'Top Down' BACT - Major Mill Expansion Project, 1990 Environmental Conference Proceedings

Conducting a ’Top Down’ Best Available Control Technology (BACT) evaluation for a multimillion dollar mill expansion is a time consuming and resource intensive undertaking. The subject project involved characterizing emissions and evaluating BACT for several unit operations, including a Kraft recovery boiler, lime kiln, package boilers , and associated ancillary operations. The BACT process involved identifying the most stringent control technique on a pollutant by pollutant basis for each affected emission source. Following this step each control option was evaluated to determine technical feasibility. If determined feasible, economic, energy and environmental impact analyses were performed to assess whether the control technique was BACT. Control technologies evaluated ranged from burner combustion design for the recovery boiler to high efficiency caustic scrubbers for the lime kiln. After extensive negotiations at both the State and Federal level the required air permit was obtained. This paper highlights the important aspects of conducting a top down BACT analysis and presents an example of the iterative control alternatives review process that must be completed.