A model of biomass char gasification describing the change in catalytic activity of ash
2012 (English)Conference paper, Meeting abstract (Refereed)
A comprehensive description of catalytic effects during chargasification under various conditions relevant for biomassgasification was made. A three-parallel reaction model was proposed to describe the dynamic change in catalyticactivity of ash during gasification of biomasschar particles. Three different regimes of conversion were identified by analyzing char reactivity experiments conducted in a vertical TGA with 9 biomasses under a wide range of operating conditions (temperature: 1023-1123 K, pressure: 0.1-3.0 MPa and gasification mixtures of CO2 –CO–H2O–H2): (1) catalyticchargasification with the deactivation of catalyst, (2) non-catalyticchargasification, and (3) catalyticchargasification with small amount of stable ash, without suffering deactivation. Amodel including the three regimes was developed and the measurements were used to fit the kinetic coefficients. It is shown that the model accurately predicts the reactivity of biomasschar in CO2 –CO mixtures during the whole range of conversion. It was detected that chargasification maintains the catalyticactivity during the entire conversion process when: (i) biomasses having small amount of silicon was used, and (ii) steam is used as part of the gasification agent. The model is still useful as predicting tool for these two conditions but its physical significance is contestable on the light of the model developed. For the conditions where the model is valid, it is shown that the model is a useful tool as sub-model in reactor simulations, predicting the conversion rate of single particles fast and accurately at different stages of conversion. The aspects that need to be further investigated for expanding the applicability of the model were identified.
Place, publisher, year, edition, pages
2012. Vol. 207-208, 616-624 p.
Research subject Energy Engineering
IdentifiersURN: urn:nbn:se:ltu:diva-35663DOI: 10.1016/j.cej.2012.07.025Local ID: a4b6a406-ecab-446c-8918-d9c143ecc016OAI: oai:DiVA.org:ltu-35663DiVA: diva2:1008916
International Symposium on Chemical Reaction Engineering : 02/09/2012 - 05/09/2012
Validerad; 2012; 20120731 (ysko)2016-09-302016-09-30Bibliographically approved