CO2-free production of hydrogen by catalytic pyrolysis of hydrocarbon fuels for transportation

The first widespread use of hydrogen is likely to be in transportation. In principle, hydrogen can be used as a fuel for internal combustion engines and fuel cells. All conventional options of hydrogen production from hydrocarbon fuels, e.g. steam reforming (SR), partial oxidation (PO) and autothermal reforming, involve production of synthesis gas with a large concentration of carbon oxides. Removal of CO/CO2 from synthesis gas requires several expensive technological steps such as water gas shift reaction (WGSR), preferential oxidation, gas separation, etc. One alternative to conventional processes is a CO/CO2-free production of hydrogen and carbon by catalytic pyrolysis (CP) of hydrocarbons. CP is a technologically simple one step process without WGSR and gas separation stages. The experimental results on catalytic pyrolysis of different hydrocarbon fuels over metal and carbon catalysts are presented. It was demonstrated that the pyrolysis gas with hydrogen concentration in the range of 70-90 v.% could be produced from gasoline in a cyclic process using Fe-catalyst at 750 degrees C. Carbon catalysts at the same temperature produced CO/CO2-free gas with hydrogen concentration equal to 50 v.%. A comparative analysis of CP and conventional methods (SR and PO) for hydrogen production for transportation applications is discussed in this paper.