Drax using biomass
Monday, May 26th, 2008 | Author: News Team
It is reported that Drax, Britain’s largest power station, has launched a £50m project aimed at replacing 10% of the coal it uses with biomass. It is estimated that by mixing materials such as wood chips, sunflower husks or grasses with coal to generate electricity could reduce the power station’s annual carbon dioxide emissions from coal by several million tonnes.
In addition executives from Drax have signed a deal with Alstom to build a processing plant that could prepare 1.5m tonnes per year of biomass for use in the power station. Under the plans, biomass would be ground into a fine powder and injected directly into the power station’s coal-fired furnaces. Building work for the processing plant could start later this year - with the first part of the facility is expected to be completed by the end of 2009.
The chief executive of Drax is quoted as saying that the “co-firing” technology would deliver 2m tonnes of CO2 savings from coal and take the power station towards their overall target of a 15% reduction in carbon emissions by 2012. Last year, we set ourselves the target of 10% of co-firing of biomass - that’s equal to the output of about 500 wind turbines. In capacity terms, that’s 400MW.” If the estimates are correct then Drax could become the single biggest site generating electricity from biomass in Europe.
The chief executive added: “We think of it as the forgotten renewables technology, we think it’s very important and can deliver a significant amount of the carbon-abatement needed across the world. We are very aware that we need to tackle climate change and we firmly believe that we, as a coal station, can be part of the transition to a low-carbon economy while still delivering reliable and secure electricity supplies.”
Meanwhile an energy campaigner at Friends of the Earth, said that using biomass in power stations or combined heat and power schemes is a better use of the resource than, for example, turning it into liquid biofuels for use by diesel-engine vehicles. “Co-firing with biomass is a reasonable way forward - it’s a logical extension of what Drax is already doing and I’ve got no qualms with it on that score. If it helps build the sustainable biomass market in the UK, then all well and good.”
Currently Drax generates around 7% of Britain’s electricity needs and is one of the country’s biggest emitters of greenhouse gases. Since biomass is regarded as carbon neutral, any CO2 it produces does not count towards the power station’s total emissions; hence Drax can claim a reduction in CO2 emissions simply by mixing biomass into its furnaces.
To test whether co-firing would work, Drax has used a 2-3% mix of biomass in some of its coal-fired furnaces for several months already. In their current experiments, the biomass fuel is mixed directly into the coal as it burns but this technique would not work for larger quantities of biomass.
Furthermore, a production director at Drax, said that the new processing plant was a crucial part of the power station’s attempt to scale up their biomass usage. He also added that it would be able to handle a wide variety of biomass fuels. Although it is not widely known, different biomass materials burn in different ways, so the processing plant needs to be able to handle the materials accordingly. The resulting fuels then need to be inserted into the coal-fired boilers at different positions to ensure they burn properly. Engineers at Drax estimate that it will take 1.5m tonnes of biomass to replace the energy that comes from 1m tonnes of coal.
If co-firing coal with biomass proves successful, Thompson said that Drax would consider increasing the proportion of plant material it adds to its fuel mix, perhaps up to 20%. Drax has also committed to upgrade its turbines to improve efficiency, which it claims will deliver a further 1 million tonne reduction in CO2 emissions.
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