It’s the new alternative fuel — decommissioned turbines. There are 21,000 wind turbines in Germany alone at the moment. With 15,000 tons a year of old blades expected to be dumped by 2019, it’s a real problem to get rid of them. The EU says they can’t be dumped in landfill. Here’s the perfect solution. Chop them, shred them, then deliver the fibreglass reinforced plastic to the local cement plant. The resins hold 15MJ per kilo. “One tonne of resin saves 600 kg of coal at the cement plant!”
It’s a win-win all round. Residents get rid of the bird chopping towers, the cement plant gets energy, and the windmills may, possibly for the first time, save some CO2 for the Greens. What’s not to like?
Indeed this is recycling you can like. The raw materials in old blades can even be used in the cement too.
Wind Turbines make good alternative fuels for cement production.
Global Cement Magazine Sept 2014 page 10
Since 2009 Zajons has been working with Holcim’s Geocycle division to process and recycle wind turbine blades for use as an alternative fuel and raw material in the cement industry. The Cross-Flow Shredder has been customised to effect 100% recy cling of fibreglass-reinforced wind turbine blades.
The huge number of new wind farms is one catalyst for this, coupled with the fact that decommissioned wind turbine blades can no longer be sent to landfill. This has been prohibited in Germany since 2005 on the back of EU regulations. Conventional low-temperature waste incineration is not an option as melted glass fibres would cause the blockages in the system. A wind turbine has a maximum life-span of 20 years.
“By 2019 we expect decommissioned wind turbine blades to exceed 15,000t/yr,” said Lempke. “There are major technical issues involved in recycling these huge blades, the first being transporting the blades to the reprocessing plant. We saw the blades into transport-friendly lengths of around 10m on-site at the wind farm and use a special liquid to minimise dust, thus preventing site contamination.” Sawing the blades into manageable lengths on-site significantly reduces transportation costs (Figure 4). Once at the reprocessing plant, the metal components are removed and the blades are sawn into smaller pieces.
Suction, filter and watering technologies largely prevent dust production. The blade is ground in a Cross-Flow Shredder. The resulting material, which is primarily composed of fibreglass reinforced plastic, is homogenised and delivered to a nearby cement plant. The calorific value of the resins (around 15MJ/kg) is harnessed in the cement calciner and is used to thermally degrade the lime. One tonne of resin replaces 600kg of coal at the cement plant.
Even better, the silicon dioxide in the fibreglass can be used instead of sand:
Ash constitutes >50% of the wind turbine blade, which is mixed with the raw meal in the calciner. This is where an additional benefit comes into play. The ash contains SiO 2 from the fibreglass, which is used in place of sand in the raw material mix. In addition to wind turbine blades, other fibreglass materials can also be used once ground. Thus, valuable raw materials can be substituted and supply conserved.
Using this method, more than 1000 wind turbine blades have been processed into homogeneous refuse derived fuel (RDF) for cement kilns. Working closely with partners like Holcim has enabled Zajons to develop innovative solutions for the manufacture of alternative raw materials for cement and incineration feedstocks, thereby generating significant added value for its cement industry customers.
h/t to Cementafriend