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Peugeot Citroen To Introduce Compressed Air Hybrid By 2016 204

cylonlover writes "With a few exceptions, such as Volvo's Air Motion Concept, major automotive manufacturers have generally shied away from compressed air technology. PSA Peugeot Citroen is bucking this trend with its 'Hybrid Air' powertrain that addresses the limited range of compressed air energy storage technology by combining it with a gasoline powered internal combustion engine. The company plans to have Hybrid Air powered vehicles on the road by 2016."
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Peugeot Citroen To Introduce Compressed Air Hybrid By 2016

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  • Rush (Score:5, Funny)

    by Citizen of Earth ( 569446 ) on Friday January 25, 2013 @01:37PM (#42692703)
    Suddenly ahead of me
    Across the mountainside
    A gleaming alloy air car
    Shoots towards me, two lanes wide
  • by Zondar ( 32904 ) on Friday January 25, 2013 @01:38PM (#42692707)

    So much different than our current ones....

    Wait - what?

    • I'm waiting for ultracap overlords. Even hybrid ones.

      All-electric car, enough UC capacity to run you around for, say, 15 minutes, and an IC engine that can charge the thing on board. No wasted idling energy (unless you spend it on AC or heat, etc., in which case it isn't wasted), all the great benefits of 4wd, regen, huge torque at any speed...

      Of course, if you had a higher efficiency source of power (like nuclear... of course I'm dreaming now), that'd be super, but for now, gas/diesel is it.

      • by dbIII ( 701233 )

        higher efficiency source of power (like nuclear... of course I'm dreaming now)

        Yes you are dreaming - higher energy density and not efficiency, because you get a choice of steam power, thermocouples or photovoltaics to be run by that radioactive decay.
        Still waiting on Mr Fusion (which won't be coming out of the USA after the ignition research got axed) and that hoverboard.

      • Sure, ultracaps would be nice, but will likely be very expensive at least initially. Compressed air on the other hand can serve much the same purpose far more cheaply using well established technology. It doesn't really matter that much whether the energy is stored as electric potential to drive electric motors, or compressed air to drive compressed air motors. In either case your combustion engine (or other mechanical energy source) can recharge the power buffer while operating at optimal efficiency whi

  • Compressed air. (Score:5, Informative)

    by serviscope_minor ( 664417 ) on Friday January 25, 2013 @01:42PM (#42692765) Journal

    Not many details about it.

    I guess you can re-use cylinders from the ICE for compression and expansion, which would save on weight.

    Though the main problem with compressed air is that it cools and lowers pressure after it's been compressed, which is a big source of inefficiency. Large amounts of the energy are lost as heat. No mention on how they tackle that. For a lot of hybrid use, I suppose that insulating the tank would work quite well, but they imply that it can run off air for a large amount of the time, suggesting that the air will stay in the tank for a while and therefore cool down substantially.

    Still though, batery charging isn't exactly 100% efficient and the simplicity could outweght the reduced efficiency.

    Also, free A/C in summer.

    • by Anonymous Coward on Friday January 25, 2013 @01:58PM (#42692971)

      I'm always free, not just in summer.

    • They should scratch the compressed air part and use hydrogen per oxide as a storage medium. You can pump small amounts into an expansion chamber and react it like you would for a jet pack and toggle the pump on and off with the pressure inside the expansion tank that would be used to power the compressed air motor.

      Something like that would give much further mileage plus a heat source for winter driving. It's relatively low temp compared with burning gas or diesel, and not much more dangerous if you do not u

      • Then it's just another fuel source.

        The point of a hybrid is to recover braking energy.

        • Why couldn't you re-energize the expansion chamber or even fill a tank that works in tandem with the braking energy?

          • by h4rr4r ( 612664 )

            How are you planning on making more h2o2 on the fly exactly?

            • The same way you make gasoline on the fly- you go to a filling station. The only significant difference in this system would be a h2o2 tank instead of an internal combustion engine and a lot further range.

              Think of it this way, imagine the h2o2 as 30 tanks of compressed air squeezed into the same space as 1 tank of compressed air. If 1 tank gives you 12 miles, you could have over 300 miles with h2o2.

              • Another significant difference is that your solution requires modifying filling stations whereas this hybrid air engine doesn't. Therefore, in the short term, air wins.
                • Modifications would be insignificant. Most likely, it would be self contained drop in units or even solar units in the owner's back yard that creates the h2o2. with a 300+ mile range and the exhaust being water and oxygen, it's not any more complicated then current tech trying to achieve the same results.

                  • It doesn't matter how insignificant the modifications are. As long as there are any at all, most stations won't lift a finger until there is an actual (as in not hypothetical) consumer demand for it. Which creates a chicken-and-egg problem because not many people will buy the car (pay the extra price for the new engine vs a proven old petrol/diesel engine) until the filling station coverage is at least 90%. Of course, with political pressure things could happen faster but the core business of car makers lik
                    • Not really. Look at the hydrogen and compressed natural gas stations on the west coast. I don't mean to be completely dismissive of your concerns, but I find them overly exaggerated.

                      If I was to offer a car that could get 300 miles "per charge", that was lower cost then a traditional electric/electric hybrid, the interest in he car alone would be enough for several gas stations to consider installation of h2o2 pumps. This could be even drastically increased if the marketing initially focused delivery vehicle

              • by dbIII ( 701233 )
                You are trying to solve a different problem to the one this vehicle's designers set out to solve. This is about stop-start traffic and recovering potential energy from going down hills instead of highway driving and maximum range. It's about using less fuel in the first place instead of getting the most out of the fuel you have.
                • Yeah, but I guess my point was that the fuel could be cleaner and pretro fuels avoided altogether by using this guys drive train with h2o2. it also gets around the use of battery packs and so on. A much more practical car can be made that is useful to quite a larger audience.

                  • by dbIII ( 701233 )
                    Guess how hydrogen is obtained industrially these days :)
                    You are better off using a slightly modified of distilled version of feedstock that provides the hydrogen (oil or gas) in terms of both energy density and total energy usage. There's a lot of effort to get hydrogen in other ways to use to make things like h2o2 but it's still vastly easier to get it out of fossil fuels than any other way.
      • Re:Compressed air. (Score:5, Informative)

        by h4rr4r ( 612664 ) on Friday January 25, 2013 @02:22PM (#42693269)

        So instead of air, which is cheap, safe and readily available, you want to use h2o2 which is none of those things. It is also corrosive. The lower the purity of the h2o2 the less energy you are storing.

        I see literally no upside to your suggestion.

        • Yes, I want to go more then a dozen miles before having to refuel or go back to using gasoline.

          You seeing no upside is why we are still using gas and oil or trying to kludge together expensive work around to simple solutions. With modern materials, the corrosive aspect is not an issue.

    • Re:Compressed air. (Score:4, Informative)

      by Charliemopps ( 1157495 ) on Friday January 25, 2013 @02:09PM (#42693089)

      You've got that backward. Air gets hot as its compressed. Very hot. To store the kind of PSI they'll need, that tank will be scortching hot unless they have some system to use that heat. Then, when it's released and the air expands, it cools. It says the drive train is hydrolic. I suspect it's a lot like a hydrostatic garden tractor. They've got a pully that when they spin it produces drive. If you've got compressed air driving that pully, and you have a gasoline engine driving it at the same time, the engine would be extremely efficient to begin with... then, as the compressed air tank loses preasure the load on the gasoline engine would become greater, reducing its efficiency. The result is that it's actually a gasoline powered car that gets a great efficiency boost while it still has air in its tank. Once it runs out, its just a normal car. So you can have a very efficient drive to and from work, but trips to grandmas not so much.

      • You've got that backward.


        Air gets hot as its compressed. Very hot. To store the kind of PSI they'll need, that tank will be scortching hot unless they have some system to use that heat.

        The system to use the heat is the air. If it stays hot then there is more stored energy. The problem is that the hot air cools, shedding a large amount of energy which went in to compressing it. That energy is not recoverable.

        For example:

        Block up the end of a bicycle pump, and compress it down. It will now bounce back w

        • by Dr. Evil ( 3501 )

          And fire is gas cooling through convection and radiation while being released in a chemical chain reaction.

          It's weird to talk that way.

        • You are partly right, but things are not quite that bad.

          You are right in that you don't want to compress air into a hot tank and then allow the tank to cool. That is energy lost. But just because gas will get hot if you compress it quickly in an insulated container does not mean you have to _let_ it get hot as you compress it.

          If you compress the gas in such a way that it does not get hot (be efficient in removing the heat of compression) and expand the gas in such a way that it does not get cold (be effici

    • by Kokuyo ( 549451 )

      On the other hand, excess heat from the gas engine could be used to raise efficiency on the compression, no?

      • Now that is a very interesting point.

        They do claim it can run for a while on compressed air, though.

        Excellent insulation coupled with a heat jacket from the exhaust could work.

    • by rwa2 ( 4391 ) *

      Well, I suppose they have it insulated well. It just needs to maintain energy through a typical stoplight cycle, so just a few minutes. Or maybe they go full retard and and hook up a stirling engine to the pressure vessel so they can at least extract some useful work out of the heat loss ;-) Well, that might actually be somewhat useful for keeping A/C and accessories powered while the ICE shuts down at stoplights.

      I don't really understand why more manufacturers are not using flywheels instead, though...

    • In principal you can compress and expand at constant temperature by exchanging heat with the outside air and get high (ideal) efficiency. Imagine many stages of compressors (or expanders) spaced by heat exchangers to ambient. In the limit of LOTS of compressors and expanders, the air never gets hot, and there is no efficiency loss. Real high presure compressors usually have a few stages with coolers inbetween.

      I don't know if there is a mechanical trick to make this practical, and I'm too lazy to calculate

    • by WoOS ( 28173 )

      I agree to the lack of details. There is some additional information on the PSA page about this [], including two presentations (the press presentation is actually better than the "technical" one).
      But nowhere can I find how much energy they can store with compressed air. I would imagine it is not very much so the "Zero emission" runs mentioned on the PSA page might be quite short.

    • by sjames ( 1099 )

      I don't know if they do, but they could re-warm the compressed air using the exhaust heat from the ICE.

    • by Quila ( 201335 )

      Ah, but in hot weather you have automatic air conditioning, just need to blow a fan by the cylinder into the passenger compartment.

    • by Belial6 ( 794905 )
      Ideally, they could use heat exchangers to cool the air as it compresses from the wind with the car moving, and use the cooled compressed air as both a coolant to the gas engine, while using the absorbed heat to increase the pressure in the air tank. Thus, recapturing energy that was previously being bled off as waste.
    • I guess you can re-use cylinders from the ICE for compression and expansion, which would save on weight.

      The working pressure of the ICE's pistons would be in the order of 10 atmospheres - look at the ratio of headspace to the volume swept by the cylinder's travel ; about 10 to one - which is negligible on the compressed air front. Off the shelf diving equipment can go up to 300 atmospheres, 4500psi. Though you would need to have the cylinder inspected and hydraulically tested every couple of years. FTFA


  • by doug141 ( 863552 ) on Friday January 25, 2013 @01:57PM (#42692955)
    Cheaper and simpler than exotic batteries, saves a ton of gas, and you don't need rare earths. []
  • French car company Peugeot has unveiled an air powered hybrid car, the Hybrid Air Concept, with the goal to have the car on the road by 2016. The air engine has been in development for more than two years with over 100 leading scientists and engineers working on the air powered car in top secret conditions at Peugeot’s research and development center at Velizy, south of Paris. The air engine system works by using a normal internal combustion engine, special hydraulics and an adapted gearbox along with
  • by ryzvonusef ( 1151717 ) on Friday January 25, 2013 @02:20PM (#42693251) Journal

    Here is some some quick responses.

    1- No, running around in car with gas full of high pressure tank is the not the end of the world, people (including yours truly) do it with CNG enabled cars.

    2- As for compression/decompression energy losses, same as for CNG, you need to cool it it blah blah, and is done so on a commercial scale at every CNG station; therefore can be done.

    3- CNG suffers from power problems on steep climbs, same seems to be the case for air. But for regular commute, it's perfect and economical.

    4- Air car suffer from low power density (much lower than CNG), but AFAIK, a full tank can last you the usual daily commute, which ought to be enough for a small city car. (which is what it will be able to power anyway, can't carry the load of bigger cars as of yet) And you could charge at work too(regular mains-running onboard compressor apparently take 3-4 hrs), so there is that.

    5- MDI realised that air alone won't be enough, so they have been developing hybrid versions themselves.

    TL;DR Air could prove to be good for the usual regular commute, since fuel costs will be minimum (air is free, all it will cost is running the compression and pump, which, looking at local CNG setups, will prove to much less than petrol equivalent, if commercially done)

    Here is some aircar nerd sites:

    - []

    - []

    (I would take their figures with a grain of salt, but well, the video shows running prototypes, so at least there is *something*)

    • 2- No, its NOT the same as CNG. Because the energy density of adiabatic expansion is a LOT less than the one of natural gas combustion. So a much higher loss fraction during the compression cycle AND combustion waste heat cannot be used to pre-heat the compressed gas to counter valve freezing and whatever.

      • The point was CNG has already explored these frontiers, and have developed technology to render this commercially feasible.

        More specifically, I was referring to the Pump-end of the equation; CNG stations cover about the same area as normal petrol station, and have an automated setup for compression, *cooling*, storing and dispensing gas at the pump; this is *not* a new or difficult thing to do, as americans presume, and you are not to blame, you have most likely not seen CNG pumps in action, so setting up a

  • by SlovakWakko ( 1025878 ) on Friday January 25, 2013 @02:24PM (#42693295)
    ...for tire inflation, otherwise they'll go out of business, and the queues to "just infllate the tires" will kill us all :)
    • Around here, gas stations have charged for tire inflation for a long time.

      If you fill up your tank, you either get a token or they turn on the compressor for you. Otherwise you pay a quarter or whatever at the air/water machines. (I've never paid, and have never noticed anybody else paying.)

      • A quarter? As someone with a slow leak in an alloy wheel, I wish it was still a quarter.

        Around Chicago it costs $1.00, and the air machines take credit cards. Wish I would have thought of that one...
        • Wow, ok, maybe I'm wrong.. I just knew they took quarters/tokens.

        • by tftp ( 111690 )

          I have a small 12V compressor. Bought it a decade ago, and it is still as good as new. The price was $30 or $40, I don't remember. If you need compressed air often then it would be a good investment.

  • Pressurized hydraulic fluid can be dangerous (especially oil-injection via pinhole leaks that can result in amputation or death depending on the target area), but in the unfortunate instance of a pressurized vessel failing, as the fluid is essentially uncompressible, the motive force quickly stops.

    Compressed gas, on the other hand... far scarier results with a ruptured vessel as the rapidly expanding gas is more than happy to forcefully hurl projectiles out of its way.
  • by g8oz ( 144003 ) on Friday January 25, 2013 @04:07PM (#42694687)

    The compressed air designation is very misleading. This is a hydraulic hybrid, using a hydraulic pump/motor the same way a normal hybrid uses a battery - for acceleration and storing braking energy.

    Hydraulic hybrid vehicle (HHV) technology has been slowly maturing and is very promising. It is already in use for some advanced heavy trucks. Garbage trucks in particular, with their stop and go usage profile benefit from their efficiencies.
    UPS is trying some out. Manufacturers like Navistar and Eaton are on board

    In the U.S the EPA has been at the forefront of the research. See their page about it: Hydraulic Hybrid Research []

    In 2011 the EPA announced a partnership with Chrysler to produce an HHV minivan that would give you a 60% improvement in city driving fuel economy.

    Hybrid Batteries are expensive and can't handle the braking energy a truck generates. Hydraulic technology is cheap, well understood, and gives you more bang for your buck.

    • by WoOS ( 28173 )

      No "compressed air" is not misleading as that seems to be exactly what is used for storage. From the PSA page about it (who should know intending to produce it):

      --- snip ---
      What is it exactly?

      A new type of full hybrid powertrain that uses petrol and compressed air:
      - An innovative combination of tried and tested technologies: a petrol engine, a unit to store energy in the form of compressed air, a hydraulic motor-pump assembly and an automatic transmission working with an epicycl

    • by jcdr ( 178250 )

      The English article don't show the details. Here is a French article with more details: []
      It say that there is two nitrogen tanks, a high pressure one and a low pressure one. A hydraulic fluid (not specified) is used to compress the nitrogen of the high pressure tank. There is no description about the utility of the low pressure tank. There say that the gear boy is actually of the same ty

      • Okay, I have to ask:

        What is your native language?

        Your grammar coupled with the spelling make it pretty clear that it's not English, but I cannot find any obvious pattern pointing to any particular language with which I'm familiar.

        Of course, if your native language IS English, consider this to be my way of poking fun at your illiteracy....;-)

        • by jcdr ( 178250 )

          Really sorry for my English. You are right it's not my native language.
          My native language is French.

  • Lightning Hybrids [] is a small company in Colorado that makes hydraulic hybrid systems. They started out by wanting to make passenger cars, but soon realized they needed to focus on vehicles that do a lot of stopping and going, like buses and delivery trucks. That seems to be working for them. At least that is how I see and remember it. Passenger cars are not ideal. Vehicles that stop and go a lot are a better target.

Disks travel in packs.