Abstract
Sustainable transportation involves reducing the CO2 emissions and the use of clean fuel, obtained as much as possible based on renewable sources. There are already plenty of solutions, mainly at pilot level, ranging from the electric cars to the hydrogen - fuel cells systems, from bio-fuel to carbon sequestration mobile solutions. Each of these solutions offers certain advantages, bringing advances in solving the evident problems. The paper presents a comparative analysis of the car fuels based on fossil resources (oil, coal), on bio-fuel and on hydrogen. While the first two types are still responsible for CO2 emissions, the use of hydrogen represents a totally clean alternative, considering the exhaust pipe emissions. Obtaining hydrogen is not necessarily sustainable on the entire lifecycle, when using the nuclear route (for water electrolysis) or the coal as raw material; obtaining hydrogen via water photolysis represents a significantly increased sustainable path and details on the fundamentals are presented in the paper. The processes, the present limitations and the future openings are discussed, correlated with the performance and the costs.
Keywords: sustainable transportation, bio-fuel, hydrogen, fuel cell.