Towards understanding the role of K during biomass steam gasification

FUEL

卷:282

Article

Dahou, Tilia^1,2,3,4  Defoort, Francoise¹  Jeguirim, Mejdi^2,3  Dupont, Capucine⁵ 

[1] Univ Grenoble Alpes, CEA, LITEN, DTBH, 17 Ave Martyrs, F-38054 Grenoble 09, France

[2] Univ Haute Alsace, CNRS, IS2M UMR 7361, 3 Rue Alfred Werner, F-68100 Mulhouse, France

[3] Univ Strasbourg, Strasbourg, France

[4] Agence Environm & Maitrise Energie ADEME, 20 Ave Gresille,BP 90406, F-49004 Angers 01, France

[5] IHE Delft Inst Water Educ, Westvest 7, NL-2611 AX Delft, Netherlands

关键词: Steam gasification;    Reaction kinetics;    Catalysis;    Potassium;    Silica;    Rice husk;   

DOI  :  10.1016/j.fuel.2020.118806

来源: Elsevier

【 摘 要 】

Steam gasification is known to be catalyzed by K. However, the exact mechanisms are not identified to this day. In the present study, the catalytic influence of K on biomass steam gasification and its interaction with Si was investigated. The study was conducted through thermogravimetric analysis (TGA) on rice husks as a Si-rich biomass and K2CO3 as a model K-compound. Experiments were conducted in three different configurations: biomass or inorganic compound alone; mixtures of biomass and inorganic powders; biomass and inorganic compound without contact in a two-compartment crucible. It was shown that K has a catalytic effect on both the pyrolysis and the gasification steps. These effects occur even when the K-compound is not in direct contact with the biomass. Therefore, it demonstrates that the mechanisms involve the gas phase through the volatilization of a K-compound, most likely KOH(g). However, the observed catalytic effect on rice husks was weaker than the effect obtained in the case of beech wood, a Si-poor and more generally ash-poor biomass, under the same conditions. It shows that there is a competition between i) the influence of K on the biomass pyrolysis and char gasification kinetics and ii) the interaction of K with SiO2 inherent to the biomass.

【 授权许可】

Free