Kinetic parameter estimation for most batch crystallization processes is necessary because nucleation and crystal growth kinetic parameters are often not available. The existing identification methods are generally based on simplified population balance models such as moment equations, which contain insufficient information on the crystal size distribution (CSD). To deal with these problems, a new optimization-based identification approach for general batch cooling seeded crystallization is proposed in this study. The final-time CSD is directly used for identification. A novel effective method for solving the population balance equation is developed and used to identify nucleation and growth kinetic parameters. Cooling crystallization of ammonium sulfate in water was experimentally investigated, where the concentration was measured by an on-line density meter and

SynopsisThe possibility of using synthetic elastomers as working substances in a rubber heat engine was investigated at the laboratory and pilot scale. Two polyurethaneurea elastomers were subjected to experimental heat engine cycles a t a variety of strains and temperature differences. It was found that optimum power and thermal' efficiency were obtained at small strain perturbations where the elastomers were close to mechanical equilibrium. Crystallization of the rubbery phase during large strain perturbations is a nonequilibrium process which should be avoided. Quasi-ideal rubber behavior is approached in the pilot-scale heat engine which supports these conclusions.