Segregation of fuel particles and volatile matter during devolatilization in a fluidized bed reactor—II. Experimental

Fiorentino, Maria; Marzocchella, Antonio; Salatino, Piero

doi:10.1016/s0009-2509(97)00019-5

Cited by 75 publications

(62 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fiorentino et al [43,44]. According to this phenomenon, for the sand experiments, the endogenous bubbles induced segregation of the fuel particle at the top of the bed.…”

Section: Visual Observationsmentioning

confidence: 96%

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Serrano

Sánchez-Delgado

Sobrino

et al. 2015

Fuel Processing Technology

View full text Add to dashboard Cite

This work studies the defluidization time and the agglomerates generation in a Bubbling Fluidized Bed (BFB) reactor during Cynara Cardunculus L. gasification using, separately, two different bed materials, silica sand and sepiolite (Mg 8 Si 12 O 30 (OH) 4 (OH 2 ) 4 8H 2 ). The high adsorption capacity and the elemental composition of the sepiolite make it suitable as an alternative bed material in order to reduce agglomeration. Experiments were performed on a stainless steel lab-scale BFB reactor operating with air as gasifying agent at different air excess ratios (u/u mf ). A quartz reactor was alternatively used for the visualization of bed material and biomass during gasification, allowing to observe the agglomerate formation process. Pressure signals were analyzed both in time and frequency domain to determine the defluidization time.Furthermore, the shape and size of the bed material after the experiments were evaluated.Higher defluidization times in the case of sepiolite were measured. Particle sizes were affected by the type of bed material and the air excess and agglomerates of different shapes were formed for sepiolite and silica sand.

show abstract

“…Fiorentino et al [43,44]. According to this phenomenon, for the sand experiments, the endogenous bubbles induced segregation of the fuel particle at the top of the bed.…”

Section: Visual Observationsmentioning

confidence: 96%

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Serrano

Sánchez-Delgado

Sobrino

et al. 2015

Fuel Processing Technology

View full text Add to dashboard Cite

show abstract

“…The amount of gaseous species increased linearly with temperature from 0.65 to 0.93 L. Besides, it takes some time for the mixture of sludge particle and oxygen carrier particle to achieve mixing/ segregation equilibrium, which depends on the fluidizing gas velocity and fuel particle size. At a given fuel particle size, the higher reaction temperature leads to the increase of fluidizing gas velocity, which results in a shorter time [42]. Nevertheless, the rise of temperature also led to the increase of reactivity of CO, H 2 and CH 4 with NiO [13].…”

Section: Effect Of Reaction Temperaturementioning

confidence: 99%

Sewage sludge combustion in a CLC process using nickel-based oxygen carrier

Niu

Shen

et al. 2015

Chemical Engineering Journal

View full text Add to dashboard Cite

“…Axial segregation of gas-emitting fuel particles and ''stratified'' combustion are promoted by devolatilization and formation of ''endogenous'' bubbles of volatile matter. [2][3][4][5][6][7][8][9][10] Poor lateral dispersion of volatile matter from the fuel feeding ports arises from the combination of short devolatilization times and long time scales of fuel particle lateral spreading. 11 The effectiveness of lateral dispersion of volatile matter across the combustor is assessed by comparing the characteristic time of solids-lateral mixing (t mix ) with the characteristic devolatilization time.…”

Section: Devolatilization Time Vs Particle Sizementioning

confidence: 99%

“…In-bed emission of volatile matter is responsible for the formation of ''endogenous'' volatile bubbles [2][3] as a consequence of the hydrodynamic interaction between gas-emitting particles and the fluidized suspension. Endogenous bubbles enhance axial segregation of fuel particles at the bed surface and favor the establishment of ''stratified'' combustion.…”

Section: Introductionmentioning

confidence: 99%

“…Endogenous bubbles enhance axial segregation of fuel particles at the bed surface and favor the establishment of ''stratified'' combustion. [2][3][4][5][6][7][8][9][10] On the other hand, the competition between fuel devolatilization and radial solids mixing crucially affects the radial distribution of volatile matter across the reactor and emphasizes the relevance of the devolatilization kinetics to volatile matter segregation. Short devolatilization times promote the release of volatile matter above the bed and close to the fuel feeding points, [11][12][13] when mixing with the fluidizing gas eventually takes place along the freeboard (in bubbling fluidized-bed reactors), or the riser (in circulating fluidized-bed reactors).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of the devolatilization rate of solid fuels in fluidized beds by time‐resolved pressure measurements

2011

Self Cite

View full text Add to dashboard Cite

in Wiley Online Library (wileyonlinelibrary.com).The characterization of volatile matter (VM) release from solid fuel particles during fluidized-bed combustion/gasification is relevant to the assessment of the reactor performance, as devolatilization rate affects in-bed axial fuel segregation and VM distribution across the reactor. An experimental technique for the characterization of the devolatilization rate of solid fuels in fluidized beds is proposed. It is based on the analysis of the time series of pressure measured in a bench-scale fluidized-bed reactor as VM is released from a batch of fuel particles. A remarkable feature of the technique is the possibility to follow fast devolatilization with excellent time-resolution. A mathematical model of the experiment has been developed to determine the time-resolved devolatilization rate, the devolatilization time and the volume-based mean molecular weight of the emitted volatile compounds. Devolatilization kinetics has been characterized for different solid fuels over a broad range of particle sizes. V V C 2011 American Institute of Chemical Engineers AIChE J, 58: 632-645, 2012

show abstract

Segregation of fuel particles and volatile matter during devolatilization in a fluidized bed reactor—II. Experimental

Cited by 75 publications

References 6 publications

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Sewage sludge combustion in a CLC process using nickel-based oxygen carrier

Characterization of the devolatilization rate of solid fuels in fluidized beds by time‐resolved pressure measurements

Contact Info

Product

Resources

About