Evaluation of an existing waste treatment system for handling of a known solid waste matrix containing PCBs and other organic contaminants.
THERMAL DESORBER PROCESS MODELING AND EVALUATION
The client owns and operates a batch hot oil thermal desorption system at its existing waste treatment facility and contracted Process Engineering Associates, LLC (PROCESS) to perform an evaluation of the system for a known solid waste matrix containing Polychlorobiphenyls (PCBs) and other organic contaminants. PROCESS completed the following tasks as part of this evaluation:
- Process design basis preparation
- Thermal desorber computer model preparation and process simulation
- Organic recovery system computer process simulation.
The process design basis consisted primarily of construction of a detailed characterization of the solid waste feed to be processed that included organic constituent compositions and physical and thermodynamic properties. The properties were determined using the thermodynamics package of PROCESS’ licensed commercial process simulation software. The engineering data associated with the desorber and organic recovery condensers were also included in the design basis, as were the performance requirements of the desorber and organic recovery system. Once the design basis was set, PROCESS developed a unique batch thermal desorber computer process simulation model that predicted desorber performance on a time-dependent basis. In this manner, PROCESS could predict overall batch processing times as well as desorber emission rates and compositions throughout the batch processing period. For the organic recovery condensers, PROCESS used an in-house computer model to predict condenser individual and overall heat transfer coefficients using classical heat transfer relationships. The licensed simulation software was then used to predict organic removal efficiencies for the desorber emissions streams previously determined from the desorber simulation runs.
Based on the results of the desorption system computer simulations, PROCESS concluded that the desorber could not remove PCBs from the solid waste to the level prescribed in the design basis. Furthermore, it was concluded that several of the light organic compounds would not be recovered via the existing condensing system to the level desired by the client. In short, it was concluded that the existing desorption system was inadequate for treating the solid waste matrix in question.
- Waste Treatment
- Basic engineering design (BED)
- Computer process simulation
- Process suitability evaluation