Even as much as 30 per cent of natural gas used in the UK could be replaced by hydrogen – this has recently been revealed by a study conducted at the Swansea University. This would reduce CO2 emission by 18 per cent[1].
Natural gas is a fuel widely used in Great Britain. It is commonly used for generating electric power and, by households, for heating and cooking. Until recently this fuel accounted for 80 per cent of energy consumed in Great Britain in winter months, when heating costs need to be taken into account[2].
One of the ways to limit emissions from natural gas is to add hydrogen to it. As a result, the side product of combustion is only water vapor, however, the physical features of hydrogen are slightly different from those of methane – lower calorific value and much lower density. It also has some problematic features, like the tendency to leak through various materials and escape from pipes and containers.
According to research by Dr Charles Dunhill and Dr Daniel Jones from Energy Safety Research Institute, even 30 per cent of hydrogen may be added to methane without any major complications. Adding more than that would result in making the gas useless in households. The scientists say that blending hydrogen with natural gas is the first step towards building hydrogen-only installations in the future, without having to use fossil fuels at all.
Now, an Australian city of Adelaide is conducting advanced tests of a technology which in its heating system uses natural gas with a 10 per cent hydrogen blend[3].
How to produce hydrogen
Unlike mining of fossil fuels, obtaining hydrogen usually does not require any gross interference with natural environment.
Today’s most popular method of obtaining hydrogen is steam reforming – producing hydrogen from methane and steam at a temperature of 700-1,100 degrees Celsius. This is the most cost-effective way of an industrial-scale production of this gas – the amount of hydrogen obtained per one unit of energy is much bigger than in electrolysis.
On the other hand, though energy efficiency of electrolyzers leaves a lot to be desired, the prospects of using electrolysis are very interesting. First of all, renewable energy surplus may be stored in hydrogen. For example, power-to-gas technology provides for electrolytic production of hydrogen, which is later used in the gas network.
Hydrogen may also be stored and used whenever needed. Although the efficiency of this process today is still low, it allows using energy from renewable sources when surpluses of that energy are available. However, today this technology is still costly.
[1] https://www.sciencedaily.com/releases/2018/06/180611133412.htm
[2] https://qz.com/1047802/the-biggest-market-for-hydrogen-as-a-clean-fuel-may-not-be-cars-but-homes/
[3] http://www.abc.net.au/news/2017-08-08/trial-to-inject-hydrogen-into-gas-lines/8782956
