RECYCLING ACTIVATED CARBON

Revision Date: 10/01
Process Code: Navy/Marines: ID-25-99, SR-15-99; Air Force: FA09, FA10; Army: N/A
Usage: Navy: Low; Marines: Low; Army: Low; Air Force: Low
Compliance Impact: Low
Alternative for: Single Use/Disposal of Spent Activated Carbon Waste Streams
Applicable EPCRA Targeted Constituents: Toxic Organic Compounds

Overview: Carbon adsorption is a process in which a contaminated waste liquid- or vapor-phase waste stream is treated by removing the targeted contaminant (the adsorbate) through contact with a solid surface (the adsorbent). Activated carbon that has been processed to significantly increase the internal surface contact area, is widely used in many applications as the adsorbent material. Use of different raw materials (e.g., coal, wood, coconut shells) and processing techniques has resulted in a range of carbon types, in both powdered and granular forms. These types have various adsorption characteristics that tend to make them better suited for specific environmental applications. Granular activated carbon (GAC) is most commonly used for removal of a wide range of toxic organic compounds from contaminated groundwater, industrial wastewater, and vapor phase waste streams. Powdered activated carbon (PAC) is used extensively in biological waste treatment systems, and typically involves different handling and disposal practices than those used for GAC systems.

Activated carbon waste stream can be classified into a variety of possible categories, including both hazardous and non-hazardous waste. The handling and disposal of activated carbon waste streams can pose a significant economic and logistical burden on the waste generator. The incentives for recycling spent activated carbon wastes include financial benefits and reduced liabilities associated with improper handling or disposal of the activated carbon waste stream.

Many companies offer activated carbon recycling services as part of an overall service arrangement or as a stand-alone service. The specific service offered will depend on such factors as the characteristics of the GAC treatment system, the volume of spent carbon to be handled, and the capabilities of the selected vendor. Spent carbon waste can be handled in either bulk shipments via tanker truck or rail cars, or in drums or alternative containers. Virtually all spent carbon waste to be regenerated is processed using a thermal destruction/scrubbing system, which destroys the organic contaminants as well as regenerates the carbon for reuse. Some vendors offering activated carbon regeneration services will segregate the waste batches handled from each customer, if required, while other vendors will "blend" together waste carbon batches from multiple customers prior to processing. This process can be a significant concern to those seeking to minimize liability associated with mixing and disposal their waste stream with other unidentified wastes from other sources.


Compliance Benefit: Recycling activated carbon (if hazardous) may help facilities meet the requirements of waste reduction under RCRA, 40 CFR 262, Appendix. If the activated carbon is non-hazardous, recycling will help facilities meet the requirements under Executive Order 13101 requiring executive agencies (e.g., DoD) to incorporate waste prevention and recycling in their daily operations.

The compliance benefits listed here are only meant to be used as a general guideline and are not meant to be strictly interpreted. Actual compliance benefits will vary depending on the factors involved, e.g. the amount of workload involved.


Materials Compatibility:
No materials compatibility issues were identified.


Safety and Health: Activated carbon may contain toxic impurities that can be irritating to the eyes, skin, and mucous membranes. Proper personal protective equipment is recommended. Consult your local industrial health specialist, your local health and safety personnel, and the appropriate MSDS prior to implementing this technology.


Benefits:
  • Eliminates the cost, handling, and related liabilities associated with spent carbon disposal at off-site facilities.
  • Significantly reduces the volume of fresh carbon that must be purchased to regenerate the system.


Disadvantages:
  • Regeneration of powdered activated carbon is typically not practical.
  • If carbon is contaminated with PCB’s, dioxins, heavy metals, or DCBP (dichlorobromopropane), regeneration may not be an option.
  • Special packaging may be required if carbon has certain chemical properties (e.g., 2<Ph>11, halide and sulfur contamination, etc.)
  • Regenerate of carbon on-site is not economically feasible unless more than 400,000 pounds of spent AC is generated per year.


Economic Analysis: It is recommended that activated carbon be purchased from a virgin activated carbon supplier that will accept the spent carbon for regeneration. Typically, activated carbon sample analysis and shipping fees are paid by the user, however, there is no charge for regeneration. The economics associated with recycling spent activated carbon will vary based on the volume, system characteristics, contaminants, and handling mode (i.e., bulk or packaged units).

One vendor, Envirotrol, Inc., which performs custom segregated reactivation by which the same carbon is shipped back to the original user, offered the following cost comparison.

Assumptions:

  • Facility uses 2,000 lbs. of activated carbon per month.
  • Spent carbon from the facility is classified as hazardous and must be incinerated.
  • Incineration costs $0.60/lb.
  • Virgin carbon costs $1/lb.
  • Reactivated carbon costs $0.65/lbs.
  • Losses during reactivation of carbon equals 15%. This is made up for with virgin carbon when carbon is shipped back to user.
  • Labor and freight costs are the same for both uses.

Cost Comparison of Annual Use of Virgin versus Reactivated Carbon

 

Virgin Carbon

Reactivated Carbon

Carbon Purchase: $24,000 $16,860
Carbon Disposal: $14,400 $0
Total: $38,400 $16,860

Economic Analysis Summary

    Annual Savings for Recycling Activated Carbon: $21,540
    Capital Cost for Diversion Equipment/Process: $0
    Payback Period for Investment in Equipment/Process: Immediate

Click Here to view an Active Spreadsheet for this Economic Analysis and Enter Your Own Values. To return from the Active Spreadsheet, click the reverse arrow in the Tool Bar.


Approving Authority: Approval is controlled locally and should be implemented only after engineering approval has been granted. Major claimant approval is not required.


NSN/MSDS:
Product NSN Unit Size Cost MSDS*
None Identified     $  


*There are multiple MSDSs for most NSNs.
The MSDS (if shown above) is only meant to serve as an example.


Points of Contact: Navy:
Mr. Charles Sokol
Environmental Engineer, ESC 423
Naval Facilities Engineering Service Center
1100 23rd Avenue
Port Hueneme, CA 93043
Phone: (805) 982-5318
DSN: 551-5318
FAX: (805) 982-4832
Email: sokolcw@nfesc.navy.mil


Vendors: This is not meant to be a complete list, as there are other manufacturers of this type of equipment.

Calgon Carbon Corporation
P.O. Box 717
1500 Calgon Carbon Drive
Pittsburgh,  PA   15230-0717
Phone: (800) 422-7266 
or (412) 787-6700
Email:  info@calgoncarbon.com
URL:  http://www.calgoncarbon.com/

 

Carbtrol Corporation
955 Connecticut Avenue, Suite 5202
Bridgeport, CT  06607
Phone: (800) 242-1150
FAX:  (203) 337-4353
Email:  info@carbtrol.com
URL:  www.carbtrol.com

 

Envirotrol, Inc.
432 Green Street
P.O. Box 61
Sewickley,  PA   15143
Phone: (412) 741-2030
FAX:  (412) 741-2670
Email:  info@envirotrol.com
URL:  http://www.envirotrol.com/


Sources: Mr. Scott Berner, Naval Air Station Jacksonville, January 1999.



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