Comparative environmental impact evaluation of hydrogen production methods from renewable and nonrenewable sources

In this chapter, a comparative environmental impact study of possible hydrogen production methods from renewable and nonrenewable sources is undertaken with a special emphasis on Turkey. The goal is to make useful and practical recommendations to the authorities in terms of research and development, demonstration projects and applications. Environmental impacts (global warming potential, GWP and acidification potential, AP), production costs, energy and exergy efficiencies of eight different methods are compared. These methods are natural gas steam reforming, coal gasification, water electrolysis via wind and solar electrolysis, thermochemical water splitting with a Cu–Cl and S–I cycles, and high temperature electrolysis. The relations between environmental impacts and economic factors are also presented using the social cost of carbon (SCC) concept. The global warming and acidification potentials of the selected production methods show that thermochemical water splitting with the Cu–Cl and S–I cycles are advantageous over the other methods, followed by wind, solar, and high temperature electrolysis. In terms of hydrogen production costs, electrolysis methods are found to be least attractive. Energy and exergy efficiency comparisons show that biomass gasification becomes advantageous over the other methods.