Just like the "water carburetor" and other miracles that never materialized, the problem is that the alternative is cheaper and simpler (which means cheaper).
It doesn't sound expensive to add water injection to an internal combustion engine, until you have to make it work in production, with end users.
YOU can make it work, because you are motivated, but what about the guy who buys it because it's cool and then forgets to fill the system. Sure it's easy to add programming to work around this condition, but is it easy to integrate and test?
Anyway, crude oil is very, very cheap, and very easy to integrate into a production process. Waste plastic in the recycling stream is dirty and heterogeneous in composition and size, which makes it hard to integrate into a production process. Not impossible, but more expensive, which means that no one will do it without outside compulsion (and maybe not even then).
> It doesn't sound expensive to add water injection to an internal combustion engine, until you have to make it work in production, with end users.
Water / methanol injection was commonly used on various piston engine aircraft in the 1940's. It had several benefits, cooling the input air, preventing pre-detonation at high compression (due to lower octane fuel in some cases), lowering the combustion temperature, and such. It was practical and worked fine for high-performance aircraft, that saw regular maintenance after every flight.
It doesn't seem very necessary or practical for a ground vehicle though.
Yeah, water/meth injection is pretty common mod for forced induction cars to squeeze some more air in there without causing detonation. People often just tap the windshield washer reservoir and use that to hold the meth, since windshield wiper fluid is a more diluted methanol mix you can still use it for your windshield. I personally don't run it because running out of meth on a vehicle that is tuned for it can have disastrous consequences.
It _is_ practical for cars, but a similar technology is easier and better: Exhaust Gas Recirculation.
The problem of water injection is engine corrosion and system maintenance. EGR further improves the exhaust gas composition by burning the CO and similar not fully oxidized parts. The main effect is the same, i.e. providing some inert material that expands after detonation using up the heat.
It's only cheaper because externalities are ignored. If we had proper legislation that took environmental externalities into account, it might not be cheaper anymore.
Yes, couldn't they just make some government subsidies to incentivize it? Then we could be rid of all the nasty plastic waste that keeps finding it's way into the ocean and everywhere else?
What's interesting is that it seems like the microwave version was the cheaper and simpler alternative. And the engineering problems were apparently solved, since they were building the product for their first deal, and were demoing the tech to the popsci reporter who visited.
> Back at the shop, Pringle is still zapping new materials. A sample labeled “bituminous coal” goes in and, 15 seconds later, Pringle ignites the resulting gas. “You see,” he says, “why they might want to kill me.”
It doesn't sound expensive to add water injection to an internal combustion engine, until you have to make it work in production, with end users.
YOU can make it work, because you are motivated, but what about the guy who buys it because it's cool and then forgets to fill the system. Sure it's easy to add programming to work around this condition, but is it easy to integrate and test?
Anyway, crude oil is very, very cheap, and very easy to integrate into a production process. Waste plastic in the recycling stream is dirty and heterogeneous in composition and size, which makes it hard to integrate into a production process. Not impossible, but more expensive, which means that no one will do it without outside compulsion (and maybe not even then).