Toyota Hydrogen

Oil & Coal provided us with a certain lifestyle over generations and most countries managed to grow and developed well with those however bad they turned out to be. My point is will any "new" power for transport or electrical AC selution be feasable in the sense that it would not cripple & bancrupt us eventually in the process trying to achive or keep current lifestyles given the resources available from the planet as a whole. Money the medium we trade with is related deep down to availability of resources where a world power can only be as rich as its ability to aquire resources from over the world and other minor countries as rich as the help they receive in the process. If the relationship between money or any other medium replacing it to resources from Earth like water metals etc and manmade like electricity sources are not cheap, the whole monetary building blocks colapses exponentially over time as everything get loaded in price from the base, so it grinds to a halt as your income gets more but your movement gets less.
Imagine living on an island and you have to come up with everyything without help from outside and you dont have the resources, not much would be able to happen indeed, no matter how intelligent you are or how much money you print...Now at 8 Billion souls the Earth seems to be that Island for most......So as a specie, I feel we must be carefull in our future choices.......The Earth is a closed system to us, and the new bad maybe worse in totality than the old bad at 8 Billion plus......using it.

I watched this video the other day and it rather suggests that not obtaining the majority of our energy needs from the Sun relegates us to being a rather primitive species.

**LINK**

Going back a bit to points about burning hydrogen with air still produces Nitrous Oxides, would engines / exhausts fitted with 'AdBlu' equipment work, as it does with diesels (and I think petrol)?

Good question, Nigel … and I don’t know the answer

This page is one on the more informative that I found: **LINK**

https://www.nationwidefuels.co.uk/oil-guides/adblue-fluid-facts-myths-usage/

Although the second paragraph did make me smile:

”AdBlue is a non-toxic, non-flammable and odourless solution that contains 32.5% of high purity water and 67.5% of deionised water.”

MichaelG.

Edited By Michael Gilligan on 15/06/2023 05:41:26

Michael's last post suggests that AdBlue is just water.

My understanding that AdBlue is merely a trade name for urea, a solution of mouse droppings.

Some engine and vehicle manufacturers have their own brand name for what is effectively the same product.

Water injection, as such was used to reduce tempertaures in the combustion chmamber, when the engine was under heavy load. In otgher instamces it was used so the combustion nheat turned intomsteam which exoanded with the products of combustion and improved engine efficiency. If it did, srely every car manufacturer would mhave include it in the engine specification?

used to excess, water did find its way intomn the sump and emulsified the oil, so not all gain!

Howard

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Only the quoted text, Howard

The technical detail there, and many places elsewhere, states otherwise.

MichaelG.

Thankyou Michael.

An interesting site though one or two parts of it are a bit badly-written.

I see filling-stations are beginning to install bulk AdBlue tanks, at least where they cater for HGVs as well as cars.

.

Sorry Howard but I think you have mis-read the site, and made two mistakes yourself.

Yes, 'AdBlue' is a trade-name, and maybe other brands are available, but I was very surprised to read it is not made in the UK since there is nothing magic about its two chemicals - urea and water. Perhaps other brands, are.

.

No, 'AdBlue' is not "just water", but its description is not very well written, as if its own author has not really understood what the technical people had told him or her; hence the rather confusing percentages.

Read it again and it becomes more clearly a solution of urea in pure water at about 37% to 63% v/v.

.

It is not a "solution of mouse droppings", (your mistake) and urea is not formed in their - and our - bodies' digestive systems (National Fuel's mistake).

Its own name - urea - is a clue. I think urea is a metabolite, one of the by-products or waste products from normal cell function. Those are made in the cells and excreted via the kidneys removing it from the bloodstream.

.

Nor is an AdBlue-catalytic system any sort of water-injection system! Those basically just added water to the fuel; and might have helped the combustion in some old, inherently inefficient engines. Otherwise they were probably no more useful in reality than those fuel-line magnet gadgets; and were soon rejected. Some manufacturers might have claimed water-injection to work as you quote, by conversion to steam, but a simple consideration of the physics shows the flaw.

The site Michael points us to, clearly explains that -

- the urea solution is used in an exhaust catalyser, not the engine;

- it treats the exhaust gases, not the engine's performance.

.

What National Fuels do not tell us, is whether 'AdBlue' also works with petrol and hydrogen, which would both also produce Nitrous Oxide. It may be that it has not been tested properly with these fuels, but I have an idea some petrol-engine exhausts do now use urea-catalyst exhausts.

Good summary, Nigel

One more brief quote from that link, which might be worth investigating:

• Check for “AdBlue according ISO 22241” on the container or dispensing system

… So it appears there is a specific ISO standard available

and indeed there is: 

 https://www.iso.org/obp/ui/#iso:std:iso:22241:-1:ed-2:v1:en

MichaelG.

Edited By Michael Gilligan on 15/06/2023 08:39:23

I can't see why the chemistry wouldn't work on any exhaust gas containing Nitrogen Oxides. The reaction uses Ammonia generated by decomposing the Urea, which isn't ideal, but Urea is an innocuous solid, whereas Ammonia is nasty stuff. It works.

How much NOx is made by an engine depends on what exactly happens during the bang part of 'suck, squeeze, bang, blow'.

The 'bang' is carefully controlled for several reasons.

• Only enough fuel is provided to produce the required amount of energy per stroke. Too much and too little fuel are both bad. The quantity required depends on the load, air temperature, and air pressure, the latter doesn't matter to road cars but is vital to aircraft engines.
• Ideally, the 'bang' is rather slow with the burning gas expanding only as fast as necessary to accelerate the piston, and with the burn ending well before the 'blow'. Fast bangs damage the engine by creating a pressure pulse that shocks the engine rather than smoothly moving the piston.
• The bang has to start at the time. Too early will damage the engine, or it won't run. Too late wastes fuel, reduces power output, increases pollution, and burns the valves.
• The temperature inside the cylinder should not overheat the lubrication or metalwork. If it does, the engine will wear rapidly or seize. Temperature is partly related to the fuel and partly by cooling effects, for example the Nitrogen in air cools IC engines down by absorbing heat in the cylinder.

These factors mean that an IC engine has to be considered as a chemical reactor as well as a simple mechanical device. At all stages - petrol is not a random mix of hydrocarbons - it's carefully purified and blended to burn properly inside IC engines. It contains additives such as Lead Tetraethyl, aromatics, or Ethanol to control 'knock' - premature or high-speed burning. Then the engine alters the fuel-air mix and ignition timing to match the load on the road: older engines crudely, compared with modern ones which have more sensors and a microcontroller. For example, a modern engine might get better performance and fuel economy by advancing the ignition until a knock is detected, and then backing backing off slightly - the burn is controlled dynamically. Very old engines required the driver to adjust ignition manually, not entirely a bad thing, but inconvenient, so most car engines were set to suit average driving. As racing and urban cycle requirements are different, enthusiasts spent many happy hours 'tuning' engines. Modern engines also adjust the burn on the fly to minimise pollution, some car makers getting into deep poo by doing this dishonestly.

Burning oil isn't simple. Maximum energy is achieved by converting all the carbon into Carbon Dioxide, but it turns out to be impractical. The engine performs better if oil is only partly consumed to Carbon Monoxide, and this is achieved by altering the fuel / air mix. Unfortunately, Carbon Monoxide is poisonous, and connecting a hose from the exhaust to the inside of a closed car was once a popular way of voluntarily leaving this cruel world. Modern cars deal with Monoxide and other nasties with a catalyser, which finishes the burn reaction outside the engine.

In a way Hydrogen is just a fuel like any other, but it's not as straightforward as feeding it into an existing IC engine. (Filling a diesel car with petrol doesn't go well either!) The control parameters have to be rethought. Hydrogen burning at a higher temperature than petrol is likely to create more NOx than a petrol engine would, but maybe less than a high-compression diesel. Might be possible engineer the engine to consume NOx inside the cylinder, or it might be easier to process it with something like AdBlue on the way out. No catalyser needed to clean up Carbon Monoxide and mangled Hydrocarbons though - the main output of a Hydrogen IC engine is water.

Other problems might stop Hydrogen vehicles becoming common, but I don't think pollution is a blocker.

Dave

Does modern unleaded petrol really contain lead? You can't buy leaded petrol in any of my local service stations.

No. As I read it; Dave gave three options for controlling 'knock', one of which was a lead containing chemical.

I think leaded petrol might still be available for old piston aircraft engines?, but no longer used for road vehicles, owing to its toxicity.

A good thing no doubt.

**LINK**

Yes, Standard "100LL" aviation gasoline still has lots of lead in it dispite the LL meaning low lead

There is a recent lead free alternative but not approved for many engines and not widely available.

So if cars can have hard valve seats fitted to cope with unleaded why not puddle jumpers?

Paperwork.

Doing the modification is easy. Proving it hasn't reduced reliability and safety is another thing altogether. It is not helped by the fact that these are typically 60 year old designs and the currrent design certificate holders have little or no incentive to support the change.

Robert.

Yes. Aircraft certification is cubicly expensive. Which is one reason why some aircraft have very old instrumentation, and manual engine controls, e.g. air fuel mixture etc.