Title: Mathematical model of biomass gasification using high temperature air in fixed beds

Authors: Carlos Lucas, Weihong Yang, Anna Ponzio, Wlodzimierz Blasiak, Yao Bin Yang, Vida N. Sharifi, Jim Swithenbank

Addresses: Energy and Furance Technology, Royal Institute of Technology, Brinelllvagen 23, S-100 44 Stockholm, Sweden. ' Energy and Furance Technology, Royal Institute of Technology, Brinelllvagen 23, S-100 44 Stockholm, Sweden. ' Energy and Furance Technology, Royal Institute of Technology, Brinelllvagen 23, S-100 44 Stockholm, Sweden. ' Energy and Furance Technology, Royal Institute of Technology, Brinelllvagen 23, S-100 44 Stockholm, Sweden. ' Sheffield University Waste Incineration Centre (SUWIC), Chemical and Process Engineering, Sheffield University, Mappin Street, Sheffield S1 3JD, UK. ' Sheffield University Waste Incineration Centre (SUWIC), Chemical and Process Engineering, Sheffield University, Mappin Street, Sheffield S1 3JD, UK. ' Sheffield University Waste Incineration Centre (SUWIC), Chemical and Process Engineering, Sheffield University, Mappin Street, Sheffield S1 3JD, UK

Abstract: A mathematical model has been formulated for predicting the main chemical and physical processes taking place during the fixed-bed gasification of biomass fuels using high temperature air (up to 1000°C). Predicted gas species concentrations profiles and their maximum values are in good agreement with measurements. The results also show that when the temperature of feed gas (air) is increased a higher gasification rate, higher molar fractions of fuel gases (CO, H2 and CmHn) are obtained, thus resulting in a higher LHV. At a high flow rate of the feed gases, the peaks of the fuel gas concentrations are slightly increased, and the gasification rate is strongly increased. A smaller particle size of the biomass fuels leads to higher peak values of the fuel gas species molar fractions, and a more stable gasification zone for a relatively long period of time.

Keywords: mathematical modelling; gasification rate; biomass fuel; fixed bed; high temperature air; gas species concentrations; unsteady state modelling; heat transfer; mass transfer; moisture evaporation; biomass pyrolysis; char combustion; gas-phases reactions; mixing.

DOI: 10.1504/PCFD.2007.011886

Progress in Computational Fluid Dynamics, An International Journal, 2007 Vol.7 No.1, pp.58 - 67

Available online: 30 Dec 2006 *

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