M.Sc Thesis

M.Sc StudentEpstein Michael
SubjectDevelopment of an Ignition Device for Continuous Combustion
of Nitrogen-Based Alternative Fuel
DepartmentDepartment of Energy
Supervisors PROF. Gideon Grader
DR. Gennady Shter
Full Thesis textFull thesis text - English Version


The increasing global energy demand coupled with the fact fossil fuels combustion is harmful to our health and environment, motivate the development of alternative energy sources. However, successful implementation of renewable energies, such as solar and wind on a large scale, requires an energy storage medium due to their intermittency and unpredictability. Using renewable energies to produce hydrogen via water splitting technologies, places the foundation for a solution. Though hydrogen can undergo a clean energy production process, the synthesis of hydrogen to produce other fuels (i.e. chemical storage) is inevitable to solve the infrastructure and safety issues that arise from large scale hydrogen storage. The chemical storage can be based on two elements: carbon or nitrogen, both derived from the atmosphere (CO2 or N2). The nitrogen route is appealing due to the potential for eliminating carbon based pollutants and to the abundance of nitrogen in the atmosphere (~79%). The aqueous solution of Urea and Ammonium Nitrate (UAN) is studied as a model nitrogen-based fuel. The UAN was previously investigated by the means of thermal analysis, batch and continuous combustion, corrosion resistance, computer simulations and catalytic post treatment.

This work is focused on improving the current UAN continuous combustion system towards its implementation as an energy production source. The effect of changing the UAN heating rate on the ignition temperature was investigated at pressures up to 20 MPa. This was followed by the development of a new ignition device that allows the effective study of the UAN. For the first time the new system enabled to measure the entire combustion process temperature profile in the wide pressure range of 1 to 15 MPa. The pressure effect on the temperature profile and on the effluent composition, which was measured continuously using a Fourier transform infra-red spectrometer, was studied.

The investigated combustion temperature profile revealed several key properties which define the combustion process, such as: the ignition position, the ignition temperature and the maximal combustion temperature. The pressure effect on these properties was analyzed to better understand how to control the process. Results from this work will be used to refine the suggested UAN combustion mechanism using computer simulations. Furthermore, the constructed system can be used to study how additional parameters (e.g. fuel flow rate, furnace temperature set-point) affect the combustion process. Finally, this system enabled to perform a catalysis study using a simple addition of a designated reactor.