Chemical engineering systems typically involve three levels of chemistry

chemical engineering and process system engineering. Each level consists of micro-

meso-and macro-scales

such as the particle

particle cluster and reactor scales in the chemical engineering level. The evolution of the micro-scale elements is naturally described by discrete simulation. However

due to the large number of elements existing in these systems

engineering simulations are mostly based on continuum methods which describe their statistically averaged behaviors and overlook the effects of meso-scale structures

leading to low accuracy and predictivity. This review will explain how this problem can be tackled in a systematic approach that keeps the structural consistency of the problem

physical model

software and hardware

and will demonstrate how discrete simulations with high accuracy

capability and efficiency can be carried out for engineering systems

such as complex molecules

granular flow

and gas-solid fluidization. Realization of virtual process engineering (VPE) is prospected finally.