Removal of PCBs from oils by solvent extraction. Final report

Technical Report · Sat May 01 04:00:00 EDT 1993

OSTI ID:10161983

Way, P F ^[1]

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1. Veridyne, Inc., Topsfield, MA (US)

The objective of this project was to demonstrate the commercial feasibility of a solvent extraction process for the removal of PCBs from transformer oil. This effort was a continuation of the development work on this subject under Research Project 2028-01, that included a determination of the optimum design parameters for a solvent extraction process. With methyl Carbitol as the selected solvent, this development work culminated in the construction and operation of a 10 GPH pilot plant. Following the successful operation of the pilot plant, a full-scale plant was designed and constructed as a joint venture between EPRI and the Georgia Power Company. It had a rated capacity of 120 GPH of contaminated oil with a PCB content of up to 500 ppM. The early design was based on a product oil purity of 10 ppM, but this criteria had to be upgraded to less than 2 ppM to meet a new EPA ruling. The facility consisted of a multistage extractor, a distillation column for separation of the solvent from the oil/PCB residue, and a water wash unit for removal of solvent from the product oil. This design incorporated two unique features that had been demonstrated in the pilot plant: a special extractor arrangement that significantly reduced the oil loss, and a two-stage distillation/decanter system for the solvent separation step. However, initial operation of the Georgia Power facility was limited by flooding problems in the extractor, and failure to achieve the necessary phase separation in the two-stage separation process. Laboratory work traced the cause to the nature of the highly aged oil, in contrast to the new or moderately aged oils used in the pilot plant. The high concentration of degradation products in the aged oil increased the solubility of oil in the solvent, and of solvent in the oil. A solution was found in the discovery that the addition of a small amount of water to the solvent reduced this mutual solubility effect.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Veridyne, Inc., Topsfield, MA (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 10161983
• Report Number(s): EPRI-TR--101979; ON: UN93014897
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
240200
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303
CLEANING
DESIGN
ECONOMIC ANALYSIS
EQUIPMENT AND PROCESSES
FEASIBILITY STUDIES
INSULATING OILS
PILOT PLANTS
POLYCHLORINATED BIPHENYLS
POWER SYSTEM NETWORKS
TRANSMISSION AND DISTRIBUTION
SEPARATION EQUIPMENT
SOLVENT EXTRACTION
TRANSFORMERS
WASTE MANAGEMENT
WASTE PROCESSING PLANTS