The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Lingyan Zeng - One of the best experts on this subject based on the ideXlab platform.
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application of eccentric swirl secondary air Combustion technology for high efficiency and low nox performance on a large scale down fired boiler with swirl burners
Applied Energy, 2018Co-Authors: Qingxiang Wang, Zhichao Chen, Liang Wang, Lingyan ZengAbstract:Abstract A 300-MWe anthracite and down-fired boiler equipped with swirl burners, which was retrofitted with the previously proposed deep-air-staging Combustion technology to reduce particularly high NOx emissions, still suffered from high carbon content in fly ash (despite this content being slightly lower than that before retrofit) on basis of significant NOx reduction. To comprehensively produce a high-burnout and low-NOx setting, a novel Combustion technology was proposed in which relative to the axis of the Primary air duct, the axes of the inner and outer secondary air ducts of the swirl burner shift away from the furnace center, and this technology is called an eccentric-swirl-secondary-air Combustion technology. The coaxial symmetrical arrangements of Primary and secondary air ducts for traditional swirl burners are broken. Full-scale industrial measurements under original, deep-air-staging and eccentric-swirl-secondary-air Combustion technologies with respect to different loads (i.e., 180, 250, and 300 MWe) were carried out to compare and analyze the validity of and improvement offered by the eccentric-swirl-secondary-air Combustion technology. Under different boiler loads, especially at low and middle loads, compared with original and deep-air-staging Combustion technologies, eccentric-swirl-secondary-air Combustion technology markedly extends the penetration depth of coal/air flow and recirculation regions below arches. The thermal resistance between Primary coal/air flow and high-temperature flue gas at the furnace center is reduced further, and the ignition of pulverized coal is timelier. The heating gradient in the burner outlet Zone is maintained throughout, and the flame fullness in the Primary Combustion Zone increases. The above three aspects contribute to pulverized coal burnout. Similar to deep-air-staging Combustion technology, a low-oxygen and strong reducing atmosphere was formed in the Primary Combustion Zone to reduce NOx formation due to the introduction of overfire air. Compared with deep-air-staging Combustion technology, for the eccentric-swirl-secondary-air Combustion technology, the air staged Combustion in the furnace is improved further, and pulverized coal Combustion in the Primary Combustion Zone is more well distributed, which is beneficial to further reducing NOx emissions. The results of low-NOx and high-efficiency performance show that compared with the original boiler, NOx emissions and carbon content in fly ash for the boiler with the eccentric-swirl-secondary-air Combustion technology are significantly reduced by above 42% and 32.5 to 20.7% at loads of 180, 250 and 300 MWe, respectively.
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Industrial Experiments on Anthracite Combustion and NOx Emissions with Respect to Swirling Secondary Air for a 300 MWe Deep-Air-Staged Down-Fired Utility Boiler
Energy & Fuels, 2018Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Liu Tao, Zhang XinAbstract:A new deep-air-staging and low-NOx technology has been introduced to a 300 MWe anthracite- and down-fired boiler with swirl burners. Industrial experiments were performed at different outer secondary air vane angles (defined as β) (i.e., 20°, 30°, 40°, and 50°) to evaluate the environmental and economic performance for the retrofitted boiler. Furthermore, combining with the previous investigations on the inner secondary air vane angle (defined as α), the influence degrees of β and α on anthracite Combustion and NOx emissions for the retrofitted boiler were further analyzed and compared. The experimental results revealed that the main factors affecting the ignition and the flame fullness for β and α are different. Compared with α, β had a relatively greater influence on NOx emissions for the retrofitted boiler. Compared with the orignianl boiler, a strong reducing atmosphere was formed in the Primary Combustion Zone for the retrofitted boiler, and for the β of approximately 30°, the arithmetic mean of NOx ...
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Effects of secondary air distribution in Primary Combustion Zone on Combustion and NOx emissions of a large-scale down-fired boiler with air staging
Energy, 2018Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Jiaquan Wang, Zhang XinAbstract:Abstract A new air-staged and low-NOx emission Combustion technology has been applied to a 300 MWe anthracite- and down-fired boiler with swirl burners. To achieve the optimum air distribution in the Primary Combustion Zone and further reduce NOx emissions, full-scale industrial experiments varying the ratios between burner secondary air ratio (Rbsa) and staged air ratio (Rsa) (i.e., Rbsa/Rsa ratios of 42.9/17.8, 47.1/13.5 and 51.5/9.3), on the premise that the overfire air (OFA) ratio was approximately 20%, were performed to evaluate the overall performance of retrofitted boiler. The improved ignition of coal/air flow was at a distance of 0.8–1.4 m to the burner outlet with increased Rbsa/Rsa ratio. Compared with the boiler before retrofit, under Rbsa/Rsa ratios of 47.1/13.5 and 51.5/9.3, the flue gas temperature in the Primary Combustion Zone of the retrofitted boiler increased slightly. Oxygen and carbon monoxide concentrations in the near-sidewall region revealed the furnace flame fullness varied under different Rbsa/Rsa ratios. With increased the air staged level in the lower furnace, NOx emissions decreased continually and the carbon content in fly ash did not necessarily increased. Under the optimum Rbsa/Rsa ratio of 47.1/13.5, the NOx reduction efficiency was approximately 46% with increasing boiler thermal efficiency slightly.
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industrial scale investigations of anthracite Combustion characteristics and nox emissions in a retrofitted 300 mwe down fired utility boiler with swirl burners
Applied Energy, 2017Co-Authors: Zhichao Chen, Lingyan Zeng, Qingxiang Wang, Xiaoyan Zhang, Xin Zhang, Tao He, Zhengqi LiAbstract:To burn anthracite and reduce NOx emissions, a new Combustion system was applied to a 300 MWe Babcock & Wilcox (B&W) down-fired boiler that included overfire air (OFA) and a decreased flow area of the inner and outer secondary air ducts of the installed swirl burners. Industrial-scale measurements (adjusting OFA ratios from 15.4% to 22.6%) were conducted to evaluate the overall performance of the retrofitted boiler. The experimental results demonstrated that the new Combustion system promoted coal/air flow ignition and Combustion stability. When the OFA ratio was less than 19.7%, the influence of the burner secondary air ratio on coal/air flow ignition was greater than that of the recirculation region below the arches. The overall Combustion level in the Primary Combustion Zone depended on the oxygen content and the recirculation region in the lower furnace instead of the early or late ignition of the coal/air flow. Oxygen and carbon monoxide concentration measurements in the near-sidewall region revealed that the fullness degree of the coal flame varied under different OFA ratios. Considering both environmental and economic effects, 19.7% was chosen as the optimal OFA ratio, thereby achieving a significant NOx reduction of 47% without increasing carbon content in the fly ash.
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Effect of different inner secondary-air vane angles on Combustion characteristics of Primary Combustion Zone for a down-fired 300-MWe utility boiler with overfire air
Applied Energy, 2016Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Che Miaomiao, Minhang SongAbstract:Abstract To achieve significant reductions in NOx emissions without increasing the levels of unburnt carbon in the fly ash, a new Combustion system was applied to a 300-MWe Babcock & Wilcox (BW however, for the vane angle of 35° the flame is spread across the entire furnace cross-section at inspection port 2. For this optimal (35°) inner secondary-air vane angle, the NOx emissions and carbon content in the fly ash reached levels of 674 mg/m3 (6% O2), and 11.4%, respectively, achieving a significant NOx reduction of 51.9% without increasing the levels of unburnt carbon in the fly ash.
Zhichao Chen - One of the best experts on this subject based on the ideXlab platform.
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application of eccentric swirl secondary air Combustion technology for high efficiency and low nox performance on a large scale down fired boiler with swirl burners
Applied Energy, 2018Co-Authors: Qingxiang Wang, Zhichao Chen, Liang Wang, Lingyan ZengAbstract:Abstract A 300-MWe anthracite and down-fired boiler equipped with swirl burners, which was retrofitted with the previously proposed deep-air-staging Combustion technology to reduce particularly high NOx emissions, still suffered from high carbon content in fly ash (despite this content being slightly lower than that before retrofit) on basis of significant NOx reduction. To comprehensively produce a high-burnout and low-NOx setting, a novel Combustion technology was proposed in which relative to the axis of the Primary air duct, the axes of the inner and outer secondary air ducts of the swirl burner shift away from the furnace center, and this technology is called an eccentric-swirl-secondary-air Combustion technology. The coaxial symmetrical arrangements of Primary and secondary air ducts for traditional swirl burners are broken. Full-scale industrial measurements under original, deep-air-staging and eccentric-swirl-secondary-air Combustion technologies with respect to different loads (i.e., 180, 250, and 300 MWe) were carried out to compare and analyze the validity of and improvement offered by the eccentric-swirl-secondary-air Combustion technology. Under different boiler loads, especially at low and middle loads, compared with original and deep-air-staging Combustion technologies, eccentric-swirl-secondary-air Combustion technology markedly extends the penetration depth of coal/air flow and recirculation regions below arches. The thermal resistance between Primary coal/air flow and high-temperature flue gas at the furnace center is reduced further, and the ignition of pulverized coal is timelier. The heating gradient in the burner outlet Zone is maintained throughout, and the flame fullness in the Primary Combustion Zone increases. The above three aspects contribute to pulverized coal burnout. Similar to deep-air-staging Combustion technology, a low-oxygen and strong reducing atmosphere was formed in the Primary Combustion Zone to reduce NOx formation due to the introduction of overfire air. Compared with deep-air-staging Combustion technology, for the eccentric-swirl-secondary-air Combustion technology, the air staged Combustion in the furnace is improved further, and pulverized coal Combustion in the Primary Combustion Zone is more well distributed, which is beneficial to further reducing NOx emissions. The results of low-NOx and high-efficiency performance show that compared with the original boiler, NOx emissions and carbon content in fly ash for the boiler with the eccentric-swirl-secondary-air Combustion technology are significantly reduced by above 42% and 32.5 to 20.7% at loads of 180, 250 and 300 MWe, respectively.
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Industrial Experiments on Anthracite Combustion and NOx Emissions with Respect to Swirling Secondary Air for a 300 MWe Deep-Air-Staged Down-Fired Utility Boiler
Energy & Fuels, 2018Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Liu Tao, Zhang XinAbstract:A new deep-air-staging and low-NOx technology has been introduced to a 300 MWe anthracite- and down-fired boiler with swirl burners. Industrial experiments were performed at different outer secondary air vane angles (defined as β) (i.e., 20°, 30°, 40°, and 50°) to evaluate the environmental and economic performance for the retrofitted boiler. Furthermore, combining with the previous investigations on the inner secondary air vane angle (defined as α), the influence degrees of β and α on anthracite Combustion and NOx emissions for the retrofitted boiler were further analyzed and compared. The experimental results revealed that the main factors affecting the ignition and the flame fullness for β and α are different. Compared with α, β had a relatively greater influence on NOx emissions for the retrofitted boiler. Compared with the orignianl boiler, a strong reducing atmosphere was formed in the Primary Combustion Zone for the retrofitted boiler, and for the β of approximately 30°, the arithmetic mean of NOx ...
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Effects of secondary air distribution in Primary Combustion Zone on Combustion and NOx emissions of a large-scale down-fired boiler with air staging
Energy, 2018Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Jiaquan Wang, Zhang XinAbstract:Abstract A new air-staged and low-NOx emission Combustion technology has been applied to a 300 MWe anthracite- and down-fired boiler with swirl burners. To achieve the optimum air distribution in the Primary Combustion Zone and further reduce NOx emissions, full-scale industrial experiments varying the ratios between burner secondary air ratio (Rbsa) and staged air ratio (Rsa) (i.e., Rbsa/Rsa ratios of 42.9/17.8, 47.1/13.5 and 51.5/9.3), on the premise that the overfire air (OFA) ratio was approximately 20%, were performed to evaluate the overall performance of retrofitted boiler. The improved ignition of coal/air flow was at a distance of 0.8–1.4 m to the burner outlet with increased Rbsa/Rsa ratio. Compared with the boiler before retrofit, under Rbsa/Rsa ratios of 47.1/13.5 and 51.5/9.3, the flue gas temperature in the Primary Combustion Zone of the retrofitted boiler increased slightly. Oxygen and carbon monoxide concentrations in the near-sidewall region revealed the furnace flame fullness varied under different Rbsa/Rsa ratios. With increased the air staged level in the lower furnace, NOx emissions decreased continually and the carbon content in fly ash did not necessarily increased. Under the optimum Rbsa/Rsa ratio of 47.1/13.5, the NOx reduction efficiency was approximately 46% with increasing boiler thermal efficiency slightly.
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industrial scale investigations of anthracite Combustion characteristics and nox emissions in a retrofitted 300 mwe down fired utility boiler with swirl burners
Applied Energy, 2017Co-Authors: Zhichao Chen, Lingyan Zeng, Qingxiang Wang, Xiaoyan Zhang, Xin Zhang, Tao He, Zhengqi LiAbstract:To burn anthracite and reduce NOx emissions, a new Combustion system was applied to a 300 MWe Babcock & Wilcox (B&W) down-fired boiler that included overfire air (OFA) and a decreased flow area of the inner and outer secondary air ducts of the installed swirl burners. Industrial-scale measurements (adjusting OFA ratios from 15.4% to 22.6%) were conducted to evaluate the overall performance of the retrofitted boiler. The experimental results demonstrated that the new Combustion system promoted coal/air flow ignition and Combustion stability. When the OFA ratio was less than 19.7%, the influence of the burner secondary air ratio on coal/air flow ignition was greater than that of the recirculation region below the arches. The overall Combustion level in the Primary Combustion Zone depended on the oxygen content and the recirculation region in the lower furnace instead of the early or late ignition of the coal/air flow. Oxygen and carbon monoxide concentration measurements in the near-sidewall region revealed that the fullness degree of the coal flame varied under different OFA ratios. Considering both environmental and economic effects, 19.7% was chosen as the optimal OFA ratio, thereby achieving a significant NOx reduction of 47% without increasing carbon content in the fly ash.
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Effect of different inner secondary-air vane angles on Combustion characteristics of Primary Combustion Zone for a down-fired 300-MWe utility boiler with overfire air
Applied Energy, 2016Co-Authors: Wang Qingxiang, Lingyan Zeng, Zhichao Chen, Che Miaomiao, Minhang SongAbstract:Abstract To achieve significant reductions in NOx emissions without increasing the levels of unburnt carbon in the fly ash, a new Combustion system was applied to a 300-MWe Babcock & Wilcox (BW however, for the vane angle of 35° the flame is spread across the entire furnace cross-section at inspection port 2. For this optimal (35°) inner secondary-air vane angle, the NOx emissions and carbon content in the fly ash reached levels of 674 mg/m3 (6% O2), and 11.4%, respectively, achieving a significant NOx reduction of 51.9% without increasing the levels of unburnt carbon in the fly ash.
Masataka Arai - One of the best experts on this subject based on the ideXlab platform.
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development of micro gas turbine combustor with a recirculation Zone induced by an upward swirl 3rd report effect of a Primary Zone configuration on spray Combustion characteristics and Combustion gas flow
Transactions of the Japan Society of Mechanical Engineers. B, 2008Co-Authors: Toru Sasaki, Shunsuke Amano, Tetsuya Watanabe, Kousaku Yotoriyama, Tomohiko Furuhata, Masataka AraiAbstract:A low NOx combustor for kerosene-fueled micro gas turbine based on a new concept was proposed. The combustor consisted of Primary and secondary Combustion Zones, and they were connected by a throat. A swirler was set between the Primary and secondary Combustion Zones. In order to enhance recirculation of burned gas in the Primary Combustion Zone, Combustion air was introduced through the swirler and forced to flow upward to the combustor bottom. In this study, effects of configuration of Primary Combustion Zone on Combustion gas flow in it were investigated. The length of Primary Combustion Zone, swirler vane angle, diameter of throat and height of guide vane were changed independently from the standard configuration. Distributions of gas flow in the Primary Combustion Zone were measured with LDA. The relation between Combustion stability and the distributions of gas flow was discussed, and it was found that appropriate Combustion gas recirculation in the Primary Combustion Zone was necessary to keep Combustion stability high.
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development of micro gas turbine combustor with a recirculation Zone induced by an upward swirl
Journal of Environment and Engineering, 2008Co-Authors: Kousaku Yotoriyama, Shunsuke Amano, Tomohiko Furuhata, Hidetomo Fujiwara, Masataka AraiAbstract:A new low NOx combustor for kerosene-fueled micro gas turbine was proposed, and the Combustion characteristics of prototype combustor were investigated. The new combustor consisted of a Primary and a secondary Combustion Zones, and they were connected by a throat. In order to enhance the recirculation flow in a Primary Combustion Zone, a swirler was set between the Primary and secondary Combustion Zones. Combustion air was introduced through the swirler and forced to flow upward to the combustor bottom, from which the fuel spray was supplied through a nozzle. To achieve high Combustion stability and low emission in wide fuel-air ratio, the optimum configuration of the Primary Combustion Zone were investigated. The optimum one was found out by measuring the fundamental Combustion characteristics such as lean Combustion limit, flame luminosity, exhaust gas composition and Combustion gas temperature.
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Development of can-type low NOx combustor for micro gas turbine (fundamental characteristics in a Primary Combustion Zone with upward swirl)
Fuel, 2007Co-Authors: Tomohiko Furuhata, Shunsuke Amano, Kousaku Yotoriyama, Masataka AraiAbstract:Abstract A low NOx combustor for kerosene-fueled micro gas turbine based on a new concept was proposed, and the Combustion characteristics of the prototype combustor were investigated. The new concept combustor consisted of Primary and secondary Combustion Zones, and they were connected by a throat. A swirler was set between the Primary and secondary Combustion Zones. In order to enhance the recirculation of burned gas in the Primary Combustion Zone, the Combustion air was introduced through the swirler and forced to flow upward to the combustor bottom, from where fuel spray was supplied through a nozzle. An optimum configuration of the Primary Combustion Zone such as length of Primary Zone, swirler vane angle, diameter of throat, etc. were investigated to achieve high Combustion stability and low emission in wide ranges of fuel flow rate and excess air ratio. The optimum value of each part in the Primary Combustion Zone was found out by measuring fundamental Combustion characteristics such as lean Combustion limit, flame luminosity, exhaust gas composition and Combustion gas temperature.
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Combustion characteristics in a micro gas turbine combustor with a recirculation Zone induced by an upward swirl
Journal of Environment and Engineering, 2007Co-Authors: Masataka Arai, Shunsuke Amano, Tomohiko FuruhataAbstract:Combustion characteristics of a prototype micro gas turbine combustor fueled by kerosene were investigated. In order to enhance a recirculation in a Primary Combustion Zone, a swirler was set between the Primary and secondary Combustion Zones. Primary Combustion air was introduced through the swirler and forced to flow upward to the combustor bottom, from which the fuel spray was supplied through a nozzle. Fundamental Combustion characteristics such as lean Combustion limit, flame luminosity etc. showed that this prototype combustor had a high potential for lean Combustion and wide flame holding. Since a strong forced recirculation flow was induced by the upward swirl, lean and non-luminous flame was maintained in the Primary Combustion Zone. Further, burned gas recirculation and highly turbulent shear flow in the Primary Combustion Zone, both of which were caused by the upward swirl, resulted in the low NOx emission characteristics.
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development of micro gas turbine combustor with a recirculation Zone induced by an upward swirl effect of a Primary Zone configuration on spray Combustion characteristics
Transactions of the Japan Society of Mechanical Engineers. B, 2006Co-Authors: Kousaku Yotoriyama, Shunsuke Amano, Tomohiko Furuhata, Hidetomo Fujiwara, Masataka AraiAbstract:A new low NOx combustor for kerosene-fueled micro-gasturbine was proposed, and the Combustion characteristics of prototype combustor were investigated. In order to enhance the recirculation in a Primary Combustion Zone, a swirler was set between the Primary and secondary Combustion Zones. Combustion air was introduced through the swirler and forced to flow upward to the combustor bottom, from where the fuel spray was supplied through a nozzle. To achieve high Combustion stability and low emission in wide fuel-air ratio, the optimum configuration of the Primary Combustion Zone were investigated. The optimum one was found out by measuring the fundamental Combustion characteristics such as lean Combustion limit, flame luminosity, exhaust gas composition and Combustion gas temperature.
Shien Hui - One of the best experts on this subject based on the ideXlab platform.
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Effect of coal-over-coal reburn on furnace temperature and heat flux distributions in 1 MW tangentially fired furnace
International Journal of Thermal Sciences, 2010Co-Authors: Qulan Zhou, Houzhang Tan, Shien HuiAbstract:The furnace temperature and heat flux distributions of 1 MW tangentially fired furnace were studied during coal-over-coal reburn, and the influences of the position of reburn nozzle and reburn fuel fraction on furnace temperature and heat flux distributions were investigated. Compared with the baseline, the flue gas temperature is 70n90 C lower in Primary Combustion and 130n150 C higher at furnace exit, and the variations of the flue gas temperature distributions along furnace height are slower. The temperature distribution along the width of furnace wall decreases with the increase of the relative furnace height. In the Primary Combustion Zone and the reburn Zone, the temperature and heat flux distributions of furnace wall are much non-uniform and asymmetric along the width of furnace wall, those of furnace wall in the burnout Zone are relatively uniform, and the temperature non-uniformity coefficients of the Primary Combustion Zone, the reburn Zone and the burnout Zone are 0.290, 0.100 and 0.031, respectively.
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optimization of air staging in a 1 mw tangentially fired pulverized coal furnace
Fuel Processing Technology, 2009Co-Authors: Shien Hui, Qulan Zhou, Houzhang TanAbstract:This paper deals with an experimental study of air staging in a 1 MW (heat input power) tangentially fired pulverized coal furnace. The influences of several variables associated with air staging on NOx reduction efficiency and unburned carbon in fly ash were investigated, and these variables included the air stoichiometric ratio of Primary Combustion Zone (SR1), the locations of over-fire air nozzles along furnace height, and the ratio of coal concentration of the fuel-rich stream to that of the fuel-lean one (RRL) in Primary air nozzle. The experimental results indicate that SR1 and RRL have optimum values for NOx reduction, and the two optimum values are 0.85 and 3:1, respectively. NO, reduction efficiency monotonically increases with the increase of OFA nozzle location along furnace height. On the optimized operating conditions of air staging, NOx reduction efficiency can attain 47%. Although air staging can effectively reduce NOx emission, the increase of unburned carbon in fly ash should be noticed. (C) 2008 Elsevier B.V. All rights reserved.
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NOx and SOx emissions of a high sulfur self-retention coal during air-staged Combustion
Fuel, 2008Co-Authors: Peng Sun, Qulan Zhou, Houzhang Tan, Shien HuiAbstract:Abstract NO x and SO x emissions of air-staged Combustion were investigated in a 1 MW tangentially-fired furnace combusting a high sulfur self-retention coal. Two variables including the air stoichiometric ratio of Primary Combustion Zone and the relative location of over-fire air (OFA) injection ports were studied. These results suggest that NO x reduction efficiency monotonically increases with increasing the relative location of OFA injection ports, and the lowest NO x emissions are achieved when the air stoichiometric ratio of Primary Combustion Zone is 0.85. In the meantime, SO x emissions can be effectively reduced when the air stoichiometric ratio of Primary Combustion Zone is 0.85 or 0.95, and SO x emissions monotonically decrease with increasing the relative location of OFA injection ports.
Yukio Noma - One of the best experts on this subject based on the ideXlab platform.
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Behavior of 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole (DBHPBT) and 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole during incineration of solid waste contaminated with thousand mg/kg levels of DBHPBT.
Journal of hazardous materials, 2010Co-Authors: Mafumi Watanabe, Yukio NomaAbstract:2-(3,5-Di-tert-butyl-2-hydroxyphenyl)benzotriazole (DBHPBT) is classified as a “Class I Specified Chemical Substance” by the Chemical Substance Control Law, Japan, meaning that DBHPBT has comparable nature and toxicity to well-known Persistent Organic Pollutants (POPs). In this study, we performed a Combustion experiment of solid waste containing DBHPBT using a pilot-scale incinerator to determine the destruction behavior of DBHPBT and the effects on emission of 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole (DBHPCBT), which is structurally similar to DBHPBT and has a persistent nature, and nitrogen oxides (NOx). DBHPBT was destroyed mainly in the Primary Combustion Zone. Overall destruction efficiency of DBHPBT in input at the concentration of 5000 mg/kg was >99.9999%. The input amount of DBHPBT did not affect the formation and destruction behavior of DBHPCBT and NOx. These results indicate that appropriate management of Combustion conditions and flue gas treatment can minimize the emission of DBHPBT.
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Influence of Combustion temperature on formation of nitro-PAHs and decomposition and removal behaviors in pilot-scale waste incinerator.
Environmental science & technology, 2009Co-Authors: Mafumi Watanabe, Yukio NomaAbstract:To gain a better understanding of the formation and decomposition behaviors of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in solid waste Combustion, incineration experiments were conducted using a pilot-scale incinerator. Nitro-PAHs were formed during Primary Combustion, although the amounts formed were several orders of magnitude lower than those of the PAHs, PCDD/Fs, and the dioxin-like PCBs. Increasing the temperature of Primary Combustion from 690 to 890 degrees C resulted in a significant decrease in the formation of most of the nitro-PAH compounds studied. More than 99% of nitro-PAHs formed in the Primary Combustion Zone were decomposed in the secondary Combustion chamber at 900 degrees C with a 3-s residence time. The results indicate that appropriate secondary Combustion conditions are the key to controlling emissions of nitro-PAHs. Under optimized conditions, the amounts of nitro-PAHs in the final off gases and in the ashes were significantly lower than those present in the incinerator input. Overall destruction efficiencies of nitro-PAHs reported in this study were 95.81-98.33%, indicating that emission of nitro-PAHs from solid waste Combustion can be minimized by appropriate Combustion control.