Pressure Engines

We, as a nation [and as a planet], are trying to rid our dependency on oil. At the moment, hydrogen seems to be the best replacement for refined petroleum products, like gasoline. It is extremely common, relatively cheap to produce (extract), and is very friendly to the environment. There are only a few things to work out before mainstream adoption will take place.

But, hydrogen-powered engines are still internal combustion designs. Is harnessing the power of a controlled explosion the only way that we can cheaply create mechanical work?

The typical internal combustion engine works because of pressure: squeeze a fuel-air mixture into a tight space (using a piston) and then ignite the fuel, either using an electrical spark or just the heat caused by the compression (I'm having flashbacks to high school chemistry: p*v/t). The resulting explosion and its rapidly expanding gases push against the piston (the only thing around that can move in response to the pressure) and moves it, which in turn rotates the crankshaft.

So, our automobile engines truly only require a source of pressure in order to perform work. The need for fuel, like gasoline, is only a secondary requirement of the design.

Is burning a fuel the only way in this universe to quickly create the pressure that is needed to perform a unit of work (like moving a piston)? Is there no other type of chemical reaction that will generate enough pressure in a very small timeframe to replace the need to burn fuel? Baking soda and vinegar-powered automobiles, anyone?


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(Oh, and shouts go out to DK and BAX readers. Yes, I check my logs regularly. I'm narcissistic)