Green hydrogen
In the kaleidoscope of hydrogen colours, green hydrogen is the one produced with no harmful greenhouse gas emissions. Green hydrogen is made by using clean electricity from surplus renewable energy sources, such as solar or wind power, to electrolyse water. Electrolysers use an electrochemical reaction to split water into its components of hydrogen and oxygen, emitting zero-carbon dioxide in the process. Green hydrogen currently makes up a small percentage of the overall hydrogen, because production is expensive. Just as energy from wind power has reduced in price, green hydrogen will come down in price as it becomes more common.
Blue hydrogen
Blue hydrogen is produced mainly from natural gas, using a process called steam reforming, which brings together natural gas and heated water in the form of steam. The output is hydrogen – but also carbon dioxide as a by-product. That means carbon capture and storage (CCS) is essential to trap and store this carbon. Blue hydrogen is sometimes described as ‘low-carbon hydrogen’ as the steam reforming process doesn’t actually avoid the creation of greenhouse gases.
Grey hydrogen
Currently, this is the most common form of hydrogen production. Grey hydrogen is created from natural gas, or methane, using steam methane reformation but without capturing the greenhouse gases made in the process.
Black and brown hydrogen
Using black coal or lignite (brown coal) in the hydrogen-making process, these black and brown hydrogen are the absolute opposite of green hydrogen in the hydrogen spectrum and the most environmentally damaging. Just to confuse things, any hydrogen made from fossil fuels through the process of ‘gasification’ is sometimes called black or brown hydrogen interchangeably. Japan and Australia announced a new brown coal-to-hydrogen project recently. This project will use brown coal in Australia to produce liquefied hydrogen, which will then be shipped to Japan for low-emission use.
Pink hydrogen
Pink hydrogen is generated through electrolysis powered by nuclear energy. Nuclear-produced hydrogen can also be referred to as purple hydrogen or red hydrogen. In addition, the very high temperatures from nuclear reactors could be used in other hydrogen productions by producing steam for more efficient electrolysis or fossil gas-based steam methane reforming.
Turquoise hydrogen
This is a new entry in the hydrogen colour charts and production has yet to be proven at scale. Turquoise hydrogen is made using a process called methane pyrolysis to produce hydrogen and solid carbon. In the future, turquoise hydrogen may be valued as a low-emission hydrogen, dependent on the thermal process being powered with renewable energy and the carbon being permanently stored or used.
Yellow hydrogen
Yellow hydrogen is a relatively new phrase for hydrogen made through electrolysis using solar power.
White hydrogen
White hydrogen is a naturally-occurring geological hydrogen found in underground deposits and created through fracking. There are no strategies to exploit this hydrogen at present.
Hydrogen is being promoted by fossil fuel companies to produce a demand for hydrogen that can't, at the moment, be supplied by green hydrogen, although in the fullness of time it might be. In the meantime the hydrogen demand will be supplied, surprise surprise, by fossil fuel fuel derived hydrogen from one of the many sources described above. Hydrogen is thus a vehicle to keep the use of fossil fuels going well into the future.
While there is a niche use for hydrogen in the future as a possible store for surplus solar energy to be used centrally to produce clean electricity for the grid through fuel cells its use, for instance in gas pipelines to be burnt in houses in hydrogen converted boilers, is a hugely inefficient way of using energy and shouldn't be countenanced at all, ever!! It is being promoted to government by the fossil fuel industry, however, as an easy way of achieving low carbon home heating.
There are laws against lying and misleading in advertising and there should be similar laws against the same in lobbying governments and the civil service.
In general most uses of hydrogen are inefficient uses of the energy available.
There are some potential industrial uses for H2, such as the production of ammonia/fertiliser and steel...
However, home heating and transport are definite 'no-nos' for me....
Making green H2 from renewables only makes sense when 100% of the grid is renewables and we're still a long way from that...
Meanwhile, in the NW, £0.5 BILLION is about to be spent on the HyNet H2 pipeline project....
Think how many homes could be insulated for that,,,,
Think how many heat pumps could be installed for that....
Mark wrote: ↑06 Nov 2022, 19:20
Meanwhile, in the NW, £0.5 BILLION is about to be spent on the HyNet H2 pipeline project....
Think how many homes could be insulated for that,,,,
Think how many heat pumps could be installed for that....
Sadly this is yet another mega "seen to be doing something" project. I guess the money is not coming from private finance!
So 500 million is to be spent demonstrating all the already known problems and shortcomings and maybe discovering a few more.
Overconfidence, not just expert overconfidence but general overconfidence,
is one of the most common illusions we experience. Stan Robinson
Some interesting colours of hydrogen that I had not heard of. The pink hydrogen in particular.
Regarding turquoise hydrogen I think there was a project discussed in Western Australia to decompose methane into carbon and hydrogen as there is some demand for carbon in batteries and metal refining processes.
