Crystallization of β-carotene by a GAS process in batch Effect of operating conditions

β-carotene has been successfully recrystallized from ethyl acetate and dichloromethane solutions using carbon dioxide as antisolvent in a batch bench plant for GAS process. The aim of this work is to study the influence of operating variables (concentration, temperature, stirring rate and type of solvent) and the efficiency of the GAS process on final size of the crystals. Crystals smaller than 1 μm are obtained at temperature of 298 K, pressure of 5.8 MPa, from 1 g/l solutions and with a stirring rate of 25 Hz. GAS process yields trans isomer with high efficiency separation. Solubility of β-carotene in CO2 plus ethyl acetate at different temperatures (298, 313 and 333 K) from 4.3 to 9.8 MPa were measured, values ranged between 0.45 (P=7.2 MPa, T=333 K) and 0.010 g/l (P=8.1 MPa, T=313 K). In addition, distribution and size of the crystals from raw and recrystallized β-carotene for the CO2–ethyl acetate system are studied.