The pulverised coal power plant of Electrabel in Ruien has been equipped with an atmospheric CFB gasifier using air, similar to the ones in Lahti (Finland) and Zeltweg (Austria). In the Ruien gasification installation, the raw fuel gas produced in the CFB gasifier is only cooled from roughly 850 to 750°C, while pre-heating the gasification air (similar as in Lahti) and is, subsequently, directly combusted in the main boiler.

Combustion of the hot and unpurified fuel gas is performed in the lower part of the tangentially-fired 540 MWth main coal (or optionally oil or gas)- fired boiler. Steam is produced in the main boiler at 540 °C and 180 bar. With this installation Electrabel gasifies approx. 100 kton/a of wood, leading to 120 ktons of CO2 reduction and 50 ktons of coal substitution. The main fuel for the gasifier is wet (up to 50% moisture content) clean wood. Pre-treatment consists of removing metal parts and optionally crushing in order to obtain the required particle size of L+W+H < 150 mm. The gasifier capacity depends on the moisture content in the fuel and varies between 40 to 80 MWth. The main coal furnace is equipped with an ESP and, from 2006 onwards, SCR de-NOx and Flue Gas Desulphurization installations.

The installation had a hot start up-in December 2002, with gasification in January 2003. After a series of test trials in 2003, the plant has been operated continuously.