Sunday, March 18, 2012

Aquaculture Habitat Lake for Mars

Corresponding with other space travel enthusiasts on the New Mars forums, I have run across the idea of using the hydrostatic pressure of water, as a pressurizing medium, in which to live on Mars. I was at first a bit skeptical of the idea, but the more I thought about it, the more its practicality became apparent.

With some simple earthmoving activities, it would indeed be fairly easy to transform a suitable large ravine or smaller crater into a suitable lakebed. The frozen nature of the surface of Mars pretty much makes that lakebed impermeable.

With the application of energy, ice could be mined from existing deposits, transported to the lake bed, and melted. This filling process would have to take place under a surface icepack layer, to prevent the water (triple point: 0 degrees C at 6 mbar vapor pressure) from boiling away into the extremely low pressure, very dry, cold Mars atmosphere (around 7 mbar, 0% humidity, subzero).

Once the lake is filled, the icepack itself could be stabilized against sublimation by burial under a Mars regolith layer, mostly the spoils from the creation of the lakebed. Done in an engineered way, this provides a stable pocket of deep liquid water, of increasing hydrostatic pressure with depth.

Adding organic sediments to the lake bottom would enable the start of an aquaculture farming enterprise down in the lake. This would also require the installation of artificial lighting, both for photosynthesis, and to keep the lake from refreezing.

The pressurized habitat accompanying this farm would necessarily be two levels (or more). One level provides surface access for personnel in appropriate vacuum suits. The other provides access for wet-suited scuba divers into the lake, which provides the needed compression on their bodies by simple hydrostatic pressure.

The submerged portion of the habitat is the shelter location for radiation protection during solar storms. It is under a thick cover of regolith, ice, and water, which is the real shielding. A meteor strike would be self-healing, in that the hole would soon freeze over, needing only reburial with more regolith.

A concept sketch of such an aquaculture lake on Mars might look like is given below. My thanks to the other correspondents who sparked this little investigation.

For an oxygen atmosphere in the neighborhood of 250 mbar total atmospheric pressure in the habitat, the equivalent water depth at 0.38 gee on Mars would be near 6 or 7 meters. The scuba could be pure oxygen at these pressures, and that level is also compatible with known designs for mechanical counterpressure vacuum suits.

For atmospheres with dilution gases, the oxygen partial pressure needs to be in the range of 200-250 mbar. The total pressure is higher, and so is the required depth, accordingly.

Divers should not risk rising higher in the lake than the appropriate pressure depth restriction, which would include the ice and regolith overburden thickness. So, if the cover on the lake is thick enough, divers can approach the bottom of the ice without pressure suits.

This may actually be the most practical way to effectively-pressurize the enormous amounts of “land” area necessary to do farming on the scale necessary to support a base or settlement. It certainly seems more practical than building immense transparent domes of some kind.

The aquaculture would be a closed ecology, something we have never before successfully constructed. Furthermore, this one would be different than anything we ever attempted in the past. Although, successful inland shrimp farms have been done. That says this technique can be done, if we but learn it.

I see this as one of the possible critical enabling technologies that we would need in order to plant permanent bases or settlements on Mars.

Hmmmmmm. I wonder what a bulldozer designed for Mars would look like?

GW

Update 1-26-13:  See "Aboveground Mars Houses" dated 1-26-13 for a pressurizable structure approach in which people might live,  garden,  and farm land-dwelling plants and animals. 




(click on this image to see an enlargement)

Sunday, March 11, 2012

“Icecrete”, a Substitute for Concrete as a Building Material on Other (Colder) Worlds

I’ve been considering what might be a good substitute for concrete, as a structural material, for use on places like Mars, the moon, and the near Earth objects (NEO's; asteroids and comets in the inner Solar System).

The fundamental idea is easy production from maximum use of local materials, namely rocks, rock dust/sand, and ice. Most of these worlds have those materials in abundance. Most are very cold, at least in the shade. Shipping stuff from Earth is very expensive, yet the construction need is real: landing facilities, buildings for bases, roadways and buildings for outposts, eventually colonies.

I'm thinking of an analog to the Pykrete that was proposed in WW2 for the "Habbakuk" iceberg aircraft carriers. I found that Pykrete formula: 80% ice, 20% wood pulp fiber. I also found out that they tested it in Canada with a small prototype boat during WW2.

It was almost as strong compressively, and about as resistant to bullet impact, as plain concrete. It did have a tendency to sag (creep), so reinforcement was mandatory. It was slower to melt, with the right kind of filler. Other people in later years using different fillers did not achieve melting resistance.

Comparative Properties of Materials: Mechanical Properties

Material ------------------- Ice Concrete Pycrete
Crushing Strength (MPa) 3.447 17.240 7.584
Tensile Strength (MPa) --- 1.103 1.724 4.826
Density (kg/cu.meter) --- 910 -- 2500 -- 980

This concept led me to the concept of "icecrete" (for lack of a better name). You barely melt some local ice, and add local sand and rocks as aggregate, just like concrete. These local aggregate materials will need to be sieved for appropriate sizes, and the rocks tumbled for correct non-angular shape. You then make the mix just like concrete here, adding just enough water to the dry ingredients to barely fluidize the mix to a thixotropic paste. Then you pour it into forms, just like here, and let it freeze in the ambient cold.



One must coat the surface to prevent sublimation (that is a whole other problem to solve). This sublimation problem is ambient water vapor partial pressures below the sublimation vapor pressure of the exposed ice in the “icecrete”.

If the ambient atmospheric pressure is low enough (or zero, as on the moon and NEO’s), there is no countervailing water vapor partial pressure to prevent exposed ice sublimation. Thus a coating is required, one which acts as a barrier between the ice matrix and ambient conditions. This barrier’s adhesion to the ice surface must exceed the vapor pressure exerted by the ice at its temperature (6 mbar max at 0 degrees C max).





In “icecrete”, there's less ice and more filler than the old Pykrete formula, and in "icecrete", the filler is very hard, and also shaped very differently. I'm only guessing that it may be as strong as, or even stronger than, plain concrete. The higher aggregate content should reduce sag (creep). However, those experiments need to be done!

Plain “icecrete” could be reinforced with tensile elements the same way we do reinforced concrete here. Those elements could be steel rebar imported from Earth, or they could be braided ropes made locally of basalt fiber (or some other rock fiber) derived by melting local rocks. A high Young's modulus for the fiber is nice, but the effective Young’s modulus of the rope will be far less than the individual fiber values.

In any event, the Young's modulus of the reinforcement should exceed that of ice, in order to behave in any way like real reinforced concrete. I'm also thinking that even pre-stressed beams for bridges and buildings could be made using tensioned steel rods, thrust plates, nuts, and washers, the same way we do here. That steel stuff would have to be imported from Earth.

“Icecrete” casting forms: sheet metal recycled from old spacecraft, stage, and tank plating? There would also need to be some sort of stake material and some sort of framing members. All of this could be recycled material from spent rocket equipment. I'm thinking some sort of vacuum wire-feed welding, of recycled aluminum rocket materials, could be used to assemble such cast forms.

Anti-sublimation coating: this would need to be a rather thick water-based (latex?) paint applied to the utterly-dry frozen surface, of sufficient adhesion to balance the vapor pressure at the frozen temperature (6 mbar at 0 degrees C, much less pressure colder). That basic water-based paint idea comes from the water-based paints used to stripe the ice layers at hockey rinks.

Or if that doesn't work, we could try covering the freshly-poured structure with a terry-cloth towel material, and let it freeze directly into the surface of the “icecrete”. Then paint the exposed towel surface with the thick paint. The peel strength ought to be really, really high that way.

We're going to need a thick paint that "dries" in vacuum, and yet doesn't bubble in vacuum, either. That’s a tall order. But it is doable, I think, based on the caulk gun repair kits developed for the old Space Shuttle’s heat shield tiles.

Some have suggested bonding thin Mylar film (or something similar) to the exposed surfaces of the “icecrete”. I’m not at all sure how to effect that bond, but an etched surface on the film seems a good starting point. If a plastic or polymer film or paint is used, it will have to be protected from exposure to ultraviolet (UV) radiation, by shading appropriately.

“Icecrete” ought to be really useful on Mars (or even the moon) for roadways, bridges, large-span open buildings, smaller buildings that have to hold pressure, etc. On the moon, just shade the structure during the day, and it stays very cold. The same is true on Mars, although day temperatures are below freezing there, anyway. For roadway surfaces on either world, a thin sand overburden on the “icecrete” surface would prevent wear.

There might even be way to build-into the structure of an NEO, anchor points made out of “icecrete”, either for anchoring outpost structures there, or else for tow points for asteroid deflection. Either could be a very important capability in the very near future.

Suggested Experiments:

Make samples in freezers here on Earth for structural properties tests. Scope would include compressive strength and creep properties of plain “icecrete”, compressive strength and creep properties of reinforced “icecrete” with a variety of reinforcing materials, and some first attempts at developing a pre-stressed “icecrete” beam. These can all be bare material.

Make “icecrete” samples for surface coating experiments in freezers here on Earth. Test various means of applying a barrier coating to prevent sublimation. Test these, at temperatures not to exceed 0 degrees C, in vacuum chambers here on Earth for effectiveness at preventing sublimation.

Develop the pre-stressed "icecrete" beam concept further.

Attempt mixing and casting small “icecrete” items in sheet metal forms in vacuum conditions here on Earth. This could be done in the space simulation chambers at NASA Houston. This would correspond to similar activities on worlds with significant gravity, such as Mars and the moon.

If successful, a similar activity could be conducted at the space station, to develop and refine casting techniques (probably "pressure-packing" into a closed space) in zero-gee conditions (similar to what would be needed to use “icecrete” on an NEO).

Conclusion:

If ever there was some basic research and development work needed to support future space exploration and colonization efforts, this is it! NASA, ESA, JAXA, the Russians, and the Chinese really, really, really need to take a look at this!

Acknowledgements:

My thanks to friends, and to on-line correspondents, who have contributed greatly to this idea.

GW

Update 1-26-13:  see also "Aboveground Mars Houses" dated 1-26-13 for some related construction concepts.  A real concrete-substitute will be required for those uses,  as "icecrete" will be inappropriate at living space temperatures,  and if exposed to sublimation.  

Saturday, March 10, 2012

On Iran and the Bomb

I hear a drumbeat for war with Iran over its acquisition of nuclear weapons. This comes from Israel, several other countries, and our own political right wing.  See also "Third North Korean Nuclear Test" dated 2-15-13 above. 

Israel, I can partly understand. Their arsenal is much smaller and less capable than ours. If, and only if, Iran is trying to use atomic bombs, then taking out Iranian nuclear facilities makes sense for them. This includes threats to use, as well as real use.

The other countries have their own decisions to make. Our policy is that “Iran shall not have an atomic bomb”, and “all options are on the table”. I submit that we are way too late for that.

For some years now, the Iranians have been acquiring the technical know-how and the hardware to make both reactors and their own nuclear reactor fuel. Their reactors (plural) are now in operation, and so is their uranium enrichment effort.

A little science and technology: natural uranium is a poor but “sort-of” usable reactor fuel. It works a whole lot better if you enrich the fissionable species U-235 (0.3% of natural uranium) relative to the nonfissionable species U-238 (99.7% of natural uranium).

There are multiple ways to “enrich” uranium, but the most popular one today is gas centrifuge technology, which works approximately like the centrifuges used in blood test work. For the enrichment process, this involves the use of aluminum tubing (but then so do a lot of other things).

Without revealing any state secrets (this has been public knowledge since about the mid 1950’s) I can say that anything over about 20% U-235 is pretty good reactor fuel. Anything over about 50% U-235 is very good reactor fuel, and good enough to build a simple bomb.

It’s just more passes through the same “still”, or somewhat fewer passes through a better quality “still”, to produce 50+% U-235. In other words, there is no difference between the technology required to build crude, first-generation atomic weapons, and the technology required to build atomic electric power. The politicians are lying to you about there being some difference.

It has also been public knowledge since the mid-1950’s that the Hiroshima bomb (“Thin Man”) was two pieces of enriched U-235 brought together by a piece of dynamite behind one of them. They didn’t even test this in 1945, they already knew it would work, they just dropped it on Japan. The more highly enriched beyond 50% U-235, the smaller the two pieces can be. See following the data from Wikipedia that describe “Thin Man”, our Hiroshima two-piece uranium bomb:

Type Nuclear weapon
Place of origin United States
Specifications Weight 9,700 pounds (4,400 kg)[1]
Length 120 inches (3.0 m)[1] Diameter 28 inches (710 mm)[1]
________________________________________
Blast yield 13–18 kt (54–75 TJ)





What that really says, and what the politicians do not want you to know, is that anyone operating a reactor on fuel they made, can build a crude “Thin Man” type of bomb. This includes Iran, who has been running a reactor they fueled themselves, for a few years now.

That there is supposed to be a difference between peaceful atomic power and atomic weapons is nothing but a convenient political lie, there is no difference. The folks that make and sell enrichment equipment simply want more customers. They own the politicians, so the political lie disguises what happens when they sell to countries like Iran, North Korea, etc.

It gets worse: the “inert” U-238 component is “fertile”, in the sense that exposure to nuclear radiation in a reactor core transmutes it to plutonium (Pu-239), which is also fissionable, and is actually easier to separate by chemical means from all that uranium.

Anybody operating an enriched-uranium reactor is generating plutonium. Fissionable plutonium is both a very good reactor fuel, and a very good bomb-making material, if you have the know-how to set it off. That is the key!

Again, all of this has been public knowledge since the mid-1950’s, I am revealing no state secrets. You might ask how I know of this: I had to understand the warheads of the missiles that I designed as an aerospace defense weapons engineer, long ago.

Plutonium bombs are a lot more difficult to detonate, requiring a very precise implosion wave to bring them to critical mass. This is the “Fat Man” bomb, which we did have to test in the New Mexico desert, before dropping it on Nagasaki, Japan.

Exactly how to do that is the state secret that the Rosenbergs died for, and I will not reveal it, either. It is not a secret that you learn from enriching your own uranium. The Iranians do not have this secret. See the following data from Wikipedia describing our “Fat Man” Nagasaki plutonium implosion bomb:

Type Nuclear weapon
Place of origin United States
Specifications Weight 10,213 pounds (4,633 kg) Length 10.7 feet (3.3 m) Diameter 5 feet (1.5 m)
________________________________________
Blast yield 21 kt (88 TJ) ~75 Million sticks of dynamite.





So, the Iranians already have nuclear weapons, contrary to the public pronouncements, but what they have is the crude two-piece enriched-uranium bomb. And only a very few of those. Yield might be in the range 5 to 50 kilotons, roughly the same as our Hiroshima bomb (15-25 kiloton). The recent earthmoving activities photographed from space at one of their nuclear sites very probably are an attempt at hiding the work on a plutonium implosion bomb trigger.

The Iranians already have a satellite-launcher rocket. We already know that any launcher is also an ICBM, and vice versa, because we ourselves “already did that” in the 1950’S. But, precision guidance, that is another matter entirely. The Iranians cannot precisely hit a city, not yet.

So, what could the Iranians actually do with a crude, low-yield, imprecisely-targeted atomic bomb capability? Scare the crap out of the Israelis? Yep. Hit one of Israel’s cities? Maybe, but unlikely. Hit one of our cities? Not very likely at all.

The Israelis have had crude nuclear weapons for many years now (first test ca. 1979, observed in the South Atlantic by one of the early VELA satellites, although that detection has been officially denied for decades). I estimate they might have around 100 such bombs.

If Iran flings one of a very few atomic bombs at Israel, what do you think is going to happen to Iran? Israel will destroy them. Those idiots in charge of Iran know that, no matter how extremist they might be.

Could Iran hurt us with a crude nuke, if backed far enough into a corner to actually fling one out of extreme desperation? Yes, but not by the blast, its yield is too low, and their targeting is imprecise.

There is an “EMP” effect of a small nuke detonated in space 100-500 miles up, over the center of the North American continent, known since the early 1960’s. It destroys all solid-state electronics: cell phones, TV’s, computers, and car ignitions. Devastating, but not very lethal. And, very imprecise guidance is all that is required. Iran actually could do that.

Iran has a single handful of low-yield nuclear weapons. We have over 1000 of them, all 100+ kiloton high-yield weapons, and we have very precise means of delivering them. If they hit us with that EMP attack, or with a “terrorist” suitcase nuke, what do you think is going to happen to Iran?

No matter how idiotically-extremist Iran’s government might be, they already know that outcome: death to nearly all in Iran, almost none in the US.

Is the government of Iran really idiotically-extremist? Yes. So what?

Are the Iranian people decent folk? Yes. We do not need to kill them.

Let the sanctions work, and forget this political drumbeat for another war. All it is doing is raising your gasoline prices due to war fears. Most analysts agree that is the major factor behind the last few month’s price rise.

It is too late to stop Iran from obtaining atomic bombs, they already have a couple of small ones. The time to fight is when they use one, or even threaten to use it. But not till then.

After 5000+ of our children dead, haven’t you had enough of wars in the middle east? I certainly have.

Thursday, March 8, 2012

Iran, Oil, and Economies

What follows is an analysis of real data. It is very, very hard to argue with measured numbers, and with historical facts. This explains why I believe what I believe, and say what I say, about the various topics of Iran (and the middle east in general), oil, and our western economic troubles in recent decades.

These things are all connected, and not in a nice way. Many of you will not like what I have to say about this. But, please, do think carefully about it, before you choose to continue believing all the propaganda we are constantly bombarded with (especially in election years).

Figure follows, as copied from zfacts.com Wed 3-7-12, to show an inflation-corrected fuel price history for US national average regular gasoline prices since the 1970's (the noted events are theirs):



Now, what follows is the same zfacts.com plot, as modified by GWJ Wed 3-7-12 to reflect more historical events during those same years:



Oops, error correction 3-15-12: Where it says "Iran invades Kuwait 1990" in this figure, it should read "Iraq invades Kuwait 1990".

There are some painfully-obvious correlations between fuel price spikes and the noted historical events, as indicated so plainly by the second figure. Here is my more detailed analysis of all those correlating features.

Re: 1973 Oil Embargo - Iran, still under the Shah, did not vote to hurt the west by an oil embargo. But, once OPEC voted, all its members, Iran included, went along, and made scads of money off it.

Re: Iran hostage crisis – Iranians deposed the Shah, invited Khomeini home, and invaded the US embassy and took hostages. We have been crossways with them ever since. Were the US embassy personnel intelligence operatives? Yes, most or all were. So what? Who has an embassy with personnel that are not some sort of spies? “Embassy spies” is irrelevant as an issue.

Re: “Carter inflation years” – these years of combined "economic stagnation" and severe inflation persisted well into Reagan’s second term. The better times came very shortly after fuel prices dropped, at almost exactly the same time as Reagan gave the Iranians the weapons they wanted, in the Iran-Contra scandal/deal.

Substantive conclusion: Reagan’s GOP economic policies did not lead to good times, low fuel prices did.

Second substantive conclusion: Democrat economic policies under Carter had little or nothing to do with stagflation, high fuel prices did.

Re: Iraq (error correction 3-15-12) invades Kuwait – One OPEC member invades another, but there was no monopoly cartel price hike (no one in the west to "punish" for it). The smaller, brief price spike measures the effects that war fears have upon fuel price speculators, and their relative impact upon fuel prices as a whole.

Re: 1st Gulf War US Invasion 1991 - this was caused by an OPEC member (Iraq) who misbehaved by invading another OPEC member (Kuwait) in 1990. The rest of OPEC actually wanted us to kick them out of Kuwait. So there was not any effect on fuel prices.

Re: US invades Afghanistan 2001 – Afghanistan is not an OPEC member. It has no oil reserves. That there was no effect on fuel prices is not really surprising. Nobody, not even OPEC, cared anything about Afghanistan. If you go back and look, the Soviet invasion of Afghanistan had no effect, either (1980-1989).

Re: US invades Iraq 2003 - the US invades looking for WMD’s that weren’t there. There is an immediate price spike-up as "punishment" to the western coalition for invading an OPEC member. There is a steady increase in price as long as we are there, right up to the Great Recession.

Re: “Great Recession” begins – 2 years above $3/gal sent us into the deepest recession/depression since the 1930’s. Evidently, the higher the spike, and the longer prices are high, the worse the recessionary effect.

Re: “trigger level” – seems to be about $2.50/gal gasoline, in March 2012 dollars. Again, the higher the price, and the longer it stays there, the worse the effect. Two bad events (’79 and ’03) show the very same thing.

Substantive conclusion: western economies, "designed" by the "dead hand of Adam Smith" to run on cheap fuel, do very, very poorly whenever fuel prices are high enough long enough.

Re: “free market” – if fuel prices were really governed by free market forces and not monopoly cartel whims, one would expect roughly factor-7.5 inflation applied to the 1958 price of regular gasoline (22-26 cents/gallon back then), for the $1.75-$2.00/gal price range shown. Soda pop and bread prices do indeed reflect this factor-7.5 inflation effect. Fuels do not.

Substantive conclusion: therefore, fuel prices are not governed by free market forces, although they do respond to them.

Substantive conclusion: fuel prices are quite evidently set mainly by monopoly cartel pricing during two periods during the last 4 decades. This graph indicates two very severe episodes of punitive pricing, which are quite evidently economic warfare aimed at the west.

Re: fixed max OPEC production ceiling – an approximation based on reported Saudi figures, justifiable since the Saudis dominate all OPEC production. They have reduced below, but never exceeded, their 2004 production rates.

Historical fact: one symptom of “peak oil” from any given field is the inability to increase production rates with the same methods, when heretofore, production increases were possible.

Historical fact: the 3 largest oil fields ever discovered anywhere on the planet are the 3 largest Saudi fields, whose 2004 production rates seem to be no longer increasable.

Well-Supported Fear: planetary “peak oil” began just about 8 years ago, with respect to about 2/3 of the world’s supply. This would constitute a change in the conditions underlying the oil market since 2004, from those conditions underlying it from 1970 to 2004. It might partly explain the steady ramp-up of fuel prices since 2002 (interrupted by the Great Recession) as world supply falling short of world demand for the very first time in history, since the first oil well was drilled in 1869.

Other Notes:

1. It is hard to argue with numbers and with recorded history. On the other hand, it is always possible that my inferences of causality are incorrect. Correlation is certain, causality is an interpretation. But I know how people behave. So, I do not think I am wrong. Not by a long shot.

2. Historically, it takes about 4 decades to replace one major industry with another in a market economy not driven by regulation or tax structures. We should have started replacing oil-based transportation fuels in 1973. We did not. We are in very deep trouble now, with the prospect of permanent economic depression due to chronic high fuel prices.

3. We are still crossways with Iran. They are the 3rd largest producer in OPEC. It sure would be nice if we were friends again. Hard to do when their government hates ours so. That their government is whacko-extremist-crazy by our standards is actually irrelevant, although it does explain a lot to me.

4. OPEC formed in 1963 specifically to be a price-fixing cartel. The US passed its peak oil production shortly after, about 1965 or 1970. After that, the influence of US oil production on world oil prices declined sharply, as did our production. Our imports soared. Today, 2/3 of world oil production is OPEC. They largely set world oil prices, therefore. If they start a rumor of war in the Mideast, world oil prices rise out of fear. Simple as that.

5. A few years after US production in the "lower 48" peaked, there was the introduction of Alaskan oil from Prudhoe Bay, via the Alaskan oil pipeline. This did not stave off US imports, being but a bump on the declining trace of US production over time. Alaskan production actually peaked in 1985, and has declined ever since. All discoveries since have been smaller still. This includes ANWR (actually just the east end of the Prudhoe Bay field), and the deepwater Gulf. Whatever there is off California, and whatever there might (or might not) be off the Atlantic coast, is smaller still. Whatever "frackable shale oil" there is in the Williston Basin is even smaller still, although it does currently support an oil boom in Montana and North Dakota.

6. Williston Basin “frackable shale oil” is not really shale oil. Shale still cannot be “fracked” for oil, only for gas. Oil is not mobile enough at those porosities and connectivities. There is a dolomite layer sandwiched within the Williston Basin shale that also contains a light crude, and that layer is “frackable”. But, it’s a smaller fraction of the Williston Basin “resource”. See also “Bakken”.

7. When US politicians promise cheap fuel at $2.50/gallon by opening up our remaining reserves, they are lying, most egregiously. We could not significantly affect world oil prices, no matter how much we produced, because those undeveloped reserves we do have, are simply too small to ever significantly affect world oil supply.

8. The only possible way to produce “cheap oil” would be to opt completely out of the world oil market (we consume what we produce, without ever putting it on the market). The only way to do that would be to nationalize the oil industry, which is political anathema to those who claim (for political campaign purposes) we could do this. And, there would never be enough oil to satisfy our domestic demand. So, why bother? Pump the oil, yes! Depend on it to “save” us? No way!

9. Substantive conclusion: believe no politician or political party when they say they know how to deal with (or even significantly affect) high oil prices, or when they claim their ideologies and party agendas have any effect on the economy, beneficial or otherwise.

GWJ 3-7-12

Update 1-3-15:

The recent explosion of US “fracking” technology (hydraulic fracturing plus horizontal-turn drilling) has modified the picture of oil prices versus recessions.  Unexpectedly,  the US has become a leading producer of crude oils for the world market.  Plus,  there has been an associated massive production increase and price drop in natural gas.

OPEC has chosen to take the income “hit” and not cut back their production in response.  Their reasoning is twofold:  (1) fear of loss of market share,  and (2) hope that low oil prices will curtail US “fracking” recoveries.  We will see how that plays-out.

Oil prices are now such (at around $55/barrel) that US regular gasoline prices are nearing $2.00/gal for the first time in a very long time.  This is very close to the price one would expect for a truly competitive commodity,  based on 1958 gasoline prices in the US,  and the inflation factor since then. 

It is no coincidence that the exceedingly-weak US “Great Recession” recovery has suddenly picked up steam.  The timing of the acceleration in our economic recovery versus the precipitous drop in oil prices is quite damning.  There can be no doubt that higher-than-competitive-commodity oil prices damage economies.  Oil prices are a superposition of the competitive commodity price,  overlain by an erratic increase from speculation,  and further overlain quite often by punitive price levels when OPEC is politically unhappy with the west.  That’s been the history. 

This economic improvement we are experiencing will persist as long as oil,  gas,  and fuel prices remain low.  (Government policies have almost nothing to do with this,  from either party.)  How long that improvement continues depends in part upon US “fracking” and in part upon OPEC.  Continued US “fracking” in the short term may depend upon adequate prices.  In the long term,  we need some solutions to some rather intractable problems to continue our big-time “fracking” activities. 

The long-term problems with “fracking” have to do with (1) contamination of groundwater with combustible natural gas,  (2) induced earthquake activity,  (3) lack of suitable freshwater supply to support the demand for “fracking”,  and (4) safety problems with the transport of the volatile crude that “fracking” inherently produces. 

Groundwater Contamination

Groundwater contamination is geology-dependent.  In Texas,  the rock layers lie relatively flat,  and are relatively undistorted and unfractured.  This is because the rocks are largely old sea bottom that was never subjected to mountain-building.  We Texans haven’t seen any significant contamination of ground water by methane freed from shale.  The exceptions trace to improperly-built wells whose casings leak.

This isn’t true in the shales being tapped in the Appalachians,  or in the shales being tapped in the eastern Rockies.  There the freed gas has multiple paths to reach the surface besides the well,  no matter how well-built it might have been.  Those paths are the vast multitudes of fractures in the highly-contorted rocks that subject to mountain-building in eons past.  That mountain-building may have ceased long ago,  but those cracks last forever. 

This is why there are persistent reports of kitchen water taps bursting into flames or exploding,  from those very same regions of the country.   It’s very unwise to “frack” for gas in that kind of geology.

Induced Earthquake Activity

This does not seem to trace to the original “fracking” activity.  Instead it traces rather reliably to massive injections of “fracking” wastewater down disposal wells.  Wherever the injection quantities are large in a given well,  the frequent earthquakes cluster in that same region.  Most are pretty weak,  under Richter magnitude 3,  some have approached magnitude 4. 

There is nothing in our experience to suggest that magnitude 4 is the maximum we will see.  No one can rule out large quakes.   The risk is with us as long as there are massive amounts of “fracking” wastewater to dispose of,  in these wells.  As long as we never re-use “frack” water,  we will have this massive disposal problem,  and it will induce earthquakes. 

Lack of Freshwater Supply to Support “Fracking”

It takes immense amounts of fresh water to “frack” a single well.  None of this is ever re-used,  nor it is technologically-possible to decontaminate water used in that way.  The additives vary from company to company,  but all use either sand or glass beads,  and usually a little diesel fuel.  Used “frack” water comes back at near 10 times the salinity of sea water,  and is contaminated by heavy metals,  and by radioactive minerals,  in addition to the additives.  Only the sand or glass beads get left behind:  they hold the newly-fractured cracks in the rocks open,  so that natural gas and volatile crudes can percolate out. 

The problem is lack of enough freshwater supplies.  In most areas of interest,  there is not enough fresh water available to support both people and “fracking”,  especially with the drought in recent years.  This assessment completely excludes the demand increases due to population growth.  That’s even worse.

This problem will persist as long as fresh water is used for “fracking”,  and will be much,  much worse as long as “frack” water is not reused.  The solution is to start with sea water,  not fresh water,  and then to re-use it.  This will require some R&D to develop a new additive package that works in salty water to carry sand or glass beads,  even in brines 10 times more salty than sea water. 

Nobody wants to pay for that R&D. 

Transport Safety with Volatile “Frack” Crudes

What “fracking” frees best from shales is natural gas,  which is inherently very mobile.  Some shales (by no means all of them) contain condensed-phase hydrocarbons volatile enough to percolate out after hydraulic fracturing,  albeit more slowly than natural gas.  Typically,  these resemble a light,  runny winter diesel fuel,  or even a kerosene,  in physical properties.  More commonly,  shale contains very immobile condensed hydrocarbons resembling tar.  These cannot be recovered by “fracking” at all. 

The shales in south Texas,  and some of the shales and adjacent dolomites in the Wyoming region actually do yield light,  volatile crudes.  The problem is what to transport them in.  There are not enough pipelines to do that job.  Pipelines are safer than rail transport,  all the spills and fires notwithstanding. 

The problem is that we are transporting these relatively-volatile materials in rail tank cars intended for normal (heavy) crude oils,  specifically DOT 111 tank cars.  Normal crudes are relatively-nonvolatile and rather hard to ignite in accidents.  DOT 111 cars puncture or leak frequently in derail accidents,  but this isn’t that serious a problem as long as the contents are non-volatile.  These shale-“frack” light crude materials resemble nothing so much as No. 1 winter diesel,  which is illegal to ship in DOT 111 cars,  precisely since it is too volatile. 

The problem is that no one wants to pay for expanding the fleet of tougher-rated tank cars.  So,  many outfits routinely mis-classify “frack” light crudes as non-volatile crudes,  in order to “legally” use the abundant but inadequate DOT-111 cars.  We’ve already seen the result of this kind of bottom line-only thinking,  in a series of rather serious rail fire-and-explosion disasters,  the most deadly (so far) in Lac Megantic,  Quebec. 

Volatile shale-“fracked” crudes simply should not be shipped in vulnerable DOT 111 cars,  period.  It is demonstrably too dangerous. 

Conclusions

“Fracking” shales for natural gas and light crudes has had a very beneficial effect on the US economy and its export-import picture.  We should continue this activity as a reliable bridge to things in the near future that are even better. 


But,  we must address the four problem areas I just outlined.  And I also just told you what the solutions are.  The problem is,  as always,  who pays.   What is the value of a human life?  What is the value of a livable environment?  It’s not an either-or decision,  it’s striking the appropriate balance!

Tuesday, March 6, 2012

Student Pulsejet a Hit at EAA Meeting

At TSTC, we have a welding student, Justin Friend, who has built some valveless pulset engines for a personal hobby. I have already posted some of his initial accomplishments with his first engine previously. That posting is titled “Student Pulsejet Project”, dated 12 November, 2011. Just scroll down, it’s not far below.

Justin Friend has since built a second, much larger valveless pulsejet engine. That unit needs to be “tuned-up” a bit before he can demonstrate it. It is very large, as Figure 1 shows. That’s Justin standing by his truck. The big engine is alongside the golf cart with the little engine, both in the bed of his truck.

This young man is looking for sponsors so that he can continue building and operating these unique jet engines. If you readers have anything to offer, contact me by email or by the “comments” here. He also graduates in May, and clearly does very good fabrication and welding work, as these accomplishments testify. If any of you readers might be interested in hiring him, again, let me know by email or in the “comments” here.



Figure 1 (P1030915.JPG) – Justin by his truck with his engines in the back

Local Experimental Aircraft Association (EAA) chapter 59, at the McGregor airport, invited Justin to demonstrate his pulsejet golf cart last Saturday morning, 3 March 2012. That event was very well attended, and the pulsejet golf cart was a really big hit with this experimental airplane crowd. There’s just not much that’s more fun, than converting perfectly good fuel into fire, smoke, and noise. This is especially true if you get to drive it around while doing it. Figure 2 is a typical view of the crowd. I’m in the straw cowboy hat chatting with the old guy with the long white hair.



Figure 2 (P1030916.JPG) – The crowd talking with Justin before the demonstration

In the next photo (Figure 3), Justin is getting ready to start the pulsejet on the golf cart. He’s hooking up the ignition. I’m telling folks to plug their ears against the noise. The leaf blower on the pavement is the source of the starting air. Once it starts, the ignition and starting air are disconnected, and the engine runs all by itself. This one runs on bottled propane, just like a barbecue grill.



Figure 3 (P1030922.JPG) – Getting ready to start

Figure 4 is Justin getting into the golf cart, to make his first run up and down the rampway between the hangars. The barrel in the cart is a big propane cylinder. That’s the fuel supply. The engine throttles up and down by raising and lowering the propane feed. The pulsejet is the only motor the cart has. No battery, no electric motor. Just steering and brakes intended for low-speed driving.



Figure 4 (P1030925.JPG) – Engine running, Justin getting in to drive it.

The second run, I drove it, but I switched hats, as you can see in Figure 5. It accelerates away pretty slowly at only 50 pounds of thrust maximum, but I got it up to around 30 miles/hour before turning around. That’s a bit much for the steering and the brakes on this old golf cart. You can see the orange glow of the hot pulsejet tube. Justin made it of 304 stainless sheet. The piece of old scrap barn tin between me and the tube keeps the radiant heat off the driver quite effectively.



Figure 5 (P1030937.JPG) – Second run, me driving

Justin later went flying with Brad from TSTC’s Aviation Maintenance department, who is also an EAA member. Brad made the third run up and down the rampway. Like me, he got it up to a pretty good speed. Figure 6 is a good photo of Brad, waiting to start the engine.




Figure 6 (P1030941.JPG) – Brad ready to start, before driving the pulsejet golf cart

These photos were all taken by Justin’s father, who also took some video clips. I put three of the video clips here. The first one, Clip 1 (P1030925.MOV) is of Justin starting out on the first run. He starts out at low thrust, accelerating rather slowly initially, and throttles up slowly as he pulls away. Clip 2 is from my second run, coming back to the EAA hangar, and turning around. Clip 3 is Brad returning at a pretty good clip from his run. There are some aircraft moving on the rampway in the background (fear not, we stayed well clear).

Clip 1 (P1030925.MOV) – Justin departing on his first run:

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Clip 2 (P1030940.MOV) – Me returning from my run, the second run:

video

Clip 3 (P1030943.MOV) – Brad returning from his run, the third run:

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