O2/CO2 coal combustion characteristics in a 50 kWth circulating fluidized bed

Duan, Lunbo; Zhao, Changsui; Zhou, Weizheng; Qu, Chengrui; Chen, Xiaoping

doi:10.1016/j.ijggc.2011.01.007

Cited by 87 publications

(62 citation statements)

References 19 publications

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“…The Schottky disorder is the preferred form of intrinsic disorder and the Na ion occupies the Ca lattice. The negatively charged impurity center, Na Ca ′, is compensated for by SO 4 2− vacancies. The Na incorporation reaction is presented as follows (with the Kroger−Vink notion in defect chemistry theory):…”

Section: Effect Of Anmentioning

confidence: 99%

Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone

Liang

Cai

2015

Energy Fuels

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The enhancement effect of Na 2 CO 3 additive on the reaction of CaCO 3 with SO 2 and O 2 at high temperature is a widely observed phenomenon; however, its mechanism remains unclear. From the solid-state physics point of view, this study proposed that the defect formation caused by the additive may explain the enhanced sulfation. The single-crystal CaCO 3 with a smooth surface was used as a sample for direct sulfation, and the morphology and Na element distribution was investigated with scanning electron microscopy and energy-dispersive spectroscopy. It is observed that the Na ion will diffuse into CaSO 4 during sulfation, and it does not diffuse into the lattice of the CaCO 3 crystal by itself. The relationship of the diffusion coefficient in the solid state with the additive fraction was established and integrated into a new sulfation model. This new model included a simplified rate equation model to describe the product island formation and an ionic diffusion model that describes the productlayer growth. The experimental data on the direct sulfation of limestone, with and without additive, were used to validate the newly developed models. INTRODUCTIONO 2 /CO 2 coal combustion in a circulating fluidized bed (CFB) boiler is one of the promising technologies for CO 2 capture 1 and is currently demonstrated in large-pilot-scale facilities such as the 30MW CIUDEN Oxy-CFB Boiler Demonstration Plant in Spain. 2 In O 2 /CO 2 coal combustion CFB systems, a high purity of oxygen is mixed with the flue gas, and then this gas mixture is introduced into the CFB furnace to burn the coal. Almost no nitrogen is introduced into the furnace; therefore, the CO 2 content in the flue gas can be higher than 95%. 1−4 For the O 2 /CO 2 coal combustion CFB, the sulfur from the coal will be released into the flue gas to form SO 2 pollutant; therefore, limestone is required in order to remove SO 2 from flue gas. Because the temperature and CO 2 fraction inside the CFB furnace are 800−900°C and ∼95%, respectively, in this case, the limestone decomposition is limited by the chemical equilibrium, and the direct sulfation reaction between limestone with SO 2 and O 2 will occur as

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Section: Effect Of Anmentioning

confidence: 99%

Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone

Liang

Cai

2015

Energy Fuels

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“…Circulating fluidized bed (CFB) technology has been recognized as a clean coal combustion technology owing to its advantages on fuel flexibility, low combustion temperature, long residence time of fuel in furnace, low cost of in-furnace desulphurization and low NO x emissions during combustion. CFB combustion under oxy-fuel atmosphere inherits the technical advantages of fluidized combustion and brings further advantages [10][11][12], especially negative CO 2 emission when burning biomass in oxy-fuel CFB combustor. Work by Jia et al [10] suggested that fluidized bed combustion can burn biomass and fossil fuels at any given ratio, ranging from 0% to 100%, thus offering the possibility of using local and seasonally available biomass fuels in a ''CO 2 -negative'' manner.…”

Section: Introductionmentioning

confidence: 99%

NO emission during co-firing coal and biomass in an oxy-fuel circulating fluidized bed combustor

Duan

Zhao

et al. 2015

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“…One is a 20 MW th PC boiler and the other is a circulating fluidised bed (CFB) combustor of 15 MW th operating in air-mode and 30 MW th operating in oxy-mode. It is believed that an oxy-fuel CFB combustor will be an important candidate for new coal fired power plants [6][7][8] mainly because the circulation of solids in the combustor can help to an effective control of the temperature.…”

Section: Introductionmentioning

confidence: 99%

Calcium-based sorbents behaviour during sulphation at oxy-fuel fluidised bed combustion conditions

Garcı́a-Labiano

Rufas

Diego

et al. 2011

Fuel

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O2/CO2 coal combustion characteristics in a 50 kWth circulating fluidized bed

Cited by 87 publications

References 19 publications

Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone

Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone

NO emission during co-firing coal and biomass in an oxy-fuel circulating fluidized bed combustor

Calcium-based sorbents behaviour during sulphation at oxy-fuel fluidised bed combustion conditions

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O2/CO2 coal combustion characteristics in a 50 kWth circulating fluidized bed

Cited by 87 publications

References 19 publications

Understanding the Enhancement Effect of Na2CO3 Additive on the Direct Sulfation of Limestone

Understanding the Enhancement Effect of Na2CO3 Additive on the Direct Sulfation of Limestone

NO emission during co-firing coal and biomass in an oxy-fuel circulating fluidized bed combustor

Calcium-based sorbents behaviour during sulphation at oxy-fuel fluidised bed combustion conditions

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Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone

Understanding the Enhancement Effect of Na₂CO₃ Additive on the Direct Sulfation of Limestone