Status of Catalytic Combustion R&D for the Department of Energy Advanced Turbine Systems Program

Abstract

This paper discusses some of the advanced concepts and research and development associated with implementing catalytic combustion to achieve ultra-low-NOx emissions in the next generation of land-based gas turbine engines. In particular, the paper presents current development status and design challenges being addressed by Siemens Westinghouse Power Corp. for large industrial engines (>200 MW) and by Solar Turbines for smaller engines (<20 MW) as part of the U.S. Department of Energy’s (DOE) Advanced Turbine Systems (ATS) program. Operational issues in implementing catalytic combustion and the current needs for research in catalyst durability and operability are also discussed. This paper indicates how recent advances in reactor design and catalytic coatings have made catalytic combustion a viable technology for advanced turbine engines and how further research and development may improve catalytic combustion systems to better meet the durability and operability challenges presented by the high-efficiency, ultra-low emissions ATS program goals. [S0742-4795(00)01502-7]

High-Pressure Methane Combustion over a Perovskyte Catalyst

“…7 Moreover, instability problems causing incomplete combustion and acoustic-pressure oscillations and representing the major drawback of lean premixed combustion for GT are avoided by CC. 8,9 For these reasons, CC seems to be the only practicable method for meeting the ever-more-stringent regulations imposed by an increasing number of worldwide agencies on NO x levels in urban areas 4,10,11 without using expensive cleanup systems. As addressed by a study commissioned by the U.S. Department of Energy (DOE), 12 CC is very attractive when ultralow NO x levels are required and for small size GT, for which secondary measures are very expensive.…”

“…13,14 Because of such material limitations, complex process designs including additional homogeneous stages have been proposed. 4,8,13,15 With respect to this hybrid (catalyticÀ homogeneous) concept, two main combustion strategies that include a catalytic stage operated under fuel lean 8,11,16 and fuel rich 5,9,10 conditions have been explored. Nevertheless, the combustor design, even for hybrid combustion, is strongly dependent on the performance of the catalyst in terms of both activity and thermal stability.…”

“…Moreover, instability problems causing incomplete combustion and acoustic-pressure oscillations and representing the major drawback of lean premixed combustion for GT are avoided by CC. , …”

“…Despite this strong interest in CC, its wide diffusion in power and heat production systems has been limited because of several issues related to the high cost of catalysts, generally based on noble metals, and to the low thermal resistance of materials that cannot withstand the current GT inlet temperatures (≈1500 °C). , Because of such material limitations, complex process designs including additional homogeneous stages have been proposed. ,,, With respect to this hybrid (catalytic–homogeneous) concept, two main combustion strategies that include a catalytic stage operated under fuel lean ,, and fuel rich ,, conditions have been explored. Nevertheless, the combustor design, even for hybrid combustion, is strongly dependent on the performance of the catalyst in terms of both activity and thermal stability .…”

System Study of Rich Catalytic/Lean burn (RCL) Catalytic Combustion for Natural Gas and Coal-Derived Syngas Combustion Turbines

“…Unfortunately Pd-PdO catalyst morphology and its reactions with methane are complex, and lead to complex behaviors such as deactivation at high temperature (above about 750 C / 1380 F), hysteresis in reaction rate over heating and cooling cycles [4][5][6][7], and oscillations in activity and temperature [8][9][10][11]. Lightoff and extinction temperatures are well above 300 C (570 F) for fuel-lean methane reaction on Pd-based catalysts, thus requiring the use of a preburner in many engine applications [12][13]. For syngas combustion, hydrogen reactivity leads to early autoignition of the fuel in the catalytic channels, and consequent temperature overrun.…”