The synthesis of Highly Energetic Materials (HEMs), including explosives and propellants, has traditionally relied on batch processing, which poses inherent safety risks due to potential thermal runaways and large inventories of hazardous intermediates. This review comprehensively examines the paradigm shift towards Continuous Flow Chemistry as a transformative solution for ensuring intrinsic safety and enhanced process efficiency in HEM manufacturing. We analyze the fundamental advantages of microreactor technology, specifically focusing on its superior heat and mass transfer capabilities that effectively manage highly exothermic nitration reactions. Key synthetic advancements are illustrated through comparative case studies of major energetic compounds, such as TNT, RDX, NTO, and MDNT, demonstrating significantly improved yield, purity, and selectivity compared to conventional batch methods. The review also critically evaluates process intensification strategies, including the implementation of multi-stage temperature zones for reaction control and the "numbering-up" approach for safe industrial scale-up. Furthermore, we address engineering challenges related to solid handling and discuss the safe, on-demand generation of unstable intermediates. Finally, a forward-looking perspective is provided on the integration of Artificial Intelligence (AI) and Machine Learning (ML) with automated flow platforms to accelerate reaction discovery and self-optimization. This work aims to provide a strategic framework for chemical engineers and researchers to facilitate the transition toward safer, more sustainable, and modernized energetic materials production. This review comprehensively examines the paradigm shift from traditional batch processing to continuous flow chemistry for the synthesis of Highly Energetic Materials (HEMs). We highlight how microreactor technology, with its superior heat and mass transfer capabilities, ensures intrinsic safety by effectively managing the thermal risks associated with exothermic nitration reactions. Key advancements are illustrated through comparative case studies of major energetic compounds—such as TNT, RDX, and NTO—demonstrating significant improvements in yield, selectivity, and process control. Furthermore, the review discusses critical engineering strategies, including 'numbering-up' for industrial scale-up and the safe handling of unstable intermediates, providing a strategic framework for modernizing the manufacturing of explosives and propellants.
Oh et al. (Sun,) studied this question.