The hydrogen, in the natural form, is a colorless, odorless and non-poisonous. It’s very light, 14.4 times lighter than air. For this reason, hydrogen is not found on Earth, because it is dispersed in space, and is the most abundant element in the Universe.
Bound to other elements, however, it is present in great abundance: each water molecule, for example, is constituted by an oxygen atom and two hydrogen atoms. In addition to water, the hydrogen is present in the mineral substances, hydrocarbons and in biological molecules.
Therefore, if you want to get natural hydrogen, it is necessary to remove it from substances containing it, consuming energy. For this reason, hydrogen is not a primary source of energy, but an “energy carrier,” or a form of energy that is not found directly in nature (as it happens, instead, for natural gas, oil or coal ).
The gaseous state is a good fuel: when burned produces a quantity of heat that is 2.6 times higher than that produced by burning methane.
The use of hydrogen as fuel was already known in the middle of last century. Until the fifties, for example, the houses in large Italian cities were heated with the “town gas” consisting of 50% hydrogen. Hydrogen also swelled the great airships, such as the famous Zeppelin, were making incredible journeys.
Today, hydrogen is an excellent fuel. When it combines with oxygen releases much energy that can be used to produce electricity and heat through special devices called “fuel cell”. Hydrogen combustion is clean because it releases only water. That is why today many hopes are betting on hydrogen, as it could provide clean and plentiful energy for the future.