TheMotorcycleBoy wrote:GrahamPlatt wrote:tjh290633 wrote:Not as much as that. You have to multiply the weight by the CV to make the comparison.
Hydrogen 2*150=300
Methane 16*55= 880
So on a volume basis about 3 times.
TJH
I was speaking of volumes. Methane has a MW of 16, H is 1. So a cubic meter of methane weighs 16 times that of a cubic meter of Hydrogen. Ah, hang on, it’s H2 in its gaseous state... 8 times then. Then you divide by the relative CVs, ~3:1. So yes, Spet was right.
The interesting thing is that there is no need to fixate on H2 necessarily. Ceres Power Steel Cell can operate on a number of substrates, which can be made from H2, e.g. CH4 a constituent of natural gas.
https://www.greencarcongress.com/2016/0 ... power.htmlAnd quite apart from all of this tech being old hand, there are continuing improvements in related fields:
https://www.sciencedaily.com/releases/2 ... 114523.htmsome of which capture carbon, making the possible solutions carbon neutral, whilst, potentially transporting the same gases (i.e. ones with greater density and stability than H2) as our current natural gas infrastructure carries. As such it seems sensible to consider leveraging parts of existing gas distribution assets.
Matt
All of these pathways have the same problems. The more C in the start point, the more processing to get it out so as to get to the clean H2. That processing costs money and costs energy, capex and opex. Then having gotten the C out, along with any other stuff, you need to dispose of it in a way that doesn't cause a bigger problem than simply combusting it in air. So basically you need to stick the C deep in the ground. More energy, more cost - capex and opex again. Oh, and having done all that there is still this H2 stuff to do something with. But before you do something with it, you need to store it and transport it. More energy, more cost - capex and opex again. And a lot of these steps have various non-trivial risks associated with them. And $bn minimum scale requirements to run an experiment (just like fusion). Then finally haven gotten your H2 to its destination you can either co-combust it with natural gas (CH4) which is non-sexy but cheap & easy, or do other sexier stuff that is difficult & expensive.
vs
Just going electric, using lithiums + wind + solar.
I remember being at a renewables conference a few years ago where a big presentation was about a wind/solar/hydrogen project (cars, fuel cells, electrolysis, tanks, the lot). They spent a serious amount of money, we all knew that, but they didn't mention the costs once. In fact they didn't even have much to say about technical successes, but they all drove nice cars and got PhD theses and greenwash funding from corporates (this was a £m's project). At the end of the presentation I dared to raise the matter of cost vs benefit, and got a very evasive answer. The next questioner raised the same topic. And the next. And the next, it was quite embarrassing really. We were all hard-bitten pro-renewables people : this was not an onslaught by anti-wind/etc types. We are/were all doing this stuff for real and we know/knew the issues, vs the base case of straight-electric. The presenters practically fled the stage to avoid our questions.
Drill into these problems and what you will find are the same people running the same start-ups, recycling hopium. Not progressing fast enough vs the mainstream adoption of straight electricity, but by spinning and marketing they can get another gig, another grant, another investor, another round, and another pay cheque.
Benchmark everything against pure electric. Ask yourself - is it cheaper both in $$ terms and in kW / % efficiency terms. Ask yourself what you are missing (normally they cut the bad part of the system out of their definition). Pretty soon you will start to recognise the problems yourself.
regards, dspp