A viable pathway for hydrogen as fuel • Hacker News Board

Re: A viable pathway for hydrogen as fuel

#21

Post by semi-extrinsic » Sat, Feb 17, 2018, 3:28 PM UTC

asgeirn wrote: post #19

Most counterarguments related to Hydrogen refer to the poor efficiency of converting (electric) energy to Hydrogen and back. True, directly using that electric energy from wind or solar is definitely the best option. However, that is not always possible, since there is no place to consume, transport or store that electric energy. Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replac…

I really don't understand why the debate on H2 is so focused on electrolysis. Even today, 95% of all hydrogen is produced not by electrolysis, but from natural gas through steam methane reforming (SMR).

SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil and gas today.

I'm entirely convinced it will be the future, and that we'll never be able to scale pure BEVs beyond 10-15% of all cars in any large country, simply due to electricity production and distribution constraints.

Re: A viable pathway for hydrogen as fuel

#22

Post by rbanffy » Sat, Feb 17, 2018, 4:00 PM UTC

semi-extrinsic wrote: post #21

asgeirn wrote: post #19

Most counterarguments related to Hydrogen refer to the poor efficiency of converting (electric) energy to Hydrogen and back. True, directly using that electric energy from wind or solar is definitely the best option. However, that is not always possible, since there is no place to consume, transport or store that electric energy. Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replac…

I really don't understand why the debate on H2 is so focused on electrolysis. Even today, 95% of all hydrogen is produced not by electrolysis, but from natural gas through steam methane reforming (SMR). SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil an…

And you can easily use that extra carbon for growing plants in vertical farms next to the SMR plant.

Would impurities in the source methane be a problem for this case?

Re: A viable pathway for hydrogen as fuel

#23

Post by VLM » Sat, Feb 17, 2018, 4:21 PM UTC

semi-extrinsic wrote: post #21

asgeirn wrote: post #19

Most counterarguments related to Hydrogen refer to the poor efficiency of converting (electric) energy to Hydrogen and back. True, directly using that electric energy from wind or solar is definitely the best option. However, that is not always possible, since there is no place to consume, transport or store that electric energy. Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replac…

I really don't understand why the debate on H2 is so focused on electrolysis. Even today, 95% of all hydrogen is produced not by electrolysis, but from natural gas through steam methane reforming (SMR). SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil an…

The problem with nifty solutions to removing carbon from raw fuels resulting in carbon free hydrogen, is the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons to make some delicious hyper optimized liquid fuels, which coincidentally we have massive infrastructure to use.

Not as snarky as might sound. Given infinite fusion energy via the real thing or solar panels, truly pure synthetic fuel opens up some interesting ideas WRT catalysts and efficient burn designs to squeek out another percent or two of performance. Inherently zero (not low, but ZERO) sulfur diesel is interesting, for example. And no one says the carbon thats added has to come from underground; go harvest some trees that sucked the carbon right out of the air, then when you put it back in the air after a couple months of storage, nothing bad happened.

Re: A viable pathway for hydrogen as fuel

#24

Post by camgunz » Sat, Feb 17, 2018, 4:29 PM UTC

I'd really (honestly) like for all this to be true, but the innovations here are that Johnson figured out some secret sauce in the electrolyzer's electrocatalyzer mix, and some more secret sauce in the fuel cell's hydrides. It's possible this happened, but I'm pretty skeptical.

Re: A viable pathway for hydrogen as fuel

#25

Post by semi-extrinsic » Sat, Feb 17, 2018, 4:34 PM UTC

VLM wrote: post #23

semi-extrinsic wrote: post #21

Earlier quoted context omitted.

I really don't understand why the debate on H2 is so focused on electrolysis. Even today, 95% of all hydrogen is produced not by electrolysis, but from natural gas through steam methane reforming (SMR). SMRs can be easily scaled up to meet all H2 demand, and they are easily fitted with carbon capture technology (since it's a single large emission point). Then you have zero-emission H2 in quantities as large as oil an…

The problem with nifty solutions to removing carbon from raw fuels resulting in carbon free hydrogen, is the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons to make some delicious hyper optimized liquid fuels, which coincidentally we have massive infrastructure t…

> the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons

If that's the case, it's equally true for H2 from renewables, no?

And I don't think it's true. LPG vehicles today are common enough, and they've solved very similar transport and distribution problems.

Re: A viable pathway for hydrogen as fuel

#26

Post by nine_k » Sat, Feb 17, 2018, 5:11 PM UTC

semi-extrinsic wrote: post #25

VLM wrote: post #23

Earlier quoted context omitted.

The problem with nifty solutions to removing carbon from raw fuels resulting in carbon free hydrogen, is the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons to make some delicious hyper optimized liquid fuels, which coincidentally we have massive infrastructure t…

> the best engineering solution to the remainder of the task list of transport, store, and burn the resulting carbon-free hydrogen, is to modify the hydrogen by synthesize up some carbon containing hydrocarbons If that's the case, it's equally true for H2 from renewables, no? And I don't think it's true. LPG vehicles today are common enough, and they've solved very similar transport and distribution problems.

Not really. Hydrocarbons are much easier to store and handle. Cars may not need it so much, but as a jet fuel, kerosene is much easier than hydrogen.

Re: A viable pathway for hydrogen as fuel

#27

Post by nine_k » Sat, Feb 17, 2018, 5:16 PM UTC

phkahler wrote: post #16

lovemenot wrote: post #6

Hydrogen does have a lot of problems which other commenters here point out. But if HyTech is to be believed, some of these problems are solved. Probably their most significant claim, is hydride storage at ordinary temperature / pressure with safe, practical, cost effectiveness in recovering that stored energy.

HyTech doesn't solve the main problem with hydrogen - that there isn't any available as fuel, and it takes more energy to extract the hydrogen than you get back from burning it or even using it in a fuel cell. The idea of injecting small amounts of hydrogen into a combustion engine to improve fuel economy is not new, but congrats if they can bring that concept to market. That would be a win, but is not the same as hy…

It takes more energy to charge a battery than can be had back discharging it.

Does it make the battery in your mobile phone useless?

Re: A viable pathway for hydrogen as fuel

#28

Post by _ph_ » Sat, Feb 17, 2018, 5:24 PM UTC

asgeirn wrote: post #19

Most counterarguments related to Hydrogen refer to the poor efficiency of converting (electric) energy to Hydrogen and back. True, directly using that electric energy from wind or solar is definitely the best option. However, that is not always possible, since there is no place to consume, transport or store that electric energy. Furthermore, scrapping all ICE vehicles for BEVs is most likely the end goal. But replac…

For a hydrogen based infrastructure we need 3x as much electricity than for one which directly uses electricity via batteries. You cannot use hydrogen in cars already built - unless you want to sacrifice your rear passenger row for an add-on tank (H2-tanks are quite bulky). So it is new cars anyway. Making them directly electric is the way more efficient way.

Re: A viable pathway for hydrogen as fuel

#29

Post by _ph_ » Sat, Feb 17, 2018, 5:26 PM UTC

sebazzz wrote: post #17

_ph_ wrote: post #3

The article names it, but then does not dive deeper into it: the hydrogen chain has huge energy losses. First, electrolysis unfortunately has not a high efficiency - I have read numbers around 70%, but then the compression of the produced hydrogen takes a lot of energy, as compressing gases heats them up. Then the hydrogen has to be transported and stored, requiring further energy. Finally, you have to use the hydrog…

How does that compare to using batteries? Batteries are re-usable of course, but also degrade over time and need to be replaced.

As do fuel cells and H2 tanks - H2 is quite aggressive to the materials. But most importantly, the charge-discharge cycle of a battery is about 90% efficient, which beats hydrogen easily. And with quickly dropping battery prices they even become feasible for large-scale storage, see the Australian battery built by Tesla.

Re: A viable pathway for hydrogen as fuel

#30

Post by MechEStudent » Sat, Feb 17, 2018, 5:50 PM UTC

Hydrogen has hard risks, and high costs. Density. Corrosion. Tunneling/leaking. A new trillion-dollar distribution infrastructure to replace the fluid-version we use for petrol.

What about methanol? We can convert hydrogen to hydrocarbon. Liquid is dense, much less dangerous, less acidic, less leaky, and our current trillion-dollar infrastructure already uses it as a substantial additive.