Comments by "Tony Wilson" (@tonywilson4713) on "From Zero to Hydrogen: The Future of Clean Energy Flight." video.

Buddy as an aerospace engineer who has spent 30+ years in industrial control systems and automation INCLUDING BEING FORMALLY TRAINED in Electrical Equipment in Hazardous Areas (EEHA) you are completely misunderstanding the nature and risk of hydrogen. Sorry this is long but everyone thinking hydrogen is the magic solution needs to understand that it has some fantastic properties and I really do think it will be a major part of future energy, but it has some very serious risks. I am proposing 2 new massive power station projects here in Australia that are partly fueled by hydrogen BUT and I can't stress enough how hard hydrogen is to engineer around. Your comment comparing kerosene to hydrogen is so far off the mark its scary. In terms of safety Hydrogen is nothing like kerosene. If I compared your skills and training as an airline pilot to a bus driver in the same way you have compared Hydrogen to Kerosene you'd be insulted. I have a pilots license so I know what that means. Here are some basic facts that they teach engineers. 1) You need 3 things to have combustion or an explosion which is basically hyper-rapid combustion. FUEL + OXIDISER + IGNITION SOURCE. Fuel alone does nothing. Fuel with just an ignition source does nothing. Fuel with just an oxidiser does nothing. You must have all 3. The reason solid rocket propellants like gunpowder & C4 explosive can be so dangerous is because they combine the fuel and oxidiser. Its why they are impossible to extinguish once ignited. Once the Space Shuttle and Artemis boosters are lit they will go until the fuel is consumed. All that can be done is detach them. 2) Flammable liquids DO NOT actually burn or ignite. The vapor above the surface burns. There's videos shown to engineering students where they drop a lit match into a jar of gasoline and it just goes out because below the surface there's no oxygen. This is also why cars don't explode when the fuel tank has a submerged pump. Because its submerged and totally surrounded by fuel there's no oxygen. Its also why cars can explode if the fuel level sensor gets a shot circuit because you can get a spark in the vapor space above the fuel level. Its why empty fuel tanks with vapor are far more dangerous than full fuel tanks where there's almost no vapor. 3) A droplet of liquid fuel does NOT BURN its surface burns because the heat boils off the liquid and that allows it to mix with air and meet oxygen molecules and react. This is why fuel injection in cars and trucks works so much better than a carburetor. There's not only finer droplets with more surface area but the droplet size is more consistent making combustion more stable and more reliable. 4) Gases and vapors at the right mixture can EXPLODE. For almost any gas you can find 2 numbers given in percentage called the LEL (lower explosive limit) and UEL (upper explosive limit). Between the LEL and UEL the mixture explodes. In room temperature air: - Methane has an LEL of 5% and UEL of 15% - Hydrogen has an LEL of 4% and UEL of 74% So hydrogen wants to EXPLODE over a much wider range of fuel-air ratios. This is also why its been so hard to get it to burn reliably in engines. It reacts so fast its hard to get a stable flame. 5) Everything that can burn or explode has an ignition energy usually expressed as MIE (minimum ignition energy) with the units mJ (milli-joules). Hydrogen has the lowest of all MIEs at 0.017 mJ (in air) and 0.011 mJ (in oxygen). By comparison methane 0.26mJ gasoline is 0.80 mJ and Kerosene is 20 mJ. Kerosene takes just over 1176 times the energy to ignite than hydrogen. A kerosene leak compared to a hydrogen leak is nothing in terms of risk. 6) Many gases and flammable substances can ignite from temperature. Again Hydrogen is very low on that scale compared to most other substances. When you select equipment that is in a area with hydrogen you have to check the temperature rating as well as all the other factors. 7) The Hydrogen molecule is the smallest molecule in the universe. That makes sealing everything incredibly hard. You can't just by valves, pistons, pumps, pipe fittings like you do for other gases. It will leak from the tiniest of holes and narrowest of gaps. If you have any leak in a place that's not well ventilated it gets very dangerous. Hydrogen is amazing. Its actually very easy to make through electrolysis of water, but its also a hassle to use which is why its never really been used as much as people think it should have been. Sorry if this feels like I am yelling but its a very serious topic. I 100% believe the hydrogen economy is going to boom and be a major part of our energy future, but I also expect some tragic outcomes because people will simply ignore what people with expertise warn them about.
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@مرحبابك-ض1ن Please look at my other comment because you've set your reply function right to left and its almost impossible to reply
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On the capturing CO2 from the atmosphere its all dependent on how its done. I'm an engineer and the major problem we collectively isn't so much we are having to transfer from dirty to clean energy, its that we are at the next great energy transition. Just as we moved on from horse & sail to coal & steam then onto oil & gas and then 1/2 way to nuclear, we are now at the next great energy transition. Its being heavily influenced by the need for clean energy but we'd be making a transition anyway. The single biggest factor is efficiency. We have more people and that means more energy is needed but that actual supply of raw materials isn't keeping up. I'm in Australia and we had a power station called Hazelwood. It was old an dirty, but worst of all was its was hopelessly inefficient. Most coal fired power stations could get about 30-35% efficiency with the very best ones with advanced boiler technology could get over 42% thermal efficiency. When it closed Hazelwood was getting about 20% thermal efficiency. So it was burning twice as much coal per watt of electricity. Hazelwood was closed NOT because it worked but because it was so inefficient. Right now we have another power station at Newport which is an old gas thermal. If we simply replace it with a gas turbine we can save about 30% on raw gas input. If we add a steam turbine to the exhaust we can increase the power output by 60%. If we then added a hydrogen supply we'd reduce the emissions by another 50% down to 30% of where it now is. This is actually a hard thing to discuss with non-engineers. If you are not being efficient with energy then ANYTHING can be insanely expensive. Also some things that look or sound inefficient aren't when you take into consideration of the overall system efficiency. With direct CO2 extraction a lot will depend on where they get the energy from and then how they use it. I think the real problem with it will be that it just can't do enough. When you look at how much needs doing the real problem is being able to do in engineering what green vegetation does already. I think it will end up with systems that blend what we can do in engineering with what we can do with plants.
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