The Green Hydrogen Problem That No One Is Talking About

[Jay McKinsey + 1,489]

5 minutes ago, Jan van Eck said:

that is when you use a stock engine block and retrofit the air intake to inject H2 gas.  You need to get the air:fuel ratio down to 180:1 in order to wrest the maximum benefit from the engine.  To do that, the engine needs to be purpose-built, a new design, which at least two companies are doing right now.  Then the NOx drops to below 1 ppm.  

Do remember that the auto-ignition temperature of  Hydrogen gas is 500 C. Octane, or C8H18, is somewhere around 1980 C.  When you use a spark ignition and you run below 500 C you are running a cool engine, one that will need supplemental heat in order to heat the cabin with the circulating fluid. With a cool engine and a low flow rate of the H2, the N2 gas in the atmosphere will flow through the engine unaffected by the combustion of the H2. 

If you have a high capital investment in the machinery to build a conventional engine and you want to change the fuel, then adding on some bolt-on features to inject the H2 into the inflow air stream is the low-cost way to go.  A lot cheaper than building a fresh engine from scratch.  And no, the production requirements are just not there to mandate investment in a new engine and block. So it does not get done, at least not by Mazda. 

But how far below 1ppm? The standard is 0.053ppm.

EPA has established National Ambient Air Quality Standards (NAAQS) for NO2 and tropospheric ozone. The NAAQS define levels of air quality that are necessary, with a reasonable margin of safety, to protect public health (primary standard) and public welfare (secondary standard) from any known or anticipated adverse effects of pollution. The primary and secondary standard for NO2 is 0.053 parts per million (ppm) (100 micrograms per cubic meter), annual arithmetic mean concentration.

https://www3.epa.gov/ttncatc1/dir1/fnoxdoc.pdf

[frankfurter + 562]

good info, re NO.  well, I have met a couple of Mazda engineers in Japan. very, very bright people. I expect they will solve the NO problem, if they have not solved already. the combination of a hydrogen fueled rotary with battery for a hybrid car for consumers could be a winner. let's see.

[Jay McKinsey + 1,489]

15 minutes ago, frankfurter said:

good info, re NO.  well, I have met a couple of Mazda engineers in Japan. very, very bright people. I expect they will solve the NO problem, if they have not solved already. the combination of a hydrogen fueled rotary with battery for a hybrid car for consumers could be a winner. let's see.

Reading up on it and it looks like Mazda stopped working on it 10 years ago. They just announced this as their next rotary:

Mazda, the small Japanese carmaker with over 50 years of rotary engine experience, has just announced that those legendary rotors will return in range-extenders for its 2022 MX-30 electric cars. 

https://www.thedrive.com/news/36961/mazda-is-really-actually-bringing-back-the-rotary-engine-as-an-ev-range-extender-for-real

[Rob Kramer + 696]

1 hour ago, Jay McKinsey said:

Reading up on it and it looks like Mazda stopped working on it 10 years ago. They just announced this as their next rotary:

Mazda, the small Japanese carmaker with over 50 years of rotary engine experience, has just announced that those legendary rotors will return in range-extenders for its 2022 MX-30 electric cars. 

https://www.thedrive.com/news/36961/mazda-is-really-actually-bringing-back-the-rotary-engine-as-an-ev-range-extender-for-real

This is a cool convo you guys have going! I think they are using the rotary engine for its size to power. Also it has low life span in hrs but not in rotation from what I'm told so high rpm is better (more power per size is better) and it's closer to a 2 stroke so that doubles power to friction.  As for the hydrogen you need clarity on what the fuel is. Theres H + air, H+O , H+O+air. Temperature + air is the NOx maker. I was always on the limit at e test with a mazda mx6 I had but with the high compression Japanese engine (klze 2.6L v6 200hp NA) running on the north American KL 164hp engines' computer. Aka leaner + higher compression. But I always wanted to make a Hydrogen hybrid .... make a battery pack and electrolysis system to make browns gas out of distilled water. Make it at the engine compartment so no boom of ever an error. Charge batteries over night. Small ammounts of browns gas speeds up combustion sometimes you get a few points more efficient. And finally cat converters. You can add air injection to an exhaust (or pure oxygen if you have a supply on board) . That may help to make what your looking for without engine redesign.  

[Enthalpic + 1,496]

On 10/30/2020 at 11:25 AM, Jan van Eck said:

 

No.  You get water in vapor form, not as steam. 

LOL

Leave chemistry to those with a clue.

Edited November 1, 2020 by Enthalpic

[Jan van Eck + 7,558]

2 hours ago, Enthalpic said:

LOL

Leave chemistry to those with a clue.

What an idiot.  Vapor is not steam. 

[Enthalpic + 1,496]

1 hour ago, Jan van Eck said:

What an idiot.  Vapor is not steam. 

Steam is water in the gas phase.

You are thinking of condensation / clouds / mist /  "wet steam."

Edited November 1, 2020 by Enthalpic

[Jan van Eck + 7,558]

14 hours ago, Enthalpic said:

Steam is water in the gas phase.

You are thinking of condensation / clouds / mist /  "wet steam."

More rubbish.   The gas phase of water is not the same as the vapor phase of water.  Vapor can be formed even from the solid state, ice, by sublimation.  Vapor cannot do any Work in that it has no retained latent heat.  Steam does.  Vapor can exist as low as -20C, indeed lower if you get the pressure down far enoough.  If you eject water from an orbiting satellite it will flash over to vapor, unable to do any work,  It is not steam.   Please don't post rubbish on this Forum. 

[Enthalpic + 1,496]

2 hours ago, Jan van Eck said:

More rubbish.   The gas phase of water is not the same as the vapor phase of water.  Vapor can be formed even from the solid state, ice, by sublimation.  Vapor cannot do any Work in that it has no retained latent heat.  Steam does.  Vapor can exist as low as -20C, indeed lower if you get the pressure down far enoough.  If you eject water from an orbiting satellite it will flash over to vapor, unable to do any work,  It is not steam.   Please don't post rubbish on this Forum. 

Water vapour has the heat of vaporization, it releases a lot of energy upon condensation.

You do not really understand kinetic molecular theory.  Temperature is a measure of the average kinetic energy of the system, some molecules will have a lot more energy than average.  Some fraction will have so much energy that they can break free from the liquid and evaporate / boil.

So yes, even at low temperatures some of the water molecules are energetic enough to "boil off" / evaporate.  When a high energy molecule escapes the remaining water is now cooler (evaporative cooling). The high energy particle that escapes will increase the temperature of whatever it hits which absolutely could be used to perform work.

Anyways, regardless of your opinion H2O(g) is referred to as steam.

 

[Jan van Eck + 7,558]

53 minutes ago, Enthalpic said:

Water vapour has the heat of vaporization, it releases a lot of energy upon condensation.

By this standard, the Canadian Pacific Railway will be building monster vapor locomotives, the vapor scooped off the frozen surface of Lake Superior by gigantic vacuum cleaners, then to be stored in that reconditioned boiler package.  Toss on a condenser on the piston exhaust pipe and off you go, using all that heat of vaporization in there.  Should be good for 4,250 HP.  Ooh-rah!

[Enthalpic + 1,496]

3 minutes ago, Jan van Eck said:

By this standard, the Canadian Pacific Railway will be building monster vapor locomotives, the vapor scooped off the frozen surface of Lake Superior by gigantic vacuum cleaners, then to be stored in that reconditioned boiler package.  Toss on a condenser on the piston exhaust pipe and off you go, using all that heat of vaporization in there.  Should be good for 4,250 HP.  Ooh-rah!

I never said humidity is a useful energy source.

Still, on a cool morning when H2O(g) condenses to form a H2O(l) dew droplet it does warm the local system by a small amount.  Water vapour is "steam" when you do energy balancing.  Anyone who has suffered on a sweltering summer day knows "It's not the heat it's the humidity!"

 

[Enthalpic + 1,496]

If you don't think water vapour can carry a scary amount of work energy you have never seen the damage from a tornado or hurricane.  All the water vapour is well below 100C and yet releases devastating damage upon condensation.

 

[footeab@yahoo.com + 2,132]

On 11/1/2020 at 9:05 PM, Enthalpic said:

I never said humidity is a useful energy source.

Still, on a cool morning when H2O(g) condenses to form a H2O(l) dew droplet it does warm the local system by a small amount.  Water vapour is "steam" when you do energy balancing.  Anyone who has suffered on a sweltering summer day knows "It's not the heat it's the humidity!"

 

Yes, you did.  Open a damned Thermodynamics book.  The equations are simple easy Jr. High Algebra. 

[Enthalpic + 1,496]

4 hours ago, footeab@yahoo.com said:

Yes, you did.  Open a damned Thermodynamics book.  The equations are simple easy Jr. High Algebra. 

I said it contains energy, I didn't say it was particularly a useful source.  Just because it is extremely difficult to generate a significant amount of power doesn't mean it is not present.

Look up how a simple hygrometer works... a humidity change physically moves a part (work was done).

 

I can tell you have not taken even moderately advanced thermodynamics, which I have, if you think the math stops at simple junior high algebra.  Numerous calculus courses are prerequisites. Unlike you, I actually have books on thermodynamics and could show you some of the math.

 

We can continue your education if you want to get more complicated (more details on enthalpy, entropy, Gibbs energy, equilibrium, and kinetics).

 

 

[Enthalpic + 1,496]

50 µW Humidity motor

[Enthalpic + 1,496]

@Jan van Eck you educated enough?