Innovations for Existing Plants
The Integrated Environmental Control Model (IECM)
The Integrated Environmental Control Model (IECM) was developed for the National Energy Technology Laboratory, by Carnegie Mellon University. The model runs on an Intel based PC under Windows 95/98/NT. The IECM allows systematic analysis of emission control options for coal-fired power plants employing a variety of pre-combustion, combustion and post-combustion control methods. The model was developed to provide preliminary performance and cost estimates for new base load power plants as well as existing plants considering technology retrofits. Of particular interest are a number of advanced environmental control technologies being developed with support from U. S. Department of Energy. For comparative purposes, however, a set of "baseline" technologies representing current commercial systems also is part of the IECM framework. The plant areas and processes currently included in the cost and performance model are: NOx control technologies, including LNB, SCR, SNCR, and NGR; SO2 control technologies, including LFSO, Limestone with Dibasic Acid additive, Mg-Lime process, and LSD; Particulate matter control technologies, including ESP, Reverse Gas Fabric Filter, Reverse gas Sonic FF, Shake and Deflate FF, and Pulse-jet FF; mercury control technologies are activated carbon injection (with and without spray cooling), and the intrinsic capture of mercury by other control technologies.
For each technology, a process performance sub-model accounts for all energy and mass flows, including air pollutants, reagent requirements, and solid wastes associated with that process. The performance sub-models also determine key process design parameters, such as the specific collection area (SCA) of an electrostatic precipitator, or the reagent stoichiometry of a flue gas desulfurization (FGD) system. Coupled to each performance model, an economic sub-model estimates the capital cost, annual operating and maintenance (O&M) costs, and total levelized cost of each technology based on plant and performance model parameters, including all emission constraints. The model reflects the most recent EPRI cost estimates. (TAG, Technical Assessment Guide, Volume 1: Electricity Supply. Palo Alto, CA, Electric Power Research Institute (EPRI), TR-102276-V1R7, 1993.)
A unique capability of the IECM model is that it allows performance and costs to be characterized probabilistically, using Monte Carlo methods to quantify performance and cost uncertainties and risks.