Humanity struggles to catch the easiest wave out of the crisis in entered, caused by its own, self-designed processes. Just like you’re hooking onto any branch of any tree when you’re in a free fall, scientists are hooking on anything that can give us more energy at a comfortable price.
Now is the time of using urine. I know – it sounds gross, but obtaining hydrogen from urea is actually cheaper than obtaining it from water, through the same electrolysis process. The study is being led by Gerardine Botte of Ohio University and it all started from an idea to recycle the wastewater.
Urine’s major constituent is urea, which incorporates four hydrogen atoms per molecule – importantly, less tightly bonded than the hydrogen atoms in water molecules. Botte used electrolysis to break the molecule apart, developing an inexpensive new nickel-based electrode to selectively and efficiently oxidise the urea. To break the molecule down, a voltage of 0.37V needs to be applied across the cell – much less than the 1.23V needed to split water.
‘During the electrochemical process the urea gets adsorbed on to the nickel electrode surface, which passes the electrons needed to break up the molecule,’ Botte told Chemistry World. Pure hydrogen is evolved at the cathode, while nitrogen plus a trace of oxygen and hydrogen were collected at the anode. While carbon dioxide is generated during the reaction, none is found in the collected gasses as it reacts with the potassium hydroxide in the solution to form potassium carbonate.
The scientists tested their process with dissolved synthetic urea at first, but found out that it works just as well with real urine. ‘It took us some time to get clearance to work with human urine – which held up publication of the research,’ says Gerardine Botte.
These kinds of innovations aren’t the first to use urine in a useful process. Recently, astronauts from the ISS processed urine to extract pure water from it. A process like this one described before may have been used, but hasn’t. I guess that if you extract hydrogen from the urine, you might just as well burn it and produce water, but because oxygen resources are scarce enough in space conditions, that solution wouldn’t have been the best. Anyway, it’s nice to hear that you can “liberate” yourself into a tank to get to the nearest hydrogen refueling station in the future.