Employing a Kinetic Monte Carlo (KMC) simulation algorithm, tandem polymerization of ethylene is thoroughly investigated. To do this, the evolution of ethylene copolymerization is evaluated in terms of ethylene consumption and 1-hexene accumulation. The results obtained are in good agreement with the existing experimental kinetic data. It is revealed that the pre-trimerization time is a key factor in controlling the architecture of copolymer chains. Moreover, the precise computation of instantaneous and cumulative comonomer contents along with the chemical composition distribution of simulated copolymers provides a comprehensive image of the growing chains during tandem polymerization. A well-established crystallization fractionation (CRYSTAF) analysis mathematical model is applied to delve into the molecular architecture and the crystallization fractionation behavior of the produced polyolefins. (c) 2014 Elsevier Ltd. All rights reserved