Effective new chemicals to prevent corrosion due to chlorine in power plant superheaters

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Martti Aho, Pasi Vainikka, Raili Taipale, Patrik Yrjas
Publisher: Elsevier
Publication year: 2008
Journal: Fuel
Volume number: 87
Issue number: 6
Start page: 647
End page: 654


Abstract

Firing or co-firing of biomass in efficient power plants can lead to high-temperature corrosion of superheaters due to condensation of alkali chlorides into superheater deposits. Corrosion can be prevented if a significant portion of the alkali chlorides present in the flue gases is destroyed before reaching the superheaters. The alkali capturing power of aluminium and ferric sulphates was determined in a pilot-scale fluidised bed (FB) reactor. The reagents were added in solution, through a spraying nozzle, to the upper part of the freeboard. Both reagents, at economical dosages, fast and effectively destroyed the alkali chlorides by producing sufficient SO3 for the sulphation. Both the mass flow rate and type of sulphate affected the sulphation ability. Thus, the cation, too, plays a role in the reaction. The required chemical dosage is not directly proportional to the Sreagent/Cl2fuel ratio because alkali chlorides must compete with calcium and magnesium oxides and probably also with alkali oxides for the available SO3.


Last updated on 2019-15-10 at 01:01