Ethylene oxide gas converted to ethylene glycol in closed circuit system

摘要

A process and device are disclosed for disposing of ethylene oxide gas used for sterilising objects within a vacuum sterilisation chamber (5) by means of a pump (10) connected to the sterilisation chamber (5) that supplies ethylene oxide after sterilisation to a gas scrubber (15) that works with acids. The sterilisation chamber (5), the pump (10) and the gas scrubber (15) form a closed gas circuit; the pump (10) continuously delivers ethylene oxide from the sterilisation chamber (5) to the gas scrubber (15), and the exhaust gas from the gas scrubber (15) is supplied to the sterilisation chamber (5). The ethylene glycol formed from ethylene oxide in the gas scrubber (15) is continuously withdrawn from the gas scrubber (15) and further acids are continuously added to the gas scrubber (15) depending on its acid consumption. This cycle is maintained until the residual concentration of ethylene oxide in the gas circuit falls below a predetermined level. An inert gas source (48) is preferably connected to the gas circuit (5, 35, 10, 39, 15, 40, 38) to supply inert gas to the gas circuit in a controlled manner when the ethylene oxide elimination causes the gas circuit inner pressure to fall, the pressure drop in the gas circuit being adjustable.