A synthetic protocoll was previously published, however it was felt improvements could reduce material costs and improve reaction safety. The synthesis involves the use of potassium 2-nitropropane as a key reactant. This molecule has been known to self detonate upon standing,2 which required WeylChem to produce and use the salt in situ. Understanding the energy involved with accumulation and reaction of this salt was necessary to ensure plant conditions would not permit a runaway reaction.
Experiments were carried out in a reaction calorimeter, automated with commercially available thermal hazard analysis software. An initial set of three experiments was run using different addition rates to assess the impact of feed rate on the heat of reaction, thermal accumulation and maximum temperature rise with cooling failure. Thermal hazard analysis software was used to consolidate data from the reaction calorimeter with data from GC and DSC analysis.
WeylChem - a a global fine chemical company specializing in custom synthesis - simplified and was able to speed up thermal hazard analysis; charts are easily generated from the experiments to show:
- KOH solution addition
- Heat of reaction
- Thermal conversion
- Thermal accumulation
From only three experiments, WeylChem was able to obtain good insight into the heat of the reaction as well as the amount of heat generated during different portions of the reaction. They found that the amount of heat generated precluded them from doing the fast feed they had envisioned. With three different feed rates and subsequent heat ups, they were able to obtain enough data to allow them to extrapolate cycle times, run-away scenarios and cooling failure issues. From this study, in conjunction with additional DSC data, WeylChem feel confident they have developed a protocol that will allow for reaction scale-up to a plant production scale in the future. In addition, this added informaton allowed for a more accurate costing on this desired intermediate molecule.
Related topics: nitroalkane chemistry, thermal hazards, thermal hazard analysis, process safety, reaction scale-up, safe scale-up, WeylChem, reaction calorimetry, reaction calorimeter, RC1, RC1e, potassium 2-nitropropane, heat of reaction, heat generation, diformylarylbenzene