Firstly, hydrogen is not a source of energy but an energy carrier. This is because hydrogen is currently produced from fossil fuels, as such it can hardly be termed "green".

However, it has significant potential for the future especially if generated from renewable sources such as biomass or the electrolysis of sea or waste water.

For sure hydrogen is a green fuel for the future. All depends on how it is produced.

Regards

GB

Nice to have your wonderful ideas.

For future Chemical Engineering Industry, Safety is its life. Up to now, I cannot say Hydrogen is SAFE enough to be used. I am confused....Thank you.

There are no low-cost measures to reducing GHG emissions and some believe that hydrogen is one of the more expensive approaches. Nevertheless, there are some interesting proposals supporting the hydrogen economy. One is Northern Gas Networks H21 North of England Project in conjunction with Cadent’s Manchester-Liverpool Hydrogen Cluster Project. The links below are for the latest technical reports for these projects.

https://northerngasnetworks.co.uk/h21-noe/H21-NoE-23Nov18-v1.0.pdf

https://cadentgas.com/getattachment/About-us/Innovation/Projects/Liverpool-Manchester-Hydrogen-Cluster/Promo-LMHC-downloads/Technical-Report.pdf

In combination, these two projects involve the construction of three coastal methane reforming plants supplying (blue) hydrogen to the north of England including the major cities of Bradford, Hull, Leeds, Liverpool, Manchester, Middlesbrough, and Newcastle. The hydrogen would replace current domestic, commercial and industrial natural gas usage, as well as motive power and peak power generation. It is a very ambitious project with hydrogen being society's major source of energy. The CO2 released would be captured and stored offshore in the North and Irish Seas.

The project developers believe this approach will allow the UK to meet its 2050 GHG reduction targets. Others are less sure, believing that the target cannot be met using this approach. The counterview favours extensive electrification from renewable and nuclear sources with a much smaller role for hydrogen. In both cases, energy efficiency plays a vital role in reducing the amount of energy required.

High production of green hydrogen will likely involve electrolysis using nuclear power with lesser amounts from excess renewable power and anaerobic digestion of bio-wastes.

Safety is, of course, a concern, but as part of the preparations for the hydrogen economy, regulations for production, transportation, and usage will be developed to reduce and manage any risk. Others opine that hydrogen is no more or less dangerous than petrol and natural gas, both of which are transported and used with acceptable risk levels. The two methane reforming projects believe that any risk can be readily managed. Nevertheless, the spectre of the Hindenburg is being raised in some quarters, although it has been long recognised that hydrogen did not cause the disaster but did make it tragically more memorable. With respect to transporting hydrogen by sea from locations of lower-cost production, conversion to ammonia is being considered as a means of risk and cost reduction.

Will the hydrogen economy evolve? I do not know, but I am sure that things need to start happening soon if the worst effects of global climate change are to be avoided.

Thank you very much to share your ideas, Mr. John M Wheeldon. I guess you are Fluidization-er. Best wishes.

Luo Guohua

Hydrogen is energy carrier with a potential of being a green source. In my opinion, Hydrogen isn't yet a green source since the majority of the global hydrogen produced comes from the reforming of fossil fuels. It can only attain the status of green source when its production is purely from non-carbon sources such as electrolysis of water where the electrolytic cell is powered by energy from renewable sources.

The energy efficiency of electrolysis is currently around 70% but this could increase to 85% as new processes emerge such as the proton exchange membrane. So, any electrolysis-for-hydrogen process installed today would “lose” 30% of the energy supplied. With respect to the hydrogen economy concept where the majority of energy is supplied as hydrogen, electrolysis is a wasteful approach: better to use the electricity directly for heating etc.

In smaller-scale applications electrolysis makes more sense (at least to me). Aberdeen is demonstrating a 1-MW electrolyser supplying hydrogen for a fleet of 10 buses driven by hydrogen fuel cells. This, of course, displaces CO2 from diesel. The electricity taken from the grid is mainly generated by natural gas but projects are being developed that use excess wind power.

An issue with wind generation is its intermittent nature resulting in an imbalance in supply and demand. Sometimes there is insufficient wind to meet demand (cold and windless days) and natural gas load picks up. At other times there is excess supply (warm windy days) and suppliers are paid to turn off the wind turbines. Rather than switching off the turbines, they could be used for hydrogen production by electrolysis. In Scotland again, such schemes are being developed. In one, a hydrogen-powered ferry is planned for the Orkneys displacing still more diesel. In another, it is planned to store the hydrogen, and use it to generate peak power and displace natural gas.

If the hydrogen economy is to progress, I think that it will be based primarily around steam reformation of natural gas producing “blue” hydrogen with the CO2 released being captured and stored. Nevertheless, there are ample opportunities to produce “green” hydrogen, albeit at a lesser scale.

Definitely yes, though the journey for integrating hydrogen as a green source for future energy demands is in early stages.

In terms of energy density and the impact on the environment, I believe hydrogen is an excellent green energy source. However, some cheap and grean technologies to produce hydrogen are required. How to store, transform and use hydrogen safely is also important.

Mankind fuel dependency being evolved from centuries, begun with wood , coal , oil etc. recent technologies has come over many difficult problem which seems to be impossible from past centuries . As energy resources are being used , as well as alternative resources are being developed , Hydrogen is abundant in our planet , and it will be surely a part of energy needed in the future technologies , the technologies we have hold this recent years may not be enough to use efficiently energy resources , we need to look insight into atomic level efficiency to control , to use and to save the fuel .

Hi

yes it could be. also i strongly agree with Kashan Bashir , Songcan Wang

Dear Luo,

There are projects to generate hydrogen using photovoltaic driven water electrolyzers. It is so that the the PV generator is separated from the electrolyzer.

So, the hydrogen generator is composed of two units. There are research to combine them in one unit by using photoelectrochemical electrodes. I worked on such project in the last decade of the past century at King Saud University in KSA.

This project was a joint project with Stuttgart university in Germany.

I think the German scientists work intensively on such projects to become real.

I do not know exactly the state of the art of such technology but solar hydrogen is a strong candidate as a fuel.

Best wishes

I think as Abdelhalim Zekry .

Dear Dr.

Yes , I think

Regards

Hydrogen from a traditional point of view, when it is produced from renewable sources, is a vector of energy, not its source (the source is either solar or wind). However, it could be the source of energy: this is the case of natural hydrogen, which is coming from geochemical reactions in the Earth's crust and mantle. Such hydrogen is carbon-free and sustainable. Moreover, it could be the cheapest source of hydrogen.

Definitely yes, I strongly believe hydrogen as an excellent green energy source.