Design of biomass and natural gas based IGFC using multi-objective optimization

Integrated Gasification Combined Cycle (IGCC) and Integrated Gasification Fuel cell Cycle (IGFC) uses Syngas in fuel cells and gas turbines to produce power. Several designs have been studied and it is common to analyze different designs (one at a time) to understand which design is more efficient. In this work we propose a superstructure that has both fuel cell topping and fuel cell bottoming cycles and use multi-objective optimization (MOO) to obtain optimal designs. The capacity of the fuel cells and the gas turbines in the superstructure is a decision variable and this gives an opportunity to size the system more efficiently. Here, we use two objectives, one is the energy generated by fuel cells while the other is the energy generated by the gas turbines in MOO and the analysis of the Pareto front gives us many networks. We identified different networks that produce about the same amount of energy when biomass is the fuel. However, when natural gas is used as fuel, the fuel cell only network produces more energy than other networks. Further, it was observed that it is only possible to produce more energy in IGFCs when the combustion and gasification units are maintained at Gibbs equilibrium.