Sensitivity Analysis for the Efficiency Improvement of a Light Integrated Gasification Fuel Cell Power Plant

The solid oxide fuel cell (SOFC) is recognized as one of high efficiency plants of electricity generation for a sustainable future system with low environmental effects. In term of fuel flexibility, SOFC is suitable for direct use of syngas from a coal gasification plant.  The application of integrated SOFC in coal gasification based power plant, such as a light integrated gasification fuel cell (L-IGFC) power plant, could be one of the most promising coal energy conversions system providing high electrical efficiency with low CO₂ emitted to the atmosphere. The system consists of a coal gasifier and intermediate temperature SOFC module on the top of a steam turbine. The syngas produced by pressurized coal gasifier is used in SOFC module after heat recovery units and cleaning processes. To minimize exergy loses in the plant, the dry gas desulfurization (DGD) unit which can operate at elevated operating temperature and pressure are adopted. The heat generated by SOFC module can be utilized by the heat recovery steam generator providing high quality steam for a steam turbine. In this work, thermodynamic analysis is carried out to develop process integration of the L-IGFC plant. The overall plant analysis of a baseline system design is performed by identifying the major factors effecting plant performance by using the Aspen Plus simulation. The Aspen plus simulation is then used to perform parametric analysis to identify optimum values for the maximum system efficiency. Modifications to the baseline system design are made in order to determine the most viable system designs based on maximizing total system efficiency.