The present invention provides a method to separate CO2 from a contaminated hydrocarbon-containing stream. The method comprises obtaining a multiphase contaminated hydrocarbon-containing stream (100) containing at least a vapour phase, a liquid phase and a solid phase, creating a slurry stream (120) from the multiphase stream. The slurry stream is fed to a crystallization chamber comprising CO2 seed particles. A liquid hydrocarbon stream (170) is obtained from the crystallization chamber (91) and a concentrated slurry (140) is obtained. The concentrated slurry (140) is removed from the crystallization chamber (91) by means of an extruder (142), thereby obtaining solid CO2. A feedback stream (141) is obtained from the solid CO2 comprising CO2 seed particles having an average size greater than 100 micron. The feedback stream (141) is passed into the crystallization chamber (91).