Vehicle: Car: Engine: Aspiration
Onboard Oxygen Engine   (+2, -3)  [vote for, against]
Sealed inlet system

I propose a completely sealed intake system on an internal combustion engine using liquid oxygen (LOX) and gasoine (or any other clean fuel, like hydrogen) metered for each cylinder. Each cylinder could be self contained, with just enough of an intake volume to allow smooth transition past the open intake valve. If a pyrometer and O2 sensor was placed on each exhaust pipe, the computer could adjust on the fly per cylinder. Good bye NOx and unburned hydrocarbons, hello massive on demand clean (and perhaps expensive) power!
-- mhuppertz, Jul 02 2004

Sure, sounds good to me. Though the mhuppertz cycle just doesn't roll off the tongue.
-- Worldgineer, Jul 02 2004


idea name suggestion: Onboard Oxygen Engine

Welcome to the halfbakery. (There is no welcoming committee).
-- Laughs Last, Jul 02 2004


Well, actually, there's a couple of beefy guys wih baseball bats you *really* don't want to meet. Fixing the idea title might help avoid attracting their attention.
-- DrCurry, Jul 02 2004


Since you're removing nitrogen, you'll cut back on the NOx, but you'll still end up with unburned hydrocarbons. Since you'll be burning pure O2+fuel, the combustion temperature will be much higher. At extreme temperatures, you'll begin to form some really nasty hydrocarbon byproducts, until the extra heat begins to melt your engine.
-- Freefall, Jul 02 2004


I thought that the nastyness of byproducts drops with increased temperatures? Or is that all that credit due to a warmer catalytic converter?
-- Laughs Last, Jul 02 2004


A tank of 02 that could be punctured seems pretty dangerous. As everyone knows, oxygen won't burn by itself (since burning is oxidizing something else)...but, pretty much anything will burn VERY fast and hot with pure oxygen around it. Safety would probably be an issue.

Where will this 02 come from? For a petrol system, this would lead to less efficiency, since you would have to account for the energy used in extracting/obtaining the oxygen. Normally, it's used from the air, which can be considered free. If it's used in a hydrogen powered car, then this wouldn't be an issue, since extracting the hydrogen from water would give (all/most? of) the oxygen.

I think freefall has a point though. Not only the hydrocarbons, but the whole engine melting issue too. Isn't that why you can't continually put laughing gas into your engine?
-- nomel, Jul 03 2004


[Admin: I changed the name of this idea to [Laughs Last]'s suggestion to make it a bit more descriptive. As author you're able to change the name of your own idea to whatever you want - the forms for editing your own ideas can be found below the idea text itself. Welcome to the HalfBakery!]
-- hippo, Jul 03 2004


[Laughs_Last] yes, catalytic converters have much to do with cleaner exhaust at high temperatures. Low temperatures produce particulates, but at really high temperatures such as what you get in a high pressure fuel-oxygen combustion, some funky chemistry starts to happen and some really nasty compounds start to form. This is one reason many cars have exhaust temperature sensors in addition to the oxygen sensors.
-- Freefall, Jul 03 2004


I know that inadequately low temperatures results in increased volatile organic compounds (VOC) emissions, due to incomplete combustion of hydrocarbons. No more scary hand waving at a non-chemist, just what will extra high temperatures make? Thermal NOx requires nitrogen, is the problem impurities and additives in the fuel? Will linguini spontaneously start shooting out the tailpipe?
-- Laughs Last, Jul 03 2004


Can't we ignore this as an effeciency idea, and look at it from the power perspective (as mhuppertz mentioned)? Running a dragster with a postive-pressure O2 tank would result in insane horsepower, not to mention being a simpler system than a supercharger.

[Laughslast] I can't say for sure, but one thing I imagine that could be produced is benzene, which is a known carcinogen.
-- 5th Earth, Jul 03 2004


Sorry about the (multiple) fauxpaux. I'm a newbie...
-- mhuppertz, Jul 04 2004


It seems to me that the efficiency advantage comes from eliminating the work done to compress the oxygen. Pressurizing the liquid requires almost no work. I am curious as to the cost advantage (disadvantage?). An old CRC handbook quotes $15/ton as the price of oxygen in quantity. I haven't found recent costs for running an air separation unit to get LOX. If I run a separation unit in my garage and carry LOX in my car, does the cost of electricity to run the separation unit, compared to the cost of gasoline that would be saved by eliminating the compression work, make this an economically advantageous idea? Anyone know?
-- DrEdwards, Jul 05 2006


//gasoine (or any other clean fuel// Gasoine [sic] is a clean fuel?
-- AbsintheWithoutLeave, Jul 05 2006


I haven't been reading articles on halfbakery for too awful long but already I have seen this or similar ideas proposed several times. All of the people annotating above have brought up a lot of good points and all I have to say is that from a person who has modified and raced cars for quite a while a vehicle would need massive modification to withstand the stress from this sort of system if it weer to be implemented successfully. The idea of using LOX may sound like a good idea when it's in your head but when it is under the hood of your car it would be nothing but dangerous.
-- williamruck, Jul 07 2006



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