Progress and Prospective of Nitrogen-Based Alternative Fuels

Alternative fuels are essential to enable the transition to a sustainable and environmentally friendly energy supply. Synthetic fuels derived from renewable energies can act as energy storage media, thus mitigating the effects of fossil fuels on environment and health. Their economic viability, environmental impact, and compatibility with current infrastructure and technologies are fuel and power source specific. Nitrogen-based fuels pose one possible synthetic fuel pathway. In this review, we discuss the progress and current research on utilization of nitrogen-based fuels in power applications, covering the complete fuel cycle. We cover the production, distribution, and storage of nitrogen-based fuels. We assess much of the existing literature on the reactions involved in the ammonia to nitrogen atom pathway in nitrogen-based fuel combustion. Furthermore, we discuss nitrogen-based fuel applications ranging from combustion engines to gas turbines, as well as their exploitation by suggested end-uses. Thereby, we evaluate the potential opportunities and challenges of expanding the role of nitrogen-based molecules in the energy sector, outlining their use as energy carriers in relevant fields.

The Four Isotopomer Reactions of NH(a) and ND(a) with NH3(X̃) and ND3(X̃)

Abstract

The reactions

were studied in a quasi-static reaction cell at room temperature and pressures of 10 and 20mbar with He as the main carrier gas. The electronically excited reactants NH(a) and ND(a) were generated by laser-flash photolysis of HN3 and DN3, respectively, at λ = 308nm and detected by laser-induced fluorescence (LIF). Also the ground state species NH(X) and ND(X) as products were detected by LIF.

From the measured concentration-time profiles of NH(a) and ND(a) under pseudo-first order conditions, the following rate constants were obtained:

The major products are the corresponding NH i D2 − i (X̃) radicals (i = 0, 1, 2), whereas quenching processes such as NH(a) + ND3 → NH(X) + ND3 are of minor importance (1%). The isotope exchange NH(a) + ND3 → ND(X) + NHD2 is negligible, and the corresponding channel on the singlet surface NH(a) + ND3(X ~) → ND(a) + NHD2(X̃) contributes with 1% to the overall NH(a) depletion in that reaction. The experimental findings are discussed in terms of a chemical activation mechanism by means of statistical rate theory.