A Study of Low NOx Combustion in Medium-Btu Fueled 1300 °C-Class Gas Turbine Combustor in IGCC

1998 ◽  
Author(s):  
Takeharu Hasegawa ◽  
Tohru Hisamatsu ◽  
Yasunari Katsuki ◽  
Mikio Sato ◽  
Masahiko Yamada ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbine Combustor ◽  
Entrained Flow ◽  
Coal Gasifier ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Co Emission

The development of integrated coal gasification combined cycle (IGCC) systems ensures cost-effective and environmentally sound options for supplying future coal utilizing power generation needs. The Japanese government and the electric power industries in Japan promoted research and development of an IGCC system using an air-blown entrained-flow coal gasifier. We worked on developing a low-Btu fueled gas turbine combustor to improve the thermal efficiency of the IGCC by raising the inlet-gas temperature of gas turbine. On the other hand, Europe and the United States are now developing the oxygen-blown IGCC demonstration plants. Coal gasified fuel produced in an oxygen-blown entrained-flow coal gasifier, has a calorific value of 8.6MJ/m 3 which is one fifth that of natural gas. However, the adiabatic flame temperature of oxygen-blown medium-Btu coal gaseous fuel is higher than that of natural gas and so NOx production from nitrogen fixation is expected to increase significantly. In the oxygen-blown IGCC system, a surplus nitrogen in quantity is produced in the oxygen-production unit. When nitrogen premixed with coal gasified fuel is injected into the combustor, the power to compress nitrogen increases. A low NOx combustion technology which is capable of decreasing the power to compress nitrogen is a significant advance in gas turbine development with an oxygen-blown IGCC system. We have started to develop a low NOx combustion technology using medium-Btu coal gasified fuel produced in the oxygen-blown IGCC process. In this paper, the effect of nitrogen injected directly into the combustor on the thermal efficiency of the plant is discussed. A 1300 °C-class gas turbine combustor with a swirling nitrogen injection function designed with a stable and low NOx combustion technology was constructed and the performance of this combustor was evaluated under atmospheric pressure conditions. Analyses confirmed that the thermal efficiency of the plant improved by 0.2 percent (absolute), compared with a case where nitrogen is premixed with coal gasified fuel before injection into the combustor. Moreover, this new technique which injects nitrogen directly into the high temperature region in the combustor results in a significant reduction in NOx production from nitrogen fixation. We estimate that CO emission concentration decreases to a significant level under high pressure conditions, while CO emission concentration in contrast to NOx emission rises sharply with increases in quantity of nitrogen injected into the combustor.

scholarly journals Test Result of Low NOx Catalytic Combustor for Gas Turbine

1993 ◽  
Author(s):  
Y. Ozawa ◽  
J. Hirano ◽  
M. Sato ◽  
M. Saiga ◽  
S. Watanabe
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Combustion Method ◽  
Combustion Efficiency ◽  
Gas Temperature ◽  
Gas Turbine Combustor ◽  
Combustion Gas ◽  
Low Nox Combustion ◽  
Catalytic Combustor ◽  
Combustion Tests

Catalytic combustion is an ultra low NOx combustion method, so it is expected that this method will be applied to gas turbine combustor. However, it is difficult to develop catalytic combustor because catalytic reliability at high temperature is still insufficient. To overcome this difficulty, we designed a catalytic combustor in which premixed combustion was combined. By this device, it is possible to obtain combustion gas at a combustion temperature of 1300°C while keeping the catalytic temperature below 1000°C. After performing preliminary tests using LPG, we designed two types of combustors for natural gas with a capacity equivalent to 1 combustor used in a 20MW–class multi–can type gas turbine. Combustion tests were conducted at atmospheric pressure using natural gas. As a result, it was confirmed that a combustor in which catalytic combustor segments were arranged alternately with premixing nozzles could achieve low NOx and high combustion efficiency in the range from 1000°C to 1300°C of the combustor exit gas temperature.

Low-Emissions Renewable Power Generation Using Liquid Fuels

2011 ◽  
Author(s):  
Leo D. Eskin ◽  
Michael S. Klassen ◽  
Richard J. Roby ◽  
Richard G. Joklik ◽  
Maclain M. Holton
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Liquid Fuel ◽  
Heat Rate ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Gas Turbine Combustor ◽  
Renewable Power ◽  
Combustion Technology

A Lean, Premixed, Prevaporized (LPP) combustion technology has been developed that converts liquid biofuels, such as biodiesel or ethanol, into a substitute for natural gas. This fuel can then be burned with low emissions in virtually any combustion device in place of natural gas, providing users substantial fuel flexibility. A gas turbine utilizing the LPP combustion technology to burn biofuels creates a “dispatchable” (on-demand) renewable power generator with low criteria pollutant emissions and no net carbon emissions. Natural gas, petroleum based fuel oil #1 and #2, biodiesel and ethanol were tested in an atmospheric pressure test rig using actual gas turbine combustor hardware (designed for natural gas) and achieved natural gas level emissions. Both biodiesel and ethanol achieved natural gas level emissions for NOx, CO, SOx and particulate matter (PM). Extended lean operation was observed for all liquid fuels tested due to the wider lean flammability range for these fuels compared to natural gas. Autoignition of the fuels was controlled by the level of diluent (inerting) gas used in the vaporization process. This technology has successfully demonstrated the clean generation of green, dispatchable, renewable power on a 30kW Capstone C30 microturbine. Emissions on the vaporized derived from bio-ethanol are 3 ppm NO(x) and 18 ppm CO, improving on the baseline natural gas emissions of 3 ppm NO(x), 30 ppm CO. Performance calculations have shown that for a typical combined cycle power plant, one can expect to achieve a two percent (2%) improvement in the overall net plant heat rate when burning liquid fuel as LPP Gas™ as compared to burning the same liquid fuel in traditional spray-flame diffusion combustors. This level of heat rate improvement is quite substantial, and represents an annual fuel savings of over five million dollars for base load operation of a GE Frame 7EA combined cycle plant (126 MW). This technology provides a clean and reliable form of renewable energy using liquid biofuels that can be a primary source for power generation or be a back-up source for non-dispatchable renewable energy sources such as wind and solar. The LPP technology allows for the clean use of biofuels in combustion devices without water injection or the use of post-combustion pollution control equipment and can easily be incorporated into both new and existing gas turbine power plants. No changes are required to the DLE gas turbine combustor hardware.

Development of Low NOx Combustion Technology in Medium-Btu Fueled 1300 °C-Class Gas Turbine Combustor in IGCC

2000 ◽  
Author(s):  
Takeharu Hasegawa ◽  
Tohru Hisamatsu ◽  
Yasunari Katsuki ◽  
Mikio Sato ◽  
Hiromi Koizumi ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Nox Emission ◽  
Test Results ◽  
Nitrogen Injection ◽  
Coal Gasifier ◽  
Coal Fuel ◽  
Thermal Nox ◽  
Low Nox Emission

The development of integrated coal gasification combined cycle (IGCC) systems ensures higher thermal efficiency and environmentally sound options for supplying future coal utilizing power generation needs. The Japanese government and electric power industries in Japan promoted research and development of an IGCC system using an air-blown entrained-flow coal gasifier. On the other hand, Europe and the United States are now developing the oxygen-blown IGCC demonstration plants. Gasified coal fuel produced in an oxygen-blown entrained-flow coal gasifier, has a calorific value of 8–13MJ/m3 which is only 1/5–1/3 that of natural gas. However, the flame temperature of medium-Btu gasified coal fuel is higher than that of natural gas and so NOx production from nitrogen fixation is expected to increase significantly. In the oxygen-blown IGCC, a surplus nitrogen produced in the air-separation unit (ASU) is premixed with gasified coal fuel (medium-Btu fuel) and injected into the combustor, to reduce thermal-NOx production and to recover the power used for the ASU. In this case, the power to compress nitrogen increases. Low NOx emission technology which is capable of decreasing the power to compress nitrogen is a significant advance in gas turbine development with an oxygen-blown IGCC system. Analyses confirmed that the thermal efficiency of the plant improved by approximately 0.3 percent (absolute) by means of nitrogen direct injection into the combustor, compared with a case where nitrogen is premixed with gasified coal fuel before injection into the combustor. In this study, based on the fundamental test results using a small diffusion burner and a model combustor, we designed the combustor in which the nitrogen injection nozzles arranged on the burner were combined with the lean combustion technique for low-NOx emission. In this way, we could reduce the high temperature region, where originated the thermal-NOx production, near the burner positively. And then, a combustor with a swirling nitrogen injection function used for a gas turbine, was designed and constructed, and its performance was evaluated under pressurized conditions of actual operations using a simulated gasified coal fuel. From the combustion test results, the thermal-NOx emission decreased under 11ppm (corrected at 16% O2), combustion efficiency was higher than 99.9% at any gas turbine load. Moreover, there was different effects of pressure on thermal-NOx emission in medium-Btu fuel fired combustor from the case of natural gas fired combustor.

Low Emissions Power Generation Using Natural Gas Condensates

2011 ◽  
Author(s):  
R. Joklik ◽  
L. Eskin ◽  
M. Klassen ◽  
R. Roby ◽  
M. Holton ◽  
...  
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Oil Field ◽  
Gas Condensate ◽  
Liquid Fuels ◽  
Gas Turbine Combustor ◽  
Combustion Technology ◽  
Wobbe Index ◽  
Surrogate Fuel

A Lean, Premixed, Prevaporized (LPP) combustion technology has been developed that converts liquid fuels into a substitute for natural gas. This fuel can then be burned with low emissions in virtually any combustion device in place of natural gas. This technology offers the possibility of using unprocessed oil-field Natural Gas Condensate (NGC) for local or export power generation using a DLN-equipped gas turbine rather than flaring, as is common practice in some regions. The ability to run a turbine on natural gas condensate with NOx and CO emissions comparable to those of natural gas has been demonstrated using a surrogate fuel made up from a mixture of naphtha (representing C4 and greater) and methane (representing <C4). The naphtha was vaporized using an LPP system, mixed with methane, and used to generate power in a 30kW Capstone C30 microturbine. The LPP Gas™ was tailored to match the modified Wobbe Index (MWI) of methane. NOx emissions in pre-mix mode on the surrogate NGC fuel were sub 5 ppm, indistinguishable from those when running on methane. CO emissions were sub 20 ppm, comparable to those on methane. At lower loads (in diffusion mode), NOx and CO emissions on surrogate NGC-based LPP Gas™ remain comparable to those on methane. No changes were required to the DLN gas turbine combustor hardware.

Combustion Technology for Low-Emissions Gas-Turbines: Some Recent Modeling Results

1996 ◽  
Vol 118 (3) ◽  
pp. 201-208 ◽  
Author(s):  
S. M. Correa ◽  
I. Z. Hu ◽  
A. K. Tolpadi
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Spectroscopic Data ◽  
Physical Models ◽  
Gas Turbine Combustor ◽  
Finite Rate ◽  
Recent Developments ◽  
Combustion Technology ◽  
Computationally Intensive ◽  
Transport Method

Computer modeling of low-emissions gas-turbine combustors requires inclusion of finite-rate chemistry and its intractions with turbulence. The purpose of this review is to outline some recent developments in and applications of the physical models of combusting flows. The models reviewed included the sophisticated and computationally intensive velocity-composition pdf transport method, with applications shown for both a laboratory flame and for a practical gas-turbine combustor, as well as a new and computationally fast PSR-microstructure-based method, with applications shown for both premixed and nonpremixed flames. Calculations are compared with laserbased spectroscopic data where available. The review concentrates on natural-gas-fueled machines, and liquid-fueled machines operating at high power, such that spray vaporization effects can be neglected. Radiation and heat transfer is also outside the scope of this review.

Gas Turbine Combined Cycle With CO2-Capture Using Auto-Thermal Reforming of Natural Gas

2000 ◽  
Author(s):  
Thormod Andersen ◽  
Hanne M. Kvamsdal ◽  
Olav Bolland
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Process Integration ◽  
Combined Cycle ◽  
Co2 Removal ◽  
Gas Turbine Combustor ◽  
Chemical Absorption ◽  
Fuel Gas ◽  
The Impact ◽  
Water Gas

A concept for capturing and sequestering CO2 from a natural gas fired combined cycle power plant is presented. The present approach is to decarbonise the fuel prior to combustion by reforming natural gas, producing a hydrogen-rich fuel. The reforming process consists of an air-blown pressurised auto-thermal reformer that produces a gas containing H2, CO and a small fraction of CH4 as combustible components. The gas is then led through a water gas shift reactor, where the equilibrium of CO and H2O is shifted towards CO2 and H2. The CO2 is then captured from the resulting gas by chemical absorption. The gas turbine of this system is then fed with a fuel gas containing approximately 50% H2. In order to achieve acceptable level of fuel-to-electricity conversion efficiency, this kind of process is attractive because of the possibility of process integration between the combined cycle and the reforming process. A comparison is made between a “standard” combined cycle and the current process with CO2-removal. This study also comprise an investigation of using a lower pressure level in the reforming section than in the gas turbine combustor and the impact of reduced steam/carbon ratio in the main reformer. The impact on gas turbine operation because of massive air bleed and the use of a hydrogen rich fuel is discussed.

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