New Fuel

Terraformer · 2008-04-05 13:07:00

Butane? It's dense, non-toxic (I think so, I don't think everyone would be allowed a bottle of it in their house if it was toxic ), and not only non-cryogenic, it's a liquid at -0.5c. That's if wikipedias correct.

I was considering this for a sort of SSTO (there is that acronoym again!) fuel actually.

JoshNH4H · 2008-04-05 15:13:45

The Isp is about 350, I'm assuming, as with all other Hydrocarbon fuels.

What about lipids? they have about 38 MJ/Kg, without the oxygen needed to burn them. (Hydrogen=43)

Terraformer · 2008-04-05 15:27:30

I was thinking Butane because of its high boiling point, but that would only help if we were using an Oxidiser that wouldn't require cryogenic storage. Such as H2O2 or NO2.

If we were going for LOX as the Oxidiser, we'd be better off with Ethane or Propane. Ethane has a similar boiling point I think. Propane is about -41c according to wikipedia.

If we used LOX as the Oxidiser for a Butane rocket, we could (I think) slush the Butane in with the LOX.

GCNRevenger · 2008-04-06 21:24:53

You really, really don't want to mix hydrocarbons with LOX.

For that matter, you would also have trouble with settling of the solid.

Terraformer · 2008-04-07 03:45:24

Well it doesn't matter what fuel we use, unless there's an oxidiser it's useless.

There's N2O (meant to put that in my original post), H2O2, and good old LOX that are non toxic. CO2 would work, but only with certain fuels. Any more?

JoshNH4H · 2008-04-07 14:02:42

There's Cl2O7, nasty stuff. According to wikipedia, H2/LOX= 13.3 MJ/Kg, Cl2O7+CH4= 17.4.

I don't think that translates linearly into Isp, but that is a big improvement.

GCNRevenger · 2008-04-08 21:12:22

Actually Jumpboy, Dichlorine Heptaoxide would have much worse Isp than LH2/LOX, because the exhaust products are much lighter (H2O). Chlorine and a lot of Oxygen are pretty heavy.

Cl2O7 would classify as a "nightmare chemical" too... You couldn't pay me enough to work with the stuff under any circumstance. Wikipedia even says it will form Perchloric Acid, not something you want in a rocket!

Terraformer · 2008-04-09 04:18:12

Propane/H2O2? Non-cryogenic fuel and Oxidiser, H2O2 can be broken down into H2O and O2, realeasing energy, and it contains more Oxygen than N2O. Propane could (possibly) be pressurized to remain a liquid, eliminating need for cooling equipment. If not, it would still need a lot less cooling equipment than LH2.

JoshNH4H · 2008-04-09 14:11:27

I think that a solid rocket based on SO3, and a plastic, say, could have ISP's in the 290's to 300's. This is at least an improvement on current solid rockets. All we have to do is keep it below 19 C. This is just air conditioning, not even barely cryogenic. Plastic + N2O = about 250, so SO3 should be higher, since it's all oxidiser.

Terraformer · 2008-04-10 04:03:13

But solid rockets can't be throttelled, stopped, or restarted.

What type of Plastic are you thinking of? Do we really want Sulpher in the exhaust?

Please can someone post the eqautions for working out ISP and Thrust here?

SpaceNut · 2008-04-10 10:17:24

With any new fuel comes the need for engine developement and this
New Division for Pratt & Whitney Rocketdyne is a start.

While aerospace giants Lockheed Martin and Boeing have their Skunk Works and Phantom Works, and some of the developmental envelope is being pushed by purely innovation-centered companies like SpaceX, a unit like Power Innovations is a unique thing in the rocket industry, Bachtel said.

GCNRevenger · 2008-04-10 13:57:09

I've actually handled SO3, its pretty scary stuff, reacts (often violently) with water to yield sulfuric acid. One thing it won't do is react strongly with plastics, which are generally pretty inert, with some exceptions. Which plastic did you have in mind?

JoshNH4H · 2008-04-10 14:09:51

I personally have no plastic in mind, but I know that they used some sort of plastic/rubber on Spaceshipone. Aluminum would be fine with me, but the radically different boiling points of SO3 and aluminum would tend to complicate that. Also, I thought that maybe some sort of paraffin wax, or poly ethyleny, or polyethene.

GCNRevenger · 2008-04-10 15:34:25

I bet the butadiene rubber used in SS1 would burn better, its much less inert than saturated versus the unsaturated butadiene to SO3 attack I would bet. But either of the polymers likely won't break down into smaller particles, more likely yielding a big gooey mess.

Terraformer · 2008-04-11 07:44:47

RobertDyck,

What was the ISP of the Aluminum/LOX rocket?

SpaceNut · 2008-04-11 10:11:53

I can give you the company that did the work on [url=http://www.wickmanspacecraft.com/lsp.html]Lunar Soil Propellant
(LSP)[/url]

[url=http://www.wickmanspacecraft.com/moon1.html]Using Lunar Soil For
Propellants[/url]

For aluminum and magnesium fuels, they would be in the form of a powder as their melting temperatures are too high. They could be injected into the combustion chamber with an inert carrier gas.
An additional option available with aluminum is to suspend the aluminum powder in gelled LOX to form a monopropellant.
The viscosity of the LOX-aluminum monopropellant was no higher than 300 cps and decreased to 100 cps with increasing shear rate. A centrifugal pump with backward leaning blades could be used to pump the monopropellant. This type of pump is commonly used to pump slurries. One of the technical issues to resolve was whether the aluminum powder would settle in the gelled monopropellant. Our tests showed that there was no indication of settling in a six to seven hour period, which was the time limit of the tests.

Liquid Oxygen (LOX) Monopropellants

JoshNH4H · 2008-04-11 14:16:40

I bet the butadiene rubber used in SS1 would burn better, its much less inert than saturated versus the unsaturated butadiene to SO3 attack I would bet. But either of the polymers likely won't break down into smaller particles, more likely yielding a big gooey mess.

I've been wondering- What about graphite? CO2/CS2 exhaust. Or, if not, P-Xylene, (http://en.wikipedia.org/wiki/P-Xylene) or phenol (http://en.wikipedia.org/wiki/Phenol)

JoshNH4H · 2008-04-11 14:21:41

Actually, I think that if these and lox were used in some kind of solid rocket, then the Isp would be equal to or better that Kerosine, right?

GCNRevenger · 2008-04-12 12:40:45

You are talking about using LOX plus a solid hydrocarbon in a hybrid liquid/solid rocket? The theoretical Isp would be similar to Kerosenes probably, but reaching that high a level of performance without the extremely intimate mixing provided by liquid bipropellants will be impractical.

The case against solid rockets for high-efficiency launch vehicles is stacked rather high with facts, like difficulty reaching high Isp, the big & thick high pressure casing, and inferior (if any) throttle control.

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