How does a hydrogen generator work? --- Sepideh, Tehran, Iran
Marshall Brain Answers:
There are two ways to think about your question. The first is, "How does an electrical generator that uses hydrogen as a fuel work?" One way is to take a normal gasoline-powered home generator, like the one you see on this page, and convert it so that it can use hydrogen gas as its fuel rather than gasoline. That is conceptually easy, because emergency generators like this are frequently converted to run on natural gas or LP gas. For example:
All that you need is a jet for the carb that handles hydrogen and you are set.
Another way is to use a Fuel Cell. It combines hydrogen with oxygen and generates electricity from the electrochemical reaction that occurs. Here is an explanation:
The second way to think about your question is, "How does a machine that creates hydrogen as a fuel work?" There are two common ways to create hydrogen: 1) by splitting water molecules into hydrogen and oxygen (electrolysis), and 2) by splitting fuel molecules (like gasoline, propane, methane) into hydrogen and carbon (reformers). Electrolysis is very simple, as demonstrated here:
You simply collect the hydrogen bubbles as they float off the electrode.
A reformer is a little more involved, as explained in How Fuel Processors Work.
You will sometimes hear the term "hydrogen generator" in the "DOUBLE YOUR CAR'S MPG!" realm. There are many, many videos and sites talking about "HHO generators" and fuel economy. Here is a typical video and an excerpt from its description:
This is a normal electrolysis system, but the hydrogen and oxygen gases are captured as a mixture (often referred to as HHO). This mixture is highly combustible. So the idea is that you will use power from the car's alternator to create HHO gas, feed this gas into the engine and it will somehow cause gasoline to burn more efficiently. It has not proven to increase efficiency, however, which is why you don't see these systems as a mainstream product, as shown here: