Zero Emissions Coal Syngas Oxygen Turbo Machinery

Abstract

Siemens Energy, Inc. (formerly Siemens Westinghouse Power Corporation) worked with Clean Energy Systems and Florida Turbine Technologies to demonstrate the commercial feasibility of advanced turbines for oxy-fuel based power systems that discharge negligible CO{sub 2} into the atmosphere. The approach builds upon ultra supercritical steam turbine and advanced gas turbine technology with the goal of attaining plant efficiencies above 50% in the 2015 timeframe. Conceptual designs were developed for baseline, near term, and long term oxy-fuel turbine cycles, representing commercial introductions of increasingly advanced thermal conditions and increasing exposure to steam-CO{sub 2} mixtures. An economic analysis and market demand study was performed by Science Applications International Corp. (SAIC), and indicated that long-term oxy-fuel turbine cycles start to look attractive in 2025 when the CO{sub 2} tax is assumed to reach $40/ ton, and by 2030 it has a clear advantage over both IGCC with sequestration and pulverized coal with sequestration. A separate risk analysis of the oxy-fuel combustor, HP turbine, re-heater, and IP turbine of the long-term cycle identified and categorized risks and proposed mitigation measures. In 2007 the program began to focus on a potential oxy-fuel turbine power generation demonstration project in the 2012 -13 time period while still maintaining a link to the requirements of the long-term oxy-syngas cycle. The SGT-900 turbine was identified as the best fit for modification into an intermediate pressure turbine (IPT) for this application. The base metals, bond coats, thermal barrier coatings (TBCs), and rotor materials used in the SGT-900 were tested for their ability to operate in the steam- CO{sub 2} environment of the oxy-fuel OFT-900. Test results indicated that these same materials would operate satisfactorily, and the plan, is to use SGT-900materials for the OFT-900. Follow-on programs for corrosion testing and evaluation of crack growth rates in oxy-fuel environments have been proposed to build on these results and provide quantifiable assessments of the effects of oxy-fuel environments on the service lives of turbine components.