Q.Write a few lines on the utility of hydrogen as a fuel.

The hydrogen economy is a proposed energy system in which hydrogen, ideally produced from renewable resources, replaces fossil fuels as the primary energy carrier — it can be transported and stored (as compressed/liquid gas or absorbed in metallic hydrides) and then converted into electrical energy in a fuel cell, giving water as the only by-product and thus offering a clean, non-polluting alternative to conventional fuels. A fuel cell is an electrochemical (galvanic) device that directly converts the chemical energy of a fuel's combustion — for hydrogen, $H_2 + \tfrac12 O_2 \rightarrow H_2O$ — into electrical energy without an intermediate combustion step, making it highly efficient and essentially pollution-free, since water is the only product. Hydrogenation is the industrially important addition of dihydrogen across carbon–carbon multiple bonds, most familiarly used to convert unsaturated vegetable oils into saturated fats (vanaspati) using a nickel catalyst. Syngas (synthesis gas) is a mixture consisting mainly of carbon monoxide and hydrogen, obtained from the steam reforming of hydrocarbons or the gasific …