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Title: Pilot scale study and design of a granular activated carbon regeneration process using supercritical fluids

Journal Article · · Environmental Progress; (United States)
DOI:https://doi.org/10.1002/ep.670120310· OSTI ID:6924946
;  [1];  [2];  [3]
  1. Univ. of Illinois, Urbana, IL (United States)
  2. Cabot Corp., Tuscola, IL (United States)
  3. Georgia Institute of Technology, Atlanta, GA (United States)

A technology which has great potential for environmental control and waste remediation is contaminant removal and separation with supercritical fluids (SCF's) or supercritical fluid extraction (SFE). Pressure tuning of solvent power allows SCF processes to adapt to a wide variety of small batch oriented separations typified by environmental cleanup operations. The ability of supercritical CO[sub 2] to extract model contaminant compounds from GAC and subsequently drop out most of the contaminant in a liquid phase has been investigated in a pilot scale apparatus. Typical desorption profiles indicate an 85% removal of the compound from the carbon which allows for reuse. The desorption results have been interpreted with a generalized desorption-mass transfer model. The results of the pilot plant studies have been applied to the design of a fixed-site GAC regeneration unit consisting of a three-element desorber with two-stage flash separation. Optimization of the process centers around minimizing the cost of recycling the SCF through an efficient recompression scheme and cycle configuration in the desorber unit. An economic evaluation shows a processing cost of 10.6 cents/lb (23 cents/kg) GAC which compares favorably with thermal regeneration and incineration. This non-destructive process allows re-use of the GAC while maintaining a high adsorbate capacity, which reduces carbon replacement costs and significantly decreases the need for carbon disposal by landfill or incineration. 25 refs., 13 figs., 3 tabs.

OSTI ID:
6924946
Journal Information:
Environmental Progress; (United States), Vol. 12:3; ISSN 0278-4491
Country of Publication:
United States
Language:
English