Supercritical CO{sub 2} cleaning for waste minimization

Conference · Tue Sep 01 04:00:00 EDT 1992

OSTI ID:10170435

Williams, J M; Bongianni, W L

Production facilities in the US Department of Energy complex employ a variety of solvent-based cleaning methods for removing residues that might after the manufacturing process, corrosion chemistry or function of weapons components. Many of the solvents are hazardous chemicals such as volatile organic compounds. Some are chlorocarbons and chlorafluorocarbons that are environmentally unacceptable, generate hazardous waste and are subject to existing or impending regulation. Supercritical C0{sub 2} is a moderately good solvent for organic compounds. It also appears to satisfy environmental criteria not met by chlorofluorocarbon solvents In use. Supercritical conditions are attained at modest conditions. The high volatility of C0{sub 2} facilitates solute separation and the likelihood of solvent recycle. C0{sub 2} is economical, naturally occurring, non toxic, unreactive and poses minimal ES&H risk. Supercritical C0{sub 2} technology is well developed and widely used for extracting organic compounds in food, polymer, pharmaceutical and synfuel industries. Large-scale supercritical fluid systems are commercially available for extraction, but only recently have several US companies begun to design and build units for cleaning. The objective of this supercritical fluid C0{sub 2} program at Los Alamos National Laboratory is to develop supercritical fluid carbon dioxide as a recyclable, non hazardous solvent for cleaning some weapons components. Prior studies at DOE`s Rocky Flats Plant show that organic residues on steel and uranium surfaces cleaned with supercritical C0{sub 2} and with 111-trichloroethane are comparable. Recent vendor tests show that large steel objects can be cleaned at easily accessible temperatures, pressures, flow rates and times to levels that are a hundred-fold cleaner than that required for plutonium weapons components. A description of the technology, some of our data, and our planned scale-up activities are presented herein.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10170435
• Report Number(s): LA-UR--92-1980; CONF-9206231--2; ON: DE92017507
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200
CARBON DIOXIDE
NUCLEAR EXPLOSIONS AND EXPLOSIVES
NUCLEAR WEAPONS
OILS
REMOVAL
SOLVENTS
STEELS
SUPERCRITICAL STATE
SURFACE CLEANING
URANIUM