A pilot scale study on co-capture of SO2 and NOx in O2/CO2 recycled coal combustion and techno-economic evaluation

This paper presents the study on co-capture of SO2 and NOx in O2/CO2 recycled coal combustion in a pilot scale facility with the heat input of 0.3 MW by using high-sulphur lean coal. Detailed comparison of SO2 and NOx emission indexes and desulphurization and denitration rates have been made among three working conditions of O2/CO2, O2/CO2 with limestone injection (O2/CO2+Ca) and O2/RFG (recycled flue gas) with limestone injection (O2/RFG+Ca). Combustion in air was performed as a base case. Results showed that in the O2/RFG with limestone injection, desulphurization and denitration rates could reach up to 96% and 89%, respectively. Limestone injection under the high-CO2 atmosphere caused a significant reduction on SO2 emission and NOx emission as well. This indicated O2/CO2 recycled coal combustion could reduce the investment on the flue gas purification. The techno-economic evaluation indicated that Oxy-combustion technique is not only feasible for CO2 emission control based on existing power plants but is also cost-effective.

[1]  M. Hasatani,et al.  The reduction of recycled-NOx in coal combustion with O2/recycled flue gas under low recycling ratio , 2001 .

[2]  Noriyuki Kobayashi,et al.  Effects of coal properties on recycled-NOx reduction in coal combustion with O2/recycled flue gas , 2003 .

[3]  Ken Okazaki,et al.  Drastic SOx Removal and Influences of Various Factors in O2/CO2 Pulverized Coal Combustion System , 2001 .

[4]  Zhen-Shu Liu,et al.  Emission characteristics of coal combustion in different O2/N2, O2/CO2 and O2/RFG atmosphere. , 2007, Journal of hazardous materials.

[5]  Behdad Moghtaderi,et al.  Factors influencing the ignition of flames from air-fired swirl pf burners retrofitted to oxy-fuel , 2008 .

[6]  RajenderKumar Gupta,et al.  Oxy-fuel combustion technology for coal-fired power generation , 2005 .

[7]  Yewen Tan,et al.  Numerical investigation of oxy-coal combustion to evaluate burner and combustor design concepts , 2004 .

[8]  K. Okazaki,et al.  Simultaneous easy CO2 recovery and drastic reduction of SOx and NOx in O2/CO2 coal combustion with heat recirculation☆ , 2003 .

[9]  Eddy H. Chui,et al.  Modeling of oxy-fuel combustion for a western Canadian sub-bituminous coal☆ , 2003 .

[10]  Eric Croiset,et al.  Combustion characteristics of coal in a mixture of oxygen and recycled flue gas , 2006 .

[11]  Noriyuki Kobayashi,et al.  CO2, NOx and SO2 emissions from the combustion of coal with high oxygen concentration gases , 2000 .

[12]  Takashi Kiga,et al.  The characteristics of pulverized coal combustion in O2/CO2 mixtures for CO2 recovery , 1995 .

[13]  B. M. Gibbs,et al.  Comparisons of pulverized coal combustion in air and in mixtures of O2/CO2 , 2005 .

[14]  Ken Okazaki,et al.  NOx reduction mechanism in coal combustion with recycled CO2 , 1997 .

[15]  B. M. Gibbs,et al.  Pulverized coal combustion in air and in O2/CO2 mixtures with NOx recycle , 2005 .

[16]  Eric Croiset,et al.  NOx and SO2 emissions from O2/CO2 recycle coal combustion , 2001 .