History of the IECM

Why IECM?

Development of the Integrated Environmental Control Model (IECM) began at Carnegie Mellon University (CMU) under the direction of Prof. Ed Rubin in the mid–1980s, when the U.S. Department of Energy (DOE) was given responsibility for developing advanced, lower–cost emission control systems for coal–fired power plants. The focus of that program was on "high risk, high payoff" technologies to control emissions of sulfur dioxide (SO₂) and nitrogen oxide (NO_x)—the main precursors of "acid rain." More stringent control of particulate matter (PM) emissions also was pursued.

A tool to assess risks and payoffs

The IECM was conceived as a tool to help DOE and others systematically assess the risks and potential payoffs of advanced emission control options. Its objective was to compare the performance, emissions and costs of coal–fired plants using existing technologies to new designs using the advanced technologies being developed at DOE's Energy Technology Centers in Pittsburgh and Morgantown (today part of the National Energy Technology Laboratory, NETL). Those R&D efforts encompassed advanced combustion controls, post–combustion processes, and pre–combustion systems, including advanced coal cleaning and coal gasification systems.

New capabilities

The IECM pioneered new capabilities in modeling and assessment. First, it integrated all major components of a power plant, so that important interactions were not overlooked. Thus, pre–combustion technologies such as advanced coal cleaning processes could be coupled with advanced post–combustion options to identify the most cost–effective approaches for controlling emissions. Cost models were developed for each supported technology and linked to process performance models to produce a fully integrated analysis tool. A stochastic modeling engine also was developed, providing a new capability to perform quantitative uncertainty analysis—a powerful tool for evaluating the risks and rewards of advanced technology.

Following the path of computer technology

The IECM was first developed in the "dark ages" of computer technology using a Digital VAXStation (a computer about the size of a refrigerator). In the early 1990s, as personal computers evolved, the IECM was moved to a Macintosh computer, allowing us to develop a graphical user interface to run the model. The result was the first PC–based power plant model that was accessible to a wide variety of users. In the late 1990s the IECM was ported to the new Windows system to provide greater access to analysts using PCs. With the advent of the Internet, the model became available to users worldwide —unimaginable in the early days of IECM development.

A state-of-the-art model

In recent years the IECM has been greatly expanded and transformed into the state–of–the–art simulation model it is today. A major focus over the past decade has been the addition of carbon capture and storage (CCS) options —a critical technology for reducing greenhouse gas emissions. The IECM was further expanded to include a full range of fossil fuel power generation options, including natural gas combined cycle (NGCC) systems, integrated gasification combined cycle (IGCC) systems, and advanced coal combustion systems. A detailed set of models for power plant water use and treatment options also was developed and incorporated into the IECM framework. The result is a fully integrated group of environmental control technology options for reducing air, water and solid waste emissions from fossil fuel power plants. This includes updated or newly developed models for controlling regulated air pollutants such as SO₂, NO_x, PM, and mercury. In addition, the uncertainty analysis capability has been expanded to allow probabilistic assessments of performance and cost differences between multiple technologies and systems.

The baton is passed

In mid-2022, with Prof. Rubin's retirement, responsibility for development and maintenance of the IECM was passed on to Prof. Haibo Zhai at the University of Wyoming (UW). Prior to this, Prof. Zhai was the IECM's Project Manager at CMU.

Ongoing efforts

Ongoing efforts today are expanding the IECM capabilities to analyze new processes for CO₂ capture and storage, and new, more efficient systems for electric power generation. Improvements to the underlying software and user interface also are being pursued to ensure that IECM remains the most powerful and widely–used tool for assessing the options, tradeoffs, risks, and opportunities for cost–effective environmental control of fossil fuel power plants.