Abstract

In this study, multivariate methods were used to select representative raw materials of the pellet assortments prior to combustion. The fuels were selected to form a range of expected slagging tendencies. During combustion, temperatures and O(2), CO, NO, and SO(2) were measured continuously. The deposits (i.e., slag and bottom ash) were quantified after every experiment and collected for analysis to identify the crystalline phases and to study the morphology and elemental composition respectively. As expected, the slagging was most severe for the whole-tree assortments because of their content of branches, foliage, and twigs. In the most severe case over three-quarters of the total amount of ash melted to form slag. This study indicates that certain concentrations of silicon, inherent in the fuel but also as silicates from contamination, together with alkali metals, mainly potassium, are prerequisites for the initiation of and progress of slag formation. Generally the concentrations of silicon and potassium are low in stemwood but higher in bark, foliage, and living tissues of the tree. Also, the contamination from sand and/or soil is present in the bark and foliage.

Published in

Energy and Fuels
2010, Volume: 24, number: 6, pages: 3456-3461
Publisher: AMER CHEMICAL SOC

SLU Authors

• Larsson, Sylvia

  • Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Renewable Bioenergy Research
Forest Science


Publication identifier

DOI: https://doi.org/10.1021/ef901571c

Permanent link to this page (URI)

https://res.slu.se/id/publ/59876