5 October 2017

Heros Sluiskil makes great sustainable steps with granova®

Granova® from Heros Sluiskil is a product that replaces conventional aggregates used in the production of concrete. Heros Sluiskil process Incinerator Bottom Ash (IBA) – residue consisting of non-combustible materials after the burning of household waste in a municipal solid waste incinerators across the Netherlands – so that this waste can be used instead of sand and gravel extracted from the earth. With a MKI of 0.071 euro per tonne and a 0.597 kg CO2 emission, granova® is significantly better for the environment than sand and gravel.

Green Deal: freely applicable

All Dutch municipal incinerators have committed to a ‘Green Deal’ to achieve agreed sustainability goals by 2020, so finding a way to re-purpose their waste is very important. However, in its raw state, IBA contains contaminants that make it potentially hazardous if used as a concrete aggregate and so it has to be processed to make it into a product that can be legally used in construction. Heros has invested heavily in research and development to make a building material of sufficient quality to be certified as free to use but their work has been successful. Martin Stouten, development manager at Heros Sluiskil said: “We have produced the first trials of the renewed Granova Combimix. These have been tested by the Rijkswaterstaat (the body responsible for the design, construction, management and maintenance of the main infrastructure facilities in the Netherlands) and the test results met all requirements. This means that Granova Combimix is listed in the Rijkswaterstaat database of approved materials. This means that we have converted a hazardous waste into a usable building material. This greatly increases applicability and we moved one step closer to a closed circular economy. The challenge is now to have sufficient production capacity as soon as possible and to develop new markets at the same time.”

Hard figures on environmental pact

Heros Sluiskil worked together with Ecochain during the development of the renewed Granova Combimix. In addition to reviewing the eco-efficiency of their current production processes, Heros Sluiskil also used Ecochain to model new processes for converting IBA and identified ways in which this could be made more efficient and so further reduce environmental impact even further. Martin Stouten says “Ecochain gives us hard data on the environmental impact of our products, which we use to continuously improve our processes and monitor progress. Also, Ecochain is well suited for reporting our performance and progress to customers and stakeholders. Ecochain enables us to prove that granova® is a sustainable alternative to conventional aggregates.“

- Sherman Tobias