Perchlorate pollution article 8/10/03

That might be mildly relevant if we buried our rocket motors. But we don't - we burn them. The byproducts are oxides and hydrochloric acid. All of the AP will be consumed unless it exceeds about 93% of the composite (which it doesn't).

One could argue, semi-seriously, that at the amateur and EX end of the spectrum, rocketeers are performing a public service of environmental remediation for Ammonium Perchlorate. A goodly fraction of the AP used by EX types is surplused from regular commercial motor production (mostly military). The stuff would otherwise sit around for who knows how long, possibly leaking out of containment and getting into the groundwater.

Decompose it, that's what I say!

The nastiest of the combustion products of HPR motors is HCl, which has a fairly short environmental lifetime, forming chlorides from ground-based carbonates quite readily.

How much AP is released from handling reload grains? Do you really think ALL the AP burned when you clean out that casing? Licking your fingers after such operations is probably not a swell idea.

HCl reacts even faster with moist lung tissue. According to my NIOSH pocket guide, hydrogen chloride has an IDLH of 100 ppm. That stands for Immediately Dangerous to Life or Health, usually defined as maximum exposure for 30 minutes or less. So deep breathing while standing in the plume is probably also not a good idea.

George W. Scheil

"David" wrote in news:%TTZa.12069$ snipped-for-privacy@twister.southeast.rr.com:

Rockets cause acid rain! Acid rain! The sky is melting! The sky is melting!

len.

again ... the issue is not what REALLY happens, it's what some uninformed/cya policy wonk in washington PERCEIVES happens.

sadly, reality does not define federal government policy. facts are selectively used to support predetermined policy based on politics or fear or heresay. as is the case with hsa and s.724, and was the case for invading iraq.

ignore now, pay later.

That's true of a lot of things. Licking your hands after fixing the lawnmower isn't a good idea. You don't see widescale bans on the use of gasoline and oil, yet released into the environment, they're not good for it...ask an Exxon duck sometime :-(

Right, but the discussion here is about longer-term environmental effects. Not immediate toxicity effects. If they're concerned about the long-term effects of having AP around in the environment, then converting it, by combustion, into rather benign products (H2O and CO2 predominantly), and nastier things that have a much-shorter environmental lifetime (HCl) is probably a good thing.

People drink gasoline in lieu of alcohol and besides inbreeding and maintainance of an already low IQ, it has no accute ill effects.

Jerry

You got some strange friends, Jerry... :)

-dave w

Yes I do DAVE :)

Jerry

snipped-for-privacy@propulsionpolymers.com (Marcus Leech) wrote in news: snipped-for-privacy@posting.google.com:

It's all a moot point as far as hobby rocketry is concerned. I'd be willing to bet that more AP is discarded during the manufacture of a single shuttle booster reaload than is used of all of hobby rocketry in an entire year.

I once got a faceful of formic acid vapour. Weird stuff. It feels like being slapped upside the head, and then your sinuses close *hard* for about 20 minutes after exposure. Kind of like that "inner eyelid" thing in Star Trek where Spock goes temporarily blind...

Jerry Irvine wrote in news: snipped-for-privacy@news.verizon.net:

Should be easy to do a back of the envelope calculation. What's the total impulse ratio of a shuttle SRB to say, a G or H motor (ballparked as the average APCP sport rocketry motor)? Assume the wastage rates are about the same. Just how much APCP is consumed annually by sport rocketry?

len.

I'd agree if you change YEAR to CENTURY.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Darn close.

Ballpark, we each consume about 10kg per year, on average. Some of us much more than this, some of us, much less. The wastage is probably on the order of 1%.

There are perhaps 5000 regular consumers of HPR APCP worldwide, so that's 10kg * 5000 = 50000kg of propellant consumed in HPR.

A single SRB consumes about 550,000kg of propellant * 1% = 5500kg of wasted propellant. That means that (if the 1% waste is correct) that a single SRB wastage is only 10% of the HPR annual consumption.

snipped-for-privacy@propulsionpolymers.com (Marcus Leech) wrote in news: snipped-for-privacy@posting.google.com:

The original question was about sport rocketry's environmental. impact. Using your numbers, annually it's about 1/10 that of a single SRB.

len.

And vastly distributed over geography and time this dilutred by nature to a HUGE degree.

Jerry

According to the ATK Thiokol website (the folks who make the SRBs), they have a perchlorate recovery mechanism in place, and have been using it for quite a while to yield a "zero emissions" closed cycle. Presumably, their scraps are part of this cycle.

Since the SRB propellant is fairly simple (PBAN+Al+Fe2O3+NH4ClO4), I imagine that they use some funky solvent to dissolve the PBAN, leaving Al, Fe2O3, and NH4ClO4. Hot water nicely dissolves the AP, leaving you with Al+Fe2O3 in the right ratio to add to your next batch of propellant. Evaporate the saturated NH4ClO4 solution, grind and grade. I bet they have a patent...

An SRB is a wimpy class AE motor (5 past Z). They are consumed in pairs, at the former rate of about a dozen a year. 1/4A:Q as M:AE

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!