TNO gas generators: Initial design and analysis of a solid state fuel storage system for hydrogen powered scramjets
conference paper
Hydrogen has long been an attractive fuel for scramjets because of its fast chemical kinetics, but its low volumetric energy density is a major drawback. As an alternative for high-pressure gaseous hydrogen storage the current study examines solid state hydrogen storage using the TNO gas generator.
The hydrogen carrier in this gas generator is ammonia borane (NH3BH3), which releases gaseous hydrogen upon ignition. The study consists of two parts: the reference vehicle X-43A is first used as a case study to assess the viability of using gas generators for the fuel supply system of a scramjet. A comparison with liquid hydrogen storage is also made. It is found that gas generators allow 9.1% more hydrogen to be carried than for gaseous storage, albeit at a small mass penalty.
In the second part the decomposition behaviour of ammonia borane is studied up to 1450 degrees Celcius, in order to optimize the gas generator design. The decomposition characterization is performed using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), X-Ray Powder Diffraction (XRD), Mass-Spectrometry (MS) and Fourier-Transform Infrared Spectrometry (FTIR). Both pure NH3BH3 and a mixture of NH3BH3 and NH4Cl are examined. A significant amount of hydrogen is found to be released in the form of borazine. The results of this study can be used to iterate on the proposed conceptual design and improve
the performance of the fuel supply system.
The hydrogen carrier in this gas generator is ammonia borane (NH3BH3), which releases gaseous hydrogen upon ignition. The study consists of two parts: the reference vehicle X-43A is first used as a case study to assess the viability of using gas generators for the fuel supply system of a scramjet. A comparison with liquid hydrogen storage is also made. It is found that gas generators allow 9.1% more hydrogen to be carried than for gaseous storage, albeit at a small mass penalty.
In the second part the decomposition behaviour of ammonia borane is studied up to 1450 degrees Celcius, in order to optimize the gas generator design. The decomposition characterization is performed using Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), X-Ray Powder Diffraction (XRD), Mass-Spectrometry (MS) and Fourier-Transform Infrared Spectrometry (FTIR). Both pure NH3BH3 and a mixture of NH3BH3 and NH4Cl are examined. A significant amount of hydrogen is found to be released in the form of borazine. The results of this study can be used to iterate on the proposed conceptual design and improve
the performance of the fuel supply system.
TNO Identifier
991914
Publisher
TNO
Source title
13th International Symposium on Special Topics in Chemical Propulsion and Energetic Materials (13-ISICP), Gjøvik, Norway, 30 May-2 June 2023
Collation
24 p.
Place of publication
Den Haag
Files
To receive the publication files, please send an e-mail request to TNO Repository.