Reuse, remanufacturing, recycling: the case of glass for buildings

5. Closed-loop recycling should become the predominant sustainable end-of-life option for flat glass products

While the reuse and remanufacturing of products offer specific sustainability benefits and stand higher in the waste hierarchy (see Figure 1), recycling is likely to become the predominant end-of-life option for most flat glass products. This is due to the various limitations to the reuse and remanufacturing of flat glass products, which are explained in the previous sections of this paper.

The closed-loop recycling of flat glass products offers many benefits in terms of CO2 emissions reduction and saving resources from virgin raw materials. The use of ‘cullet’, i.e., recycled glass, as raw material is critical for the glass industry. Because it requires less energy to melt, it contributes to reducing energy consumption and ‘heat-related CO2 emissions. It also helps reduce ‘process emissions’ as using cullet saves 1.2 times the same amount of raw materials.

The share of recycled glass (i.e., cullet) used as raw material has increased over the last decade thanks to collection schemes set in place by the industry with transformers and recyclers. Moving from 20 to 26% of cullet has made possible a further reduction of 6% of CO2 emissions[9].

The flat glass industry is actively looking for ways to recover more flat glass cullet to produce new flat glass. This requires better dismantling, sorting and cleaning of end-of-life glazing to reach quality levels good enough for remelting into new flat glass products. Glass for Europe is collaborating with EU authorities to that end[10].

To reap all the sustainability benefits of flat glass recycling, Glass for Europe supports ‘closed-loop’ recycling whereby end-of-life building glass products are recycled into new flat glass products (see Figure 2). Recycling flat glass into other types of glass products or recovering it for use as aggregate are forms of downcycling and should be avoided.

Please read the Glass for Europe paper on closed-loop recycling of flat glass for more information.[11]