The Hydrogen fuel thread

[William930t]

Just some varied thoughts on the subject, hoping for a good discussion from the PP Brain Trust, is it really the new energy source with unlimited capabilities?

The talk of hydrogen fuels has been long and not much to really show, yet. I understand the conversion process, storage, transportation, infrastructure and safety factors as reasons for slow acceptance. Then there is the "creation" argument on blue gas (from natural gas) versus green gas (from water). Which process will be acceptable?

Certain areas of Southern California have hydrogen vehicles in service and a network of refueling stations. Cars typically have a 300 mile range, but filling tanks only takes around 5 minutes, sure beats EV recharging times. Also noted, 1 kg of hydrogen is about the same energy content as 1 gallon of gasoline, and range is touted at 70 miles per kg. But it do the fuel cell tanks really need hydrogen compressed to 10,000 PSI?

I am following the continued rise of companies like Plug Power, Ballard Power and Bloom Energy. Not much in the way of profits yet, but likely good long term investments. Also there appears to be a growing home market for hydrogen generators. Several retailers are already selling a 50 lb unit that can generate 160 ml/min, supposedly enough to power a home. All they need is a solar panel and a water source.

A side note, I have followed the slow progress of hydrogen powered race cars. There have been a few aborted projects, with reliability, performance, and heavy weight being the obvious issues. The best success so far was actually back in 2019. A student built prototype, (Forze VIII) finished P2 in the Netherlands Supercar challenge. I haven't read much advancement since then, however Le Mans 2024 will have a class for hydrogen power.

Feel free to post your thoughts and any professional experience, thanks.

[RWebb]

Your OP is mixing H for ICE and H for fuel cells.

BMW gave up on the former, but Oracle has a bunch of the latter (or maybe the Ballard fuel cells they bought are methanol?).

[id10t]

No professional experience, but there are a couple of issues I see with hydrogen powered stuff.

1 - Energy density. As noted, to have any kind of decent travel distance/run time you need to have plenty of gas with you, which means weight and lots of compression just do deal with the size. Not sure how much hydrogen is used per engine revolution but whatever amount it is at thousands of revolutions per minute it is gonna be a lot per minute of run time.

2 - getting the hydrogen to begin with. Sure, crack water with electricity. How are we going to generate all of that electricity? You mention a home unit that could produce 160ml/min but at 3000 rpms but for that to power an engine it needs to consume less than 0.054ml per revolution. That ain't a lot. Would it be better to instead store that and use direct electric power? Some type of chemical reaction? Also possible - but how do we obtain and process sufficient reactive agents in order to run the process in bulk to satisfy fuel needs?

[unclebilly]

I will preface my comments with the following.

In 1999, as a project course in University, I built a alkaline fuel cell from scratch. It worked but had a very low power density. The electrolyte was novel but the electrodes being fluidized beds couldn’t handle high gas flow rates needed for high power densities despite the massive active areas of the cathode and anode electrodes.

This project resulted in me getting my first job as a newly graduated mechanical engineer at Global Thermoelectric, the world leaders in Solid Oxide Fuel Cell (SOFC) technology. I was hired 3 months before I finished school so had no stress about finding a job. I was the 16th person in fuel cells and watched the company grow to about 200 with the tech bubble. I was a fuel cell stack design engineer right from the start, I was working on the cutting edge of the cutting edge.

My first patent was the fuel cell stack compression system for the fuel cells in the trunk on that BMW shown in this photo. I probably was part of hand assembling the very fuel cell stacks in this photo.



https://www.autointell.com/News-2001/February-2001/February-21-02-p3.htm

I learned a lot, built some cool stuff, got several patents (I currently have 33 issued patents), and made some amazing friends with some very talented people.

The company had a board that didn’t understand the technology and sold the company to FuelCell Energy (FCE) for less money than we had in cash. FCE spun us out into a consortium with The Gas Research Institute, Colorado School of Mines, and some group in Utah. The new co was called Versa Power Systems, I worked for 3 companies in a year and sat at the same desk. I got head hunted regularly and eventually after 5 years left for a very lucrative job in the oil patch. Financially I made the right choice.

Versa is now back under full control of FCE. They have done some neat projects for DARPA, Cummins, and others over the years.

So here is my take on the OPs questions.

Hydrogen has a really poor energy density, even compressed. If you liquify it, you consume 1/2 - 2/3 of the usable energy in the hydrogen getting it there so this is not an efficient option. Anything hydrogen powered will have a terrible range.

Hydrocarbons such as natural gas (CH4), propane (C3H8), etc have far better energy densities and can be compressed efficiently. This is the right type of fuel to use for transportation.

PEM fuel cells (Ballard) can only run on hydrogen unless you reform the hydrocarbons in the balance of plant which can be done. These fuel cells run at about 80°C so they have an issue with dealing with the water in the exhaust stream on the cells and this kills power density (basically it makes part of the active area of the electrolyte ineffective).

SOFC fuel cells run at 600°C - 800°C (there is a temperature gradient across the cell, especially if you are doing on cell reforming). The higher temps lead to accelerated corrosion and degradation in performance. These can run on any hydrocarbon fuel, CO is a fuel, and of course you can run them on hydrogen but thermal management can be an issue that needs to be mitigated. SOFCs can also be run backwards to electrolyze water back into hydrogen and oxygen. This has an interesting application for spacecraft and other applications. During the night you can run a drone or whatever off of the fuel cell, during the day you can run your drone or whatever off of a solar panel that is large enough to run the fuel cell backwards to replenish your fuel for the night.

The way I see things is this...

Once the hoopla and BS is settled, the right technology will be used in the right applications. For example, SOFCs will be used in auxiliary power units in big trucks because they can run on the diesel tanks already on the trucks.

PEM cells have applications to replace batteries in many applications (I had an opportunity to join Angstrom Power when it kicked off). These guys made fuel cell powered cell phones and power tool batteries. Camping generators are another good application for PEM cells and there was even a Coleman product at one point.

FCE has built large backup generation stations for hospitals using their molten carbonate fuel cell technology. I think SOFCs would have been better.

Internal combustion engines are NOT going away. They are the right tool for the job in many applications and a fuel cell can’t replace them.

There are lots of ways to do stuff and there is not one silver bullet technology that does it all. As an example, Diesel engines are spectacular for over the road transport and heavy equipment. You won’t find a diesel powered lawn mower or weed trimmer. You can get electric versions of both, even cordless. These are examples of where a PEM fuel cell could replace the batteries but then you would need a fuel source, and a hydrogen infrastructure to support it.

I will get off my soap box now. Sorry to bore you all.

Here is a picture of a 25 year old me testing one of my new fuel cell stack designs (it had the highest power density of any stack we had built up until that time)...




A bunch of my friends left to go to Bloom and other places. My old boss is the VP of Engineering at Bloom.

[red-beard]

You use energy going from CH4 to Hydrogen. Look at the syngas and water gas conversion process. and be mindful of the molar energy balance.

Hydrogen is a storage means. It is zero emission where it is used. But it has to be generated.

[unclebilly]

Originally Posted by red-beard

You use energy going from CH4 to Hydrogen. Look at the syngas and water gas conversion process. and be mindful of the molar energy balance.

Hydrogen is a storage means. It is zero emission where it is used. But it has to be generated.

Not really, sure reforming is endothermic but if you do it on the cell like we did with SOFCs, it assists with cooling and thermal management of the fuel cell stack. In fact, we found (and I mentioned this in another thread weeks ago) that we were better off to run our anode exhaust through an eductor and a nickel bed (heat exchanger for our incoming fuel or air) and recycle part of the stream so we could get more cooling duty. This resulted in us running at a lower on cell fuel utilization but a higher overall system efficiency.

I think you are missing the conversion efficiencies related to putting that hydrogen into meaningful storage and taking it out and putting it to use. To make it meaningful storage, you need to compress it to several thousand PSI. This ain’t a free ride. The part that makes me shake my head is the notion that renewable energy from tidal, solar, wind, and hydroelectric can be wasted on inefficient processes because ‘free’... I think we’d be far better off using the off peak power from these ‘green’ energy conversion technologies wisely such as charging batteries and other useful things with better storage and power extraction efficiencies as opposed to making hydrogen out of water.

[LWJ]

I can't credibly comment on anything here except I used to sell Hydrogen. It scared the absolute sh11t out of people who sold dangerous gases every day.

It burns with no visible flame and has no scent, if I remember correctly.

I never saw any accidents involving Hydrogen. But they wouldn't have been pretty.

[id10t]

Originally Posted by LWJ

I can't credibly comment on anything here except I used to sell Hydrogen. It scared the absolute sh11t out of people who sold dangerous gases every day.

It burns with no visible flame and has no scent, if I remember correctly.

I never saw any accidents involving Hydrogen. But they wouldn't have been pretty.

The words "Oh, the humanity!" come to mind....

[red-beard]

Originally Posted by unclebilly

Not really, sure reforming is endothermic but if you do it on the cell like we did with SOFCs, it assists with cooling and thermal management of the fuel cell stack. In fact, we found (and I mentioned this in another thread weeks ago) that we were better off to run our anode exhaust through an eductor and a nickel bed (heat exchanger for our incoming fuel or air) and recycle part of the stream so we could get more cooling duty. This resulted in us running at a lower on cell fuel utilization but a higher overall system efficiency.

I think you are missing the conversion efficiencies related to putting that hydrogen into meaningful storage and taking it out and putting it to use. To make it meaningful storage, you need to compress it to several thousand PSI. This ain’t a free ride. The part that makes me shake my head is the notion that renewable energy from tidal, solar, wind, and hydroelectric can be wasted on inefficient processes because ‘free’... I think we’d be far better off using the off peak power from these ‘green’ energy conversion technologies wisely such as charging batteries and other useful things with better storage and power extraction efficiencies as opposed to making hydrogen out of water.

Not missing that. Storage is a huge problem for hydrogen, especially in that the hydrogen can leak from something that methane can't. And H2 has a much wider flammability range than methane or other hydrocarbon fuel.

There are some interesting storage work on reverse pressure swing adsorption. Normal PSAs you sucking the contaminants and flow the gas, for purification. This instead absorbs the hydrogen into a mineral matrix, reducing the storage pressure for a given mass of hydrogen. Ratio is about 10:1 pressure reduction. You lose about 50% capacity by volume for the absorbent. But it is still a win. 300 psig instead of 3000 psig.

My issue on using hydrogen as a storage means is the losses are higher than batteries.

For stationary applications, I think flow batteries are going to come out on top. The latest work is an iron based system, which will be dirt cheap. Vanadium is great and already commercial, but it is expensive.

[unclebilly]

Redbeard - I think we are on the same page.

The big thing for me is once the hype dies down, the right tool will be used where it makes sense. Fuel cells aren’t always the answer, much like how Solar isn’t always the answer. Each application brings its own unique challenges that some energy conversion technologies address better than others.

I also think geography plays a big role in this. Where I live, we don’t have much hydroelectric power generation but we are sitting on a huge natural gas resource, we have wind generation here and some distributed solar generation. We also have an abundance of coal...

I think this plays into the equation because if you are going to have a hydrogen economy, in some locals it makes sense to electrolyze water in off peak power demand times but in other areas, it may make more sense to reform natural gas (or use it as is).

Cheers.

[porsche930dude]

[red-beard]

No matter the source of power, wind, gas, coal, solar or nuclear, energy storage makes the system more efficient. Everything can be base load, running full power at most efficient level.

If the H2 storage can be solved, it will be so much better than battery EV.

On Battery tech, Honda is working on a Calcium based battery, that if it can be commercialized, is DIRT CHEAP with double energy density of Lithium-Ion.

[Mark Henry]

The government vehicles here are going to run on hydrogen. Quebec James bay has all kinds of electricity and is suppose to start producing hydrogen soon.

[Nick Triesch]

It takes electricity to produce hydrogen. It takes electricity to turn the hydrogen back into electricity.

[oldE]

Uncle Billy, thank you for your detailed post based upon your work. When I was a guide at the tidal power facility, I spent a lot of time telling folks there wasn't one magic bullet which would solve their energy problems and that anyone who tried to convince them there was, was selling something.

Best
Les

[wdfifteen]

Seems like hydrogen would be a good replacement for natural gas in gas turbine power plants. Use the compressed natural gas for vehicles, since it's easier to store and transport.

[red-beard]

Originally Posted by wdfifteen

Seems like hydrogen would be a good replacement for natural gas in gas turbine power plants. Use the compressed natural gas for vehicles, since it's easier to store and transport.

No. Just no. There are a multitude of reasons, not limited to: change in hazardous area classification, different fuel nozzle design, heat of combustion temperature issues and thermal efficiency. Fuel cells are around 94% efficient while the best practical combined cycle is around 55%.

If you have hydrogen, the best and most efficient way to turn that into electricity is a fuel cell.

The issue is always, where do you get the H2?

If you have CH4, the most efficient way to convert that to electricity is a combined cycle gas turbine. By the time you get it to hydrogen, you will have lost a bunch of the energy, even with going to a fuel cell.

[RWebb]

you get the H2 by splitting water

you split the water with electricity from your PV farm

- that's the dream; maybe only a dream too

[pmax]

https://www.caranddriver.com/news/a29581764/toyota-2021-mirai-cow-manure-hydrogen

The splashy Mirai could be powered for a year from hydrogen from a single cow's manure.

Toyota has been interested in cow manure for several years. In 2017, the Japanese company announced with Shell that they were building a powerplant in Long Beach, California, that would capture methane gas from dairy cattle manure and convert it into water, electricity, and hydrogen. The companies went ahead with their project, called Tri-Gen, as a "hydrogen-truck refueling station" in 2018.

"Toyota continues to demonstrate that fuel cells are one of the most innovative and sustainable technologies for light and heavy-duty vehicle electrification. This initiative with Shell further strengthens our combined commitment to hydrogen as a viable transport fuel," said Craig Scott, Toyota’s director of advanced technology vehicles, at the time.

[red-beard]

We were looking at doing this the above with landfill gas. But with the way things are in California right now, dairy is the way to go.