The invention concerns a method of processing eggshell residues, which emanate from an egg breaking unit (1) and comprise eggshell portions as well as membrane portions. The method comprises feeding of the eggshell residues into a cyclone (5), which is driven by a process gas having a temperature of less than 85°C. In said cyclone (5) vortex processing of the eggshell residues leads to peeling of said membrane portions off of said eggshell portions, such that said eggshell portions become separated from said membrane portions. A mix mainly of process gas, vapour and droplets is released through a top outlet (6) of said cyclone (5), whereas a mixture mainly of separated eggshell portions and membrane portions is released through a bottom outlet (7) of said cyclone (5). Finally in a sorting device (8) sorting of said released mixture is performed into an eggshell portion part and a membrane portion part.