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This study addresses computational fluid dynamics (CFD) for designing internally heat-integrated pressure-swing distillation (HIPSD) with improved energy efficiency in azeotropic distillation. An extended concept of pinch pressure is applied to determine the operating pressure of the HIPSD in a double annular column configuration for the circumvention of a distillation boundary and adequate heat transfer. For the separation of a highly azeotropic ternary mixture of butyl acetate, butanol, and water, the combination of a single unit of HIPSD and a decanter is employed. This azeotropic mixture is separated in different design alternatives for the given initial feed compositions. In each sequence, the heat transfer rate inside the HIPSD was calculated by the CFD method, and the total utility consumption accordingly decreased by 9.72% and 15.44%. The reboiler and condenser duty in the HIPSD were reduced by up to 48.65%. The separation efficiency in the condenser of the high-pressure column was improved enough to reach a zero reflux by the internal heat integration.

Nitrogen dispersed amorphous aluminum powders were synthesized by high energy grinding using a planetary ball mill under N2 atmosphere at room temperature. The modes of amorphization and recrystallization during the grinding were investigated by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The grinding process can be classified into three stages, i.e. agglomeration, disintegration and homogenization. During the disintegration stage, an amorphous phase was formed and N2 was supposed to diffuse into the aluminum. Recrystallization of N2 dispersed amorphous aluminum powders was also studied. By annealing the final ground product in air and in vacuum at 1373 K for 3600 s, the particles were recrystallized to AIN/AI2O3 and AIN/Al composite, respectively.