A distributed activation energy model for cellulose pyrolysis in a fluidized bed reactor

Abstract

Cellulose pyrolysis is used to give solid char, condensable vapors and non-condensable gases. This is a complex process and to model this using CFD simulations, Euler-Euler approach with multi-fluid is applied. The objective of the present study is to develop a CFD model to combine the reaction kinetics with the hydrodynamics to study the cellulose pyrolysis in the fluidized bed reactor. The distributed activation energy model to compare the product yield with and without distribution of activation energy has been incorporated. Simulations of cellulose pyrolysis in a fluidized bed reactor using two different kinetic schemes have been conducted. Model has been validated using global kinetic scheme and then optimized kinetic parameters are introduced with a distribution of activation energy. The predicted values of activation energies, frequency factor and standard deviation impact the overall pyrolysis product yield. The yield of tar and char increases, however the fraction of gases decreases significantly because of higher activation energy. Tar yield is 82.1 wt% in the presence of DAEM, while the gas yield is 8 wt% and char yield comes out to be 9.9 wt%.