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Research article2024Peer reviewedOpen access

Bed material performance of quartz, natural K-feldspar, and olivine in bubbling fluidized bed combustion of barley straw

Backman, Marjan Bozaghian; Rebbling, Anders; Kuba, Matthias; Larsson, Sylvia H.; Skoglund, Nils

Abstract

The present study investigates how three different silicate-based bed materials behave in bubbling fluidized bed combustion of a model agricultural residue with respect to ash composition, namely barley straw. Quartz, natural K-feldspar, and olivine were all used in combustion at 700 C-degrees, and the resulting layer formation and bed agglomeration characteristics were determined. Based on this, a general reaction model for bed ash from agricultural residues was proposed, taking into account the reactivity of the different silicates investigated towards the main ash-forming elements K, Ca, and Si. The proposed reaction model links bed material interaction with Krich bed ash to the degree of polymerization of the silicate bed material, where addition reactions occur in systems with high polymerization, predominately in quartz, and substitution reactions dominate for depolymerized silicates such as K-feldspar and olivine.

Keywords

Agricultural residue; Agglomeration; Bed particle; Layer formation; Bioenergy

Published in

Fuel
2024, Volume: 364, article number: 130788Publisher: ELSEVIER SCI LTD