Alkali-wall interactions in a laboratory-scale reactor for chemical looping combustion studies
Journal article, 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. 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. 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

Laboratory-scale reactor

High temperature corrosion

Chemical looping combustion

Alkali

Author

Viktor Andersson

University of Gothenburg

Amir H Soleimani Salim

Chalmers, Space, Earth and Environment, Energy Technology, Energy Technology 2

Xiangrui Kong

University of Gothenburg

Fredrik Hildor

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Henrik Leion

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry 2

Tobias Mattisson

Chalmers, Space, Earth and Environment, Energy Technology

Jan Pettersson

Chalmers, Gothenburg Centre for Sustainable Development (GMV)

Fuel Processing Technology

0378-3820 (ISSN)

Vol. 217 -106828

Driving Forces

Sustainable development

Subject Categories

Energy Engineering

Chemical Process Engineering

Environmental Sciences

Areas of Advance

Energy

Infrastructure

Chalmers Power Central

DOI

10.1016/j.fuproc.2021.106828

More information

Created

5/31/2021