Sciencemadness Discussion Board

Nitrous Oxide and ethanol under pressure

Morgan - 27-10-2013 at 18:31

I don't know that this would be unsafe, but suppose you used some 151 rum or Everclear 190 proof vodka and nitrous oxide cartridges to make a "rapid infusion." If you had a spark plug installed on this ISI canister, I wonder if you could get the top to blow off? Anyway this video below seemed at least potentially unsafe if static electricity were generated somehow or if you used a more concentrated libation.
Out of curiosity, I just lit a 1.75 liter Bacardi white rum bottle with a small amount of 80 proof still in it. A flat blue flame front slowly traveled down the irregular shaped bottle. Perhaps if I had aired the bottle out it would have gone a bit faster. I removed the plastic insert that slows the pouring process.
Another time I lit a very small volume of pure oxygen and methanol vapor in a footlong tube open at both ends. It caused my ears to ring, not too smart.

http://vimeo.com/37736183#

One time at a fancy bar in town they were making flaming hurricanes with 151 rum and the drinks which were lit also lit the Bacardi bottle with a pour spout and somehow the flame front entered the bottle which then erupted lighting a few customers on fire.

I tried to find something on the electrostatic properties of N2O but only found a heading in a reference book.
I recall CO2 fire extinguishers make static.
http://www.ece.rochester.edu/~jones/demos/charging.html


[Edited on 28-10-2013 by Morgan]

Morgan - 28-10-2013 at 05:25

I was thinking when he says "You want to rapidly discharge the gas", that if you had a static spark from a sweater or other article of clothing you could conceivably create a dramatic flambe' effect with the alchohol/nitrous oxide escaping gases. Yesterday I was shopping for odd shaped metal objects at a Goodwill store and happened across a like new ISI whipped cream maker for $6.99. It had 4 N2O cylinders in the box as well. So I was thinking I could test this scenario but then again if the flame front happened to enter the bottle when the escaping gas slowed enough, it might be risky. Maybe the bottle could handle the pressure or the reactants not that energetic, I just don't know. They make little toy rockets using N2O cartridges so maybe the whipped cream canister would make a lively display. Another thing is the unique ritual/bar theater effect says to "Keep in mind ingredients plus liquids should never exceed the fill line" and that "to let it sit until the bubbling subsides". It might be interesting to not let it sit and light the fizzing effervescent alchohol/nitrous vapor for some sort of effect, like hydrogen/oxygen bubbles. The bar theater could be so much more. ha
The clip again for review.
http://vimeo.com/37736183#

nitrous alcohol rocket cato.wmv
http://www.youtube.com/watch?v=TSyljeVEN9o

DubaiAmateurRocketry - 28-10-2013 at 05:38

Nitrous oxide is one of the safest Nitrogen oxides, and ... however, yes it is still unsafe.

Morgan - 28-10-2013 at 17:12

Here's another perspective using two N2O cartridges/16 grams for more pressure. Interesting how the iSi Cream Whipper ejects some of the vodka when depressurizing. Could it be from foaming or eddy currents or both?
http://gizmodo.com/5955339/how-to-rapidly-flavor-any-booze-u...

I would be curious the results if you charged a plastic 2 liter Coke bottle with the above depressurization technique and lit whistling bottles all in one fell swoop instead of using the two part charging method as shown below. I have to say the whole idea seems interesting yet potentially dangerous, maybe some scenarios even worse if the canister were to somehow explode from a static charge or some other unforeseen Darwin Award aspect. I didn't like this video but it seems to illustrate vodka, or some green tinted liquid in a bottle, and nitrous oxide, probably not stoichiometric ratios but perky non-the-less. A 151 rum or 190 proof Everclear would be better than a common 80 or 100 proof vodka of course. In cool, dry air plain methanol and air will send a 3 liter Coke bottle with cap nozzle downrange so fast your eye can't track it.
Dangerous home made rockets with Vodka and N2O
http://www.youtube.com/watch?v=NJ3QNT3Q5U4

As pure oxygen or nitrous oxide mixed with a fuel isn't very fussy about fuel/air ratios or LEL and UEL, I would treat any strongly confined combination as potentially life threatening. Untill you know every possible variable, realize you could be risking your life. Recall even the Mythbusters accidentally shot a cannonball through someone's house.
Maybe charging a whipped cream canister with alcohol and N2O oxidizer is completely safe. But I wonder though if the confined pressurized vapors in the canister would go off like a bomb if safely wired, charged, and sparked from a safe distance, behind a plexiglass viewing stand and all? Maybe the Mythbusters could try that one, using various hard liquors and varying the N2O charging pressure.

N2O product information
http://cnmosa.en.ec21.com/8g_N2O_Charger--886446_886457.html

Some blending of nitrous oxide with fuel tidbits.
NOFBX has been used to fuel a reciprocating engine to power high-altitude, long-endurance drone aircraft under a DARPA contract.[2]
The patent claims a mixture of nitrous oxide (oxidizer) with ethane, ethene or ethyne as the fuel; as an example, the mixed gases are condensed into a liquid at –70 °C.[8]
Recent work on the decomposition of nitrous oxide has raised concerns about the safety risks of mixing hydrocarbons with nitrous oxide. By adding hydrocarbons, the barrier to an explosive decomposition event is lowered significantly.[9]
http://en.wikipedia.org/wiki/Nitrous_oxide_fuel_blend


[Edited on 29-10-2013 by Morgan]

Morgan - 30-10-2013 at 07:36

I came across some literature on the Mojave Desert explosion. There're some fun facts and points to ponder. It doesn't seem like everything is known about nitrous oxide yet. It's interesting though.

“The body of knowledge about nitrous oxide (N2O) used as a rocket motor oxidizer did not indicate to us even the possibility of such an event.”
http://www.knightsarrow.com/rockets/scaled-composites-accide...

Nitrous Oxide Explosive Hazards
Claude Merrill
Air Force Research Laboratory, Edwards AFB, CA
http://www.dtic.mil/dtic/tr/fulltext/u2/a489459.pdf

[Edited on 31-10-2013 by Morgan]