Oxy-co-gasification of coal and biomass in an integrated gasification combined cycle (IGCC) power plant

摘要

Oxy-gasification, or oxygen-blown gasification, enables a clean and efficient use of coal and opens a promising way to CO_2 capture. Moreover, oxy-co-gasification with biomass implies the use of a renewable resource and additional CO_2 reduction. Proper gasifier operation is a key issue in both techniques. A model of an entrained flow gasifier, validated with nearby 3000 actual steady-state operation data (4800 h), is used to study co-gasification of coal, petroleum coke and up to 10% of several types of biomass. As a result, influence of fuel variation in gasifier efficiency and modifications in operation that should be made in oxy-co-gasification are obtained. The model is also used to build reference operation maps (graphs where the main gasification parameters are related to the degrees of freedom that the operator has). A general method for building experimental operation maps only from plant data has also been applied to the gasifier. Tendencies of the maps are the same of those of the model-made maps. In conclusion, oxy-co-gasification is possible providing that operation is adapted. A validated model can be very useful to predict operation points for new fuel mixtures. Operation maps are practical tools that help to operate and diagnose a system (e.g. a gasifier). They allow to understand how it works, to optimise its operation and to avoid wrong operation that may cause plant shut off.