An interim evaluation of the Green Deal bottom ash programme has shown that the participating companies are well on their way to achieving the programme’s objectives. The companies are using innovative technologies to improve the quality of bottom ash so that this secondary raw material is suitable for useful applications without the need for isolation measures. “This gives bottom ash a positive value allowing it to compete with primary raw materials,” says Jaap Pranger, AEB’s CFO, in his capacity as chairman of the Waste-to-Energy Department of the Dutch Waste Management Association (WMA).
Green Deal bottom ash programme
The Dutch waste management sector plays a pioneering role in Europe with regard to the improvement of bottom ash quality. “The innovations in our sector have attracted interest from various EU member countries, including Denmark, Sweden, France and Austria,” Pranger explains. “This is another way in which the Green Deal bottom ash programme gives the secondary raw material a positive value. The Dutch waste management sector is able to export its knowledge and expertise.”
A freely applicable building material
Bottom ash is a residual by-product of waste-to-energy plants (WEPs). It has been used safely in civil engineering projects for more than twenty years, where it is used instead of primary raw materials like sand and gravel. So far, the material has been used as an ICM (Isolation, Control, Maintenance) material according to the regulations set out in the Dutch Soil Quality Decree. The Green Deal programme agreed between the Dutch Waste Management Association and the Dutch government specifies that at least half of the bottom ash produced will be suitable for use as “freely applicable building material” (not just as ICM material) in 2017.
AEB Amsterdam, ARN, Attero, AVR, EEW Energy from Waste Delfzijl, HVC Groep, Omrin, SITA Nederland and Twence have signed up to the objectives set out in the Green Deal. The new technologies being developed by these companies to improve the quality of the bottom ash they produce, come down to integral washing or separation of dry fractions that are then processed separately. These methods result in a building material that can be used to replace sand and gravel in concrete construction. The interim evaluation was carried out on behalf of the Waste Management Association (WMA) by PricewaterhouseCoopers (PwC).