Cleaner power from coal

High-ash coals have been widely used for generating power and industrial steam in India and Turkey, and this is likely to continue for the coming decades. Unfortunately, burning coal directly to produce steam for a turbine produces high levels of pollution.

Coal gasification is an alternative to its direct combustion, providing cleaner power. The EU-funded project OPTIMASH (Optimizing gasification of high-ash content coals for electricity generation) is optimising a relatively new technology called integrated gasification combined cycle (IGCC) for the properties of Indian and Turkish coals' ash content.

The overall project goal is to optimise the operating conditions of IGCC technology. The consortium has found that a fluidised bed gasifier is the optimal gasification technology for converting high-ash coals. Indirect and direct fluidised bed gasification processes are being evaluated and tested.

To characterise ash content, researchers have conducted chemical and thermal analysis as well as petrographic analysis, and carried out particle size distribution and heavy liquid tests on coal samples. Using thermal analysis and mass spectroscopy methods, researchers have also studied pyrolysis, combustion and gasification kinetics. This work has been supported by computational fluid dynamics models. Design of the gasifier has started.

As a low-carbon coal technology, the OPTIMASH pilot gasification system will contribute to reducing harmful emissions from power plants. IGCC is a particularly attractive choice given that it can be combined with technology for capturing carbon dioxide and sequestrating it in fields.