The summary

The GtoG project has put in place an integrated approach to C&D waste by holistic management, starting from the major refurbishment/demolition sites to the reincorporation of the recycled gypsum in the manufacturing process via the processing of gypsum waste as a secondary raw material. The project structure has been conceived to be simple and comprehensive at the same time. Indeed, the project has developed all its technical activities through three actions:

1) Action A analyzed and evaluated the current practices in deconstruction/demolition, C&D waste characterization, processing the gypsum waste for the production of recycled gypsum and its reincorporation into the manufacturing process. This action represented a sort of introduction to GtoG, where a technical, economic, environmental and legislative analysis was carried out for the different stages of the value chain.

2) Action B the project implementation actions, where five pilot projects implementing the deconstruction techniques, the decontamination and the waste qualification, reprocessing and reincorporation in gypsum manufacturing plants have been carried out in Belgium, France (2), Germany and UK. This action has been developed through the following sub-actions:

  • The 5 deconstruction projects. This activity has been implemented by the five demolishers in the project, who selected commercial buildings, where gypsum products and systems have been audited and deconstructed, using various techniques and practices.
  • The 5 recycling projects. In this sub-action, the plasterboard wastes supplied by the deconstruction project have been processed and then transferred as recycled gypsum powder to the five manufacturer’s plants to be reincorporated in the production process.
  • The 5 reincorporation projects. Within the sub-action, the recycled powder supplied by the recyclers has been re-incorporated into the production process. The recycled gypsum powder used during the reincorporation phase has also been tested by a laboratory.

3) Action C which monitored the impact of the project actions. The end results have been a report on best practice indicators, the assessment of the carbon footprint of gypsum: landfilling versus landfilling route and the roadmap for implementing a gypsum sustainable value chain, where an outline plan has been determined in order to achieve a more widespread implementation of gypsum C&D waste recycling.

The GtoG outcomes

The full set of the GtoG reports and deliverables are available on the GtoG website! Just click on this link and you will access a page where you can download them.

  • Preliminary study:
    - The inventory of current practices for deconstruction, recycling and re-incorporation in the manufacturing process of the recycled gypsum
  • Dismantling VS Demolition:
    -The European handbook of best practices for controlled deconstruction of gypsum system
    -The European manual of best practices for the audit of building prior to deconstruction
  • Recycling:
    - European guidelines on gypsum waste acceptance criteria
    - Guidance document for the quality criteria of the recycled gypsum Technical and Toxicological Parameters
  • Re-incorporation:
    - Techno-economic assessment of recycled gypsum incorporation into the plasterboard manufacturing process
  • Final study:
    - Report on best practices for deconstruction, recycling and re-incorporation in the manufacturing process of recycled gypsum
    - Assessment of the carbon footprint of gypsum waste recycling
    - Roadmap for future implementation of a sustainable value chain

The conclusion

Closed loop recycling involves a close collaboration among all the stakeholders throughout the entire value chain: from the dismantling and collection of plasterboard waste in buildings, via the recycling of this waste and culminating with the reincorporation of the recycled gypsum by the plasterboard manufacturing plants, in order to create a highly efficient reverse logistics.

Overall, the projects implementation:

  • Proved that re-incorporation (up to 30%) of recycled gypsum in Type A plasterboard manufacturing is feasible in practice, even under the adverse conditions of non-permanent process adjustments. The GtoG 30% target was fully reached in 2 out of the 5 plants. For the examined cases, the net average impact on the total variable manufacturing cost and energy consumption per m2 of plasterboard was found to be practically negligible taking into account the uncertainty margin of the assessment, the current market prices and quality characteristics of recycled gypsum. Potential cost benefits were levelled, mainly due to the requirement of higher amounts of relatively costly additives. From the cost point of view, process modification investments may become more attractive in the near future, depending on raw material prices and national legislations (e.g. gate fee for land-filling). Stronger economic and environmental benefits can arise in the future, when the necessary process modifications will be optimised and the recycled material quality will consistently rely with the quality specifications set by the GtoG project.
  • Proved that the reincorporation of recycled gypsum up to 30% does not noticeably affect the basic performance characteristics of Type A plasterboards; all samples were found to conform to the EN-520 Standard. GtoG made possible the collection and analysis of a significant number of recycled material and plasterboard samples from different origins, which otherwise would not have been feasible.
  • Highlighted potential production bottlenecks in terms of recipe modifications (e.g. in additives) and production process equipment (e.g. storage, feeding conveyors, recycled gypsum pre-processing etc) that may arise when the increased percentage becomes standard practice in the plasterboard manufacturing. The analysis of the impacts on individual process parameters and cost elements indicated dependence on specific feedstock and process characteristics. The outcome of the production trials allows each manufacturer to develop plans for the relevant and necessary industrial adaptations, which are costly and require further trials and time.
  • Showed that the end-of-waste status is appealing but in practice is today challenging to achieve at EU level for the recycled gypsum. Indeed, the GtoG project gave the recyclers and producers the opportunity to have together a round robin test on 20 recycled gypsum samples testing by a third party laboratory, partner to the project. It is the first time that recyclers and producers have a collaborative approach for the establishment of quality criteria for the recycled gypsum on a scientific basis. The gypsum recycling business is growing in France, the UK, Germany, Scandinavia, Belgium and the Netherlands. New recyclers businesses are emerging. This will give the Gypsum sector the opportunity to establish further collaborations, also with other recyclers across Europe, taking advantage of the lessons learnt from the GtoG pilot tests.
  • Showed that the GHG emissions between natural and recycled gypsum are minor. This minor difference means that decreased emissions derived from gypsum mining and transport of natural gypsum are almost balanced by the increased emissions from the pre-processing stage
  • Demonstrated in practice the full engagement of plasterboard manufacturers to develop recycling practices that will permit higher re-incorporation percentages in the future. For the first time, the plasterboard manufacturing industry performed controlled and synchronized production trials in five different plants in four European counties.

The overall findings and the collective knowledge-experience obtained by the manufacturers are promising and permit planning of future investigations even at higher re-incorporation percentages, above the 30% target of the GtoG project.