Continuous Production of Microcrystalline Nitrocellulose

摘要

The technical feasibility of continuous flow production of highly nitrated microcrystallinenitrocellulose (MCNC) from microcrystalline cellulose (MCC) was established. A setup for this highlyexothermic multiphase (solids, liquids, gas) continuous process was successfully designed, build andtested. Optimal reaction conditions for the reaction in continuous flow (in terms of maximum nitrogencontent of the product) were estimated using the results of a design of experiments (DoE) applying batchconditions. The tested parameters in this DoE included; the concentrations of nitric acid, sulfuric acid, andwater, the amount of MCC added to the nitration mixture, the reaction temperature and the residencetime of the particles in the nitration mixture. After each experiment the product was isolated andstabilized before its nitrogen content was determined using elemental analysis. The continuous setup wasconstructed from tubing, pumps, a continuously stirred vessel, and a screw feeder powder doser, all ofwhich had to be resistant against the challenging corrosive reaction conditions. The continuous flowsystem was tested using the optimal parameters identified during the design of experiments. Within thetested range the nitrogen content of the product proved to be insensitive towards residence timevariations. The setup was scaled to produce MCNC at a rate of 50 g/h (dry product) with nitrogen contentsbetween 13.5 and 14.1 %.