Reactions of potassium chloride with chromium as a first step towards high temperature corrosion in biomass combustion

B3 Non-refereed conference proceedings


Internal Authors/Editors


Publication Details

List of Authors: Lehmusto Juho, Yrjas Patrik, Hupa Mikko
Place: Naantali
Publication year: 2009
Book title: Finnish-Swedish Flame Days 2009


Abstract

Reactions between potassium chloride (KCl) and chromium oxide (Cr2O3) as well as pure chromium (Cr) have been studied as model reactions for high temperature corrosion. The compounds have been used as powders because of their big area-to-mass ratio, which results in clearer signals in thermogravimetric measurements. The changes in mass and heat of reaction were measured by means of differential thermal analysis and thermal gravimetry (DTA/TG). The runs were performed mainly in synthetic air, but also nitrogen was used. After the DTA/TG runs the samples were analyzed with a scanning electron microscope (SEM).


Chromium oxide seems to be inert in the used conditions, but pure chromium reacted with potassium chloride forming chromium oxide as product. In some runs, a yellow intermediate, probably potassium chromate (K2CrO4) was detected. The reaction needs both oxygen and potassium chloride to proceed, but already a tiny amount of potassium chloride is enough to maintain the oxidation of chromium.


Keywords

Biomass combustion, Chromium, High-temperature corrosion

Last updated on 2019-23-10 at 03:37