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Submersible Robot Diesel Recycles Its Exhaust
An Anonymous Coward writes: "This might be a good weekend topic to kick around. Trends in Japan has a short article on an undersea robot that uses a contained diesel. 'The engine itself is a completely closed system that needs no intake of air to run and chemically processes exhaust gas inside the robot. On-board devices reinfuse the exhaust with oxygen after removing its carbon dioxide and reuse the gas in the fuel mixture. The seawater is kept clean, as no gas is released.' Any /.'s working with this tech? Can it be applied to low emission vehicles?"
That sounds very interesting. Is there anyway this could be applied to other types of vehicles? I know turbo's on cars work off of the exhaust in cars, but it's not the same thing.
Twitter.com/TrentonHyatt
Isn't this probably the exact same thing that's been done on diesel submarines for the last half a century?
Can it be applied to low emission vehicles
Eventually... maybe, forseeably... no.
This little robot cannot possibly be consuming as much fuel as your 2 ton car. Now if we can make your 2 ton car consume as much as the little robot, we're in business...
Sounds great on paper, and it'll probably work quite well in smaller applications, but can this tech really be transferred to personal transportation?
I would imagine the delicate nature of the devices would make it hard and very expensive to enlarge. Hydrogen and solar power would probably be more practical for personal transportation, but underwater (especially deep sea) you don't have much solar energy and you probably wouldn't need all the power hydrogen can shovel at you.
... the Draeger closed circuit breathing apparatus I used to use when I was on a mine rescue team. The only downside to these units was the fact that after about 10 minutes of use, the air would start getting /real/ hot. The chemical reaction that took place when cleaning the CO2 out of the exhaled air made everything hot. After a half hour of use, it would start to get almost to hot to breathe, and even more so if there was strenuous work involved.
That's pretty cool. Just try running a normal diesel in a sealed environment and watch the air pressure drop. It's not fun. Your ears will hate you for it. I still get the willies every time I play UT Pressure...
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This article is rather dated. I wonder what kind of developments have been made on the project in the time between 1996 and now?
No, the diesel engine was only used on the surface. Batteries powered the subs under the water. Hence the slower speed, range, etc when submerged- even though there is less resistance underwater. Nuclear solved all of that mess.
One might stop to notice the date of November 22, 1996 on this article.
Don't you love cutting edge Slashdot.
Does sound like a somewhat useful step in submersible development, though of course it would have to surface sooner or late to refresh it's supply of fuel and vent spent fuel byproducts. Conservation of energy and all that.
" Instruments aboard the robot take quick measurements of the seawater's oxygen content, salinity, temperature, and pH value at four-second intervals, or about every five meters. The robot can also be equipped with instruments to measure magnetic fields and metal concentrations in the water, and otherwise investigate the oceanic environment."
Well ain't that nice. Is this supposed to imply that seawater is somehow used in the function of the engine, or are those sensors for other purposes?
--
"Karma can only be portioned out by the cosmos." - Homer Simpson [1F10]
My question is why not use a fuel cell, then I saw the date. That's why.
"Mr Peabody, set the way-back machine"
"You never truly understand a thing until you can explain it to your grandmother" -Albert Einstein
Interesting to see this posted now, nearly 5 years after the article was written. Anyone know of more recent articles about closed-loop combustion?
I expect that whatever oxygenator they are using on the exhaust may be extremely expensive to implement on POVs.
It could be a catalyst, for example, that costs big $$ to make, and could be toxic and expensive to displose of when finished.
There's no magic here. In the past I've been a huge fan of EVs, but am disolusioned by the slow rate at which battery energy density has improved, especially considering the toxicity and expense of the new materials -- even compared to lead.
Slowly, I'm warming up to the hybrids. Something must be done to cut down on fossil fuel usage.
Treatment, not tyranny. End the drug war and free our American POWs.
See my user info for links.
Man...my dog has been recycling his exhaust for years. Nothin' new to me.
I got nothin'.
There's a Thyssen system that uses liquid oxygen, diesel fuel, and argon. The liquid oxygen and argon are mixed to produce an "air" mixture for the engine, and then the argon is separated from the exhaust and recycled. This requires much less storage volume than carrying compressed or liquid air. Something like this is probably what's being discussed.
This could open the door for more research and explorations to be done in the deep ocean due to the lower cost of diesel engines (even this system) when compared to the expensive, heavy batteries used to power un-tethered subs. Unless fuel cell technology pan out and the development and implementation speed along faster, this could be the technology that will be adopted in the next generation of cheaper and more capable undersea exploration vessels.
Now if they can only fit one of these systems in a hardsuit, I'd go out and buy one. (with other poeple money ofcourse)
You might want to reconsider that statement. That is unless this is a story about how there are no longer any laws of thermodynamics.
I don't remember all of the facts, and someone may have already mentioned it, but the Germans used this back in WW1 for torpedos. Very effective. Not bubble - less, though. Think about it, the combustion process generates gas. You will always have extra gas that must be expended. Additionally, the deeper you go, the higher pressure the gas must be, which really robs the efficiency of the motor. There would be an absolute limit to depth. Re-breathers really work differently - they scrub the CO2 and add O2. The CO2 doesn't need to be removed for operation with an engine. FYI, Diesel Subs only use the diesels to recharge the batteries while they are on the surface. Once under water, they run off battery. Interesting approach, but limited application. Any one heard of other modern app's?
about 5 years ago they could make a sub which could go under its own power for about 24 hours. 5 years later we've heard zero revolutions related to this . . . how about cars that go under their own power for 24 hours on a cupful of gasoline? And no exhaust?
oh wait, what am i thinking, we can't have those sorts of revolutions . . . the gasoline companies would go bankrupt and our economy would fall into ruin . . .
well, maybe if we all pretend really hard . . .
Of course, back in the 1960's Al Capp's Lil' Abner comic introduced the concept originally.
In the past I've been a huge fan of EVs, but am disolusioned by the slow rate at which battery energy density has improved, especially considering the toxicity and expense of the new materials -- even compared to lead.
Slowly, I'm warming up to the hybrids. Something must be done to cut down on fossil fuel usage.
Fuel cells work adequately as a solution to the fossil fuel problem, if you can live with less fuel or a bigger gas tank (hydrogen is the most often proposed fuel, and can't be stored at liquid densities). Many varieties of hydrogen-based fuel cells are made from cheap materials, so cost shouldn't be a problem. This skips the carbon cycle all together (source water -> hydrogen -> water vapour -> rain -> source water).
Another solution is to switch to burning methanol. You can either produce this by fermentation, or build it directly from air (for CO2), water (for H2), and power (solar, nuclear, or whatever). Both ways draw carbon back in from the environment, stopping the short-circuit of the carbon cycle that's causing problems with fossil fuels. Methanol can be burned (cleanly) in conventional internal combustion engines, and can also be burned in advanced fuel cells (which may be expensive; I'd just use a normal engine). It can be stored as a liquid, though you'd probably want to put it in a pressure vessel (like propane) to keep it from slowly boiling off.
In practice, neither of these solutions will be implemented until the cost of gasoline and diesel rises to a level high enough to justify the switchover cost.
In any case, I think solar energy is better suited to stationary or low power mobile devices, not transportation. I am a big fan of biomass energy [biomass.org] for cars. Biomass methanol has a very high net energy value, a closed carbon cycle, and is safer than compressed hydrogen.
You could also produce methanol directly from air, water, and power, which might have higher efficiency (as long as you have an efficient source of energy). I'm told that the solar conversion efficiency of plants is actually rather low (your linked page didn't list figures to check this).
Hydrogen comes by electrolysis, which is very efficient.
CO2 comes out of air by fractional distillation or by effusion (take your pick; I'd personally go with fractional distillation). Energy cost of producing the low temperatures needed will be much less than the cost of the hydrogen electrolysis, so efficiency of this step isn't very important.
Then you burn the CO2 incompletetly in a hydrogen atmosphere, and fractionally distill the results to get the methanol. The other products (water and some other simple compounds of carbon, hydrogen, and oxygen) can either be sold as solvents or for use in industrial processes, or burned (producing heat or power) and fed back into the system. Even the primary reaction (burning of CO2 in hydrogen) is exothermic, so you'll get some heat recovered from this stage too.
Cleanly powering the conversion plant is left as an exercise to the reader, but either a solar heat plant or a nuclear plant should be adequate and reasonably clean (compared to fossil fuels).
It's probably not a 'closed system' in the scientific sense, but is perhaps a closed system in the 'catalyst, fuel, waste' sense.
It must generate waste heat, for example, and I'm pretty sure that this waste heat is lost into the effectively infinite depths of the ocean, using it as a huuuge cold resevoir. On the other hand, there's no technical reason that the waste heat, in tandem with a complex metal catalyst, and a secondary cooling cycle, plus another process to trap 'waste' fuel byproducts, couldn't scrub the exhaust in such a way that it can be reused in the combustion cycle.
More bluntly:
water cooled air + disel => work, waste heat, emissions
work is work
waste heat + catalyst + emissions => hot air, hot gases, hot waste byproducts
hot air + heatsink + ocean => water cooled air
hot gases + hot waste byproducts + catalyst => contained wastes
Then N months later, when the fuel is completely spent, the submersible is collected, the solid waste cartridge is cleaned, and a new supply of fuel is fed into the system.
I'm guessing at this cycle, of course, but it's conceivable. =)
GPL Deconstructed
Volvo advertises it as the Prem-aire system, but I think they developed it in conjunction with Dow or some other chemical/manufacturing giant.
It is a big catalytic converter+radiator, using the waste heat piped into the radiator plus some really expensive and fancy metal catalyst/complexes to break down some emission gasses, NO2, NO3, O3, whatever, into cleaner and safer compounds. It probably is similar to what the Japanese sub does too, actually, but directly on the output of it's own emissions. I would think that the sub is able to store/trap the emissions because of a second cycle that takes advantage of the ocean as a big cold resevoir, otherwise volume/pressure/gas storage becomes a big deal under the ocean =)
The Volvo just lets the emissions free, but because they are technically cleaner and safer, it's okay, or something.
GPL Deconstructed
I'm sure that the substance used to scrub the CO2 back down to O2 is Lithium Hydroxide, just like in space vehicles. Lithium Hydroxide is a much more polluting substance than a little CO2. Using this idea in our atmosphere where O2 is freely available is not a viable idea.
TAANSTFL.
I think an interesting point should be raised. People talk about fuel cells for power all the time, however they seem to think that Hydrogen can be gotten for free without energy expenditure. If we need to supply Hydrogen to a fuel cell, where would we get it? Electrolysis of water? That would work, but would require more energy to break the bonds than would be redeemed in the recombining generates. That's simple chemistry...no free lunch energy wise.
SAAB had a similar concept known as the vehicle exhaust recirculation concept. It was an experiment to address the fact that the majority of pollution given off by modern automobiles occurs at startup, before the catalytic converter reaches the critical temperature needed to properly "scrub" the exhaust of its pollutants.
SAAB's response was to develop a system that would route the exhaust of the car for the first 25 seconds into a balloon. After 25 seconds, the catalytic converter SAAB was using had heated sufficiently to properly scrub the exhaust, so the balloon's exhaust contents would then be filtered back through the intake manifold into the engine to be run through it again. The flow is regulated so as not to affect engine performance.
The net result from this system was lower emissions than the US Ultra Low Emission Vehicle (ULEV) standard, but SAAB hasn't announced any plans to put it into commercial use.
There is an article with more details here. Once the page loads, you can quickly get to the SAAB information by searching for "SAAB".
I greatly appreciated the anti drug war links on your Slashdot user info page. However, one of the links is slightly broken...
It looks like your link to the Charles Whitebread speech transcript needs to be revised.
Ever hear of an EGR valve, otherwise known as Exhaust Gas Recirculation? Any unspent gases get contained in a charcoal filter after being expelled from the cylinder, then they are reintroduced into the intake for use. Nothing new here, this has been in use since the 70s in all cars.
They used a tank of O2(liquid?), a small tank of Argon or Helium for ballancing appropriate pressures/volumes when using pure O2 for smooth combustion in the diesel engine(this being the only reused gas), a tank of diesel fuel, a condensation loop to remove the H2O vapor from the combustion products (simple, since theres cold seawater surrounding the whole deal) and from the inert pressurizer and a giant canister of Lithium Hydroxide. The LiOH removes the CO2 from the combustion products via:
2 Li(+) + 2 OH(-) + CO2 -------> Li2(CO3) + H2O.
The only "On-board devices that reinfuse oxygen" I'm guessing are going to be O2 tanks. Maybe I'm missing something but there dosen't appear to be anything revolutionary here.
- "Hear that?! The percolations are imminent! Cease your ingress!"
...we obey the laws of thermodynamics!
Photos.
In this house we obey THE LAWS OF THERMODYNAMICS!
One way to go full out with this technology is to use biodiesel (fatty acid chains matching the carbon length of the petroleum product), which has 80% less CO2 production. SInce CO2 must be removed from this machine, it stands to reason biodiesel would be a better bet. More on this here in a fun article about a car powered by hemp oil biodiesel, here: http://villagevoice.com/issues/0132/baard.php
Biodiesel also has no sulfur, little particulate matter, no hydrocarbons and fewer smog-generating elements. All this, and the power density and viscosity is the same, with greater lubricity.
So in other words, you like getting your ASSHOLE licked? Since you like a tongue probing the inner circumference of your ASSHOLE, who knows what else you like inserted there?
Brief product spec page from Matsui
Fuller details from U of Tokyo. Huge amounts of technical detail, but a January 1995 article (ie before the sea trials). Should answer most of the calls for "but how does it work?".
Paper describing and appraising the sea trials. Less detail on the CCDE, but a better overview (and written after they've tested the thing for real!).
This sub is only changing the form of the exhaust. The equavilent would be to put a balloon around your tail-pipe. This sub just stores the exhaust in solid form in a filter. There is no less exhaust.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Reminds me of a funny quote I ran across awhile back. This is exactly how I feel about life:
So I can't do some of those things, but I wouldn't mind learning! That's probably what sets us geeks apart from a lot of other people: we like to learn as much about everything as we can."I say consider this day seized!" -Hobbes
"Tomorrow we'll seize the day and throttle it!" -Calvin
Don't get me wrong, this sound's pretty cool, but the article makes false claims:
The Autonomous Benthic Explorer (ABE) built at the Deep Submergence Laboratory of the Woods Hole Oceanographic Institute originally used lead-acid batteries and now uses lithium cells.
I worked on a building a brain upgrade for ABE. The original system runs in FORTH and C on an agglomeration of hand-coded microcontrollers and Transputers. The new system (still under development) is a PC104 stack... running Linux.
The "charcoal filter" stores fuel vapor for later release into the intake system. The EGR system is, (was? Haven't driven a US spec car for a long time), an early and patently rediculous method of controling combustion temperature. It did horrid things to both fuel consumption and power output. The best examples are found in late 70s/early 80s cars with 5 liter engines producing about 125 BHP -- and getting aboout 12 mpg, (about 20L/100 Km).
Good quote. However, that was written by Lazarus Long, not Robert Heinlein.
Sheesh, people. Get your sources straight.
If you're going to have a huge oxygen tank to supply an ineffient internal combustion engine, and something to store the leftover CO2, you might as well just use fuel cells. It would be about 100 times more efficient, and give you more power per $ and kilogram
Repeal the DMCA!
The German navy -Kriegsmarine, MTU and probably Pielstick as well- experimented with what is known as "Kreislauf-Diesel" if memory serves me right during WWII but not very successfully;ok they worked but the state of metallurgy today plus advances in cheramics perhaps can make this,the recirculating-diesel a viable option today. Otherwise if Stirling engines is the only alternative to going with nukes.
This is fantastic news. Hopefully this technology can be applied to cars around the world.
Sad comment about the real state of our advanced society!
The system as described isn't impossible, I don't think. We're not talking about complete reuse of byproducts; there is waste heat and waste fuel (Nitrates and Carbon stuff), with the heat being vented into the ocean and the waste stuffs being captured for later.
Only oxygen is recycled, or whatever combustion accelerant is used.
GPL Deconstructed
We've got Air Independent Propulsion on some of our subs in the Swedish Navy... (well, as some of you would point out, it's only independent for a period of time.) The trick is to use liquid O2 and a diesel burner to drive a Stirling engine, and use enough pressure during combustion to be able to feed the exhaust out into the water. Since it's mostly CO2 it dissolves quickly. For the burner to get "air-like" oxidizer the O2 is mixed with a small back feed of reused exhaust. There is a more thorough explanation on Kockums website.
This is not as clean as the drone in the original article, but OTOH, the collected exhaust in the drone has to be disposed of somewhere - it's not gonna disappear just because it's not in the atmosphere.
Score:-1, Wrong
Lazarus Long is a fictional character created
by... Robert Heinlein.
Air-Independent Propulsion (AIP) has been a hot topic in naval warfare circles for years. It's a big deal because few nations can afford to operate nuclear submarines and diesel subs are vulnerable to long-range IR detectors when they recycle the air. The solutions have been somewhat exotic- here is a good URL to check out-
a rt _AIP.htm
http://members.nbci.com/sabbi/pakarmy/articles/
Now with diesel subs it becomes an order of magnitude cheaper to build these things as you will not require the specialized hull designs or engines. Therefore we will not be able to control the proliferation of these devil beasts.
The world just got really dangerous again. Can you say Iraqi subs prowling the oceans looking for payback? Couple these things with cruise missiles and you don't need an ICBM or worry about missile defense.
Darn Japanese would come up with the tool to do themselves in. Now China can come up with 300 of these infernal things to blockade Nippon.
________________________________________ History Must Not Fall Into The Wrong Hands ___________________________________
Run Whales Run!
Hands.
.gov in the world just about has the potential to build nuke subs. So no worry about invasion there. What about drug cartels? This is the type of low tech that they *CAN* and probably *WILL* use to smuggle contriband across borders.
I know any
Cool, I hope gas bud goes away!
--toq
Why not petrol to fuel cell to electricity to motor? Should be more efficient than burning petrol in a combustion engine.
I don't see why people are trying to think up fancy ways to store hydrogen for cars when they can just store hydrogen around carbon atoms.
Why wouldn't that work? No problem with distribution. That way it doesn't matter to the car whether the petrol comes from the ancient hydrocarbons or somewhere else.
Am I missing something?
Link.
a normal car emits the emissions into the enviroment, this 'contained' unit stores them (presumably), it takes exause and scrubs the oxogen out of it and adds more to replentish it, presumably storing the emissions, not reducing them, just storing them to be later disposed of. this is a better system then our current system, but it wasnt even revelutionary in 1996, the system creates high heat, cool air is better, hot air is worse, less power with hot air. it also for your 2 ton truck, would have to be a little faster at doing its job. and btw as some people would say 'this would put the oil companies out of business' why ? it doesnt reduce fuel consumption, accually to get the same horsepower you would have to increase fuel consumption. they would love this.
note to slashdot: get some current articles, start screening the articles, find some intelligent trolls.
Chris Lee
lee@mediawaveonline.com
If modern small diesel and spark-ignited engines could be raised to the efficiency levels of say -- larger gas turbine and combined cycle systems, the net C02 emmissions into the atmosphere would drop by around 50%. As is, the average thermal efficiency of these engines is less than 30%, and this class of engines makes up easily 95% of the total engine output for all vehicles worldwide.
I also don't buy the "evil petroleum company" theory because it assumes that if such efficient vehicle enginess could be produced, petroleum companies would necessarily lose money. Fact is, sometimes conservation raises prices, because there is less commodity required to maintain operations, the cost per unit of commodity goes up.
What would happen is that worldwide demand for crude oil would drop the price of the raw materials to better levels, and the profit would move from mass production of auto fuels into niche value-added product development, which AFAICT would not be a that horribly bad of a thing anyway. I mean, consider just the economic impact in the US alone if all of the diesel trains and trucks could move freight around at say 30-40% of current fuel costs, and mass transit (AKA buses, light rail, etc. were made more effective in the process...
--humor mode on--
of course, in order to maintain harem and profit margin growth standards, the major royal houses of about 50% of (the more currupt)Middle Eastern contries would have to declare on their major customers.... :-)
...Open Source isn't the only answer -- but it's almost always a better value than the alternatives...
Yah, it's Volvo. And a catalytic radiator that cleans the air. Also, it's PremAir.
;)
"By covering the surface of the radiator with a catalytic coating, it helps to remove dangerous, smog-forming ozone from air flowing through the radiator."
read here
and here.
Developed by Englehard Corporation.
Sounds awesome! Now if only we could get a fleet of them driving through the valley in LA
-mrsmalkav
Volvo says this:
"As part of our global environmental commitment, the new Volvo S80, S60, V70 and Cross Country feature the Volvo PremAir® radiator system. It helps reduce ground level ozone as you drive. PremAir can best be described as coating on the radiator that actually turns ground level ozone into oxygen as air flows through it. At high temperatures, almost 75% of this is converted into oxygen."
The world leader in the production of liquid hydrogen is Air Products & Chemicals. Their website includes information on how they produce liquid hydrogen, and current research they are doing on powering automobiles with hydrogen.
First, hydrogen is rarely produced by electrolysis--it's cheaper to use a reformer to extract it from waste gas at a petroleum refinery.
Second, there are two proposed methods of powering fuel cells in cars with hydrogen. One way is to separate the hydrogen from gasoline (or propane) in the vehicle. This is less efficient, but is simpler: you don't have to replace the gas station infrastructure. The other route is to ship and store liquid hydrogen, and go through the hassle of replacing the gas station infrastructure.
There are a lot of benefits of liquid hydrogen. There's lots of power there--but nobody should forget that liquid hydrogen is what sends the space shuttle blasting into space. While the explosion risk is real, the more likely risk is the extreme temperatures: liquid hydrogen boils at more than 400 degrees (F) below zero. If a little bit of liquid splashes on you, you can lose a limb.
no kidding.. that was my poor attempt at facetious humor :P