Adding Biomass to Coal in the UK
One of the easiest ways to utilise biomass to produce energy, is to partially substitute biomass for coal in a traditionally coal-fired power plant. Yorkshire based Drax power plant intends to do exactly that, making Drax the largest biomass producer of electricity in the UK.
Executives from Yorkshire-based Drax 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 will start later in 2008 and the first part of the facility is expected to be completed by the end of 2009.Biomass CHP or cellulosic electricity, is clearly the most efficient way of producing energy from cellulosic biomass. The only reason for taking the less efficient route of producing liquid fuels (BTL) from biomass is that most of the transportation infrastructure cannot run without liquid fuels, at this time. It will likely require 20 years or more to achieve significant conversion of transportation from liquid fuels to electric drives running on stored electricity. Even fuel cells will probably need to run largely on liquid fuels such as methanol, for the next 10 to 20 years minimum.
...Neil Crumpton, 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."
...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.
"When you burn just a few per cent of biomass, you can afford to use exactly the same lines as coal," said Patrick Fragman, managing director of Alstom, the company that will build the biomass processing plant at Drax. But, for a higher percentage, he said, dedicated infrastructure is needed.
Peter Emery, 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.
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. __Guardian