Methanol - H fuel cells for marine transport

[BWV]

This privately held company developed a technology to extract H from methanol stored onboard marine craft, then the H can be used in a fuel cell for power. I assume the reason for a H fuel cell vs a direct methanol fuel cell (DMFC) in a marine vessel is that direct methanol cannot deliver large enough amounts of power needed. DMFCs can provide low wattages over long periods but cannot deliver the large bursts of power needed to accelerate a vehicle like a tow boat, whereas an H fuel cell could. Methanol is easier to produce, store and transport than H and can use existing infrastructure. The process can be made carbon neutral through the use of either e-methanol or bio-methanol

thoughts?

https://www.e1marine.com/technology

 

[tech99]

How does the fuel cell compare with burning the methanol in an IC engine?

 

[BWV]

How does the fuel cell compare with burning the methanol in an IC engine?

A related issue, but electric motors are around 2x as efficient in converting the iput to mechanical energy as ICEs. So there is a large cushion there for some inefficiencies in creating the electrical energy

 

[russ_watters]

The website is flashy but it's hard to find substance in it. The details are what matter, not the platitudes.

• Where does the methanol come from? Google tells me most of it in the US comes from natural gas. Is this just a convoluted natural gas fuel cell marketed as "Hydrogen!"?
• Does the water need to be distilled before use?
• What is the total cycle and fuel cell efficiency?

 

[BWV]

The website is flashy but it's hard to find substance in it. The details are what matter, not the platitudes.

• Where does the methanol come from? Google tells me most of it in the US comes from natural gas. Is this just a convoluted natural gas fuel cell marketed as "Hydrogen!"?
• Does the water need to be distilled before use?
• What is the total cycle and fuel cell efficiency?

I’m sure the economics are better for methanol from nat gas rather than the green sources above, but in that case is it still potentially better than diesel from an emissions standpoint and competitive economically?

 

[russ_watters]

I’m sure the economics are better for methanol from nat gas rather than the green sources above, but in that case is it still potentially better than diesel from an emissions standpoint and competitive economically?

I don't think there's any way to know if they don't tell us in detail what they are doing. But I think it is unlikely. A direct natural gas ICE is better than diesel, but here we're talking about a lot of intermediate steps with costs and efficiency losses. Natural gas and natural gas -> hydrogen fuel cells have not caught on for exactly that reason.

 

[anorlunda]

I assume the reason for a H fuel cell vs a direct methanol fuel cell (DMFC) in a marine vessel is that direct methanol cannot deliver large enough amounts of power needed.

What is the foundation for that assertion?

The article you link says that you start with methane, the outputs are some mechanical power and CO2 emissions to the atmosphere. That's the same as direct burning of methane.

How is that more green than direct burning of methane?
How is that more efficient than direct burning of methane?

It is certainly more complex, and thus necessarily less reliable than traditional power plants.

If there are advantages to this new system, they must be spelled out in much more detail.

 

[BWV]

What is the foundation for that assertion?

did not think that was controversial - ICEs lose far more energy to heat than electric motors

Electric motors makes vehicles substantially more efficient than internal combustion engines (ICEs). Electric motors convert over 85 percent of electrical energy into mechanical energy, or motion, compared to less than 40 percent for a gas combustion engine.

https://www.nrdc.org/experts/madhur...les substantially,for a gas combustion engine.

 

[russ_watters]

The article you link says that you start with methane, the outputs are some mechanical power and CO2 emissions to the atmosphere. That's the same as direct burning of methane.

How is that more green than direct burning of methane?
How is that more efficient than direct burning of methane?

Not methane, methanol. That's the big catch: it assumes a green/carbon neutral source of methanol when in reality the vast majority comes from methane. So *if* there is green methanol then it offers a carbon benefit. If it comes from methane, then it's probably not better than just burning the methane in the first place.

 

[russ_watters]

did not think that was controversial - ICEs lose far more energy to heat than electric motors

That in itself is not controversial, what's controversial is the validity of the comparison because electricity is not a primary energy source. You're skipping/omitting other energy conversion processes. Consider the following systems (#4 is what is described in the website I think):

1. Methane ICE -> Gearbox -> Wheels (or propeller)
2. Methane ICE -> Generator -> Motor -> Wheels (direct drive)
3. Methane Fuel Cell -> Motor -> Wheels
4. Methane to Methanol Reformer -> H2 Reformer -> Fuel Cell -> Motor -> Wheels

You're comparing only one energy conversion step for each process when in reality there are 2-5 of them. Just because Process 1 of System 1 is less efficient than Process 4 of System 4, that doesn't mean System will be more efficient overall than System 1. We need to know all the other process efficiencies.

 

[BWV]

That in itself is not controversial, what's controversial is the validity of the comparison because electricity is not a primary energy source. You're skipping/omitting other energy conversion processes. Consider the following systems (#4 is what is described in the website I think):

1. Methane ICE -> Gearbox -> Wheels (or propeller)
2. Methane ICE -> Generator -> Motor -> Wheels (direct drive)
3. Methane Fuel Cell -> Motor -> Wheels
4. Methane to Methanol Reformer -> H2 Reformer -> Fuel Cell -> Motor -> Wheels

You're comparing only one energy conversion step for each process when in reality there are 2-5 of them. Just because Process 1 of System 1 is less efficient than Process 4 of System 4, that doesn't mean System will be more efficient overall than System 1. We need to know all the other process efficiencies.

Yes, that is what I addressed in #3 -by mentioning a 'large cushion there for some inefficiencies in creating the electrical energy'.

This math does work, for example in my plug-in Hybrid car, where the I get ~40MPG in city driving burning gas to generate electricity for the electric motor (but there are other systems like braking to capture energy that may not have analogs in a boat)

 

[anorlunda]

The OP does not mention ICEs. So that is not necessarily the standard of comparison. External combustion is another possibility.

 

[BWV]

The OP does not mention ICEs. So that is not necessarily the standard of comparison. External combustion is another possibility.

Sorry, just realized I answered the wrong question from you, you were asking about the foundation on DMFCs not generating enough power relative to H fuel cells, just took that from the Wikipedia article on DMFCs:

Application[edit]​

Current DMFCs are limited in the power they can produce, but can still store a high energy content in a small space. This means they can produce a small amount of power over a long period of time. This makes them ill-suited for powering large vehicles (at least directly), but ideal for smaller vehicles such as forklifts and tuggers[10] and consumer goods such as mobile phones, digital cameras or laptops. Military applications of DMFCs are an emerging application since they have low noise and thermal signatures and no toxic effluent. These applications include power for man-portable tactical equipment, battery chargers, and autonomous power for test and training instrumentation. Units are available with power outputs between 25 watts and 5 kilowatts with durations up to 100 hours between refuelings. Especially for power output up to 0.3 kW the DMFC is suitable. For a power output of more than 0.3 kW the indirect methanol fuel cell presents a higher efficiency and is more cost-efficient.[11] Freezing of the liquid methanol-water mixture in the stack at low ambient temperature can be problematic for the membrane of DMFC (in contrast to indirect methanol fuel cell).

 

[russ_watters]

The OP does not mention ICEs. So that is not necessarily the standard of comparison.

I'm comparing it to what powers normal ships, which is ICEs. It has to show it's better than that.

External combustion is another possibility.

What is that?

 

[russ_watters]

This math does work, for example in my plug-in Hybrid car, where the I get ~40MPG in city driving burning gas to generate electricity for the electric motor

Sometimes the math works. Hybrid cars are more efficient than direct ICEs especially in city driving because that's an extremely inefficient way to run an ICE. For highway driving a hybrid is worse than an ICE. A ship is more like a highway-driving car than a city-driving car.

 

[BWV]

Sometimes the math works. Hybrid cars are more efficient than direct ICEs especially in city driving because that's an extremely inefficient way to run an ICE. For highway driving a hybrid is worse than an ICE. A ship is more like a highway-driving car than a city-driving car.

for highway driving, still get 40MPG, a Honda Accord (my car is a Clarity, which slightly larger) gets 38 MPG hwy

 

[russ_watters]

for highway driving, still get 40MPG, a Honda Accord (my car is a Clarity, which slightly larger) gets 38 MPG hwy

The Accord is a different car with a different engine, and I'd expect your car runs direct ICE->wheels on the highway. Frankly, the difference is disappointing given the compromises/efficiency enhancements.

 

[anorlunda]

I'm comparing it to what powers normal ships, which is ICEs. It has to show it's better than that.

What is that?

For example, a boiler and a steam turbine. Or more modern, gas turbine, boiler, steam turbine, up to 60% thermal efficiency to make electricity. On huge ships, size is less of a constraint.

The biggest thing done recently to improve the efficiency of merchant ships is to reduce the speed. If they average 5 knots rather than 18 knots, it is much more fuel efficient. At the slow speeds, supplemental sails also become more attractive.

There's another surprising trend. The economics of container ships say the larger the betters. But there are shortages of steel to make them. So fleet owners are finding it profitable to scrap 4 existing vessels, even if they not very old, and to use the scrap steel to build a single supersized ship.

 

[russ_watters]

For example, a boiler and a steam turbine. Or more modern, gas turbine, boiler, steam turbine, up to 60% thermal efficiency to make electricity. On huge ships, size is less of a constraint.

Ok, yeah, I blanked on what "external combustion" meant, lol.

Google tells me plain marine diesels are 60% efficient (not sure if that includes combined-cycle), which is probably why they are favored over conventional boilers these days.

 

[BWV]

ought to be higher priority targets than towboats, which is the focus of the link I posted. In the US the ships burn diesel, not the low grade bunker fuel that powers large ocean vessels. Transporting goods by barge on rivers or intracoastal waterways is inherently far more efficient than truck or rail.

With deepwater vessels, high-sulfer bunker fuel is being phased out with IMO 2020

https://www.reuters.com/article/us-...r-shake-up-for-oil-and-shipping-idUSKCN1SN2BX

Nuclear power would seem to be the best option for containerships and other large vessels, but that aint going to happen

to get an idea of the power involved:

The [Emma Maersk container]ship is powered by a Wartsila Sulzer RTA96-C 14-cylinder diesel engine, the largest single diesel unit in the world. The 2,300t engine delivers a maximum power of 108,920hp at 102rpm and a maximum torque of 5,608,312lb/ft at 102rpm. The engine measures 89ft in length and 44ft in height. Each cylinder displaces 1,820lhp and produces 7,780hp. The total displacement of the cylinders is 25,480l.

https://www.ship-technology.com/projects/emmamaerskcontainers/

there are attempts to supplement with sails

 

[Vanadium 50]

Or more modern, gas turbine

Do container ships use GTs? Or even steam? Thought they wee mostly diesels.

 

[anorlunda]

Do container ships use GTs? Or even steam? Thought they wee mostly diesels.

Yes they are, but the topic in this thread is looking at alternate propulsion systems. Warships still use turbines. They need more speed.

Transporting goods by barge on rivers or intracoastal waterways is inherently far more efficient than truck or rail.

There have been a couple of pilot projects using towlines attached to apparatus on the river/canal bed to propel barges. That offers the promise of powering them from the grid. Capital costs, I think would not be high. The idea never took off, so no doubt operation/maintenance problems overcame the advantages.

 

[BWV]

There have been a couple of pilot projects using towlines attached to apparatus on the river/canal bed to propel barges. That offers the promise of powering them from the grid. Capital costs, I think would not be high. The idea never took off, so no doubt operation/maintenance problems overcame the advantages.

Limited use though - can't imagine constructing a towline over the navigable length of the Mississippi and its tributaries, our around the gulf intracoastal waterway

The old early-19th century canals did use animal-powered towlines of course

 

[BWV]

That in itself is not controversial, what's controversial is the validity of the comparison because electricity is not a primary energy source. You're skipping/omitting other energy conversion processes. Consider the following systems (#4 is what is described in the website I think):

1. Methane ICE -> Gearbox -> Wheels (or propeller)
2. Methane ICE -> Generator -> Motor -> Wheels (direct drive)
3. Methane Fuel Cell -> Motor -> Wheels
4. Methane to Methanol Reformer -> H2 Reformer -> Fuel Cell -> Motor -> Wheels

You're comparing only one energy conversion step for each process when in reality there are 2-5 of them. Just because Process 1 of System 1 is less efficient than Process 4 of System 4, that doesn't mean System will be more efficient overall than System 1. We need to know all the other process efficiencies.

Trains employ diesel engines to generate electricity for electric motors, there is an efficiency gain in not needing a gearbox, which would also apply to autos. This would be included in the 40% vs 80% efficiency numbers I quoted in ICEs vs EMs. So would the simpler drivetrain of a propeller driven ship make the economics that worked for diesel electric motors in trains long before anyone cared about CO2 not applicable to ships?

 

[anorlunda]

Limited use though - can't imagine constructing a towline over the navigable length of the Mississippi and its tributaries, our around the gulf intracoastal waterway

The fixed components would obviously need to be segmented. With segments, there is no upper limit on total length. Look for videos of the cable cars that carry tourists up the Matterhorn in Italy. It is not one cable. It is several cable segments. Clever mechanisms allow the cars to hop from one segment to the next. In a river system, only the segment under the vessel would be energized.

But there's no need to look deeply into clever designs if it won't be used anyhow.