Optimisation of Integrated Gasification Combined Cycles in Refineries

In this paper, a systematic methodology has been presented for the optimal integration of the IGCC systems with the exiting refinery infrastructure, the hydrogen network and the utility network. The proposed approach determines the new unit investment scheme for the existing refineries, as well as operational strategies of all the units in order to maximise the annual profit taking into account the annualised capital cost. The proposed methodology follows a two-stage procedure, namely analysis stage and optimisation stage. The analysis stage screens among various integration alternatives and identify the promising options considering the trade-off between the economic and environmental benefits and the capital expenditure. Because only economically viable options are included, the superstructure will be potentially much smaller than a general superstructure which includes all the candidate options. With a reduced superstructure, the mathematical optimisation problem is formulated as an NLP model which can be solved effectively even for large problems.