Patent ID: 7282099

Claim:
A method for processing an article comprising: (a) introducing the article into a sealable processing chamber and sealing the processing chamber; (b) preparing a single-phase supercritical dense fluid by: (b1) cooling fluid in a separate liquefier to produce condensed subcritical fluid; (b2) supplying condensed subcritical fluid from the liquefier into a supply vessel; (b3) introducing the subcritical fluid from the supply vessel into a pressurization vessel and isolating the pressurization vessel; and (b4) heating the subcritical fluid at essentially constant volume and essentially constant density to yield a single-phase supercritical dense fluid; (c) transferring at least a portion of the single-phase supercritical dense fluid from the pressurization vessel to the processing chamber, wherein the transfer of the single-phase supercritical dense fluid is driven by the difference between the pressure in the pressurization vessel and the pressure in the processing chamber, thereby pressurizing the processing chamber with transferred dense fluid; (d) contacting the article with the transferred dense fluid to yield a spent dense fluid and a treated article; and (e) separating the spent dense fluid from the treated article.