<< He is no expert in other fields.- NADA>>
I guess a chemical engineer should be able to opine on hydrogen
With the hydrogen hype that is bandied about expert opinion is badly needed.
Do you generally agree,, it takes more energy units to manufacture hydrogen ,,than it gives back.
Are you as qualified to opine on hydrogen as Martin or Musk is? I’m not.
Tired of reading all the hydrogen hype that ,,from a layman’s point of view,,, looks like pie in the sky bullshit.
The rest of the Martin article,, a few years old from LinkedIn.....
“”Does this mean that hydrogen is dead for personal transport applications? In a word, and in my opinion, YES. Elon Musk and I agree violently on that topic. Erm, I'd qualify that by saying except in a world where electricity somehow costs nothing, or even worse, its price goes negative, because renewable generation basically becomes so cheap that it costs basically no capital to install. But I’m betting that a) that will never happen, and b) even if we were to come close to that puzzling economic outcome, the capital cost and other practical problems with the electrolyzers, compressor trains, storage tanks and fuelcells would kill the idea deader than a doornail anyway.
A comparison of two real vehicles you can buy (in California at least) makes it clear that my estimates are optimistic in favour of hydrogen. For cars of similar features and the same EPA range, the hydrogen car uses 3.2x as much energy (i.e. much more than the 2.4x minimum I've calculated above) and costs 5.4x as much per mile driven:
linkedin.com
Of course BOTH can improve from where they are now- but the calculations in my paper above set the limits. You can't overcome thermodynamics with invention or wishful thinking.
Does this mean there is no use for PEM fuelcells? Absolutely not! There ARE established markets where PEM fuelcells make good sense- but they’re all applications where energy efficiency matters a lot less than something else- rapid refuelling as an example. Hence, Plug Power is finding a niche market powering warehouse forklift trucks, particularly in refrigerated warehouses.
(FC forklifts, from www.plugpower.com)
The same goes for the so-called “power to gas” or P2G schemes that some are developing. These are an entirely different model: they use “excess” renewable electricity to make hydrogen which is then dumped at low pressure into the natural gas grid where it is ultimately used to make heat- often in devices which actually finally recover the heat of condensation of the water of combustion. As a means of storing electricity, P2G schemes are so ridiculously inefficient that they’re not even worth talking about, but they’re also very low in capital investment AND they reduce GHG emissions when the H2 displaces methane. That’s not all bad.
Other Transport Uses for HydrogenBatteries are either marginally feasible or infeasible for some forms of transport right now: aircraft, long-distance transport, trains and ships. The real question for these applications is simply this: how much do we care about toxic tailpipe pollution? If we care about this most of all, then hydrogen is the only game in town. But if our primary focus is fossil GHG emissions, we have the option of using biofuels for these applications as an alternative to hydrogen. For aircraft, biofuels are likely the only practical solution until something which is as much better than Li ion than Li ion was better than lead-acid batteries is invented- perhaps a rechargeable metal-air battery. And while the total replacement of diesel and gasoline with biofuels is infeasible even if economics are thrown aside completely (see www.withouthotair.com for the figures on that), if we were to do 90% of the car miles with electricity, we should have enough biofuels production potential to handle the remaining 10% PLUS all these other applications for which batteries are currently infeasible. Toxic tailpipe emissions matter a lot less when they're emitted between cities.
The option of using hydrogen or electrochemical means to reduce CO2 to produce liquid hydrocarbons is, obviously, significantly less efficient than hydrogen. The same with ammonia, which is trotted out as a way to overcome some of hydrogen's deficiencies. Ammonia is a toxic gas- and making it is again less efficient than making hydrogen. The thought of using ammonia as a vehicle fuel absolutely terrifies me, given the scale of ammonia-related deaths from its existing uses as a refrigerant and agricultural chemical.
The Real Future of Renewable HydrogenRight now, over 96% of the hydrogen produced in the world is produced from fossil fuels either deliberately (coal gasification or natural gas in SMR or ATR units), or as a byproduct of petroleum manufacture. We're going to need to become very, very good at making hydrogen from renewable resources like PV solar and wind electricity, not to waste it as an inefficient vehicle fuel, but to use it to make things like ammonia and urea which are used in fertilizers. We'll need to replace this enormous fossil hydrogen generation infrastructure so that we can get the fossil monkey off our backs without starving.
More on the future of renewable hydrogen from renewable electricity: is it the future? Or a greenwash?
linkedin.com
My next article will address the bogeyman of embodied energy, particularly in batteries.
Disclaimer: everything in this series of articles is my own opinion, for which I try to state sources and references whenever possible. It’s highly likely that something I’ve said is just plain wrong- for which I apologize in advance. Whenever you can show that I’m wrong with a good reference, I’ll go back and edit the text with the correct information. My employer, Zeton Inc., is in an entirely different business, and doesn’t endorse or even have an opinion on these issues. We design and build pilot plants- that’s it- and we love doing it! “ |
