Kinetics and Process Selectivity Studies for the Preparation of 3, 7-Dinitro-1, 3, 5, 7-Tetraazabicyclo [3, 3, 1] Nonane

Abstract

The key intermediate for the manufacturing of a powerful explosive, HMX, is 3, 7-Dinitro-1, 3, 5, 7-tetraazabicyclo [3, 3, 1] nonane (DPT). It is being manufactured by the nitration of hexamine under mild acidic conditions and at low temperature yields of DPT in the initial stage, which upon further nitration gives HMX. The yield of DPT decides the productivity and economy of the HMX process. The present study's aim is to achieve the rate of formation of products and the stimulus of process parameters on the reaction for essentially enhancing the yield of DPT. The rate of formation of DPT has been studied in a continuous process under a wide envelope of residence times and temperatures. The rate expressions and activation energies of DPT and side products have been derived. The optimal temperature of reaction has been derived to obtain a higher yield of DPT at the lowest formation of side products. The selectivity of process has been enhanced by varying the concentration of limiting reagent.The qualitative and quantitative picture has been highlighted to realize the role of formation of DPT in HMX formation, and the study reveals that the yield of DPT and side products is sensitive toward the concentration of nitronium ion.