@Solar: Just because a patent has been issued, does not mean the idea will work. The patent office's only job when issuing such a thing is to ensure it's individuality, not it's practicality.
In spite of it's own claims, it does break the laws of physics.
Nothing can generate more energy than it consumes, under any circumstances -
anything that promises that is lying, no matter what explanation they try to give for it.
Now, when it's talking about compression not adding any energy to the air, that
is actually true, and any extra energy added by a compressor is lost as heat. If you use absolute pressures, 10 litres of air at one atmosphere is the same as 1 litre at 10 atmospheres.
But what it fails to mention is the most important rule. There is energy in ambient air, however it cannot be used.
For example. Say you have... I don't know. A mix of juice that you want to freeze into ice lollies. For that, you need to take some of the heat energy it has away. You can't do that unless you put it somewhere where it's temperature will flow away - the freezer.
Same thing with something on your desk. That has energy. To get some of that energy out of it, you need to push it off the desk - having it's height "flow".
You can't use the energy from anything unless you have somewhere with a lower density of energy. So, in order to use the energy in regular air, you need to have a vacuum to move some of that energy to in order to be able to use it. This flow of pressure can then be used to do work.
So, to do work, you need a "gradient" of an intensive quantity - temperature (not heat), pressure, height - anything not dependent on how much of the substance there is.
Looking back at the earlier example, when you consider the amount of energy that can actually be used - the 1 litre at 10 atmospheres has infinitely more available energy than the 10 litres at 1 atmosphere - because the last atmosphere in both cases cannot be used, because it cannot flow. The 10 litres has only one atmosphere in the first place, so it can't be used.
That makes the usable energy of the 1 litre at 10 atmospheres equal to 900 joules, compared to 0 joules in the opposite case, even though the absolute energy of both is 1000 joules.
So, when I pressurize one of my launchers, there is strictly no more energy in the chamber than there was in the air before, but there is a heck of a lot more that can be used, because of the pressure difference.
In short, the laws of thermodynamics do not allow machines that creates more energy than they use, or even a machine that perfectly recycles it's energy.
The laws of thermodynamics are much neglected by people hoping for cheap or free energy. Usually when the projects they are watching (while hoping for this ideal) fail, they will cry havoc - "The government made them disappear!!!" - completely neglecting the fact it wouldn't have worked in the first place. (Earning them the nickname of tinfoil-hatters - "O noes, theyre reeding mi brian" - as if there were anything useful in there in the first place...

)
Sometimes when you see these things, the people doing them are blissfully unaware they're destined to fail. But many people know they're destined to fail, and it's just a scam designed to get money out of people.
These critical laws boil down to:
#1: You can't get over 100% efficiency (more energy out than in)
#2: You can't get 100% efficiency (equal out and in)
#3: Absolute zero cannot be reached (for the same reasons as before. To get to that point, you need to be able to move it's heat to somewhere colder - and there is nowhere.)
Personally, I think anyone with an interest in areas of science (for whatever reason) should have these firmly stuck in their brain, along with Newton's laws of motion.