Evaluation of CO2 Capture and Sequestration Using Oxyfuels with AMIGA Economic Modeling

Process Design studies for Oxyfuel retrofit to PC boilers of various sizes for several types of coal were linked with an ongoing effort employing the AMIGA (All-Modular Industry Growth Assessment) macroeconomic model to survey the domestic coal-fired power fleet. This project assessed the applicability of Oxyfuel CO₂ recovery for retrofit of the existing fleet. The coal preparation, power generation, existing environmental regulations, facility water use, pipeline CO₂ conditioning, and pipeline transport of CO₂ to sequestration were all considered and costs were estimated. This will provide input to a macroeconomic analysis employing the AMIGA model, a climate and energy- security model with a great deal of economic and technology detail. AMIGA steam power plant unit inventory (boilers, generators, control equipment) contains about 2000 boiler-level records and the questions examined will be where Oxyfuel systems fall on the dispatch against load curve, how to manage capacity expansion to meet load growth and to replace derated capacity, calculate the fuel demands, costs, and investment requirements. Cost and performance estimates for all major generating types may be viewed as technologies that are competing for investors. Hence, in terms of dynamic paths, the effort will show how transitions from Oxyfuels to IGCC could be managed. However, the technology options will not be limited to gasification, but will include coal-to-liquids, advanced refinery processes, CHP (combined heat and power), nuclear power, wind, PV, biomass, and end-use efficiency. These are embedded within a multi-sector, multi-region global model. Businesses and industries choose technologies and investment. Macroeconomic investment is build up from sector and technology investments. Household consumers by type and income choose energy-using durable goods. Changes in real income are calculated endogenously. While recognizing the importance of the CCS retrofits in the dispatch order as embodied in the AMIGA analysis, phased construction strategies for Air-fired PC to Oxyfuels and then to IGCC are a means of distributing the capital investment over time while realizing some level of benefits in the near term through building “capture ready” facilities. Oxyfuel firing requires the addition of air separation on the front end and CO₂ compression and liquefaction on the back end all of which are retrofitable in a transition to IGCC. Preliminary analysis supports the importance of investigating the benefits of Oxyfuels as a transitional strategy.