High temperature catalytic combustion of methane and propane over hexaaluminate catalysts: NOx emission characteristics

2003 ◽  
Vol 83 (1-4) ◽  
pp. 223-231 ◽  
Author(s):  
Ryuji Kikuchi ◽  
Yoshiaki Tanaka ◽  
Kazunari Sasaki ◽  
Koichi Eguchi
Keyword(s):  
High Temperature ◽  
Catalytic Combustion ◽  
Nox Emission ◽  
Emission Characteristics ◽  
Catalytic Combustion Of Methane ◽  
Hexaaluminate Catalysts

scholarly journals NOx Emission Characteristics of a Catalytic Combustor Under High-Temperature Conditions

1995 ◽  
Author(s):  
Martin Valk ◽  
Nicolas Vortmeyer ◽  
Günter Kappler
Keyword(s):  
High Temperature ◽  
Flame Temperature ◽  
Plug Flow ◽  
Nox Emission ◽  
Thermal Reactor ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Temperature Conditions ◽  
Conversion Rates ◽  
Catalytic Combustor

A catalytic combustor concept with short catalyst segments and a thermal reactor is investigated with regard to NOx production of this concept under high-temperature conditions. The maximum combustor exit temperature was more than 1800 K with catalyst temperatures below 1300 K. For combustion of iso-octane, NOx emissions of 4 ppm (dry, 15% O2) at a flame temperature of 1800 K were measured. No significant influence of catalyst length, reference velocity and overall residence time on NOx emissions was observed. Additionally, the test combustor was fuelled with commercial diesel and kerosene (Jet-A). In this case, NOx emissions were noticeable higher due to fuel-bound nitrogen. The emissions measured were for diesel, 12 ppm, and for kerosene, 7 ppm, (each dry, 15% O2), again at a flame temperature of 1800 K. To evaluate the conversion ratio of fuel-bound nitrogen to NOx iso-octane was doped with various amounts of ammonia and metyhlamine. The conversion rates were 70 to 90%, with a slight tendency to lower values (50%) for nitrogen mass fractions above 0.1%. Considering the NOx emission level of actual premix burners, the lower emission value of the presented catalytic combustor results from a perfect premixed plug-flow combustion system incorporating a catalyst herein and not from a specific advantage of the principle of catalytic combustion itself. Again similar to a premix-combustor are the NOx emission characteristics in the case of lean combustion of nitrogen bound fuels, which yield very high conversion rates.

High Pressure Test Results of a Catalytic Combustor for Gas Turbine

1998 ◽  
Vol 120 (3) ◽  
pp. 509-513 ◽  
Author(s):  
T. Fujii ◽  
Y. Ozawa ◽  
S. Kikumoto ◽  
M. Sato ◽  
Y. Yuasa ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Combustion Process ◽  
Combined Cycle ◽  
Nox Emission ◽  
Test Results ◽  
Catalytic Combustor

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.

The Effect of Distance Between Fuel and Oxidizer Nozzles on NOx Emission From High Temperature Air Combustion

2011 ◽  
Author(s):  
Yuzuru Nada ◽  
Yasutomo Zenman ◽  
Takahiro Ito ◽  
Susumu Noda
Keyword(s):  
High Temperature ◽  
Flame Temperature ◽  
Dilution Effect ◽  
Nox Emission ◽  
Emission Characteristics ◽  
High Temperature Air Combustion ◽  
Flamelet Model ◽  
Scaling Parameters ◽  
Fuel Nozzle ◽  
Emission Index

This study describes NOx emission characteristics of a high temperature air combustion furnace operating with parallel jet burner system. In the parallel jet burner system, fuel nozzles are separated with a distance from an oxidizer nozzle. Objectives of this study are to clarify the effect of the distance between the fuel nozzle and the oxidizer nozzle on NOx emission. The emission index of NOx (EINOx) decreases with the increase in the distance. This is due to the dilution through entrainment of burned gas. A scaling concept is proposed to assess the dilution effect on the NOx emission. Scaling parameters employed here are the global residence time of fuel and the flame temperature evaluated on a modified flamelet model in which the dilution effect is included. The overall EINOx production rate is scaled with the flame temperature. This scaling indicates the importance of the distance between the nozzles for NOx emission.

scholarly journals High Pressure Test Results of a Catalytic Combustor for Gas Turbine

1996 ◽  
Author(s):  
T. Fujii ◽  
Y. Ozawa ◽  
S. Kikumoto ◽  
M. Sato ◽  
Y. Yuasa ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Combustion Process ◽  
Combined Cycle ◽  
Nox Emission ◽  
Test Results ◽  
Catalytic Combustor

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.

Sign in / Sign up

Export Citation Format

Share Document