DMAZ rocket fuel

[Andiron]

Hi !

I browsed a bit about different liquid fuels when I searched about the methane-lox propelled Raptor engine after IAC 2016. I wondered what kind of propellants will fuel the future rockets and found many interesting things, like this weird Hydroxylammonium nitrate  developed by Nasa as a mono-propellant. There is also this rocket fuel, called DMAZ, which stands for 2-Dimethylaminoethylazide and is studied to replace the very toxic UDMH.

The DMAZ is hypergolic with NTO, denser than UDMH (933 vs 791), have a little bit less Isp at sea level (283 vs 285, theoretically) and a good ignition time of 64ms with NTO (although higher than UDMH and MMH). Against UDMH, the most important point is that DMAZ isn't carcinogenic. It can also works well with H₂O₂, with a high density impulse of 360.2s and a correct Isp of 280.8s, but the mix is not hypergolic.

Source :  http://www.tandfonline.com/doi/full/10.1080/07370652.2013.877101, http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?2004ESASP.557E..22M&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf and https://en.wikipedia.org/wiki/2-Dimethylaminoethylazide

      

Edited September 28, 2016 by Andiron

[DDE]

Nobody really wants to deal with major quantities of H₂O₂, though. Ignition's chapter on it is subtitled Always a bridesmaid.

[Andiron]

8 minutes ago, DDE said:

Nobody really wants to deal with major quantities of H₂O₂, though. Ignition's chapter on it is subtitled Always a bridesmaid.

That's a good pun

[Steel]

25 minutes ago, DDE said:

Nobody really wants to deal with major quantities of H₂O₂, though. Ignition's chapter on it is subtitled Always a bridesmaid.

Realistically, if as much effort was put into the safe handling of Peroxide as, say, UDMH, Liquid Hydrogen, hydrazine or any of those other fun propellants there would not really be a problem with handling large quantities. Unfortunately, it just never happened.

[DerekL1963]

5 hours ago, Steel said:

Realistically, if as much effort was put into the safe handling of Peroxide as, say, UDMH, Liquid Hydrogen, hydrazine or any of those other fun propellants there would not really be a problem with handling large quantities. Unfortunately, it just never happened.

There was just as much effort - in Britain.  But the relevant people in the US are blinkered by the very limited experience in the US and NIH.

[Kryten]

Currently there is also a peroxide effort being done by SAST in China. They already have the CZ-6 with a peroxide/kerosene third stage and peroxide roll thrusters on the first two stages, and are working on a peroxide/kerosene upper stage for larger vehicles, AUS.

[todofwar]

13 hours ago, Steel said:

Realistically, if as much effort was put into the safe handling of Peroxide as, say, UDMH, Liquid Hydrogen, hydrazine or any of those other fun propellants there would not really be a problem with handling large quantities. Unfortunately, it just never happened.

From the chemist perspective I can see why. Hydrogen? No problem. Hydrazine? I use it all the time. Hydroxylamine? Gentle as a lamb. But I can't even buy anhydrous peroxide for use as a reagent. I know they do work with it, but of the things you listed it's the most dangerous. A spec of iron or copper dust gets in your batch and the whole thing goes boom. 

[Streetwind]

Honestly, I think that this AF-M315E (the aforementioned hydroxylammonium nitrate ionic liquid blend used in NASA's Green Propellant Infusion mission) is a good contender for a new standard. It's a drop-in replacement for hydrazine in any monopropellant application... okay, not drop-in, it needs different tanks and nozzles. But that's merely a minor engineering task.

In return, it has both significantly higher density and higher specific impulse than hydrazine - which combines into as much as 50% more density impulse delivered by a tank of the same size. At the same time, it can be handled in an open container without randomly going off or poisoning you. All the decomoposition products are inert and nontoxic, too. And to top it off, it resists freezing where hydrazine needs to be kept artifically heated. It sounds like the kind of holy grail that John D. Clark was searching for but didn't manage to find - either because it wasn't practicable back then without a newfangled additive that only exists today, or because the science of the day didn't consider it viable to try in the first place. We probably will never know, since Clark is deceased and Ignition! doesn't mention hydroxylammonium nitrate specifically.

I've seen claims that it has potential for use in a bipropellant system, but I can't find any sources that back that up with performance examples.

 

[todofwar]

14 hours ago, Streetwind said:

Honestly, I think that this AF-M315E (the aforementioned hydroxylammonium nitrate ionic liquid blend used in NASA's Green Propellant Infusion mission) is a good contender for a new standard. It's a drop-in replacement for hydrazine in any monopropellant application... okay, not drop-in, it needs different tanks and nozzles. But that's merely a minor engineering task.

In return, it has both significantly higher density and higher specific impulse than hydrazine - which combines into as much as 50% more density impulse delivered by a tank of the same size. At the same time, it can be handled in an open container without randomly going off or poisoning you. All the decomoposition products are inert and nontoxic, too. And to top it off, it resists freezing where hydrazine needs to be kept artifically heated. It sounds like the kind of holy grail that John D. Clark was searching for but didn't manage to find - either because it wasn't practicable back then without a newfangled additive that only exists today, or because the science of the day didn't consider it viable to try in the first place. We probably will never know, since Clark is deceased and Ignition! doesn't mention hydroxylammonium nitrate specifically.

I've seen claims that it has potential for use in a bipropellant system, but I can't find any sources that back that up with performance examples.

 

Do you know what it's really made of? Because wiki says it's just ammonium nitrate, but ammonium nitrate itself is a solid. So they must be making it a liquid somehow, or they melt it maybe? But heating a mixture of hydroxylamine and nitrate in the tank does not sound like a safe idea 

[Streetwind]

I don't know, sorry. It says it's stored as an ionic liquid. But I don't know the process, or what (if any) additives are present.