M.Sc Thesis

M.Sc StudentElishav Oren
SubjectThe Nitrogen Economy: Techno-Economic Analysis and
The Utilization of Nitrogen-based Fuels
DepartmentDepartment of Energy
Supervisors PROF. Gideon Grader
DR. Gennady Shter
Full Thesis textFull thesis text - English Version


The enabling key for using renewable intermittent energy sources relies on developing effective energy storage solutions. Future hydrogen produced economically by water splitting will open new opportunities for implementing renewable energy. However, a pure hydrogen economy presents unresolved challenges involving safety, costly infrastructure, and low energy density. Conversion of the hydrogen into transportable and environmentally-friendly chemical fuels can facilitate the implementation of renewables into the energy grid. Both carbon and nitrogen can serve as hydrogen carriers leading to carbon- or nitrogen-based fuels. These suggested alternative fuels, are an attractive approach since fuels are unmatched in terms of transportability, energy density and also can rely on existing infrastructure.

In this current work the feasibility of expanding the nitrogen economy to the energy sector by using nitrogen-based fuels as a hydrogen carrier is investigated. This work is consisting of three main parts; the first presenting an energy return basis analysis, addressing the technology feasibility of nitrogen-based fuels in comparison to carbon-based fuels. The second part addresses the economic feasibility of nitrogen-based fuels in comparison to other alternative technologies and investigates the influences of expanding the nitrogen economy to both fertilizer and energy sectors. The third part demonstrates the utilization of a model nitrogen-based fuel by investigating the auto-ignition process. Finally, previous work on the continuous combustion of a model nitrogen-based fuel are briefly described, demonstrating the potential for its environmentally clean utilization as an energy vector.

The energy analysis elaborates a metric method for comparison of suggested hydrogen carriers and shows that liquid nitrogen-based fuels can be energetically favorable with respect to carbon-based fuels. The economic competitiveness for a model nitrogen-based fuel was demonstrated with respect to other under developed alternative technologies. In addition, renewable hydrogen price used as a feedstock was found to be the most critical parameter for implementation of the suggested technology. We also discuss the conditions for a model nitrogen-based fuel to be competitive with mature alternative approaches used for balancing and managing the grid. In the third part, the boundaries that support auto-ignition of a model fuel were outlined, demonstrating the safe use and handle of the fuel under ambient condition and defined the condition for effective ignition process of the fuel.

It was concluded that expanding the nitrogen economy by using nitrogen-based fuels offer a storage solution that can provide effective, environmentally clean and economically feasible power, thus fertilizing our future energy portfolio.