How green is green hydrogen?

Tuesday 02 February 2021

This month, CEO Jon Duffy talks about why there's so much in the press about green hydrogen. 


I read an article in the Telegraph recently. The author wrote at length about dirty resources, the UK renewables race, the green industrial revolution, and more, and it provoked my thoughts.


Before I go on, let's look at the term green hydrogen. Everyone has an interpretation of green hydrogen. Some call it green others call it clean. But in basic terms, it means hydrogen produced from electricity generated from renewable sources such as wind, solar or tidal. If you put renewable electricity in, you get green hydrogen out. Simple. But what about the equipment that produces the hydrogen? 


Firstly, CPH2 specifies that only readily available and reusable materials are used in our membrane-free electrolyser. Currently, 98% of the components in our systems are recyclable. Secondly, we use considerably less aqueous electrolyte in our system - 2% KOH (w/w), compared to membrane-separated alkaline electrolysis that is around 30% and is, therefore, more hazardous both to health and the environment. Thirdly, our electrolyser is robustly designed for a 25-year life-span, more than double that of other electrolysers, and matches the life-span of solar and PV. 


But by far, the most sizeable eco-friendly factor of our electrolyser is that we do not use precious metals. Both Palladium and Platinum are used either in the filtration process or used as a catalyst in most other electrolysers but not in CPH2’s.

Platinum is thirty times rarer than gold and occurs at a very low concentration in the earth’s crust. When compared to gold and silver mine production, the rarity of platinum is highlighted further. At the end of 2018, known global platinum reserves totalled around 7,720 tonnes, and in 2019, the mined production platinum was around a further 190 tonnes. There are only four countries in the world that have platinum mining operations of any significance and, of these, South Africa has the largest platinum resource by far. Platinum is rarely found in isolation. It's found more commonly alongside other metals, primarily palladium and the other PGMs, and base metals such as nickel, copper, and chrome. Platinum is extracted, processed, and purified through a complex series of physical and chemical processes, namely mining, concentrating, smelting, and refining. And at around $750/ounce is an expensive and finite resource. Little Platinum is recycled at the end of its life cycle; as little as 60 tonnes a year comes from mainly autocatalyst and jewellery recycling.[1]


Labour and resource intensive, it can take up to 6 months and 7 to 12 tons of ore to produce 1 ounce of pure platinum. The first step in the production process is to break platinum containing ore and immerse it in indicator containing water, a process known as froth flotation. During flotation, air is pumped through the ore-water mix. Platinum particles rise to the surface in a froth that is skimmed off for further refining. Once dried, the concentrated mixture still contains less than 1% platinum. It's then heated to over 1500C° in electric furnaces, and air is blown through again, removing iron and sulphur impurities. Aqua regia (a concoction of nitric acid and hydrochloric acid) is used to dissolve platinum metal from the mineral ore by creating chlorine that attaches to platinum to form chloroplatinic acid. In the final step, ammonium chloride is used to convert the chloroplatinic acid to ammonium hexachloroplatinate, which can be burned to form pure platinum metal.[2] 

And all that is before it’s shipped around the world.


So, in our efforts to manufacture the most efficient electrolyser possible, with the lowest CAPEX and OPEX and the lowest lifetime cost of hydrogen, we’re also doing our little bit to ensure that green hydrogen is green hydrogen. It's a win-win situation - what's not to like?


CPH2 technology produces hydrogen as green as green can be from beginning to end.  It's safe to say that hydrogen production in any form may never be 100% green, but to answer the original question with another question, 'What shade of green do you want?'

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[1] WPIC_Platinum_Essentials_June_2020 (Platinum 101_An introduction for investors) (

[2] platinum mining, mining of platinum, platinum, platinum places. platinum occurrence, platinum production, platinum usage (