England aluminum complex ponders switch to biomass power

By Lisa Gibson | August 17, 2011

Faced with increasing pressure to reduce emissions, the Rio Tinto Alcan Lynemouth Aluminum Smelter, located in Northeast England’s village of Lynemouth, is considering a switch from coal power to biomass at its on-site 420-megawatt (MW) power station.

The power station produces enough electricity for the smelter and some backup power, which can be exported to the grid when it is not needed, according to John McCabe, corporate affairs director for Alcan Aluminum U.K. Ltd.

“The existing station is the most thermally efficient of its kind in Europe and is compliant with all existing legislation,” McCabe said. But legislative pressure on carbon and sulfur emissions is increasing in Europe and especially in the U.K., and will cost Rio Tinto Alcan in excess of £70 million ($115 million) per year after 2013, he added. “Faced with these unsustainable costs, we are forced to consider alternative low-carbon energy options. We have looked at all options, including carbon capture and storage but we have settled on a conversion to dedicated biomass as the most feasible and achievable in the required time scales.”

Rio Tinto is test-firing wood pellets with encouraging results, McCabe said, but the conversion to biomass is still a high-risk option and the company is pondering whether to make the investment or sell the power station to a third party who can then convert it. “Rio Tinto is conducting a strategic review of Lynemouth Smelter and Power Station, under which all options including the sale or closure of part or all of the assets are being considered,” McCabe said.

The capital cost of the conversion is estimated to be more than £50 million, with an additional annual feedstock cost of £170 million. The plant will consume about 1.8 million metric tons (2 million tons) of wood per year, the majority of which will be imported to the U.K., McCabe said. Running on wood only would reduce the power produced to 330 MW, requiring imported power to meet the smelter’s needs. The company plans to have the conversion completed by April 2013, regardless of who pays for and owns the power station.