Influence of the pyrolysis heating rate on the steam gasification rate of large wood char particles
Résumé
Thisworkwascarriedoutinordertoquantifytheimpactofthepyrolysisheatingratebothonthepropertiesoftheresidualcharcoalandonthe behaviourduringgasificationbyH 2 Oofthecharcoal.Theexperimentswereconductedon10mmdiameterbeechwoodspheres,pyrolysedat atmosphericpressureunderheatingratescoveringtherangefromveryslow,2.6Kmin K1 ,toveryrapid,over900Kmin K1 ,i.e.thehighestvalue thatcanbereached.Whencharcoalissubmittedtogasificationat20%H 2 O i nN 2 at1200K,theratioofthetimesforcompleteconversionreach 2.6.Suchadifferenceisconsiderableasfarasanindustrialapplicationisconcerned.Theinitialpropertiesofthecharcoalsuchasapparentdensity, porosity,andporesurfaceareaobtainedbyN 2 orAradsorptionweremeasuredinordertoexplainthedifferencesingasificationkineticswithinthe charcoal.Thecharcoalparticlesexhibitdensitiesasdifferentas219-511kgm K3 andporositiesbetween87and70%forcharcoalpreparedat900 and2.6Kmin K1 respectively.Thespecificsurfaceareaishigherthan600m 2 g K1 forthreecharcoals.Influenceofashcontentoftheinitial charcoals,at1.6-2.7%,isalsoregardedwithparticularattentiontoexplaintheobserveddifferencesingasificationkinetics.
Domaines
Sciences de l'ingénieur [physics]| Origine | Fichiers produits par l'(les) auteur(s) |
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