Influence of K/C ratio on gasification rate of biomass chars

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Oskar Karlström, Meheretu Jaleta Dirbeba, Mario Costa, Anders Brink, Mikko Hupa
Publisher: ACS
Publication year: 2018
Journal: Energy and Fuels
Journal acronym: Energy Fuels
Volume number: 32
Issue number: 10
Start page: 10695
End page: 10700
Number of pages: 6
ISSN: 0887-0624
eISSN: 1520-5029


The present study investigates the influence of the K/C ratio on the gasification rate during char conversion. Chars of five agricultural biomasses are investigated: kiwi branches, olive branches, grape pomace, torrefied grape pomace, and sugarcane bagasse. Chars of the biomasses were produced in N-2 in a single particle reactor at 800 degrees C and subsequently gasified in CO2 in a TGA at 800 degrees C. The sugarcane bagasse char had a high Si content and a lower reactivity, which often is attributed to the presence of noncatalytic silicates. SEMEDX analysis of the initial Si-rich char revealed that most of the K was not bound as silicates. Around 30-60% of the K was lost during the char gasification of the chars. The K/C ratio increased as the char conversion proceeded. The instantaneous char gasification rate increased until the K/C ratio was around 0.1 for four of the chars. For coal chars and pure carbons, it has been suggested that the catalytic char gasification rate is saturated when the K/C ratio is 0.1. The results of the present study imply that catalytic char gasification rate may become saturated at high degrees of conversion. From 0% to 80% of conversion, the chars showed a similar catalytic behavior: the rate increased almost linearly with the K/C ratio.

Last updated on 2020-09-08 at 06:02