How the TSCA Incinerator Works - U.S. Bechtel Jacobs Company LLC (DOE)

Utilizing a highly instrumented kiln, secondary combustion chamber, and off-gas treatment system (click here for schematic), the TSCA Incinerator meets or exceeds environmental regulations and DOE requirements for the treatment of RCRA and TSCA- regulated waste.

The kiln operates at a minimum temperature of 1,572 Fº. The portion of the waste that is not combustible (ash) exits the kiln into the mix chamber. In the mix chamber, ash is cooled with water and removed by a conveyor. The combustion gases exit the kiln to a mix chamber and then go to a secondary combustion chamber where temperatures reach between 1,832 (RCRA only) and 2,200 Fº. This higher temperature is required for achieving a 99.9999 percent destruction and removal efficiency required by TSCA. The gases remain in the secondary combustion chamber for greater than 2 seconds and then pass into the quench tower.

In the quench tower, a caustic solution (20% sodium hydroxide) is sprayed into the combustion gases. This is done to cool the gases to approximately 187 Fº and neutralize the acid gases. The venturi scrubber uses a pressure drop to remove particles greater than 1 micrometer in size. The demister separates water carryover (water droplets) from the combustion gases and returns the water through the quench recycle system. The packed bed scrubber removes the remaining acid gases. The two ionizing wet scrubbers use electrical charges to remove particles less than 1 micrometer in size. Water that is generated by the air pollution control system is treated in the Central Neutralization Facility at East Tennessee Technology Park.

By the time the off-gases reach the 100-foot stack, 99.99 percent of the hazardous organics and 99.9999 percent of the PCBs have been destroyed. Ash and other residues from the incinerator are stabilized, if necessary, and disposed off site at a commercial mixed waste disposal facility. DOE sites in other states are required to provide contingency plans for return of incinerator residues to their sites in the event Oak Ridge cannot otherwise dispose of them.