Development of a Catalytic Combustor for a Biomass Fueled Gas Turbine

Author(s):  
Etienne Lebas ◽  
Gérard Henri Martin

Combustion of biomass derived fuels often results in high emissions levels of pollutants such as NOx, CO and unburned hydrocarbons. In gas turbines, catalytic combustion of biofuels has the potential to reduce emissions of these undesired species. The ULECAT project (Ultra Low Emissions CATalytic combustor), European project led by IFP, initiated the development of an ultra-low emission gas turbine in the range of 1 to 5 MWe, able to run with both biomass derived gases and liquid fuels. The first part of the project has been devoted to the definition of the system and the development of catalysts capable of burning both biomass derived fuels and Diesel fuel. It was mainly focused on high temperature catalyst durability and the reduction of NOx formation. This last point is of primary importance in biofuels combustion and certain catalysts have shown an important potential in reducing ammonia conversion into NOx in some operating conditions. The pilot scale tests have proven the dual fuel operability. Numerical tools were developed and have been validated by pilot tests. They provided useful help in designing the catalytic section of the combustor. An economical analysis of the system have shown the great potential of catalytic combustion in reducing the operating costs and investment compared to SCR or ammonia scrubbing.

Author(s):  
Jean-Hervé Le Gal ◽  
Gérard Martin ◽  
Daniel Durand

Biomass derived fuels are an essential alternative for heat and energy production, in order to minimise environmental impact, since they make no net contribution to the increase of CO2 emissions into the atmosphere. In certain countries, biofuels are also interesting since they are available as waste products from the agricultural or forestry industry. Unfortunately, combustion of biofuels often results in high emissions levels of pollutants such as NOx, CO and unburned hydrocarbons. In gas turbines, catalytic combustion of biofuels has the potential to reduce emissions of these undesired species. The ULECAT project (Ultra Low Emissions CATalytic combustor) described in this paper is the first step of a program aiming at the development of an ultra-low emission gas turbine in the range of 1 to 5 MWe, able to run with both biomass-derived gases and liquid fuels. The objective of the project is to assess the feasibility of a dual fuel catalytic combustor. Combustor design issues are investigated at full and part load conditions. For the comparison of combustor configuration, modelling provides a useful help for catalytic section design, in particular for the estimation of catalytic activity and wall temperature which strongly influence catalyst life time. Catalyst development is one of the main topics of this project. It is mainly focused on high temperature catalyst durability and the reduction of NOx formation. This last point is of primary importance in biofuels combustion and certain catalysts have shown an important potential in reducing ammonia conversion into NOx in some operating conditions. Catalyst performances are evaluated at lab scale and also pilot scale in representative gas turbine combustor conditions with both Diesel fuel and biomass derived fuels.


Author(s):  
Ralph A. Dalla Betta ◽  
James C. Schlatter ◽  
Sarento G. Nickolas ◽  
Martin B. Cutrone ◽  
Kenneth W. Beebe ◽  
...  

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.


1997 ◽  
Vol 119 (4) ◽  
pp. 844-851 ◽  
Author(s):  
R. A. Dalla Betta ◽  
J. C. Schlatter ◽  
S. G. Nickolas ◽  
M. B. Cutrone ◽  
K. W. Beebe ◽  
...  

The most effective technologies currently available for controlling NOx emissions from heavy-duty industrial gas turbines are diluent injection in the combustor reaction zone, and lean premixed Dry Low NOx (DLN) combustion. For ultralow 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 MS9OO1E 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-dia 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 nonuniformities that 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 MS9OO1E 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 baseload 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.


1998 ◽  
Vol 120 (3) ◽  
pp. 509-513 ◽  
Author(s):  
T. Fujii ◽  
Y. Ozawa ◽  
S. Kikumoto ◽  
M. Sato ◽  
Y. Yuasa ◽  
...  

Recently, the use of gas turbine systems, such as combined cycle and cogeneration systems, has gradually increased in the world. But even when a clean fuel such as LNG (liquefied natural gas) is used, thermal NOx is generated in the high temperature gas turbine combustion process. The NOx emission from gas turbines is controlled through selective catalytic reduction processes (SCR) in the Japanese electric industry. If catalytic combustion could be applied to the combustor of the gas turbine, it is expected to lower NOx emission more economically. Under such high temperature and high pressure conditions, as in the gas turbine, however, the durability of the catalyst is still insufficient. So it prevents the realization of a high temperature catalytic combustor. To overcome this difficulty, a catalytic combustor combined with premixed combustion for a 1300°C class gas turbine was developed. In this method, catalyst temperature is kept below 1000°C, and a lean premixed gas is injected into the catalytic combustion gas. As a result, the load on the catalyst is reduced and it is possible to prevent the catalyst deactivation. After a preliminary atmospheric test, the design of the combustort was modified and a high pressure combustion test was conducted. As a result, it was confirmed that NOx emission was below 10 ppm (at 16 percent O2) at a combustor outlet gas temperature of 1300°C and that the combustion efficiency was almost 100 percent. This paper presents the design features and test results of the combustor.


Author(s):  
P. Dutta ◽  
D. K. Yee ◽  
R. A. Dalla Betta

The goal of the Advanced Turbine Systems (ATS) program is to develop a high thermal efficiency industrial gas turbine with ultra-low emissions (<10 ppmv NOx, CO and UHC @ 15% O2) over the 50 to 100% load range. Catalytic combustion was chosen as an approach likely to meet ATS emissions goals. A subscale catalytic combustor development program was designed to develop a technical knowledge base for catalyst design (catalyst construction, length), performance (ignition, activity and emissions) and operating limitations (fuel-air turndown and sensitivity to combustor operating variables). A novel catalyst design with preferential catalyst coating to limit substrate temperatures was used in the tests. The catalytic combustor consists of a fuel-air premixer, catalytic reactor and a post-catalyst zone for completion of homogeneous gas phase reactions. In situ measurements of mean fuel concentrations at the exit of the premixer were completed to characterize fuel-air premixing levels. Performance of the catalyst was monitored through global emissions measurements at the exit of the post-catalyst combustor under simulated engine conditions, and measurement of catalyst substrate temperatures. Ultra-low emissions were achieved for relatively uniform fuel-air premixing (<10% peak to peak variation in fuel concentration) with higher inhomogeneities (>10% peak to peak variation) leading to either locally high or low substrate temperatures. Regions with low substrate temperatures led to high CO and UHC emissions. Modeling of post-catalyst homogeneous reactions using a standard stationary, one-dimensional, laminar premixed flame formulation showed good agreement with measurements. In short term tests, the catalysts showed the desired chemical activity and ability for multiple light-off. The subscale combustor development work provided the necessary technical information for full scale catalytic combustion system development for the ATS gas turbine.


Author(s):  
K. W. Beebe ◽  
M. B. Cutrone ◽  
R. N. Matthews ◽  
R. A. Dalla Betta ◽  
J. C. Schlatter ◽  
...  

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.


Author(s):  
T. Fujii ◽  
Y. Ozawa ◽  
S. Kikumoto ◽  
M. Sato ◽  
Y. Yuasa ◽  
...  

Recently, use of gas turbine systems such as combined cycle and cogeneration systems has gradually increased in the world. But even when a clean fuel such as LNG (liquefied natural gas) is used, thermal NOx is generated in the high temperature gas turbine combustion process. The NOx emission from gas turbines is controlled through selective catalytic reduction processes (SCR) in the Japanese electric industry. If catalytic combustion could be applied to the combustor of the gas turbine, it is expected to lower NOx emission more economically. Under such high temperature and high pressure conditions as in the gas turbine, however, the durability of the catalyst is still insufficient. So it prevents the realization of a high temperature catalytic combustor. To overcome this difficulty, a catalytic combustor combined with premixed combustion for a 1300°C class gas turbine was developed. In this method, catalyst temperature is kept below 1000°C and a lean premixed gas is injected into the catalytic combustion gas. As a result, the load on the catalyst is reduced and it is possible to prevent the catalyst deactivation. After a preliminary atmospheric test, the design of the combustor was modified and a high pressure combustion test was conducted. As a result, it was confirmed that NOx emission was below 10ppm (at 16% O2) at a combustor outlet gas temperature of 1300°C and that the combustion efficiency was almost 100%. This paper presents the design features and test results of the combustor.


Author(s):  
Huayang Zhu ◽  
Greg S. Jackson

The development of lean-premixed catalytic reactors for ultra-low emissions combustors in gas turbines presents many design and operability challenges that are not addressed with conventional steady-state reactor models with one-step chemistry mechanisms. These challenges include transient light-off from low temperatures, catalyst deactivation, and hysteresis in catalytic activity. To address these issues, a transient 1-D reactor model with a validated multi-step surface chemistry mechanism has been developed to explore such behavior in catalytic combustors. The surface chemistry sub-model has been incorporated for investigating lean catalytic combustion of CH4 on Pd-based catalysts. The current study investigated the effects of operating conditions — such as pressure, inlet temperature, and velocity — on catalytic reactor ignition and deactivation. The transient modeling provides curves for reactor light-off for a range of inlet pressures and velocities and reveals conditions wherein Pd-catalyst undergoes reduction/deactivation. Model results are compared with some experimental measurements and implications for catalytic combustor design and operation for gas turbine applications are discussed.


Author(s):  
G. L. Touchton ◽  
L. C. Szema ◽  
M. B. Cutrone ◽  
R. Cellamare ◽  
W. Vonkleinsmid

Laboratory tests of catalytic combustors with distillate fuel have achieved ultra low NOx formation at catalytic reactor exit temperatures and combustion efficiencies consistent with state-of-the-art gas turbine requirements. Concomitant with these features, however, are design limitations such as narrow turn down range and unique reactor mounting requirements. This paper presents fully analyzed conceptual design solutions to these problems within the constraints of fixed geometry, full catalytic combustion over 80% of the turbine load range, and retrofit to an existing gas turbine. The combustor design incorporates (a) a gutter stabilized pilot burner downstream of the reactor for operation from ignition to full speed no load, (b) a segmented fuel-air preparation system for fuel staging of the reactor, (c) a reactor mounting system which accommodates thermal growth and start-up and shutdown transients, and (d) a graded cell reactor. These features were achieved while maintaining low reactor face velocities and system pressure drops.


1983 ◽  
Vol 105 (4) ◽  
pp. 797-805 ◽  
Author(s):  
G. L. Touchton ◽  
L. C. Szema ◽  
M. B. Cutrone ◽  
R. Cellamare ◽  
W. Vonkleinsmid

Laboratory tests of catalytic combustors with distillate fuel have achieved ultralow NOx formation at catalytic reactor exit temperatures and combustion efficiencies consistent with state-of-the-art gas turbine requirements. Concomitant with these features, however, are design limitations such as narrow turn-down range and unique reactor mounting requirements. This paper presents fully analyzed conceptual design solutions to these problems within the constraints of fixed geometry, full catalytic combustion over 80 percent of the turbine load range, and retrofit to an existing gas turbine. The combustor design incorporates (a) a gutter stabilized pilot burner downstream of the reactor for operation from ignition to full-speed no-load, (b) a segmented fuel-air preparation system for fuel staging of the reactor, (c) a reactor mounting system which accommodates thermal growth and start-up and shutdown transients, and (d) a graded cell reactor. These features were achieved while maintaining low reactor face velocities and system pressure drops.


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