Development of NMP-001, a Nitromethane-based Green Propellant

Kurzfassung

This paper discusses the development of a model monopropellant that is aimed at exploring the applicability of nitromethane-based propellants as an alternative to hydrazine. This approach addresses the challenges faced by HAN-, ADN-, and hydrogen peroxide-based propulsion by being more cost-effective than the former two while providing similar performance figures and avoiding the storability issues of the latter. The development began with determining the solubility of ferrocene in nitromethane. This substance was identified as a promising low-pressure combustion catalyst in a previous study. A BAM Fallhammer screening was then conducted to determine the required phlegmatizer amount to reach a minimal impact sensitivity of 10 J, resulting in two formulations. Testing in a liquid strand burner showed that the formulation with 2 wt.% ferrocene and 13 wt.% dimethyl sulfoxide achieved a low-pressure combustion limit of 12.5 bar, which is significantly lower than pure nitromethane (27 bar).This property enables the effective use of nitromethane-based propellants in state-of-the-art blowdown propulsion architectures as used with hydrazine. Therefore, this formulation was designated NMP-001 and selected for further research.