Paper details

Title:

Experimental Characterisation of Materials for Biomass Co-Firing

Author(s):

O'Hagan, C.P., O'Brien, B.J., Leen, S.B., Monaghan, R.F.D

Document(s):

Abstract:

Increased rates of corrosion during the co­firing of peat with biomass have been identified as a limiting factor on the level of biomass viable to use. The present work is motivated by the need for mechanisms­based models to simulate this process. Experimental studies on pure iron are presented, without the complexities of alloying elements, to develop a fundamental understanding of the corrosion process during co­firing of peat and biomass. A synthetic salt with chemical composition representative of in­situ plant measurements is applied to specimens in a furnace at 540°C for up to 4 weeks. The corrosion layer from interrupted tests is analysed using scanning electron microscopy (SEM), optical microscopy (OM) and energy dispersive X­ray spectroscopy (EDX) to provide insight into the material degradation and structure of the corrosion layer. Two distinct types of oxide are identified from the tests. The first, a compact, uniform oxide layer which forms over the substrate initially. As corrosion proceeds, this layer degrades, leading to spallation and formation of a mixture of corrosion debris into the salt layer. Healthy iron was found to separate from the substrate and undergo oxidation from both above and below. A mechanism for this corrosion process is suggested.

Keywords:

biomass, co-firing, corrosion, oxidation, power generation, fluidized bed

Topic:

Biomass Conversion Technologies for Heating, Cooling and Electricity

Subtopic:

Solid biofuels combustion in large utilities

Event:

22nd European Biomass Conference and Exhibition

Session:

2BV.2.45

Pages:

723 - 730

ISBN:

978-88-89407-52-3

Paper DOI:

10.5071/22ndEUBCE2014-2BV.2.45

Price:

FREE