium, or a mixed oxide, Uranium-Plutonium fuel seemed to be the quickest route to both nuclear energy and a nuclear bomb. However, apparently, Thorium can release 40,000 times more energy, pound for pound than uranium and can also "burn" all other radioactive isotopes along the way. Until then lets make hydrogen & electricity from municipal sewage first.