Title:
Do All Biomasses Exhibit the Same Alkali Release Behaviour During Steam Gasification? An Answer through a Thermodynamic and Experimental Study
Author(s):
Defoort, F., Durruty, J., Dupont, C., Guillaudeau, J., Bedel, L., Ravel, S., Campargue, M., Da Silva Perez, D., Labalette, F.
Document(s):
Paper
Abstract:
Comprehension of alkali behavior in biomass gasification is essential because it can impact process (corrosion, agglomeration …). Several workers have used thermodynamic calculations and observed that some biomasses volatilised more HCl than others. However, none of them has explained explicitly and checked it experimentally until now. Hence, the aim of this paper is to study the alkali volatilisation of various biomasses representative of the feedstock diversity during steam gasification both through thermodynamic calculations and gasification experiments in the CEA fluidized bed. Eight different biomasses were studied. Thermodynamic calculations predicted two different alkali volatilisation behaviors in the typical temperature range of fluidized bed. For silica rich biomass (Wheat Straw, Triticale and Miscanthus) the composition of the gas phase is calculated to be KCl and HCl. The K/Cl molar ratio in the gas phase is lower than 1. It is in agreement with our measurements. For silica poor biomasses (Calys, Coniferous wood, SRC poplar, Eucalyptus, Tall fescue) the composition of the gas phase is KCl and KOH. The K/Cl molar ratio in the gas phase is thus higher than 1. It is in disagreement with our measurements. These discrepancies can be explained partly by an incorrect alkali sampling and also by lacks in the thermodynamic database used for calculations.
Keywords:
alkali, biomass, gasification, measurement, thermodynamic calculations
Topic:
R&D on Biomass Conversion Technologies for Heating, Electricity and Chemicals
Subtopic:
Gasification for synthesis gas production
Event:
20th European Biomass Conference and Exhibition
Session:
2DO.5.3
Pages:
926 - 932
ISBN:
978-88-89407-54-7
Paper DOI:
10.5071/20thEUBCE2012-2DO.5.3
Price:
FREE
