A technical and environmental comparison between hydrogen and some fossil fuels Giovanni Nicoletti ⇑ , Natale Arcuri, Gerardo Nicoletti, Roberto Bruno Mechanical, Energetic and Management Engineering Department, University of Calabria, Arcavacata di Rende, CS 87036, Italy article info Article history: Received 4 July 2014 Accepted 19 September 2014 Keywords: Fossil fuels Hydrogen Combustion Environment pollution Technical quality indexes Environmental quality indexes abstract The exploitation of some fossil fuels such as oil, intended as gasoline or diesel fuel, natural gas and coal, currently satisfy the majority of the growing world energy demand, but they are destined to run out relatively quickly. Beyond this point, their combustion products are the main cause of some global prob- lems such as the greenhouse effect, the hole in the ozone layer, acid rains and generalized environment pollution, so their impact is extremely harmful. Therefore, it is clear that a solution to the energy problem can be obtained only through the use of renewable sources and by means of the exploitation of new low-polluting fuels. In this scenario an important role might be played by hydrogen, which is able to define a new energy system that is more sustainable and cleaner than current systems. For the comparison of the different fuels investigated in this paper, a methodology, which defines appropriate technical and environmental quality indexes, has been developed. These indexes are connected to the pollution produced by combustion reactions and to their intrinsic characteristics of flammability and expansiveness linked to the use of the considered fuels. An appropriate combination of these indexes, in the specific sector of utilization, allows to evaluate a global environmental index for the investigated fuels, highlighting that hydrogen reaches the highest score. In the final part of the paper, a new hydrogen energy economy that would lead to solving the serious environmental problems that damages all the ecosystems of the planet earth, is presented. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction In recent years, the problem of air pollution has reached limits of considerable dangerousness both human health and for the environment that surrounds them [1,2]. This situation is the direct consequence of the continuous and copious reversal in the atmo- sphere of combustion products provided by energy systems, which employ, especially, fossil fuels. Unfortunately, these emission levels have been increasing pro- portionately according to industrial progress, pursued by different nations for a long time, together the relative population growth. Three possible scenario trends of industrial development with a well-defined model of population growth are shown in Fig. 1. The latter concomitant factors are the main reasons for the energy requirement growth, and they lead to emissions of large quantities of pollutants, such as SO x ,N x O y , particulate, carbon monoxide and carbon dioxide, which create serious environmental problems and liveability. In this context, hydrogen has a role of primary importance to solve these serious environmental problems [3–7]. If hydrogen is introduced into the actual energy system based on the exploitation of fossil fuels, it would allow for a reduction of the local environ- mental impact of fuels, whilst also reducing the global impact. If hydrogen production is carried out starting from renewable sources, the world impact will also be solved. However, molecular hydrogen is not available in nature, so it must be produced using energy. Hydrogen can be stored both in liquid or gas form, and it could later be converted into thermal energy by its combustion. For this reason, hydrogen is an energy carrier. The advantages of using hydrogen in energy systems are numerous; the main reason is the ability to produce electricity and heat using fuel cells [11–13]. These devices are characterized by high efficiency and no pollutant emissions (water vapour). In this sense, it can be defined as a clean energy carrier. Currently, despite different ways of producing hydrogen in a molecular form, it is more expensive than fossil fuels, but only if the costs concerning social and environmental impacts are excluded [14–16]. http://dx.doi.org/10.1016/j.enconman.2014.09.057 0196-8904/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +39 0984494610; fax: +39 0984494673. E-mail address: giovanni.nicoletti@unical.it (G. Nicoletti). Energy Conversion and Management 89 (2015) 205–213 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman