Synergistic effect of co-firing woody biomass with coal on NOx reduction and burnout during air-staged combustion

Abstract Hybrid technologies combining fuel blending and air-staging processes have been applied to a pulverized coal fired furnace to reduce NO x emissions. In this study, an Australian bituminous coal (Whitehaven), an Indonesian sub-bituminous coal (Adaro), and an Indonesian woody biomass were selected as fuel with blending ratio of 10%, 20%, and 30% of the low-rank fuels, and the air-staging levels were set to 235 mm, 390 mm, 585 mm, and 760 mm. The purpose of this study was to investigate the synergistic effect of woody biomass co-firing on the level of NO x emissions and the degree of carbon burnout under air-staged conditions. For single coals, sub-bituminous coal was more favorable than that for bituminous coal to reduce NO x emissions due to low fuel-N composition. This tendency was more dominant with increasing the air staging levels. In the co-firing of woody biomass with coal, as the biomass is highly volatile but has a low carbon content, it could be successfully applied to low-NO x combustion under air-staged conditions. In addition, the degree of carbon burnout and the flame temperature both increased. As a result of this research, we determined that hybrid NO x reduction technologies have the potential to reduce exhaust gas emissions and enhance combustion performance. A dominant synergistic effect on NO x reduction and carbon burnout was observed when woody biomass co-firing with coal was applied to air-staged combustion.

[1]  Anes Kazagic,et al.  Synergy effects of co-firing wooden biomass with Bosnian coal , 2009 .

[2]  Jing Li,et al.  Effect of the Air Temperature on Combustion Characteristics and NOx Emissions from a 0.5 MW Pulverized Coal-Fired Furnace with Deep Air Staging , 2012 .

[3]  P. G. W. Hawksley,et al.  Kinetics of Thermal Decomposition of Pulverized Coal Particles , 1970 .

[4]  Mário Costa,et al.  Detailed measurements in a pulverized-coal-fired large-scale laboratory furnace with air staging , 2009 .

[5]  Zhong-yang Luo,et al.  Experimental Study on the NO and N2O Formation Characteristics during Biomass Combustion , 2013 .

[6]  W. V. D. Kamp,et al.  The Co-Firing of Pulverised Bituminous Coals with Straw, Waste Paper and Municipal Sewage Sludge , 1996 .

[7]  Hao Li,et al.  Air-Staged Combustion Characteristics of Pulverized Coal under High Temperature and Strong Reducing Atmosphere Conditions , 2014 .

[8]  Shien Hui,et al.  NOx and SOx emissions of a high sulfur self-retention coal during air-staged combustion , 2008 .

[9]  Jinghai Li,et al.  NO reduction in decoupling combustion of biomass and biomass-coal blend , 2009 .

[10]  Cheoreon Moon,et al.  NOx emissions and burnout characteristics of bituminous coal, lignite, and their blends in a pulverized coal-fired furnace , 2015 .

[11]  Cheoreon Moon,et al.  Thermochemical and combustion behaviors of coals of different ranks and their blends for pulverized-coal combustion , 2013 .

[12]  B. M. Gibbs,et al.  The effect of air staged, co-combustion of pulverised coal and biomass blends on NOx emissions and combustion efficiency , 2011 .

[13]  W. Fan,et al.  The effect of air staged combustion on NOx emissions in dried lignite combustion , 2012 .

[14]  Zhengchun Lin,et al.  Impact of air staging along furnace height on NOx emissions from pulverized coal combustion , 2010 .

[15]  Jiaxun Liu,et al.  NOx emission characteristics of superfine pulverized anthracite coal in air-staged combustion , 2013 .

[16]  Jenny M. Jones,et al.  Some Aspects of Modeling NOx Formation Arising from the Combustion of 100% Wood in a Pulverized Fuel Furnace , 2014 .

[17]  Gerry Riley,et al.  Oxy-fuel combustion of coal and biomass, the effect on radiative and convective heat transfer and burnout , 2010 .

[18]  A. Jensen,et al.  Fuel nitrogen conversion in solid fuel fired systems , 2003 .

[19]  Mário Costa,et al.  Impact of the air staging on the performance of a pulverized coal fired furnace , 2009 .

[20]  Jungwoo Shin,et al.  Analyzing public preferences and increasing acceptability for the Renewable Portfolio Standard in Korea , 2014 .

[21]  Li Baoming,et al.  Devolatilization characteristics of biomass at flash heating rate , 2006 .

[22]  Cheoreon Moon,et al.  Influence of pulverized coal properties on heat release region in turbulent jet pulverized coal flames , 2011 .

[23]  Tao Wu,et al.  Characteristics and synergistic effects of co-firing of coal and carbonaceous wastes , 2013 .

[24]  Jeong-Hun Kim,et al.  Mercury emission trend influenced by stringent air pollutants regulation for coal-fired power plants in Korea , 2009 .

[25]  Mário Costa,et al.  Detailed measurements in a laboratory furnace with reburning , 2011 .

[26]  P. Ashman,et al.  A new method for determining the conversion of low-ash coals using synthetic ash as a tracer , 2005 .

[27]  V. Semião,et al.  CO-COMBUSTION OF PULVERIZED COAL, PINE SHELLS, AND TEXTILE WASTES IN A PROPANE-FIRED FURNACE: MEASUREMENTS AND PREDICTIONS , 2004 .

[28]  Klaus R. G. Hein,et al.  Effect of co-combustion of biomass on emissions in pulverized fuel furnaces , 1998 .

[29]  Gongliang Wang,et al.  Evaluation of the combustion behaviour and ash characteristics of biomass waste derived fuels, pine and coal in a drop tube furnace , 2014 .

[30]  R. Axelbaum,et al.  Nitric Oxide Emissions during Coal and Coal/Biomass Combustion under Air-Fired and Oxy-fuel Conditions , 2010 .

[31]  G. Choi,et al.  Effectiveness between swirl intensity and air staging on NOx emissions and burnout characteristics in a pulverized coal fired furnace , 2015 .

[32]  Mário Costa,et al.  Co-combustion of biomass in a natural gas-fired furnace , 2003 .

[33]  Asri Gani,et al.  Characteristics of Co-combustion of Low-Rank Coal with Biomass , 2005 .

[34]  Anes Kazagic,et al.  Experimental investigation of ash behavior and emissions during combustion of Bosnian coal and biomass , 2007 .

[35]  B. M. Gibbs,et al.  NOx control in coal combustion by combining biomass co-firing, oxygen enrichment and SNCR , 2013 .

[36]  Hisao Makino,et al.  Emission characteristics of NOx and unburned carbon in fly ash during combustion of blends of bituminous/sub-bituminous coals , 2003 .