Reactor Structure for the Decomposition of ADN-Based Monopropellant

Abstract

Ammonia dinitramide (ADN)-based liquid monopropellants are considered to be environmentally friendly alternatives to the toxic and carcinogenic hydrazine-based propellants. Hence, Space Solutions Co., Ltd. is developing a 1N ADN-based liquid monopropellant thruster by conducting a combustion performance in different types of reactors. Various parameters, such as preheating temperature and the size of thermal and catalyst beds, were examined. The results showed that the decomposition of the propellant in a Pt-LHA catalyst bed, which was used in the Type-1 reactor, resulted in insufficient combustion at low preheating temperatures. Furthermore, increasing the preheating temperature led to partial reaction of the propellant, but resulted in low combustion efficiency due to disintegration of the catalyst. However, when a thermal bed (STS ball) was used in addition to the catalyst bed (Pt-LHA) in the Type-2 and Type-3 reactors, the combustion efficiency was improved, with a minimal pressure drop of 0.2 bar. It was also confirmed that the catalyst was not damaged even after repeated operations. In conclusion, this study suggests that the propellant needs to vaporize before decomposing on the catalyst bed to achieve optimal combustion efficiency.

Performance Evaluation of Ammonium Dinitramide-Based Monopropellant in a 1N Thruster

“…As previously discussed in our published work, the thermal bed plays a significant role in the reactor [12]. Therefore, the total length of the reactor was 45 mm, including the thermal bed (10 mm), the catalytic bed (30 mm), and the chamber (5 mm) (Figure 5).…”

“…The diameter and length of the reactor were specified as 10 mm and 40 mm, respectively. Further, it was segmented into a heat bed and catalyst bed, based on the findings of a previous study [12]. Following the injector and preceding to the catalyst bed, a 10 mm thermal bed of STS balls (1.0 mm) was installed.…”

“…Hydrazine, the traditional propellant, has good performance but produces toxic vapor, is carcinogenic, and poses risks to both humans and the environment. In recognition of the advantages of ADN-based propellants, extensive research has been undertaken in the past decades [11][12][13][14][15][16][17]. This has led to several companies, such as ECAPS, the Lithuanian company, Nano-Avionics, Beijing Institute of Control Engineering (BICE), etc., continuously commercializing green propulsion systems for satellites [4,18].…”

“…Hence, here, we investigate a 1 N ADN-based monopropellant propulsion system. In our previous work, different types of reactors were used in order to study the combustion of 1 N ADN-based propellant [12]. The composition of the propellant used for the study was similar to that of LMP-103S.…”

Thermal Decomposition of Ammonium Dinitramide (ADN) as Green Energy Source for Space Propulsion

“…One promising eco-friendly option is ammonium dinitramide (ADN)-based liquid propellant, which is a blend of ADN [NH 4 N(NO 2 ) 2 ], methanol, and water. This highperformance green propellant offers a potential solution for replacing hydrazine [6][7][8][9]. In recent years, numerous studies have invested in the research and development of ADNbased green propellant thrusters, with a focus on their environmental and eco-friendly benefits.…”