| A study on the extraction of essential constituent from the fresh flowers of pomelo with supercritical carbon dioxide is described. The effects of operating temperature, pressure, time and flowing rate of carbon dioxide on the extraction rate are investigated systematically. The results showed: the technology of extraction of essential constituent from the fresh flowers of pomelo with supercritical carbon dioxide is feasible, and the products remained raw savor of the fresh flowers of pomelo. The optimum operating conditions are optimized between 13-18MPa, 47℃, 100-140 minutes, and the flowing rate of carbon dioxide between 22.8-27L/min. With processing and fitting the experimental data,, the model equation of the volume solubility of the essential constituent of the flowers on the density of supercritical carbon dioxide is concluded.The crystallizer with the ratio of 30:1 of length (30) to diameter (1) (long crystallizer) was designed and constructed to study on the dependence of the crystal size, particle-size distribution, crystal morphology on the structure of the crystallizer and the operating pressure using supercritical carbon dioxide as anti-solvent crystallization. As the operating pressure increasing, the crystal size decreased in the long crystallizer, and the crystal morphology was unchanged. The crystal morphology was changed in the short crystallizer. At relative high pressure (22MPa) the crystal size distribution of the long crystaliizer was uniform. However the crystal size distribution of the short crystallizer was various.At the relative high pressure (22MPa) the crystals of the crystallizer upper were different from the middle and lower in the long or short crystallizer. At the relative low pressure (8.5MPa) the crystals of the upper, middle, lower of the long or short crystallizer were uniform. With the operating pressure increasing, the growth of the upper crystal of the long or short crystallizer may be different from the middle and lower. |
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