Methods and systems of collecting an anaesthetic agent from a collection vessel are described herein. The systems include a fluid storage tank and a collection vessel housing an adsorbent material for adsorbing the anaesthetic agent. The collection vessel is configured to receive the heated fluid from the fluid storage tank, the heated fluid having a temperature and a pressure sufficient to thermally desorb the anaesthetic agent from the adsorbent material. The system also includes a heat exchanger configured to receive an outlet stream from the collection vessel comprising the anaesthetic agent and cool the outlet stream to a temperature below a threshold temperature to produce a liquid stream comprising the anaesthetic agent. The system also includes an accumulator configured to receive the liquid stream and separate the liquid stream into a waste stream and a collection stream, the collection stream comprising the anaesthetic agent.