Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 4 replies
  • Subscribers 15 subscribers
  • Views 322 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

And we got high high high on Hydrogen

Helios
Texas songs aside , theres a lot of movement on green hydrogen , and by the looks of it some big energy players are starting to stir , because the rise of mechguy is starting to meeting the PR from if future energy propositions is well , either true or the best we can do , to help the natural life systems of the planet (which ime sure we all agree is about the most amazing piece of biological engineering you could think of) 

So who are the runners and riders , well some business investment is a bit sniffy about green hydrogen , it costs too much (as in equipment) and for those of us who like the engineering calculations or even just nice designed things , we start to scratch our heads at kgs of  Hydrogen per MW of electricty.

If you take the classic electrolysis cell of two electrodes suspended in an electrolyte , and passing an electrical current between them , best lab results are around 60% efficiency and 45% probebely near to real life which gives the eyewatering fact of figures of 200kw to make a kg of Hydrogen , and you sort of get to see , why early tries at making Hydrogen from water electrolysis , got dismantled as soon as the company accountant , worked out the coal required !!. 

The water molicule , which as natures solvent , is so truly wonderful and stable , needs a lot of energy to get those Hydrogen atoms free from the Oxygen ,but then the plastics people got more technical and came up with a membrane that would allow proton exchange efficicently and PEM technology was borne and this shifted cell efficiency to over 70% .Meanwhile the company you perhaps didnt here much about called NELL has been perfecting a high temperature alkali (uses potassium hydroxide) electrolysis and they claim 80% cell efficiency. the PEM membranes are expensive and NELL has some cost advantages .

The cell efficiency figures are a guide but dont explain the full story , as not all ways of getting commercial quantaties of Hydrogen work quite the same and Siemens silyser 300 system is a refined PEM system and has some nice design touches such as being able to start with very low currents and it was designed to hook up to wind turbine arrays , which as we know have variable outputs , and we perhaps got some more meaningful figures of 1kg of Hydrogen for 60kwh .

Bill Gates has just invested in  new boy company H2pro who are claiming 90% cell efficency with a sort of cold electrolyte chemical reaction and then a hot high pressure electrolysis system (i dont know it looks a little unexplained to me at the moment)  , which I guess has some attractions as it claims to produce very high pressure hydrogen , which has industrial chemistry applications (ammoinia and sabatier reactions etc) as well as reducing the energy cost of actual liquid hydrogen , so i kind of get his smart thinking , and it doesnt need expensive plastics that PEM uses , so everyones excited ... well except me ... I dont think Hydrogen will be used in road vehicles or as sole fuel source in trains either ,

This is what i mean , were starting to see the big energy people appear and place there bet on what the energy future will looklike and its getting abit wierd , because suddenly the most important person in the room is not the company ceo , but the person with the physics degree who understands energy transitions and efficiencent storage solutions , really is king in the land of the wonk  PR announcment that doesnt stack up too well in egineering knowledge, as state of art as we understand it. If your sensative look away , the engineers are comming for the lies and liars , sometime soon?


I dont know i keep seeing these PR announcements and the Shania Twain song "that dont impress me much" pops into my mind , and then i perhaps have other days when its bit more (for the really wonk ideas)

"Ive seen angels fall from blinding heights , but you yourself are nothing so divine... just next in line"
  • 0
    Could make an Interesting debate, although I'm still looking for the specific question.

    Maybe you're heading towards cold fusion or is that fision?

    Legh
  • 0
    Hi Legh Its getting a bit more complex , as in electrolysis the kg per mw figure is your market proposition. and the people who do the investing understand more H2 per MW is a safer bet .

    Cold fusion mmmm what a day that was on the front cover of all the science mags , two men peering at a large testube and they managed to disripute the university and them selves within 4 weeks of the first announcement. Its always a little sad when . the high places of learning dont kinda help the energy thinking to work out the best or better effencies.

    The flux capacitor and fusion reactor on the deloren from back to the future , did look mysteriously like a food blender , but that aside i think nuclear fisson is pretty much done with , the fusion people are confident they can do it , and a lot of money has been spent on fusion and it still has never produced more than the energy input for longer than 15 seconds , and to put it mildly if a fusion reactor suffers some sort of magnetic containmment failiure , at 3,000,000oC it will pretty much vapourise everything in the reactor hall , so its got few problems even if they do a lab demonstration.

    I think we need to recycle stuff and that includes stuff we can term as a fuel , and much simpler than fusion is just using wood in construction , planting more trees and looking after our forests , so no nuclear physics degree required.

    I dont know when the questions start flying , the peddlers of all the wonk are going to be in trouble.
  • 0
    There's more to the H2 argument. From a vehicle point of view, battery technology has a long way to go before we can not take up huge amounts of vehicle room and the additional weight  An electric vehicle uses additional energy every time the car moves as energy is wasted from the additional dead load,  even if a battery could be 100% efficient. Also battery storage suffers leakage ( so does H2, I know) so 70% might not be so bad. There's a finite amount of materials to make batteries and issues with disposal/recycling. Additionally, renewables do not provide constant power so storage is essential. Practically, we may just all have to rely on smaller lighter vehicles, human power, or travel less, and only time will tell, but theoretically, mass production of hydrogen may well be the only long term solution environmentally.

  • 0
    and thers problems with H2 , such as pressure cracks on manifold heads into matrix , but agree battery on large heavy vehicles was a pretty bad proposition from energy efficiency point of view from the start .

    700,000 kg of H2 is used by uk chemicals business , that will take a lot of electricty , and could have priotiy

Community Rules & Guidelines