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Fool cells and laughing gas

Fool cells and laughing gas

The heading is click bait. I reserve the right / write to change it.
I have this new ability to post, to create new topics....thanks Tesla.
OK, I was only down for a few hours but your generosity of spirit in showing me how to regain my privileges has resulted in net gain for you.( :) )

This is a topic about Fuel Cells.
How much do we actually know?
Below is the current (pun) extract from Wikipedia about hydrogen fuel cells.

Do we know of any fires, any risks qualified, any dangers proven?
I am amongst the first to reject H2 as a car fuel, but what do I know?

If you know of the expected risks of fire, accident, tank ruptures, expllllosions, please speak up.
We are all effectively early adopters here, but we do have and show our preferences.

In the spirit of the scientific principle, do we have evidence, and can/ will it be replicated?

Fuel cell
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For other uses, see Fuel cell (disambiguation).

Demonstration model of a direct-methanol fuel cell. The actual fuel cell stack is the layered cube shape in the center of the image

Scheme of a proton-conducting fuel cell
A fuel cell is an electrochemical cell that converts the potential energy from a fuel into electricity through an electrochemical reaction of hydrogen fuel with oxygen or another oxidizing agent.[1] Fuel cells are different from batteries in requiring a continuous source of fuel and oxygen (usually from air) to sustain the chemical reaction, whereas in a battery the chemical energy comes from chemicals already present in the battery. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied.

The first fuel cells were invented in 1838. The first commercial use of fuel cells came more than a century later in NASA space programs to generate power for satellites and space capsules. Since then, fuel cells have been used in many other applications. Fuel cells are used for primary and backup power for commercial, industrial and residential buildings and in remote or inaccessible areas. They are also used to power fuel cell vehicles, including forklifts, automobiles, buses, boats, motorcycles and submarines.

There are many types of fuel cells, but they all consist of an anode, a cathode, and an electrolyte that allows positively charged hydrogen ions (protons) to move between the two sides of the fuel cell. At the anode a catalyst causes the fuel to undergo oxidation reactions that generate protons (positively charged hydrogen ions) and electrons. The protons flow from the anode to the cathode through the electrolyte after the reaction. At the same time, electrons are drawn from the anode to the cathode through an external circuit, producing direct current electricity. At the cathode, another catalyst causes hydrogen ions, electrons, and oxygen to react, forming water. Fuel cells are classified by the type of electrolyte they use and by the difference in startup time ranging from 1 second for proton exchange membrane fuel cells (PEM fuel cells, or PEMFC) to 10 minutes for solid oxide fuel cells (SOFC). A related technology is flow batteries, in which the fuel can be regenerated by recharging. Individual fuel cells produce relatively small electrical potentials, about 0.7 volts, so cells are "stacked", or placed in series, to create sufficient voltage to meet an application's requirements.[2] In addition to electricity, fuel cells produce water, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions. The energy efficiency of a fuel cell is generally between 40–60%; however, if waste heat is captured in a cogeneration scheme, efficiencies up to 85% can be obtained.

The fuel cell market is growing, and in 2013 Pike Research estimated that the stationary fuel cell market will reach 50 GW by 2020.[3]

reed_lewis | 2019年3月22日

The cost to produce the hydrogen for a fuel cell is many times the amount of energy you get out of the fuel cell.

With a BEV, if you put 50 kWh into the battery, you can get almost 50 kWh out of the battery. With a fuel cell, it takes on average about 200 kWh of power to get 50 kWh out of the fuel cell considering production, shipping, etc. costs.

So a fuel cell just does not make any sense.

DonS | 2019年3月22日

The attractiveness of hydrogen is that it can be stored and moved similarly to gasoline or natural gas. Ultimately, it is all about cost, and batteries have the upper hand today.

Batteries need to improve the energy density per weight to take over transportation. Hydrogen needs to reduce the cost of production (and cannot depend on fossil fuel extraction) to gain on batteries.

There is a lot of money being spent in research, so the long term outcome is yet undecided.

Earl and Nagin ... | 2019年3月22日

@Ross1,
I'm not a Fool Sell expert but I have worked peripherally with them in a past life. Here are my first hand impressions:
That's a great technical description of the Fool Sell itself. The Fool Sell will necessarily be quite expensive because controlling the proton flow across the catalyst plate is fairly complex since the temperatures and pressures need to be precisely regulated.
However, the Fool Sell itself isn't the only issue. There are a few other issues that are far more pedestrian (hence, of no interest to scientists) that are at least as tough to deal with when trying to actually make a Fool Sell system work:
1) obtaining the H2 - you have to get it from somewhere. Splitting H2 from water, while clean, takes a lot of energy, hence is expensive.
2) containing the H2 - Hydrogen, being the smallest molecule, is pretty tiny. Essentially everything is permeable to it. Its going to leak. This means that unless you're very carefully, you can't easily store it for long times. Since it's explosive, that which leaks out isn't great to have around. Liquid fuels will at least pour on the ground where they are obvious and can be cleaned up. Hydrogen leaks need detectors to find. It isn't so great to park FCEVs in garages or other places where you don't want H2 to accumulate.
3) transferring the H2 - like with CNG, transferring a gas from a storage tank to your car's fuel tank isn't as easy as pouring a liquid. Chinks in the nozzle caused by dropping will be problemmatic. Regular inspections will be necessary.
4) carbon gumming up the catalyst - Remember, that, unlike the theoretical description you found. One really uses Air and Hydrogen, not Oxygen and Hydrogen. Air consists of mostly nitrogen (hence the nitrogen dioxide emissions mentioned) but also carbon dioxide (CO2). If one is not careful, the carbon in the CO2 can clog up the membranes. Sure, it might be great if a FCEV is also a CO2 scrubber for the environment but doing it by clogging up platinum catalysts is a bit expensive.
5) freezing of the H2O - as I mentioned in a different thread, that water byproduct of the Fool Sell needs to be handled. There are ways to do so but they take work.
My conclusion:
if one finds a way to obtain, contain, and transfer the H2, then one can burn it in a ICE like any CNG vehicle for a lot cheaper. A hybrid drivetrain brings the efficiency up to fairly close to that of a Fool Sell.
The electrochemists who love selling their Fool Sells should, IMHO, spend their time addressing the mundane plumbing problems and less playing with their fancy anodes, cathodes, and catalysts.
In the mean time, BEV is here, it works great. Let's use it.

SO | 2019年3月23日

@DonS - did can see hydrogen “maybe” working well for cases that absolutely need quick refueling.

But for home use daily driver? No way. EV wins hands down. Battery efficiencies appear to be moving quicker than fuel cells.

carlk | 2019年3月23日

The name "fuel cell" is very misleading. Those who say it will produce only water are just outright lying. Like Earl and Nagin said hydrogen gas is not, and likely will never be able to be, extracted in its natural form. It's nothing more than just an energy strorage medium that need to use a secondary energy source that will generate the same pollution and green house gases. That is true even when electrolysis process is used. However the convertion efficiency is very low and you are wasting about half of the energy and/or produce twice as much green house gases. With BEV advanced to this point there is no foundamental reason to use the fool cell even without considering those engineering challenges. Totally against the first principle. That's why Elon has such a strong opinion of the idea.

Earl and Nagin ... | 2019年3月23日

@carlk,
As mentioned on another thread, there is research looking into whether catalysts can reduce the inefficiencies of electrolysis or enable low-grade waste energy sources to be used. I have not, however, heard of any that ended up actually being viable.
I, for one, have no problem with some modest (hard to quantify and regulate "modest') amount of research money going in to trying to solve the fuel cell challenges. It just should not be used as a reason to NOT support BEVs, nor should people wait for that unobtanium to arrive instead of doing something (BEV) now.

carlk | 2019年3月23日

@Earl and Nagin I have a very different take on this. I do not see a possibility of fuel cell as main stream product at least in our life time. Theory, and imperfect theory, is very far from a practical technology. I'm a trained physicist I've seen too many of this kind of things happening. An example is when I was in graduate school cold fusion was the hottest thing going. You can imagine how attractive that is compares to anything including the fuel cell. I almost choose that as my research field but luckily I did not get in because everyone wants to do that too. There were on and off hopes over the next few decades but it remains an elusive possibility. The point is, borrowing what Elon said about new battery technology, show me the sample not the power point.

Earl and Nagin ... | 2019年3月24日

@carlk,
I, too don't figure it will happen in my lifetime, that's why the "modest' qualification on how much money is devoted to it.
The problem is that when something gets hyped like fuel cells have been (heavily motivated by those who don't want anything to replace ICE), people jump in to the field in hopes of making a living. When that doesn't pan out, especially after wasting one's post-graduate education on it, they get desperate to find any way to make a living and often ethics are compromised. A UC campus near Sacramento, CA has been the poster child for much of this although many other research institutes are also guilty.
Most of the solutions I see to the challenge are in chemistry and materials science, not so much physics. Most chemists with realistic goals, however, have focused on batteries instead of fuel cells. Its nice that Tesla exists to reward work done well.

Roger1 | 2019年3月24日

Battery electric power seems to be the efficient answer to powering personal automobiles and small trucks but semi-trucks, agricultural equipment, and construction equipment could be a different story. Hydrogen fuel cells may have a role to play in these applications.
Equipment standing around fueling does not make money. How long will charging a semi-truck take? If the truck has a megawatt of batteries and a megawatt charger is available then the time to charge is one hour. That's a long time compared to pumping diesel fuel into the tank. Hydrogen could be pumped as quickly as diesel.
Facilities for charging numbers of trucks is also an issue. A truck stop that handles 20 diesel vehicles per hour will need 20 spaces with megawatt chargers and a power grid connection capable of supporting the 20 chargers. How many existing truck stop locations will be able to source the power for truck charging from the existing local power grid. Some locations will require investment in higher capacity transmission lines and transformers. The point is powering trucks is a different issue than personal automobiles.
Consider the same issue with hydrogen powered vehicles. Hydrogen can be delivered in tank trucks and stored in underground tanks just like diesel. The safety considerations will be different than liquid fuel. Hydrogen has the advantage that it is lighter than air and will drift upward when released rather than pooling on the ground in low places like propane. Transferring hydrogen to a truck will require less equipment investment because the dwell time for the truck at each 'pump' will be much shorter than at an electric charging station.
The argument against hydrogen is rightly focused on power efficiency. Power is lost in electrolysis of water, compressing the gas, transportation and conversion to electricity in the fuel cell. Even with these losses, the real question is how much does it cost to move some quantity of freight over some unit distance. The price of electricity to make hydrogen is a key factor.
Hydrogen production provides a storage medium for power from wind farms and photovoltaics with variable output and base load nuclear during overnight hours. Wind power is said to be cheaper than conventional coal plants. The price for hydrogen will depend on the source of electricity and the flexibility of the hydrogen production facility to expand or contract production depending on the price of electricity.
Agricultural and construction equipment is often refueled in the field. Hydrogen delivery by truck is feasible but battery recharging is not as substantial cost would be incurred to develop a charging facility onsite.
These are a few ideas to consider when discussing hydrogen fuel cells. More than one solution will be needed to power electric vehicles and equipment.

TeslaTap.com | 2019年3月25日

@Roger1 - I politely disagree with H2 for truckers. It's far from clear that Hydrogen can be pumped as quickly as diesel. There there is the cost of fueling stations. So far $1-2M each for 1 stall - which can service one car per hour (it requires a long repressurinazion cycle between fillings). In fact to fill a much larger tank on a truck, it may take hours before the next truck can charge. Can be solved by many more filling stations, but the infrastructure costs rise dramatically. Whos going to pay the needed billions to make the needed stations? The truckers? The shipping companies? The government?

Costs for adding MW charging system is a small fraction of H2 per stall. Yes, there might be some locations that don't have enough power, but most do. For those with less power, it can often be solved with on-site battery storage, but this does increase the costs.

TeslaTap.com | 2019年3月25日

hen the entire idea is for trucks to charge while the truck is being loaded/unloaded. In this situation, it takes 5 seconds or so to connect and disconnect. Far faster than using H2 or diesel! The charging time is not so important, as often it takes 30 minutes or more to load/unload a truck, and with Mega chargers can provide 400-500 miles of range in 30 minutes - but the trucker can be doing other things (loading/unloading/eating/sleeping), etc. while this is happening - no need to wait in line, then fill up taking 15+ minutes fueling diesel.

I'm sure there are pockets of applications where diesel may work better, but see zero value in H2 over diesel. H2 has no real infrastructure and causes the same amount of pollution as diesel. The costs for H2 much more than electric or diesel - which for cost sensitive truckers totally kills any desire for H2. The final nail-in-the-coffin of H2 is the cost to make a H2 truck is 2x or more than either an EV or diesel truck. Who's go to buy these when H2 provide zero benefits and a lot of costly drawbacks.

finman100 | 2019年3月25日

we still want to waste the extra energy to use hydrogen versus putting that same energy into a battery? It's like one-third! Why, again? Why are we STILL fighting physics...and math? and the cost? makes zero sense.

Maybe Mars will have different laws of physics and fuzzier math. i doubt it.

Earl and Nagin ... | 2019年3月25日

Most likely, there will be places where batteries are less optimal than liquid fuels used today. However, I assume that despite the fact that we all like to be contrarians and look for the places where batteries won't work, it seems likely that those places will be few and far between. In those rare instances, should we need a sustainable source of fuel, rather than going to all of the complexities of creating a whole new vehicle fleet and infrastructure based on Hydrogen, we can always just use bio-diesel or, probably simpler; just burn vegetable oil in an existing diesel. While that fad from a while ago proved to not be economical compared with dino-diesel or gasoline for all users, it looks to be a lot more cost effective than Hydrogen. Perhaps it will work for those few applications where batteries absolutely won't work.
Remember how the farmers hated to give up their mules, horses, and oxen because the steam and gasoline tractors required them to buy fuel? That's ok I don't remember either but my Grandfather did :-)
A big challenge with truckstops today is finding enough places to park then while the truckers get their mandated rest periods. I believe there is plenty of time to Megacharge a truck during those breaks.
Sure, farmers truck diesel out to the fields to fill their harvesters in the field. However: how many of those fields have a power line near them? How many would have a power line near then if electricity was a lot cheaper than diesel or they had a wind turbine that also brought in extra revenue?