Simulation of biomass char gasification in a downdraft reactor for syngas production

• Published in: AIChE journal Vol. 62; no. 4; pp. 1079 - 1091
• Main Authors: Ephraim, Augustina, Pozzobon, Victor, Louisnard, Olivier, Minh, Doan Pham, Nzihou, Ange, Sharrock, Patrick
• Format: Journal Article
• Language: English
• Published: New York Blackwell Publishing Ltd 01.04.2016; American Institute of Chemical Engineers; Wiley
• Subjects: Atmosphere; Biofuels; Biogas; Biomass; biomass waste; Chemical engineering; Combustion; Computational fluid dynamics; Computer applications; Computer simulation; Conservation; Conversion; Data processing; Design; Design analysis; Design engineering; Design optimization; Downdraft; downdraft reactor; Engineering Sciences; Evolution; Experimental data; Fluid dynamics; Fluid flow; Fuels; Gas composition; Gasification; Heat; Hydrodynamics; Inlet temperature; Kinetics; Mathematical models; model simulation; OpenFOAM; Reaction kinetics; Reaction mechanisms; Reactors; Sensitivity; Sensitivity analysis; Simulation; syngas; Synthetic fuels; Temperature effects; Wood; OpenFOAM; model simulation; downdraft reactor; gasification; downdraftreactor; syngas; modelsimulation; biomass waste; biomasswaste
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.15111

A steady state, one‐dimensional computational fluid dynamics model of wood char gasification in a downdraft reactor is presented. The model is not only based on reaction kinetics and fluid flow in the porous char bed but also on equations of heat and mass conservation. An original OpenFOAM solver is used to simulate the model and the results are found to be in good agreement with published experimental data. Next, a sensitivity analysis is performed to study the influence of reactor inlet temperature and gas composition on char conversion, bed temperature profile and syngas composition. In addition, the evolution of the complex reaction mechanisms involved in mixed atmosphere gasification is investigated, and the most suitable operating parameters for controlling syngas composition are evaluated. Our simulation results provide essential knowledge for optimizing the design and operation of downdraft gasifiers to produce syngas that meets the requirements of various biofuel applications. © 2015 American Institute of Chemical Engineers AIChE J, 62: 1079–1091, 2016