Continuous Flow Recrystallization of HMX

Continuous flow recrystallization presents one of the largest challenges and opportunities in continuous flow preparation of nitramines. The pharmaceutical industry has demonstrated use of continuous flow recrystallization to result in improved purity, particle size control and particle size distribution (PSD). This project aims to develop continuous flow recrystallization strategies for direct recrystallization to both coarse and fine grades of HMX class sizes (eliminating grinding steps) with tighter particle size distribution, greater process control and improved process waste profiles while retaining the desired polymorph. This proposed work includes evaluation of several technologies and methodologies for continuous recrystallization of the energetic nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The most promising continuous crystallization platform and methodology will be down-selected for both fine and coarse material and further characterized via an optimized design of experiments (DoE). The desired output of the DoE will be identification of process parameters which influence mean particle size and optimal conditions to recrystallize HMX into specific sizes. Selection of recrystallization process parameters designed to tailor particle size of HMX will enable different size classes of HMX, as well as any desired specialized PSD without the requirement to sieve or mill the recrystallized material.