Purifying technical surfaces, e.g. filter elements, spinning nozzles and catalyst materials contaminated with polymers comprises contacting surfaces with super-critical water, dissolving impurities, and removing water from surface

摘要

Purifying technical surfaces having a structure that is difficult to access, is coated with organic impurities and/or is sensitive to oxidative attack comprises contacting the surfaces with super-critical water, dissolving the impurities in the water and removing the water together with the dissolved impurities from the surface before or after converting into a sub-critical state. Preferred Features: The super-critical water is held under a pressure of at least 250, preferably 320-380, especially 420-480 bar. Oxygen is added to the super-critical water.