This paper gives an overview of the recent development of modeling and simulation of chemically reacting flows in gas-solid catalytic and non-catalytic processes.General methodology has been focused on the Eulerian-Lagrangian description of particulate flows.where the particles behave as the catalysts or the reactant materials.For the strong interaction between the transport phenomena(i.e.,momentum.heat and mass transfer)and the chemical teactions at the particle scale.a cross-scale modeling approach.i.e., CFD-DEM or CFD-DPM.is established for describing a wide variety of complex reacting flows in multiphase reactors.Representative processes,including fluid catalytic cracking(FCC).catalytic conversion of syngas to methane.and coal pyrolysis to acetylene in thermal plasma.are chosen as case studies to demonstrate the unique advantages of the theoretical scheme based on the integrated particle-scale information with clear physical meanings.This type of modeling approach provides a solid basis for understanding the multiphase reacting flow problems in general.