I got lost in the details pretty quickly when I read the paper. The thermal integration is a stroke of genius IMHO, pairing endothermic reactions with exothermic ones to conserve both heat and energy. Hydrogen works beautifully as a heat-transfer fluid, too.

Looks pretty clever to me, Davemart. I didn't see anything about energy efficiency, though. That may be because the system can operate as either a generator with low-pressure H2 production, or a load operating as an H2 compressor.

Agreed, so why doesn’t VERBIO just convert the biomass to Bio-methanol? It's wasteful to do auto-thermally, and I wouldn't be surprised if the terms of the "bio" or "R" designation require microbial conversion. What do you think? I think Google Translate failed utterly on the .fr site that it fed back to me, and 10 km/liter of MeOH isn't at all bad but is hardly impressive especially at 50 km/hr. My 2013 Ford Fusion Energi could probably beat that handily if the engine was re-tuned for methanol fuel; it already beats 60 MPG at a steady 40 MPH, and it's 9 years old.

There should be as much biomass available as cobs, leaves and stalks as there is in kernels, yet the EtOH-equivalent production of RNG is less than 1/3 as much as the EtOH. There appear to be some serious inefficiencies in the process.

Look at it this way; powdered dunite sells for about $35/tonne in India (that's just the first place I could find a price), and a ton of it mineralizes about 0.8 tons of CO2, so it takes about $44 of it to mineralize a ton of CO2. It would make sense to attach an environmental remediation penalty to FF use, so extracting 2 tons while emitting 1 ton would only cost $88 per ton. That's pretty much a ceiling on the cost.

The cheapest and easiest way to pull CO2 from the air is by weathering of certain minerals. Humanity can enhance this process with relative ease, and it is high time we did.

We're waiting for a manufacturer to adopt a non-lithium battery technology, whether for EVs, PHEVs or even HEVs. Until one of them makes that cut, it's all academic. Frankly, I'd like to see one automaker go hybrid with supercaps. As power-levelling devices, they are peerless. They would allow the main powerplant to have a response time of seconds to power demands, while providing instant power both for acceleration and braking. This would permit the main powerplant to be optimized for thermal efficiency and emissions rather than responsiveness and NVH; it could simply be operated outside the envelope where those were problems.

I find it difficult to believe this cost estimate. Powdered dunite is available at a cost of around USD 35/tonne. Given that 1 tonne of dunite can mineralize about 0.8 tonnes of CO2, and biologically (through solution of silica) enable the capture of much more through growth of diatoms, limiting warming should be far cheaper than a USD 200/tonne CO2 tax. Reversing warming to pre-industrial levels should cost more like USD 100/tonne.

You are simply clueless, aren't you GdB?

Why are they even investigating this? The sulfur-iodine cycle beats 50% efficiency at a mere 1000°C. Of course, the economics of using solar energy for water-cracking are dismal. You've got the restriction to places with cloudless skies and a lousy capacity factor imposed by day-night cycles, not to mention all the thermal cycling problems. The best sites for this are deserts, which are notoriously poor in water resources for feedstock. Nuclear energy can supply heat 24/7/365 and be put where the water and consumers are.

Ethanol production consumes about 1/3 of US-grown maize, but produces only about 10% of US gasoline consumption by volume (less by energy). Obviously, we can't do very much with it... at least not the way we're doing it today. (Yes, I'll see to it that the spammer gets whacked.)

Nick is right. The LH2 plane schemes I've seen either had tanks fore and aft or one running the length of the plane (which would certainly have been subdivided) for just that reason.

Start quantifying the amount of material required (lithium, zinc, lead, whatever) and compare against world production. That will tell you what you're up against. If you haven't done this, you're ignorant and shouldn't opine. If you can't do this, you're innumerate and should shut up.

The narrow flammability limits of NH3 had me skeptical about this, but seeing that they intend to crack it to H2 and N2 before feeding the engine gets around this problem. They still have the issue of low energy/mass of NH3. It has about 8000 BTU/lb, compared to Jet-A at about 20,000 BTU/lb. I suspect the cracking process will take some energy too. On the other hand, if they can crack the NH3 with heat obtained by cooling the first few stages of turbine nozzles, that might enable greater engine performance (no dilution of the combustion gas by nozzle cooling air, less bleed air tapped for cooling). It'll be interesting to see just what they do.

yoatmon, the stubbornness is entirely on the other side. Check out the Gordian Knot book version wN, appendix A6 (pp. 293-4), available at http://gordianknotbook.com/ Everything Devanney wrote is true. Unreliable "renewables" can only lock in fossil fuels permanently, and trying to go that way will destroy civilization, with our species and possibly most life on Earth becoming casualties of a "green" ideology which refuses to acknowledge resource limits and even physics.

Bauxite residues pose significant environmental risks due to its large volumes, high alkalinity and storage complicationsThe oceans are threatened by high acidity and low productivity due to lack of iron. I see a "two birds, one stone" fix here.

Two major chains built out big-box stores near me in the last few years, and NEITHER included EV charging in their plans. Disappointed way understates my reaction.

Two major chains built out big-box stores near me in the last few years, and NEITHER included EV charging in their plans. Disappointed way understates my reaction.

Two major chains built out big-box stores near me in the last few years, and NEITHER included EV charging in their plans. Disappointed way understates my reaction.

Old fat and (vegetable) oil are typically used as animal feed. There is really no "surplus".

I've got a plug-in hybrid car. It's fuel-agnostic for local driving; if it puts watts on the grid, I can use it. Hydrogen, nuclear, they're all the same to me. Why would I want a hydrogen car? I could use hydrogen to replace natural gas. I already have the pipeline to my house, I just need to replace what's in it.

In last night's Atomic Book Club discussion of "Fear of a Nuclear Planet", Michael Conley mentioned the potential of iron-air batteries for stationary storage. He mentioned the figure of $20/kWh. I've run the numbers before. At $20/kWh, you can profitably buffer nuclear power across nights and weekends. Renewables require weeks of storage and aren't sufficiently cheap until you get well under $10/kWh.

Even if gold hydrogen is feasible, it's still a fossil resource and won't last long. As a way to decarbonize in the short term it may have a lot of merit; it can pick up the slack until we've built out our nuclear thermochemical hydrogen production. Reference: https://www.goldhydrogen.com/

I ripped Hossenfelder a new one in the comments of her video. https://www.youtube.com/watch?v=0kahih8RT1k&lc=UgzQfpNxsoB5x-SLK-l4AaABAg

The molten salt reactors are plausible but there is no vast body of long term data about the materials of the containment vessels.Container materials take a back seat to physics. We can design containers for replacement. We cannot design "renewables" for dispatchability. The competing tech is coming up with a decent grid scale battery to buffer ridiculously cheap renewables and make them dispatchable. I'd say the latter is by far the lighter technical lift. The most expensive kWh is the one you need and do not have. Look at Europe's year-scale "wind drought" and the Russian gas crisis. Europe's "renewables" have come at the dire cost of Germany's (and so many other countries') political reliance upon an (alleged) aggressor's supplies of energy. While Germany shuts down its reliable, carbon-free plants, Russia builds more and sells them for export. There is a lesson. Relatively complex Li-ion is headed under$100/KWh since sufficient demand appeared. World extraction of lithium is grossly inadequate for seasonal storage of so-called "renewable" energy, let alone annual and larger-scale "droughts". Humanity learned centuries ago that "renewables" were inferior to inventories of fuel. Coal was that first inventory, later supplemented by oil and then by natural gas. Uranium and thorium were latwcomers to the party, but have turned out to be the best of all. When climate change came to the forefront of humanity's problems, the actinide elements came out as our saviors: they gave vast amounts of energy and put NOTHING into the atmosphere. Not toxic pollutants, not greenhouse gases, NOTHING. And what did they get for that? Relentless demonization from so-called "environmentalists" and "greens". The hell with them, and the hell with YOU.