Characterization of ashes from a 100kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

Wu, Yinghai; Wang, Chunbo; Tan, Yewen; Jia, Lei; Anthony, Edward J.

doi:10.1016/j.apenergy.2011.03.007

Cited by 81 publications

(24 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The quantitative phase analysis verified that for the limestone that underwent calcination and sulfation simultaneously, there indeed are some CaCO 3 packets that are not calcined to CaO in the interior of the particles even after 90 min of reaction. It maybe be concluded that some CaCO 3 will not experience calcination and sulfation since they are completely blocked by CaSO 4 . The limestone that calcined in N 2 then sulfated has higher utilization than that calcined and sulfated simultaneously.…”

Section: Discussionmentioning

confidence: 97%

“…CFBB can be used to combust many types of fuels including different kinds of coals, coke, and biomass [1][2][3][4][5][6][7]. Apart from its excellent fuel flexibility, other advantages of CFBB are the low NOx production due to its low combustion temperature, and low SO 2 emissions which are attributed to the in situ desulfurization using calcium based sorbents [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Simultaneous calcination and sulfation of limestone in CFBB

Wang

Chen

Jia³

et al. 2015

Applied Energy

Self Cite

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Simultaneous calcination and sulfation of limestone in CFBB

Wang

Chen

Jia³

et al. 2015

Applied Energy

Self Cite

View full text Add to dashboard Cite

“…

CaO + {CO}_{2} \to {CaCO}_{3}

{CaCO}_{3} \to CaO + {CO}_{2}

Calcium‐based sorbents are widely used for the control of SO 2 emitted from the combustion of sulphur‐containing fuels . The key reactions are commonly described by:

I n d i r e c t s u l p h a t i o n : CaO + {SO}_{2} + 1 true/ 2 {normalO}_{2} \to {CaSO}_{4}

D i r e c t s u l p h a t i o n : {CaCO}_{3} + {SO}_{2} + 1 true/ 2 {normalO}_{2} \to {CaSO}_{4} + {CO}_{2}

When SO 2 is present in the flue gas, SO 2 can also be adsorbed by CaO in the calcium looping cycles for CO 2 adsorption; CaCO 3 and CaSO 4 are simultaneously generated after the adsorption step . CaSO 4 remains stable below 1050 °C, which leads to irreversible loss of the CaO in each cycle.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous CO₂/SO₂ adsorption performance of carbide slag in adsorption/desorption cycles

Wu¹,

Li²,

Zhao³

et al. 2015

Can J Chem Eng

View full text Add to dashboard Cite

Simultaneous CO2/SO2 adsorption performance of CaO derived from carbide slag (an industrial waste product from a chlor‐alkali plant) in multiple adsorption/desorption cycles was investigated in a dual fixed‐bed reactor. The effects of adsorption duration, SO2 concentration, adsorption temperature, desorption conditions, and particle size on carbonation conversion, cumulative sulphation conversion, and total Ca utilization of the carbide slag over multiple cycles were discussed. SO2 presence appreciably impedes the cyclic CO2 adsorption capacity of the carbide slag. A longer adsorption duration causes a sharper drop in the carbonation conversion due to the adverse effect of SO2. The presence of SO2 intensifies the effect of adsorption temperature on the carbonation conversion of the carbide slag. The optimum adsorption temperature for cyclic simultaneous CO2/SO2 adsorption by the carbide slag is 700 °C. The high desorption temperature and CO2 concentration (950 °C, 0.9999 L/L CO2) are not beneficial to cyclic CO2/SO2 adsorption. Both the carbonation conversion and cumulative sulphation conversion of the carbide slag decrease with increasing sorbent particle size in the cycles. The compact CaSO4 product layer covers the surface of CaO derived from the carbide slag during the multiple cycles, which results in a sharp drop in the surface area and pore volume with the cycle number. Compared with limestone, the carbide slag exhibits higher SO2 adsorption capacity and similar CO2 adsorption capacity during the cyclic simultaneous CO2/SO2 adsorption.

show abstract

“…Over the past several decades, many researchers have explored these reactions . The calcination of limestone is reversible, and the reaction rate is usually related to three steps: heat transfer, CO 2 diffusion, and the intrinsic reaction.…”

Section: Introductionmentioning

confidence: 99%

The combined effect of H₂O and SO₂ on the simultaneous calcination/sulfation reaction in CFBs

et al. 2019

Self Cite

View full text Add to dashboard Cite

The combined effect of H2O and SO2 on the reaction kinetics and pore structure of limestone during simultaneous calcination/sulfation reactions under circulating fluidized bed (CFB) conditions was first studied in a constant‐temperature reactor. H2O can accelerate the sulfation reaction rate in the slow‐sulfation stage significantly but has a smaller effect in the fast‐sulfation stage. H2O can also accelerate the calcination of CaCO3, and should be considered as a catalyst, as the activation energy for the calcination reaction was lower in the presence of H2O. When the limestone particles are calcining, SO2 in the flue gas can react with CaO on the outer particle layer and the resulting CaSO4 blocks the CaO pores, increases the diffusion resistance of CO2, and, in consequence, decreases the calcination rate of CaCO3. Here, gases containing 15% H2O and 0.3% SO2 are shown to increase the calcination rate. This means that the accelerating effect of 15% H2O on CaCO3 decomposition is stronger than the impeding effect caused by 0.3% SO2. The calcination rate of limestone particles was controlled by both the intrinsic reaction and the CO2 diffusion rate in the pores, but the intrinsic reaction rate played a major role as indicated by the effectiveness factors determined in this work. This may explain the synergic effect of H2O and SO2 on CaCO3 decomposition observed here. Finally, the effect of H2O and SO2 on sulfur capture in a 600 MWe CFB boiler burning petroleum coke is also analyzed. The sulfation performance of limestone evaluated by simultaneous calcination/sulfation is shown to be much higher than that by sulfation of CaO. Based on our calculations, a novel use of the wet flue gas recycle method was put forward to improve the sulfur capture performance for high‐sulfur low‐moisture fuels such as petroleum coke. © 2019 American Institute of Chemical Engineers AIChE J, 65: 1256–1268, 2019

show abstract

Characterization of ashes from a 100kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

Cited by 81 publications

References 26 publications

Simultaneous calcination and sulfation of limestone in CFBB

Simultaneous calcination and sulfation of limestone in CFBB

Simultaneous CO₂/SO₂ adsorption performance of carbide slag in adsorption/desorption cycles

The combined effect of H₂O and SO₂ on the simultaneous calcination/sulfation reaction in CFBs

Contact Info

Product

Resources

About

Characterization of ashes from a 100kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

Cited by 81 publications

References 26 publications

Simultaneous calcination and sulfation of limestone in CFBB

Simultaneous calcination and sulfation of limestone in CFBB

Simultaneous CO2/SO2 adsorption performance of carbide slag in adsorption/desorption cycles

The combined effect of H2O and SO2 on the simultaneous calcination/sulfation reaction in CFBs

Contact Info

Product

Resources

About

Simultaneous CO₂/SO₂ adsorption performance of carbide slag in adsorption/desorption cycles

The combined effect of H₂O and SO₂ on the simultaneous calcination/sulfation reaction in CFBs