Method and device for separating carbon dioxide from a respiratory gas mixture

A method for separating a respiratory gas mixture which contains at least O2 and CO2 and at least one volatile anesthetic and flows in a respiratory gas path, wherein the method comprises

• guiding the respiratory gas mixture under a first flow to a first separation material which is present in the form of a diffusion filter, where the first separation material separates at least oxygen O2 and carbon dioxide CO2 from the at least one volatile anesthetic, the at least one volatile anesthetic being returned to the respiratory gas path or remaining in the respiratory gas system,
• guiding separated remaining respiratory gas mixture containing at least oxygen O2 and carbon dioxide CO2 under a second flow to a second separation material which is present as a diffusion filter, where the second separation material separates at least carbon dioxide CO2 from the respiratory gas mixture, removed carbon dioxide CO2 being released into the environment or into a respiratory gas scavenging system, and
• returning a remaining portion of the respiratory gas mixture, namely essentially oxygen O2, to the second flow.