Turning Animal Waste into Green Hydrogen — without Fossil Fuels or Discharge
It’s the promise of a new technology train invented by scientists at ASU and other universities.
Managing animal waste from concentrated animal feeding operations (CAFOs) is a worldwide challenge.
Splitting water to make hydrogen without using solar (which is too intermittent) or worse, fossil fuels like coal to power the split — another global challenge.
What if combining these challenges could solve them both — a totally green process that generates renewable energy, all without any discharge?
That’s the promise of a new technology train invented by scientists at three US universities including ASU — one that should be containerized and ready for customer view in 18 months.
The technology train turns highly concentrated animal waste into hydrogen using microbes and algae (perhaps supplemented by solar in spots) to generate the fuel to split the water.
This tech train solves the problem by having innovation in three places: the microbes, the algae, and sensors that make the whole thing work.
The microbes feed on the solids in the waste. As they feed, they create an electrical current that splits the water. The liquid waste is first treated by algae, then is put through both forward- and reverse-osmosis to produce clean water, which is then the product that goes in to be electrolyzed by the microbes. The system produces heat and biochar which will be used to generate more current for splitting hydrogen as well as a novel material for hydrogen storage. Essentially, it’s a circular economy.
We needed to invent a train of different technologies to achieve this breakthrough. So often in the lab you’re working on one technology that’s a breakthrough but which needs several subsidiary or complementary breakthrough technologies to solve the problem. This tech train solves the problem by having innovation in three places: the microbes, the algae, and sensors that make the whole thing work.
We’re still facing challenges to solve. For instance, the range of recipes of what goes in — and its consistency — still needs to be fine-tuned. Another key challenge is producing a substrate for the microbes to live on — the biofilm — that can be easily replaced, because fouling commonly occurs in any water treatment system.
But imagine the possibilities, especially with growing global meat production — not just in the United States, but also China, Brazil and soon in Africa. CAFOs could essentially create the fuel out of their wastewater for all their vehicles on site. They would reduce greenhouse gas emissions, reduce their water pollution, and reduce their fuel costs.
This is water abundance innovation. I’ll report back in 18 months to let you know the status.
For more information about ASU Future H2O’s work and research on creating opportunities for global water abundance, visit our website and subscribe to our newsletter.
