A comprehensive modelling methodology for analysis of the kinetics of non-native protein aggregation based on general population balance model within the Extended Lumry-Eyring framework is presented. The population balance model is formulated in terms of key parameters, describing relative importance of (un)folding and aggregation kinetics of a protein in diffusion-driven conditions. Both the analytical and numerical solution provide a detailed insight on the intrinsic aggregation kinetics via time-dependent evolution of a variety of experimentally measurable quantities.