Hydrogen hope

BMW’s Hydrogen 7 – soon to be even cleaner

Imagine filling your car with fuel and driving as far as your dreams could take you without worrying one little bit about your green credentials.

Well, you could… if that fuel was hydrogen.  Clean, full of energy and zero carbon, hydrogen is the fuel of the future, and scientists in China have just taken us one step closer to a sustainable source.

The only by-product of burning pure hydrogen in air – which produces a flame of around 2000⁰C – is harmless water, plus the occasional whiff of nitrogen oxide.  But despite its tree-hugger stamp of approval, hydrogen fuel isn’t without its problems.

The gas doesn’t occur naturally in large volumes, it must be manufactured.  This usually means you have to put energy in to get hydrogen out.  One method reacts methane with steam at high temperatures to produce hydrogen, but the process also releases large amounts of CO2.

Other projects use wind-generated electricity to produce hydrogen by splitting water, but this technique is inefficient and, due to the nature of wind energy, intermittent.  However, the discovery by researchers from Hangzhou and Shanghai offers a more promising alternative.

The team, led by Dr Mei-Qiang Fan, produced large volumes of hydrogen by reacting aluminium, lithium and bismuth alloy with water.  Aluminium has long been a candidate for hydrogen production due to its abundance and low cost.  It has the potential to produce considerable amounts of the gas on its own, but this requires additional heat and dangerous, corrosive chemicals.

By adding bismuth and lithium, the team could do away with nasty reactants, using pure water instead.  Their alloy, described in this month’s Renewable Energy journal, yielded the highest volume of hydrogen per gram of material yet achieved at room temperature, with 100% efficiency.

What’s more, after the reaction, the alloy could be recycled, meaning it can be used again and again to produce ever more hydrogen.

Much work needs to be done to translate this lab experiment into cost-effective industrial solutions, but the team believes that their alloy could soon be the basis of low-cost, portable sources of hydrogen fuel.


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