High temperature corrosion of boiler waterwalls induced by chlorides and bromides - Part 2: Lab-scale corrosion tests and thermodynamic equilibrium modeling of ash and gaseous species

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Bankiewicz D, Vainikka P, Lindberg D, Frantsi A, Silvennoinen J, Yrjas P, Hupa M
Förläggare: ELSEVIER SCI LTD
Publiceringsår: 2012
Tidskrift: Fuel
Tidskriftsakronym: FUEL
Volym: 94
Artikelns första sida, sidnummer: 240
Artikelns sista sida, sidnummer: 250
Antal sidor: 11
ISSN: 0016-2361


Abstrakt

In Part 1 of the work a measurement campaign was carried out to determine the occurrence of corrosive ash components in a bubbling fluidized bed (BFB) boiler combusting solid recovered fuel (SRF). It was found out that the main ash-forming elements that had been vaporized and subsequently condensed from the gas phase were Na, K, S and Cl together with minor amounts of Zn, Pb, Cu, and Br. Both, Cl and Br were found in the corrosion front of the waterwalls prior to the measurement campaign. In this work, the forms of ash forming elements in the combustion gases and in the waterwall deposits of the examined boiler were predicted by means of thermodynamic equilibrium modeling. Laboratory tests were also carried out to estimate the degree of corrosion of boiler steels under bromine containing deposits. A mixture of ZnBr2 and K2SO4 was selected for high temperature lab-scale corrosion testing since Zn, Br and K as well as sulfates were present in the deposit and it was possible to compare these results to previously published results with ZnCl2-K2SO4 mixtures. The comparison showed that more severe material degradation was caused by the ZnBr2 containing salt than by the corresponding chloride and corrosion was significant already at 400 degrees C.


Nyckelord

Bromine, Chlorine, Corrosion, Solid recovered fuel, Waterwall

Senast uppdaterad 2019-19-10 vid 04:02