Simulation analysis of Co-Pyrolysis of oil shale and wheat straw based on the combination of chain reaction kinetics and improved CPD models

• Proposing a co-pyrolysis model of oil shale with biomass. • Constructing more than 10 pathways and reaction kinetics equations. • The distributions of the products were accurately predicted using this model. In order to fill in the blank of the prediction model about the co-pyrolysis of oil shale with biomass, we proposed a novel co-pyrolysis model based on chemical structure using improved chemical percolation devolatilization ( CPD ) with chain reaction kinetics ( CRK ). Three basic elements of aromatic cluster, aliphatic bridge, and oxygen-containing bridge are chosen as the representative structure units for building the simplified pseudo-grid model. According to the pyrolysis characteristic, we divided the model to five processes: the breakage of bridge bonds, the adsorption of free radicals, the reaction of aliphatic chains, the aromatization reaction and the cross-linking reaction, and described it through 14 reaction pathways and 18 reaction kinetic equations. The predicted results are compared with experimental results of fixed bed and thermogravimetry ( TG ) analysis, while the error is within a reasonable range indicating the accuracy and rationality of our model. We believe that this paper provides a deep understanding of the co-pyrolysis processes and discovery of the distribution characteristics of different kinds of pyrolytic intermediates and free radicals at an atomic level beyond what laboratory experiments could achieve.