Abstract
Hydrogen is the cleanest fuel as it only emits water when combusted. Furthermore, it has the highest combustion energy as compared to fossil fuels. Steam-methane reforming is the dominant process for hydrogen production, but it is energy intensive and suffers from chemical equilibrium limitation. In this paper, alternative technologies for hydrogen production are discussed. This includes gasification of fossil fuels, electrolysis and biological techniques. Carbon dioxide emissions from these processes are discussed as well. The paper also compares the technologies in terms of technical and economic points of view.