Design Considerations for Syngas Turbine Power Plants

Market demands such as generating power at lower cost, increasing reliability, providing fuel flexibility, increasing efficiency and reducing emissions have renewed the interest in Integrated Gasification Combined Cycle (IGCC) plants in the Indian refinery segment. This technology typically uses coal or petroleum coke (petcoke) gasification and gas turbine based combined cycle systems as it offers potential advantages in reducing emissions and producing low cost electricity. Gasification of coal typically produces syngas which is a mixture of Hydrogen (H) and Carbon Monoxide (CO). Present state of gas turbine technology facilitates burning of low calorific fuels such as syngas and gas turbine is the heart of power block in IGCC. Selecting a suitable gas turbine for syngas fired power plant application and optimization in integration can offer the purchaser savings in initial cost by avoiding oversizing as well as reduction in operating cost through better efficiency. This paper discusses the following aspects of syngas turbine IGCC power plant: • Considerations in design and engineering approach • Review of technologies in syngas fired gas turbines • Design differences of syngas turbines with respect to natural gas fired turbines • Gas turbine integration with gasifier, associated syngas system design and materials • Syngas safety, HAZOP and Hazardous area classification • Retrofitting of existing gas turbines suitable for syngas firing • Project execution and coordination at various phases of a project This paper is based on the experience gained in the recently executed syngas fired gas turbine based captive power plant and IGCC plant. This experience would be useful for gas turbine technology selection, integration of gas turbine in to IGCC, estimating engineering efforts, cost savings, cycle time reduction, retrofits and lowering future syngas based power plant project risks.