Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels

The main aim of this work was to investigate the propensity of bed materials to retain ash-forming elements from biomass under conditions relevant to dual fluidized bed gasification (DFBG). The investigation was carried out in a laboratory-scale bubbling fluidized bed reactor in which biomass was g...

Descripción completa

Detalles Bibliográficos
Autor principal: Folkeson, Björn
Formato: Second cycle, A2E
Lenguaje:sueco
Inglés
Publicado: 2014
Materias:
Acceso en línea:https://stud.epsilon.slu.se/7528/
_version_ 1855571199070830592
author Folkeson, Björn
author_browse Folkeson, Björn
author_facet Folkeson, Björn
author_sort Folkeson, Björn
collection Epsilon Archive for Student Projects
description The main aim of this work was to investigate the propensity of bed materials to retain ash-forming elements from biomass under conditions relevant to dual fluidized bed gasification (DFBG). The investigation was carried out in a laboratory-scale bubbling fluidized bed reactor in which biomass was gasified with steam and the unconverted char was combusted in the temperature range 800–900 ° C. Three bed materials (sand, olivine and bauxite) and two biomass fuels (forestry residue and wheat straw) were studied. From the results obtained and literature on the ash transformation chemistry during thermal conversion of biomass, it was found that the extent to which ash-forming elements from biomass are retained on bed materials depend among other factors on (1) the abundance of ash-forming elements in the fuel, (2) the ability of the bed material to react and form compounds with ash-forming elements and (3) the atmosphere surrounding the fuel in the reactor. For example, Ca, P and K (which were among the most abundant ash-forming elements in the forestry residues) were also the main ashforming elements retained on sand, olivine and bauxite during thermal conversion of the forestry residues. However, the retention of these elements differed on the three bed materials. With respect to reactor atmosphere, Ca and P were retained on olivine primarily during char combustion while the retention of K on olivine was somewhat similar during gasification and char combustion. In addition to the experimental results, the effect of the retention of ash-forming elements on bed agglomeration tendency and the composition of the product gas is discussed as well as the relevance of the obtained results for the DFBG process.
format Second cycle, A2E
id RepoSLU7528
institution Swedish University of Agricultural Sciences
language Swedish
Inglés
publishDate 2014
publishDateSort 2014
record_format eprints
spelling RepoSLU75282014-12-12T12:41:27Z https://stud.epsilon.slu.se/7528/ Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels Folkeson, Björn Renewable energy resources Chemistry Technology The main aim of this work was to investigate the propensity of bed materials to retain ash-forming elements from biomass under conditions relevant to dual fluidized bed gasification (DFBG). The investigation was carried out in a laboratory-scale bubbling fluidized bed reactor in which biomass was gasified with steam and the unconverted char was combusted in the temperature range 800–900 ° C. Three bed materials (sand, olivine and bauxite) and two biomass fuels (forestry residue and wheat straw) were studied. From the results obtained and literature on the ash transformation chemistry during thermal conversion of biomass, it was found that the extent to which ash-forming elements from biomass are retained on bed materials depend among other factors on (1) the abundance of ash-forming elements in the fuel, (2) the ability of the bed material to react and form compounds with ash-forming elements and (3) the atmosphere surrounding the fuel in the reactor. For example, Ca, P and K (which were among the most abundant ash-forming elements in the forestry residues) were also the main ashforming elements retained on sand, olivine and bauxite during thermal conversion of the forestry residues. However, the retention of these elements differed on the three bed materials. With respect to reactor atmosphere, Ca and P were retained on olivine primarily during char combustion while the retention of K on olivine was somewhat similar during gasification and char combustion. In addition to the experimental results, the effect of the retention of ash-forming elements on bed agglomeration tendency and the composition of the product gas is discussed as well as the relevance of the obtained results for the DFBG process. 2014-12-09 Second cycle, A2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/7528/1/folkeson_b_141209.pdf Folkeson, Björn, 2014. Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels. Second cycle, A2E. Uppsala: (NL, NJ) > Dept. of Energy and Technology <https://stud.epsilon.slu.se/view/divisions/OID-565.html> urn:nbn:se:slu:epsilon-s-4023 eng
spellingShingle Renewable energy resources
Chemistry
Technology
Folkeson, Björn
Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title_full Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title_fullStr Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title_full_unstemmed Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title_short Propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
title_sort propensity of bed materials used in dual fluidized beds to retain ash-forming elements from biomass fuels
topic Renewable energy resources
Chemistry
Technology
url https://stud.epsilon.slu.se/7528/
https://stud.epsilon.slu.se/7528/