Supercritical antisolvent precipitation of calcium acetate from eggshells

[Display omitted] •Calcium acetate was prepared from eggshells and processed by supercritical antisolvent precipitation.•The effect of temperature, pressure, solute concentration and flow rate ratio on the precipitation efficiency was evaluated.•The parameteres that had more influence on the micronization process are the pressure, the combination of pressure and temperature, and the flow-rate ratio.•The obtained particles have a rod-like morphology and present different sizes depending on the operating conditions. The search for sustainable resources remains a matter of global interest. The presence of calcium in food waste may be a material to be valued. In this paper we show a new way of precipitating calcium acetate, produced from eggshells, using the supercritical antisolvent technique (SAS). It also presents the study of the precipitation efficiency as a function of the experimental conditions that affect the SAS results - temperature, pressure, liquid solution concentration and injection flow. It was possible to obtain good results under almost all experimental conditions, highlighting a higher yield for 200 bar pressures and lower solution injection flows. The obtained particles have a rod-like appearance having different sizes depending on the operating conditions.