Three pseudo-components kinetic modeling and nonlinear dynamic optimization of Rhus Typhina pyrolysis with the distributed activation energy model

摘要

In this work, a model using the Friedman method was applied to describe thermal decomposition of a biomass sample, Rhus Typhina (RT). The kinetic parameters such as activation energy and pre-exponential factor were achieved from this method. To provide more detailed description of biomass pyrolysis, a three pseudocomponents distributed activation energy model (DAEM) was developed. In this DAEM model, a probability density function (PDF), the normal distribution function, was utilized to describe the distribution of activation energies for chemical reactions during pyrolysis. More importantly, three pseudo-components were proposed to represent hemicellulose, cellulose, and lignin & others. The three pseudo-components DAEM model was employed to predict biomass conversion and thermal decomposition rates. Moreover, a nonlinear dynamic optimization model was built and integrated with the DAEM to achieve better model-fitting. The model predictions were compared and validated with 3 sets of experiment data. Case studies were also conducted to investigate the impact of the PDF on thermal decomposition of hemicellulose, cellulose, and lignin.