**2.1. Multi-scale model for steam cracking**

A multi-scale model is proposed in this chapter to reveal the nature of the steam cracking process and to generate a reliable and robust model for accurately predicting the yields of

**Figure 2.** Comparison of experimental and calculated feedstock component mole fractions [39].

products. The multi-scale model is built up from the molecular level, to the reaction level to the process level. The establishment of the multi-scale model is discussed in detail in the following sections.
