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From: Henry Spencer <>
Subject: Re: Need hydrazine rocket fuel price bogey
Date: Sun, 31 Dec 1995 23:26:25 GMT

In article <4c2iiu$> (BFGorinPE) writes:
>Hydrazine (as in anhydrous) is a monopropellant.  While it requires
>careful handling, it is far less hazardous than this response would imply.

While the hydrazines are not instant death, they are fairly dangerous
industrial chemicals.  Nitrogen tetroxide, the usual oxidizer for them,
is worse, comparable to WW1 war gases.  Neither is anything you want to
handle in your back yard.  Even for professional space operators they are
a nuisance; NASA has repeatedly identified "non-toxic propellants" as a
possible shuttle upgrade with the potential to reduce operations costs

> Concentrated Hydrogen Peroxide (as opposed to the stuff sold in drug
>stores) is not exactly easy or safe to handle and far harder to store.  It
>can begin decomposing spontaneously and cause real problems.  

While there are some storage headaches -- the stuff decomposes slowly no
matter what you do, so you must provide for tank venting -- otherwise
peroxide is much easier and safer to handle.  Its bad reputation is half
outright myth and half the result of 1940s experience with seriously
impure peroxide.  To quote a friend, a rocket-propulsion professional, who
investigated the matter as part of a study some years ago: 

"As far as we could find out, the stories about problems with peroxide
were just that, stories...  Peroxide, now, seems to only very rarely do
anything exciting, at all.  And, even then, it seems to never do many of
the things attributed to it in the stories."
Look, look, see Windows 95.  Buy, lemmings, buy!   |       Henry Spencer
Pay no attention to that cliff ahead...            |

From: (Jeff Greason)
Subject: Re: Unadvisable Rocket Science
Date: 2 Aug 1996 15:22:29 GMT

In article <>, Peter Bellini
<> writes:
|> david l burkhead wrote:
|> > 
|> > In article <> Henry Spencer
|> <> writes:
|> > >In article <> Mark and Kersten Hamilton
|> <> writes:
|> >
|> > 
|> >      According to an episode of "Wings" recently (on The Discovery
|> > Channel), the Me163 used two fluids, C-stof and T-stof. (I forget
|> > which was which.) One was the concentrated peroxide and the other was
|> > a catalyst containing hydrazine and other things.  The voice-over on
|> > Wings said that it was the peroxide that was nasty, not the other.
|> > 
|> I just saw a "wings" episode, too, that said the same thing about the H2O2
|> in
|> the German Rocket Assisted Take-Off (RATO) units used on the Ar-something
|> reconaissance plane.

Before this thread expands into another round of the Hydrogen Peroxide
myth, let me suggest people check out an article in JBIS from a few
years ago (reference not at hand, but it's the summary issue on Britain's
Black Knight program), covering hydrogen peroxide as a rocket propellant.

H2O2 just isn't that nasty.  It's not corrosive, not poisonous, not
carcinogenic, not cryogenic.  It is, of course, a strong oxidizer (which
is true, almost by definition, of any good rocket oxidizer :-).

It's *only* bad habit is that it decomposes exothermically -- and since
the rate of decomposition is accelerated with temperature, this reaction
can run away from you.  But that hardly deserves the bad press it's gotten.
LOX will also bite you, quite readily, if you're careless.  "Wings" simply
got it wrong.  (Even _Ignition!_, while pretty sour on hydrogen peroxide due
to the decomposition hazard, has the facts right, and only the emphasis is
arguable -- I don't understand how someone can cozy up to ClF5 while
considering peroxide dangerous; but that was Clark's position! )

Disclaimer: While I am an Intel employee, all opinions expressed are my own,
     and do not reflect the position of Intel, NETCOM, or Zippy the Pinhead.  
Jeff Greason                 "We choose to go to the Moon in this decade,
  <>  and do the other things, not because they 
  <>     are easy, but because they are hard." -- JFK 

From: Henry Spencer <>
Subject: Re: Unadvisable Rocket Science
Date: Fri, 2 Aug 1996 03:31:56 GMT

In article <4tp3hq$> (david l burkhead) writes:
>>Actually, the peroxide was not the problem.  It was the *fuel* -- a nasty
>>hydrazine-based mixture -- not the *oxidizer*, that caused these problems
>>in the Me163B...
>...The voice-over on
>Wings said that it was the peroxide that was nasty, not the other.

This is a common belief, but is incorrect.  There is a *lot* of mythology
surrounding peroxide in the US, almost all of it totally false.  To get
past it, you have to dig for primary sources, and disregard thirdhand
reports.  Even usually-dependable references have picked up the myths and
repeated them as fact. 
 ...the truly fundamental discoveries seldom       |       Henry Spencer
occur where we have decided to look.  --B. Forman  |

From: Rick Ballard <>
Subject: Re: Unadvisable Rocket Science
Date: 13 Aug 1996 14:02:02 GMT

Paul F. Dietz wrote:
> The Silent Observer <> wrote:
> >I remember the fuel component in the Komet as alcohol with dissolved
> >potassium permanganate (which acted to catalyze the peroxide, rendering
> >the pair hypergolic).  The permanganate also accounted, I gather, for the
> >very dark, purplish smoke seen in German takeoff shots of the Komet.
> Dissolving permanganate in alcohol seems like a bad idea, since it
> will oxidize the alcohol and produce manganese dioxide to clog up the
> plumbing.  Acetone would be a workable organic solvent, however.
> I think some of the German engines actually had a separate catalyst
> solution that was injected along with the fuel and oxidizer.  I think
> they used calcium permanganate; it is much more soluble in water than
> potassium permanganate.

Actually, different versions of the Me-163 Komet used different fuels, but the 
oxidizer was always T-Stoff, a mixture of 80% hydrogen peroxide plus 
oxyquinoline or phosphate as an stabilizer.

Initial versions of the Me-163 (i.e., the Me-163A) actually used a liquid 
catalyst instead of a fuel, called Z-Stoff, which was an aqueous solution of 
either sodium or calcium permanganate (both were used, but not at the same 
time).  The engine, known as the R11-203B, suffered from reliability problems 
due to Z-Stoff clogging the injection jets, resulting in insufficient flow of 
catalyst and causing severe fluctuations in pressure and thrust.  After a 
number of engine explosions, the fuel was changed from the Z-Stoff catalyst to 
the hypergolic C-Stoff fuel for use on the R11-211 engine, also known as the 
109-509A engine.

C-Stoff is a mixture of 57% methanol + 30% hydrazine hydrate + 13% water, with 
traces of either cupro-potassium cyanide or copper oxide (probably as a 
stabilizer).  The propellant combination of T-Stoff/C-Stoff was used for all 
subsequent versions of the engines used on the Komet, although one experimental 
engine used M-Stoff (100% methanol) as a fuel.

Hope this clears up a few things.


Any opinions expressed in the above message are my own, and does not
indicate any views supported by NASA or Sverdrup Technology.

From: (George Herbert)
Subject: Re: Advantages of The Expander Cycle Engine
Date: 31 Jan 1997 15:32:05 -0800

Jim F. Glass x60375 <> wrote:
>Yes it has been done; of course the problem is the low energy content of
>peroxide.  A secondary problem is that, today in the US, the highest
>commercially-available peroxide concentration is 70%; the Germans make 85%.
>I called every vendor I could find to inquire about 90%, 95%, and 98%
>H2O2.  Some laughed; one hung up on me.  Yes; you can concentrate it
>yourself from the low-octane variety; is it worth it?  I don't think so.

It's not very difficult, actually.  It's a tossup as to whether it's
cheaper to do it yourself or convince Olin to do it for you
(I found the right person there to say "Yes, we will if you'll
pay for it and disclaim explosion liability" a couple or three
years ago).  Their normal sales people won't say yes, but some
further up the food chain will if you poke around some.

I will note for the record, however, that my current working
propellant is HNO3 rather than H2O2...  there's an order of
magnitude price difference.

-george william herbert
Retro Aerospace

From: (George Herbert)
Subject: Re: Advantages of The Expander Cycle Engine
Date: 11 Feb 1997 12:04:26 -0800

Tom Carman <> wrote:
> (John Schilling) wrote:
>> (Filip De Vos) writes:
>>>But George, you just said that productivity and learning curves would
>>>reduce the cost of the BDB. Surely some price reduction is envisageable
>>>as volume of H2O2 production increases?
>>Global H2O2 production is already close to a million tons per year;
>>it would take an *awful* lot of launches to result in a noticeable
>>increase in production volume.  And even then, I suspect that most
>>of the economies of scale to be had, have already been achieved.
>>You might get some small benefit in the concentration stage.  Current
>>H2O2 plants almost universally produce 70% peroxide, and higher grades
>>are a specialty product.  But concentration isn't particularly hard,
>>and IIRC the few peroxide manufacturers that have been willing to talk
>>about selling 90+%, seemed more concerned with getting a large enough
>>order to justify their time than with jacking up the unit price.
>>So it seems likely that, regardless of concentration, peroxide is
>>about as cheap as it is going to get.
>This isn't my field of knowledge, but...  What are the majority of the
>current uses of H2O2, what is the typical unit-quantity, and how
>price-sensitive are they?

Last I checked, the statistics were that most H2O2 produced went into
bleaching operations, largely bleaching paper.  Some 30% grade is used
and some 70% (it is cheaper to ship 70%, so some sites mix it down onsite).
I think the million tons (plus or minus a bit) figure above is correct.

When talking to the producers a couple of years ago, they indicated that
once you reach rail tank-car loads (at about $0.50/lb for 70%) they were
fairly inflexible on price until you did large committments for ongoing
regular bulk purchases, and wouldn't go much below that number anyways.

>Obviously, they don't _require_ high
>concentrations, and if "what the market will bear" is a lot, the price
>may not have "bottomed out" yet.  While the increase in total
>production may be small, if peroxide rocket propellant involves much
>larger unit-quantities, price might be significantly impacted.

I suspect that the answer is no.  I am willing to be proved wrong by
someone doing an analysis, however.

-george william herbert
Retro Aerospace

From: Henry Spencer <>
Subject: Re: H2O2/RP1 Rocket Motors
Date: Wed, 2 Jul 1997 15:57:07 GMT

In article <>,
CONPUTE <> wrote:
>: No, it is rocket grade.  This company stops at 85%...
>Is the remaining 15% water? Can we freeze out most of the water then if
>we chill the H2O2 to just below the freezing point of water????

The balance is indeed water.  There are several ways of getting most of
the remaining water out; the question is whether you want to set up your
own fuel-processing plant, or stick with what you can buy commercially
and accept the performance penalty.

>What is the ISP at 85%, 90%, 95%, 99% ????????

To a first approximation, Isp scales with sqrt(energy_release/mass), and
100% will release about 18% more energy per kilogram than 85%, yielding
about 8% higher Isp.  What the base number is, depends on other things.
Committees do harm merely by existing.             |       Henry Spencer
                           -- Freeman Dyson        |

From: (Henry Spencer)
Subject: Re: Peroxide Chemistry Question
Date: Sat, 4 Jul 1998 16:31:39 GMT

In article <>,
R. C. Colgrove <> wrote:
>...but would have poor performance if stabilizers were added.
>Now, I am circumspect about applying my biochemist's intuition to the
>high-energy world of rockets but I would've thought that the chemistry
>would be different between H202 monopropellant decomposition and H202
>hydrocarbon oxidation...

Many (although not all) peroxide/hydrocarbon engines decompose the
peroxide before getting it together with the kerosene.  This has a number
of advantages, such as hypergolic ignition and improved combustion
stability (from gas/liquid rather than liquid/liquid mixing).  This makes
the chemical situations more similar than one might at first think.

The problem with stabilizers in the peroxide is not poor combustion
performance, but the fact that they are too effective and make catalytic
decomposition very difficult.  A few years ago, HMX spent considerable
time and effort looking for a solid catalyst that worked well on
stabilized commercial 70% peroxide, and could not find one.  (They
eventually resorted to what they dubbed "lean bipropellant", injecting a
couple of percent of triethyl aluminum.  Inelegant but workable.)
Being the last man on the Moon is a |  Henry Spencer
very dubious honor. -- Gene Cernan  |      (aka

From: (Jordin Kare)
Subject: Re: Peroxide Chemistry Question
Date: Sat, 04 Jul 1998 21:26:14 -0700

In article <>, wrote:

> There have been several statements over the years that peroxide needs to
> be at high concentrations to be useful in rockets, can become
> dangerously unstable at these concentrations, but would have poor
> performance if stabilizers were added.
> Now, I am circumspect about applying my biochemist's intuition to the
> high-energy world of rockets but I would've thought that the chemistry
> would be different between H202 monopropellant decomposition and H202
> hydrocarbon oxidation.
> I can see where a good stabilizer would make peroxide a lousy
> monopropellant but shouldn't it still work fine in a bipropellant like
> H2O2/Kerosene?

Many peroxide/hydrocarbon engines catalytically decompose at least part of
the peroxide before injection into the main engine.  This may be done to
run the propellant pumps, or to ensure ignition in an intermittently-fired
engine.  A major reason is to improve the combustion characteristics by
injecting hot oxygen-rich gas, rather than liquid -- this gives a simpler
injector, better combustion stability, and faster combustion, allowing a
shorter combustion chamber.  An injected liquid catalyst will work with
stabilized peroxide, as will thermal decomposition.  But because many
groups are using solid catalysts (either for the main engine, or in small
monopropellant thrusters running off the main oxidizer supply) there's a
demand for high-purity non-stabilized peroxide that won't poison solid

Jordin Kare

From: "Jeff Greason" <>
Subject: High Concentration Peroxide (was Re: X-1/XLR-11 Replica Project)
Date: Mon, 25 Oct 1999 16:25:19 -0700

Kirk Voelcker <> wrote in message =
> Jeff Greason wrote:
> >  High Concentration Peroxide -- can't buy it
> Is peroxide commercially unavailable or is it restricted from sale?

I hesitate to post on this, since I will undoubtedly
tread on some religiously held views of the pro- or
anti- peroxide camps.

The short form is: high concentration peroxide (above
70%) is commercially unavailable.  If you could buy
it, you could ship it; the threshold for various
regulations is either 52% (OSHA) or 60% (DOT). Note,
however, that those shipping regulations are highly
non-trivial and that 70% isn't too easy to get.

There are persistent attempts to get higher
concentrations into production; the basic problem is
lack of demand at high enough quantity that it's worth
the trouble for the chemical companies to provide it.
I don't know whether one of the small houses might be
trickling it out right now or not; H2O2 Inc was doing
it for a while, but I didn't see it on their website

I've worked with peroxide now, and I'd say I fall in
the middle.  Peroxide isn't as safe and wonderful as
its ardent supporters would suggest, but it is pretty
safe *by the standards of high strength oxidizers*,
has good density, is expensive but not too expensive
for auxiliary propulsion, and is especially nice in
monopropellant applications.  For biprop applications
with higher performance, it's a much murkier trade.

Peroxide goes in and out of fashion over the years --
right now, it's a very "trendy" propellant; but I
would hesistate to base commercial work on it due to
the supply problem.  As soon as the fashion fades,
since there aren't any non-rocket customers for high
concentration stuff, the supply problem will

I recently found one of the old papers by Walther in
1943 Germany, which could have been written yesterday
by a peroxide advocate.  I'll quote parts here, with emphasis added on =
the implied "con" issues.

"With the strongest excitation by extraneous shock,
 pure T-stoff (peroxide) can be detonated ONLY IN
  (Note that the Walther rockets used 80% H2O2, which
   really is about as safe as 70%, while modern
   proposals use up to 95%, which is a bit touchier)

"Splashes on work clothing are undesirable because of
 the danger of fire and the damage to the fabric.
 The service crews are therefore directed to wear
 rubber or Mipolam aprons, foot coverings, and
 protective glasses, which, however, are ONLY TOO
 READILY FORGOTTEN when the work has become somewhat

  (I've often said that if peroxide *looked*
   dangerous to handle, it would be a lot safer!)

"The customary 30-percent commercial product certainly
 offered no incentive for use as a source of energy.
 Conversely, higher concentrations had acquired the
 unfavorable reputation of being dangerous with
 respect to storage, probability of explostion, and so
 forth.  This reputation found expression, for
 example, even in the freight rules of the state
 railways.  This prejudice, nourished by some
 accidents due to lack of knowledge and experience
 with higher concentrations, had an extraordinarily
 retarding effect on the technical utilization of
 hydrogen peroxide as an energy carrier and to some
 extent must still be contended with today."

  (and from 1943 to 1999, little has changed :-)

"Limited funds are a blessing, not       Jeff Greason
a curse.  Nothing encourages creative    President & Eng.Mgr.
thinking in quite the same way." -L. Yau XCOR Aerospace
   <>             <>

From: "Jeff Greason" <>
Subject: Re: High Concentration Peroxide (was Re: X-1/XLR-11 Replica Project)
Date: Tue, 26 Oct 1999 11:19:50 -0700

Kirk Voelcker <> wrote in message
> How is peroxide stabilized? Is it through the  concentration ratio with
> water, or some other substance? Or are there weak bonds with the water
> content that are disrupted with mechanical energy?

Well, diluting it with water certainly does improve the safety of the
chemical -- while rendering it increasingly useless as a propellant, alas.

However, that's not what "stabilizing" means in this context.  Peroxide
at 50% and 70% concentrations is usually sold "stabilized", which
means it contains dissolved chemical compounds which "tie up"
small amounts of active metal ions.  The active metals catalyze
peroxide decomposition, so that the presence of "stabilizers" reduces
the tendancy for peroxide to decompose when exposed to *trace*
contamination.  Gross contamination still sets the peroxide off, so
these don't (IMO) improve the safety all that much.  What they do
is make the peroxide pretty much useless for monopropellant rocket
applications -- since the stabilizers plate out on catalytic surfaces in
catalyst packs and quickly deactivate the catalyst :-(

You can still decompose stabilized peroxide, but you have to go back
to the other way the Germans did it in WW2 -- injecting a liquid catalyst.
This adds complexity, and takes away one of the big advantages of
peroxide for attitude control thrusters (simplicity).  The catalysts are
propellants in their own right, and need to be treated as such.  They
do work nicely, however.

"Limited funds are a blessing, not         Jeff Greason
a curse.  Nothing encourages creative      President & Eng. Mgr.
thinking in quite the same way." --L. Yau  XCOR Aerospace
   <>                <>

From: Bruce Dunn <>
Subject: Re: Beal in trouble...
Date: Sun, 08 Oct 2000 17:46:17 GMT

Henry Spencer wrote:

> Beal may be decomposing his peroxide before
> throwing in the kerosene -- I don't believe this has been revealed -- and
> the TRW engine design doesn't adapt well to that.

There is no particular reason why peroxide has to be decomposed prior to
combustion. The TRW coaxial pintle engine should be adaptable to run
directly with liquid peroxide.  In my mind, decomposition of peroxide is
an unnecessary complication in an engine.  Sure, it leads to reliable
ignition.  However, just the same result could probably be had by
ignoring the catalyst bed, and leading the fuel with a slug of aqueous
potassium or calcium permanganate (a liquid decomposition catalyst used
for example by HMX in some of their work for Kistler).  The second
advantage of peroxide decomposition is stable combustion.  However, this
is an inherent feature of coaxial pintle engines without having to fuss
with catalyst packs.

There is a lot of art in catalyst beds for peroxide, and most of the
current art isn't necessarily applicable to 98% of 100% peroxide.  The
catalytic activity depends on the precise manufacturing details of the
catalyst, and subtle changes in manufacturing can make large changes in
activity.  Catalyst bed activity is dependent on its temperature, and
its preveious history of use.  Catalysts can be poisoned, and a catalyst
bed which works fine at ignition may no longer be working well at the
end of a long burn.  Cold catalysts can have substantial delays before
they "light off", which has led some experimenters with small engines to
have to "burp" the bed with a bit of oxidizer to warm it up before the
main ignition sequence.  The pressure drop across a catalyst bed is
substantial, leading to a heavier oxidizer tank in pressure fed
systems.  The catalyst bed itself can be very bulky and heavy, adding a
further penalty.  Finally, there is the KISS principle - catalyst beds
add an element to engines which drive up development and production
costs, and lower reliability.

From: (Henry Spencer)
Subject: Re: Alternatives to LH/LOX
Date: Thu, 16 Nov 2000 20:16:18 GMT

In article <>, Doug Jones  <> wrote:
>> >The ignition delay of H2O2/kerosene isn't short enough...
>> Out of curiosity, is there anything you can put in kerosene which
>> helps that?  Does permanganate dissolve in it?
>No, kerosene is a classic nonpolar solvent and permanganate is a salt...

However, there are organic salts which will dissolve well enough in
kerosene and will make peroxide do its thing.  The Sept/Oct 1998 JP&P has
a paper on non-toxic OMS/RCS propellants which discusses work on this.
When failure is not an option, success  |  Henry Spencer
can get expensive.   -- Peter Stibrany  |      (aka

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