Synthetic natural gas (SNG) has been around for a few decades now, primarily using coal as an input, but SNG version 2.0, being developed in Germany by companies including Audi, is different. It is not renewable natural gas (RNG), which is made from biogas; SNG is made from the methanation of renewably produced hydrogen.
My colleague Mackinnon Lawrence explains that RNG is produced by collecting raw biogas from anaerobic digesters, landfills, wastewater treatment facilities, etc., then stripping out the CO2 and other trace gases. This yields pipeline quality, purified methane. The new form of SNG, on the other hand, uses excess wind power to produce electrolytic hydrogen, which is then combined with CO2 (the methanation step) to produce another stream of pipeline-quality natural gas.
So we have one process of producing natural gas that has as a by-product CO2 and one that requires CO2 to produce natural gas. Handy! But why could SNG be so important in the coming decades?
Out of Love
Europe is falling out of love with natural gas – at least the stuff that is extracted from the ground and tends to be imported from outside the EU. However, one legacy of the continent’s 30-year love affair with natural gas is a very substantial natural gas infrastructure. At the same time the European Commission has stated, without yet forming a concrete policy plan, that the entire 27 nations of the European Union will decarbonize by 2050.
EU GHG Reductions Compared to 1990 (% Reductions; 1990 = 100%): 2005-2050
(Source: Pike Research)
Long term, the European economy could well be hydrogen-based. A recent report from the H2Mobility grouping in the United Kingdom, for example, shows that there could be 1.5 million hydrogen fueled cars on the road in the United Kingdom by 2015. But any significant energy transition takes decades to accomplish, and there is no black and white switch approach to this. We must move step by step and plan for the transitional steps.
Although in 2013 electrolysis is not new technology, the storage of large volumes of hydrogen, in any size and scale, is still tricky. There are research and pilot schemes to store hydrogen at volume in salt caverns, but the scale of inter-seasonal hydrogen that could be needed to store and balance out seasonal demand is beyond the levels that we can currently achieve – that’s where SNG could come in. Producing large volumes of hydrogen, cheaply from electrolysis using excess wind power, and then turning this into easy to store and transport natural gas, could well be the key stepping stone from the 2013 fossil fuel-based economy to the 2040 hydrogen-based economy.
Tags: Biofuels, Natural Gas, Renewable Energy, Smart Energy Practice, Synthetic Natural Gas
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