Abstract

This paper endeavours to give an objective account of the background to gasification based processes for power generation with carbon capture. Such processes are a development of IGCC plant designs in which coal or heavy fuel oil is first gasified and to produce a fuel gas for a CCGT unit. Although the IGCC concept does lend itself, very well, to high levels of carbon capture, and could lead the way to the hydrogen economy, it does create some important technical challenges. In particular, it restricts the type of gasifier that can be used to the high temperature entrained flow type. Furthermore, because the fuel gas that is produced in an IGCC consists of over 90% hydrogen, this will reduce the efficiency of the plant. Given that the hydrogen economy is some decades away, a more reasonable gasification-type option would be to produce natural gas from coal. This substitute natural gas could be used as a fuel gas in standard gas turbines (with no efficiency penalty) and can be used to supplement the UK and EU fast declining reserves of natural gas. The main drawback is that only about half as much carbon would be captured as in the IGCC “clean coal” systems currently being envisaged.