Alkali-wall interactions in a laboratory-scale reactor for chemical looping combustion studies
Artikel i vetenskaplig tidskrift, 2021

Alkali metal-containing compounds are readily released during thermal conversion of solid fuels, and may have both detrimental and beneficial effects on chemical looping combustion. Here, we characterize alkali interactions with the inner walls of a laboratory-scale reactor under oxidizing, reducing and inert conditions at temperatures up to 900 °C. KCl aerosol particles are continuously introduced to the stainless steel reactor and the alkali concentration is measured on-line with a surface ionization detector. Aerosol particles evaporate at temperatures above 500 °C and KCl molecules rapidly diffuse to the reactor wall. Up to 92% of the alkali reaching the wall below 700 °C remains adsorbed, while re-evaporation is important at higher temperatures, where up to 74% remains adsorbed. Transient changes in alkali concentration are observed during repeated redox cycles, which are associated with changes in chemical composition of the wall material. Metal oxides on the reactor wall are partially depleted under reducing conditions, which allow for the formation of a new potassium-rich phase that is stable in a reducing atmosphere, but not under inert conditions. The observed wall effects are concluded to be extensive and include major transient effects depending on gas composition, and the implications for laboratory studies and improved experimental methodology are discussed.

Surface ionization detector

Chemical looping combustion

Alkali

High temperature corrosion

Laboratory-scale reactor

Författare

Viktor Andersson

Göteborgs universitet

Amir H. Soleimanisalim

Xiangrui Kong

Göteborgs universitet

Fredrik Hildor

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Henrik Leion

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Tobias Mattisson

Chalmers, Rymd-, geo- och miljövetenskap, Energiteknik

Jan B. C. Pettersson

Göteborgs universitet

Fuel Processing Technology

0378-3820 (ISSN)

Vol. 217 106828

Förbränningskemi för biomassa med syrebärarmaterial

Vetenskapsrådet (VR), 2017-01-01 -- 2024-12-31.

Ämneskategorier

Materialkemi

Annan kemiteknik

Korrosionsteknik

DOI

10.1016/j.fuproc.2021.106828

Mer information

Senast uppdaterat

2021-04-14