Aliancys promotes co-processing as viable recycling route for glass filled composites

Co-processing is the simultaneous use of composite regrind as raw material and as a source of energy in cement manufacturing, replacing natural mineral resources (material recycling) and fossil fuels such as coal, petroleum and gas (energy recovery). The co-processing process has been recognized by the EU Commission as recycling route for composites.

Already in 2012 Aliancys worked with cement manufacturer Holcim/ Geocycle to better quantify the ecological benefits of using composite regrind for making cement. For this purpose, the companies used a detailed LCA model developed in close collaboration with the Swiss Federal Institute of Technology (ETH) in Zürch, Switzerland.

Glass filled composite regrind can be used up to levels of 75% of raw material weight in the process. Interestingly, it was calculated that at those levels the addition of composites allows reducing the CO2 emissions of the cement clinker production with 16%. This is a major reduction for a process that inherently generates fair amounts of CO2 because of the chemistry involved. Additional detail on study and results can be found in the new Aliancys brochure. Click here to view.

While recycling composites through co-processing may be a viable solution from a technical, environmental and economic perspective, it does require a fair volume of composite regrind in order to have a stable and consistent raw material stream. A typical cement manufacturing plant produces 5000 tons of cement clinker per day. If half of that volume would be composite regrind, it translates to ~800kT per year.

The current volume of composite regrind generated annually in Europe is estimated to be in the order of 80-100kT. This assumes a 5% waste in composite manufacturing processes (which may be on the high side), and an average composite component working life of 20 years (average across end-use applications). So for the short term, the composite regrind quantity available will only be used in a small number of cement manufacturing plants. Taking into account the backlog for processing old wind turbine blades and end-of-life boats, it can be expected that the composite end-of-life streams will further increase in the coming years.

Two companies in Europe are actively involved in the conversion at a larger scale of glass reinforced composite components into regrind. Neowa (www.neowa.eu) is collecting parts from Northern Germany and Denmark in its operation near Bremen (Germany), and combining the composite regrind with plastic and paper waste stream for achieving a constant caloric value. The company supplies the resulting mix to the nearby Holcim plant in Lägersdorf (Germany). In 2016 the volumes of composite regrind will be in the order or 9-10 T.

www.aliancys.com