One of the criticisms of hydrogen fuel cells is that it isn’t really a truly “green” energy source because you still have to expend energy to get the hydrogen to make fuel cells with. In other words, while the use of hydrogen fuel cells is emission free, the process of getting the hydrogen is accomplished by electrolysis using electricity from coal fired power plants—in essence getting hydrogen from coal just shifts the pollution to the power plants. To be truly green we’d need a natural way of collecting hydrogen. Say perhaps via a multitalented bacterium with a sweet tooth?
The team fed Escherichia coli bacteria diluted caramel and nougat waste. The bacteria consumed the sugar and produced hydrogen, which they make with the enzyme hydrogenase, and organic acids. The researchers then used this hydrogen to power a fuel cell, which generated enough electricity to drive a small fan.
The process could provide a use for chocolate waste that would otherwise end up in a landfill. What’s more, the bacteria’s job doesn’t have to end once they have finished chomping on the sweet stuff. Mackaskie’s team next put the bugs to work on a production line that recovers precious metal from the catalytic converters of old cars.
The article is brief and doesn’t mention whether the amount of hydrogen produced by the bacteria is high enough to make large-scale hydrogen production via this method practical (let alone profitable), but it gives a new avenue to explore. Perhaps it could be possible to grow a bunch of sugar in a field and then toss it to some hungry bacteria and produce enough hydrogen to make for truly green fuel cells. Even if we still have to supplant this process with hydrogen produced by electrolysis anything that reduces the amount of “dirty” hydrogen we need to produce would be helpful.