Kenneth Winston Beebe

Development of catalytic combustion technology for single-digit emissions from industrial gas turbines

Abstract Catalytic combustion has demonstrated potential for attaining the firing temperatures of current and next generation gas turbines with nitrogen oxides (NOx) production less than 3 parts-per-million by volume (ppmv), using natural gas fuel. The technology necessary to achieve this extremely low emissions performance with typical heavy-duty industrial and utility gas turbine operating cycle conditions, has been under development as a joint effort by the General Electric Company (GE) and Catalytica Combustion Systems Incorporated (CCSI) for several years with the support of Tokyo Electric Power Company Inc. (TEPCO). The most recent phase of this program, which began in late 1997, is focused on the durability of catalytic reactors in the gas turbine combustor operating environment. This paper presents the results of subscale catalytic reactor endurance testing at simulated steady-state and cyclic operating conditions typical of utility gas turbine service. The results of full-scale, full-pressure, laboratory testing of a catalytic combustion system having the most advanced catalytic reactor mechanical design features developed by CCSI are also presented.

Single-Digit Emissions in a Full Scale Catalytic Combustor

Catalytic combustion offers the possibility of attaining the firing temperatures of current and next generation gas turbines [up to ∼1450°C (2640°F)] with nitrogen oxides (NOx) production as low as 1 part per million by volume (ppmv). Such catalytic combustion technology has been under development at Catalytica for several years, and the first full scale test of the technology took place at the General Electric Company under TEPCO sponsorship in 1992. The results of the most recent and most successful full scale test in this program are reported in this paper.The catalytic combustor system was designed for the GE Model MS9001E gas turbine fired with natural gas fuel. The 508-mm (20-in) diameter catalytic reactor was operated at conditions representative of the startup and load cycle of that machine. It was verified that the observed NOx levels were produced not in the catalyst, but in the diffusinn flame of the preburner used to start the system and maintain the necessary catalyst inlet temperature. Even so, NOx levels below 5 ppmv (at 15% O2) were achieved at the simulated base load operating point. Carbon monoxide (CO) and unburned hydrocarbons (UHC) emissions were likewise below 10 ppmv at that condition. Single digit emissions levels also were recorded at conditions representative of the combustor operating at 78% load, the first such demonstration of the turndown capability of this system. Throughout the test, dynamic pressure measurements showed the catalytic combustor to be quieter than even the diffusion flame combustors currently in commercial service.© 1997 ASME

Design and Test of a Catalytic Combustor for a Heavy Duty Industrial Gas Turbine

The most effective technologies currently available for controlling NOx emissions from heavy duty industrial gas turbines are either diluent injection in the combustor reaction zone, or dry low NOx (DLN) combustion, coupled with selective catalytic reduction (SCR) De-NOx in the gas turbine exhaust. A competing technology with the potential for achieving comparable emissions levels at substantially lower capital investment and operating cost is catalytic combustion of lean premixed fuel and air within the gas turbine. A preliminary design of a catalytic combustion system using natural gas fuel has been prepared for the GE Model MS9001E gas turbine. A full scale test combustor has been constructed for a full pressure development test based upon this design work and was operated at the GE Power Generation Engineering Laboratory in Schenectady, New York. Discussion of the catalytic combustor design, the catalytic reactor design and laboratory development test results is presented.Copyright

Development of a Catalytic Combustor for a Heavy-Duty Utility Gas Turbine

The most effective technologies currently available for controlling NOx emissions from heavy-duty industrial gas turbines are either diluent injection in the combustor reaction zone, or lean premixed Dry Low NOx (DLN) combustion. For ultra low emissions requirements, these must be combined with selective catalytic reduction (SCR) DeNOx systems in the gas turbine exhaust. An alternative technology for achieving comparable emissions levels with the potential for lower capital investment and operating cost is catalytic combustion of lean premixed fuel and air within the gas turbine. The design of a catalytic combustion system using natural gas fuel has been prepared for the GE model MS9OOIE gas turbine. This machine has a turbine inlet temperature to the first rotating stage of over 1100°C and produces approximately 105 MW electrical output in simple cycle operation. The 508 mm diameter catalytic combustor designed for this gas turbine was operated at full-scale conditions in tests conducted in 1992 and 1994. The combustor was operated for twelve hours during the 1994 test and demonstrated very low NOx emissions from the catalytic reactor. The total exhaust NOx level was approximately 12–15 ppmv and was produced almost entirely in the preburner ahead of the reactor. A small quantity of steam injected into the preburner reduced the NOx emissions to 5–6 ppmv.Development of the combustion system has continued with the objectives of reducing CO and UHC emissions, understanding the parameters affecting reactor stability and spatial non-uniformities which were observed at low inlet temperature, and improving the structural integrity of the reactor system to a level required for commercial operation of gas turbines. Design modifications were completed and combustion hardware was fabricated for additional full-scale tests of the catalytic combustion system in March 1995 and January 1996. This paper presents a discussion of the combustor design, the catalytic reactor design and the results of full-scale testing of the improved combustor at MS9OOIE cycle conditions in the March 1995 and January 1996 tests. Major improvements in performance were achieved with CO and UHC emissions of 10 ppmv and 0 ppmv at base load conditions.This ongoing program will lead to two additional full-scale combustion system tests in 1996. The results of these tests will be available for discussion at the June 1996 Conference in Birmingham.Copyright