Gasification is defined as the process of reacting a carbon-rich feedstock (coal, petroleum coke, biomass, waste, etc.) with steam and oxygen to form a synthesis gas containing H2 and CO. It can be viewed globally as extremely rich combustion and usually utilizes solid or liquid feedstocks. Developing an understanding of the physical, chemical and dynamic processes involved in gasification through multiscale simulation will allow us to optimize gasifier design and plant layout, increasing reliability, availability and maintainability of gasification-based energy systems, while decreasing costs.