Comparing Active Bed Materials in a Dual Fluidized Bed Biomass Gasifier: Olivine, Bauxite, Quartz-Sand, and Ilmenite
Artikel i vetenskaplig tidskrift, 2016

Active bed materials are in this work investigated for in situ gas upgrading of biomass-derived gas. Previous research on in situ gas upgrading has focused on assessing gas quality, in terms of the concentrations of tar and permanent gases. Other aspects of fuel conversion, such as char conversion and the impact of oxygen transport on the final gas, are not as well documented in the literature on gasification. In this paper, the overall biomass conversion in a dual fluidized bed biomass gasifier is investigated in the presence of the catalytic material olivine and the alkali-binding material bauxite. The impact of these materials on fuel conversion is described as the combination of four effects, which are induced by the bed material: thermal, catalytic, ash-enhanced catalytic effect, and oxygen transport. Quartz-sand and ilmenite are here used as the reference materials for the thermal and the oxygen transport effects, respectively. Olivine and bauxite show activity toward tar species compared to quartz-sand. After 1 week of operation and exposure to biomass ash, the activities of olivine and bauxite toward tar species increase further, and the water gas shift reaction is catalyzed by both materials. Additionally, bauxite shows a stronger ability to increase char conversion than olivine. Under the conditions tested, olivine and bauxite have some degree of oxygen transport capacity, which is between those of quartz-sand and ilmenite. The oxygen transport effect is higher for bauxite than for olivine; nevertheless, the catalytic activities of the materials result in higher yields of H-2 than in a similar case with quartz-sand. The implications of the findings for the operation of dual fluidized bed gasifiers are discussed.

system

dolomite

catalysts

tar reduction

reactor

steam-gasification

Engineering

elimination

chemical-looping combustion

conversion

Energy & Fuels

gas

Författare

Teresa Berdugo Vilches

Chalmers, Energi och miljö, Energiteknik

Jelena Maric

Chalmers, Energi och miljö, Energiteknik

Martin Seemann

Chalmers, Energi och miljö, Energiteknik

Henrik Thunman

Chalmers, Energi och miljö, Energiteknik

Energy & Fuels

0887-0624 (ISSN) 1520-5029 (eISSN)

Vol. 30 6 4848-4857

Ämneskategorier

Kemiteknik

DOI

10.1021/acs.energyfuels.6b00327