Does blue and turquoise hydrogen emissions qualify as renewable hydrogen?

As you probably are aware, we are having in mind several types of renewable hydrogen in addition to green: namely blue (steam reforming of methane + carbon capture and storage, CCS), turquoise (pyrolysis of methane), pink (electrolysis with nuclear) and even these days white (natural hydrogen).

In order to come out from the colour’s discussion the different countries have put values of kgCO2,eq per kg of H2 to be considered renewable hydrogen. In the USA is 4.0, in the EU 3.38 and in the UK 2.4 kg CO2,eq per kg of H2. Therefore, in order to know which hydrogen should be produced is important to determine these values for each type of hydrogen.

Scientists in Finland has produced a very interesting work (a comparison figure from the paper is shown below) where they show that only green hydrogen would qualify for the EU regulations with results far from 0 kg CO2,eq per kg of H2. According to this, it will not even qualify as green in the UK if the electricity comes only from PV sources.

However, the most interesting result from this work is the pressure that put to blue and turquoise hydrogen because they come from fossil gas, most of the cases wrongly neglected when talking about these types of hydrogens. In a recent work from Financial Times, it has been shown the large amount of leakages happening in this industry and hence, high methane emissions, 80 times more powerful in greenhouse effect than CO2.

Anyway, even reaching captures up to 90 %, blue cannot reach those emission thresholds with emissions as high as 5 kg CO2,eq per kg of H2. The article also show that LNG is worse than having the gas from a pipeline. It ends up saying that even using the Finish grid in electrolysis would lead to less emissions that to produce blue or turquoise.

Finally, this is not only the opinion of these Finish folks as they have been studies (Bauer et al. in 2022, Wei et al. 2024) pointing into this direction. I am sure that we can find more supporting this, as the issue with the methane emissions is largely acknowledge by many institutions as also shown by Financial Times.