Drax has an expansive fuel delivery and processing network. The part-conversion to biomass necessitated construction of additional storage facilities on site, along with a supply chain from North America.
Coal Handling and Storage
The original fuel processing and storage facilities at Drax is a relatively standard affair, similar to those at other large power stations in the UK. The coal was delivered via rail from the nearby collieries, mainly Kellingley, but since the closure of the UK’s last deep-level mine in 2016, coal is now imported from overseas. A merry-go-round system allows trains to be unloaded without stopping, before returning to collect more coal. Coal can be stored outside, open to the elements until it is ready to be used. Two bucketwheel excavators load coal from the stacks into the conveyor network to feed the power station.
Biomass Transportation and Handling
Biomass requires much more care when being handled and stored than coal. It must be kept dry at all times – the pellets would need to be scrapped if they became wet. In addition, the dust created while handling biomass can create an explosive atmosphere, so must be carefully controlled.
The biomass used at Drax is sourced from Louisiana and Mississippi where pelleting plants have been constructed especially for this purpose. The pellets are then transported via road and rail to the port of Baton Rouge, Louisiana where they are loaded onto 50,000-tonne cargo ships. Handling facilities at Hull and Immingham have been constructed to receive the ships. The pellets are then loaded onto specially designed trains for the final leg of the journey to Drax.
An automated rail to storage handling and screening facility was constructed, consisting of four 50m by 63m storage domes with a capacity of 11,000m3. The domes are designed to be fully water resistant, and the controlled atmosphere inside contains nitrogen to mitigate the explosion risk.