Microwave-initiated catalytic dehydrogenation of fossil fuels for the facile production and safe storage of hydrogen

Hydrogen offers the prospect of a highly effective fuel for future sustainable energy, not only because of its intensive energy density per unit-mass but also because its combustion produces no environmentally damaging CO2 at its point-of-use. Hydrogen is presently manufactured on an industrial scale by steam reforming or partial oxidation of methane and to a lesser degree by gasification of coal. However, these processes also generate significant quantities of CO2, with obvious attendant environmental problems. The utilisation of solar energy now yields increasing amounts of hydrogen by the splitting of water, as does the harnessing of other sources of natural energy. But even if the photocatalytic or electrolytic breakdown of water could be greatly improved to produce the necessary huge quantities of hydrogen, the resulting challenge of its safe storage and rapid release for immediate use in fuel cells, for example, is problematic. An alternative platform is to utilise the high intrinsic hydrogen content of fossil fuel hydrocarbons but in such a way as to rapidly release only their constituent hydrogen without any CO2 production. Such CO2-free hydrogen production from hydrocarbons has been advanced through pioneering studies on the catalytic thermolysis of methane and petroleum-range hydrocarbons. My doctoral research work centres on a method of rapidly liberating high-purity hydrogen from hydrocarbons without CO2 emission. An innovative system combining microwave technology and heterogeneous catalysis is thus proposed. As a result, a H2 production selectivity from all evolved gases of some 98%, is achieved with less than a fraction of a percent of adventitious CO and CO2 through the microwave-initiated catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide.
In this doctoral work, the complex interaction between the heterogeneous catalyst system and the induced microwave electric field was carefully studied by scanning a variety of metals and supports. Consequently, the optimised catalyst system was developed in effectively response to the microwave irradiation. Another enthusiastic and exciting part of the work is that a variety of actual, real petroleum products, ranging from heavy crude oil, crude oil through diesel, petrol to natural gas (methane) have been demonstrated that can be the vehicle for high-purity hydrogen production through the microwave-initiated catalytic dehydrogenation.
Based on this work, we showed that the undoubted attractive attributes of fossil fuels - relatively inexpensive, widely available and readily adaptable to applications large and small, simple and complex, - can significantly assist in the staged transition to a hydrogen-based, sustainable hydrogen energy economy. A new scientific and technological era of “Fossil fuel decarbonisation" can arise where we will not destroy naturally-occurring fossil fuels by combustion – with the attendant CO2 emissions, but rather utilise them to produce clean hydrogen. Carbonaceous fossil fuels are thereby transformed from carbon-rich to hydrogen-rich fuels for future energy.

Advisor: Edwards, PP
Compton, RG