Audi just created diesel fuel from air and water http://www.gizmag.com/audi-creates-e-diesel-from-co2/37130/
This is just another version of the fictitious perpetual motion machine. The process will consume more energy than it will make available due to inefficiencies in electrical conduction, energy transfer, and the list goes on. There is no free lunch, no free energy, and no way to eliminate carbon dioxide from the atmosphere in significant quantity, it can only be stored as other chemicals which will eventually revert to CO2, such as vegetation when it dies, including the forests, and every living organism on earth, all of which are based upon carbon chemistry. The premise that CO2 is the cause, or a principal cause of global warming, if there is such a phenomena presently occurring, is almost completely conjecture based upon cherry picking selected data to rationalize a premise which has taken on mythic and dogma status. Sunlight intensity variation, a well known phenomena to astronomers is also a factor in varying light energy received on earth, and thusly global temperature patterns. Other factors affecting global temperature patterns are too numerous to list, much less discuss coherently in this forum. Climate change has been ongoing since the earth was formed, and will continue for infinity. The arrogance of humans to believe we control, or will ever control the earth's climate is a scientific falsehood of immense proportion. We no more control climate than we do the ocean's tides, which are principally driven by gravitational effects. It is time for the adults with formal training and understanding of physical sciences, including chemistry, thermodynamics and energy to debunk the premise of human controllability of the earth's climate. Ron Sparks
I rather doubt that an auto company would be pursuing this technology if it were so impossibly inefficient to ever make sense, ...it just would not make economic sense for them to be throwing away monies like that. I think you need to review what CO2 is doing to our oceans. I wrote a private email about this recently: ...an excerpt from http://www.nybooks.com/articles/archives/2015/jun/04/new-solution-climate-club/
This thread is of interest and it is certainly possible and give the input energy being cheap enough feasible. The WW1 German Zeppelins were both floated and powered by Hydrogen. MTU had engines that worked on hydrogen. Now as hydrogen basically burns but has a high tendency to detonate in combustion, particularly in a internal combustion engine. It is best controlled and burned by a diesel cycle type engine... constant pressure type combustion rather than constant volume like a typical spark / gas engine as the tendency to detonate can be controlled better... and the stronger engine structure. In WW2 German trucks were powered by CO produced by a pull-along trailer unit burning in a reducing atmosphere (restricted oxygen supply) various coal/wood fuels... anything that could be found. The CO produced was ducted to the truck's conventional internal combustion engine. However, the problem was an engine that might produce 100-120 hp on gasoline or diesel might only produce 10-20hp on the CO. So the Germans had a sophisticated variable vane turbo that supplied the engine with a supercharge to produce a much lower output (but adequate 40 hp typically) than conventional hard to come by fuels to operate. This was in wide spread use during the war. What is funny Garret Airresearch had difficulty creating a workable variable vane turbo some 30-40 years later when they started up this track again, using some of the old German ideas and engineers but with more modern materials.
Below an example of one of those "Wood-Gas-Generators" as they were called in WW II. My grandfather had a car equipped with one of those Misérables. Lousy performance and it took some time to get the car started. But as General Carl von Clausewitz said: "War is the father of all things" or better "Necessity is the mother of invention". To my knowledge, Audi was not trying to prove an economical way of producing fuel out of air and water. It was more or less a way to show how to propel a vehicle if fossil oil would not be available anymore. We have a big discussion in Germany at the moment about storing renewable energy. Storing electricity from wind and solar generators by using it to convert all kinds of stuff into combustible fuels is one of those ways. Not very effective but at least much better than converting human food into gasoline and having people starving elsewhere.
If a diesel engine works this way why and how do we measure peak pressures as a measure of engine performance? If they were constant pressure how would we get combustion air into the cylinder? Do the terms swept volume and clearance volume ring any bells? The volumes of a typical spark/gas engine do vary as do the pressures. Given this was used so widely do you think you could see through the haze of poorly combusted dodo birds to find and post a link to an example of this?