A team from RMIT University (Australia) claims to have discovered a cost-effective way to produce hydrogen using wastewater and wastewater. The process not only produces clean H2 gas, but it also captures all the carbon in human faeces and puts it to good use.
In doing so, he could not only generate clean energy from a virtually unlimited resourceIt could also lead to a completely emission neutral wastewater sector. If hydrogen is to play a major role in the future green economy, such production methods could kill two birds with one stone.
Treated wastewater, according to the team, is mainly used as a fertilizer in agriculture, but around 30% globally is stored or sent to landfills.
Biogas, mainly methane, which is produced when wastewater settles and decomposes in a sewage treatment plant, can be burned as a renewable fuel, but not clean in terms of emissions.
Instead, the study by the RMIT team, published in the peer-reviewed International Journal of Hydrogen Energy, proposes a new method in which “biosolids” or poo are converted into biochar, a type of carbon. rich in carbon. This biochar contains enough heavy metal particles to function as an “ideal” catalyst, whereby the methane-rich biogas can be split into carbon and hydrogen.
The process can be done in a high efficiency and high temperature pyrolysis reactor, designed by a team from RMIT’s own engineering school, which can separate hydrogen while simultaneously converting carbon into another form of carbon nanomaterial-coated biochar, which has great value in a range of uses including the environment, improving agricultural soils and even energy storage.
More importantly, where burning biogas releases a ton of carbon into the atmosphere, this pyrolysis process captures and sequesters all this carbon in a useful form that does not reach the atmosphere.
We have radically optimized the heat and mass transfer in our reactor, while reducing the technology to make it very mobile. There are no reactors available that can achieve such phenomenal integration of heat and mass, in such a small, cost-effective package. And while already energy efficient, with further integration, this reactor could turn the conversion of biosolids and biogas into a process that actually produces energy rather than consuming it.
Kalpit Shah, Principal Investigator.
Our new hydrogen production technology is based on wastes whose supply is essentially unlimited. By harnessing the power of biosolids to produce totally clean fuel from biogas – while avoiding greenhouse gas emissions – we can deliver real environmental and economic gain.
South East Water, a utility company in the state of Victoria, has started building a pilot plant to test this hydrogen-powered poo technology and evaluate it for incorporation into the wastewater treatment process.
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