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#26 2015-01-09 20:47:52
- RobertDyck
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- From: Winnipeg, Canada
- Registered: 2002-08-20
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Re: LOX-Acetylene/CO rocket by Landis for a complete ISPP
If the two liquids have different partial pressure, then the composition of the boil-off gas will be dominated by a single constituent. That may mean the combustion properties of the gas changing over time, or (shock-horror) a tank full of concentrated actylene.
Since warming liquid can hold less dissolved gas, that means acetylene would boil off faster. That means over time you would have lower concentration of acetylene. Since pressure above 200 kPa absolute is dangerous, you would have to let it boil off. And acetylene requires absolutely no copper or copper alloys such as brass in plumbing. And propylene must have no metallocene, because that cause polymerization. But metallocene is a metal with a hydrocarbon. Not likely to occur by accident. But this still sounds like a dangerous fuel mixture. Perhaps for rocket fuel, but sounds dangerous for vehicles.
Interesting, though. The first post of this thread was by Quaoar, who posted a paper about dissolving acetylene in liquid carbon-monoxide. That would work. However, CO must be chilled below -191.5°C at one Earth atmosphere. Triple point is -56.6°C @ 517.8 kPa absolute. That's 75.1 psia. CO requires cold and pressure. Triple point graph for CO, click here.
While propylene remains liquid much warmer, and lower pressure. It's triple point is 7.44E-09 bar @ -185.2°C. Boiling at 1 atmosphere is -47.62°C. Critical point is +91.06°C @ 45.55 bar. Graph for propylene is harder to find. The British often have other words, their word is propene. I found this graph...
The second graph deals with specific volume, what that page talks about. It's about density of the liquid. It's included just because it's one image; I linked the image from their website.
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