IECM 12.0 beta User Manual > Modules Included with the IECM > Pulverized Coal (PC) Plant > SET PARAMETERS > Mercury >

Retrofit or Adjustment Factors

Inputs for the capital costs of modifications to process areas of the activated carbon and water injection system are entered on the Retrofit or Adjustment Factors parameter screen. See Retrofit or Adjustment Factor Inputs for an explanation of retrofit costs. The activated carbon and water injection system has the following capital cost process areas:

•Spray Cooling Water: This capital cost area represents the materials and equipment necessary to inject water into the flue gas duct for the purpose of cooling the flue gas to a prerequisite temperature. Equipment includes water storage tanks, pumps, transport piping, injection grid with nozzles, and a control system. The direct capital cost is a function of the water flow rate.

•Sorbent Injection: This capital cost area represents the materials and equipment necessary to deliver the activated carbon into the flue gas. Equipment includes silo pneumatic loading system, storage silos, hoppers, blowers, transport piping, and a control system. The direct capital cost is a function of the sorbent flow rate.

•Sorbent Recycle: This capital cost area represents the materials and equipment necessary to recycle ash and activated carbon from the particulate collector back into the duct injection point. The purpose is to create an equilibrium state where the carbon is reintroduced to improve performance. Equipment includes hoppers, blowers, transport piping, and a control system. The direct capital cost is a function of the recycle rate of ash and spent sorbent. (NOTE: Sorbent recycling is a feature which may be added in a future version of the IECM.)

•Additional Ductwork: This capital cost area represents materials and equipment for ductwork necessary beyond the other process areas. Extra ductwork may be required for difficult retrofit installations. (NOTE: Future versions of the IECM may include parameters to determine a capital cost for this area. The current version assumes no additional ductwork.)

•Sorbent Disposal: This capital cost area represents materials and equipment required to house and dispose the collected sorbent. Equipment includes hoppers, blowers, transport piping, and a control system. This is in excess of existing hoppers, tanks, and piping used for existing particulate collectors. The direct capital cost is determined by the incremental increase in collected solids in the particulate collector.

•CEMS Upgrade: This capital cost area represents materials and equipment required to install a continuous emissions monitoring system (CEMS) upgrade. The direct capital cost is determined by the net electrical output of the power plant.

•Pulse-Jet Fabric Filter: This capital costs area represents an upgrade to an existing cold-side ESP, where one section at the back end of the unit is replaced with a pulse-jet fabric filter. This can be considered a pseudo-COHPAC. Equipment includes pulse-jet FF, filter bags, ductwork, dampers, and MCCs, instrumentation and PLC controls for baghouse operation. Equipment excludes ash removal system, power distribution and power supply, and distributed control system. The direct capital cost is a function of the flue gas flow rate and the air to cloth ratio of the fabric filter. (NOTE: The IECM currently does not support multiple particulate devices in the same configuration nor a modified cold-side ESP.)