Site visit to TNB (Tenaga Nasional Berhard) Janamanjungs Stesen Janakuasa Sultan Azlan Shah Power Plant – Manjung

The Asian sub-bituminous coal user’s (Asian SBC) meeting in Penang, Malaysia, began with a site-visit out to Perak, 3 hours away, to visit the Manjung coal-fired power plant. Manjung unit 4 will be the first supercritical boiler in Malaysia and will be on-line by 2015, providing an additional 1000 MW to the existing 2,100 MW sub-critical output. The whole Manjung plant will then provide around 10% of total Malaysian energy requirement. If the plant runs at partial load it will not achieve design efficiency and there will also be a tripping risk and so it is planned that the plant will be run as baseload. The new plant will have OFA for NOx control and sea water FGD.

The existing plant (3 units of 750 MW each) has sea water FGD covering 60-65% of the total flue gas emissions from the 3 existing sub-critical units. The plant also fires low sulphur (0.1%) Indonesian coal. Low NOx burners (OFA) are installed. The emissions comply with the World Bank and national emission limits of 750 mg/m3 for sulphur and 650 mg/m3 for NOx (ie around 2-3 x allowable emissions in the EU).

The plant fires sub-bituminous Indonesian coals (Kalimantan) from multiple suppliers and rudimentary blending is achieved by stockpiling several shipments together. They are also considering Russian coal as the price is competitive. There are significant issues with spontaneous coal combustion in the coal supplied.

Currently the fly ash from the plant is sold for cement but, unusually, the bottom ash is still regarded as a toxic waste and requires storage in an ash pond and then disposal. However, it is hoped that a change in the legislation will allow use of the bottom ash for aggregate applications in the future.

The whole site is housed on reclaimed land in the bay, providing excellent access for Panamax coal shipments.

The Asian SBC meeting itself was well attended with over 150 delegates from 15 countries, including the UK, USA, Germany and Russia and a very healthy local attendance from coal suppliers and utilities based in the SE Asia region.