Use Of Digital Technologies And Development Of A Mobile System To Implement R-Strategies For Existing Glass In The Construction Sector

The "GLADIR" collaborative project addresses key barriers to R-strategies (focusing on: Rethink, Reduce, Reuse, Remanufacturing and Recycle) for existing glass in the construction sector and utilizes digital technologies to systematically improve its recovery, reuse and high-quality upcycling. It also focuses on innovative and circular approaches to façade systems (keyword: Design-for-Disassembly). In this way, the project contributes to the conservation of resources, the reduction of CO₂ emissions and the development of sustainable window and façade solutions.

Initial Situation

The construction and glass industries in Germany are associated with high resource and energy consumption. Around 1,670 kilotons of flat glass are used in buildings each year. Its production is energy-intensive, requiring around 1,000 kWh of energy per ton of glass and generating around 500 kg of CO₂ emissions.

At the same time, considerable quantities of cullet are generated, which to date have been insufficiently channeled back into high-value recycling loops. Of a total of around 526 kilotonnes of cullet, approximately 400 kilotons are downcycled and only 55 kilotons are upcycled to high value. In particular, post-consumer glass from demolition and modernization projects have so far scarcely found its way back into float glass production or into applications with high value-added potential. Similarly, the reuse of existing glass in new insulating glazing for façades has so far only been established to a limited extent.

The main reasons for this are technical, logistical and data-related shortcomings. A lack of transparency regarding material qualities, demolition potential and material flows hinder systematic recycling. As a result, the potential for saving raw materials and reducing CO₂ emissions has so far remained largely untapped.

Objective

The aim of the project is to systematically remove barriers to the recycling of existing glass in the construction sector. The focus is on digital tools, standardised processes and design-for-disassembly approaches, with a view to making circular processes along the value chain practicable and scalable.

Furthermore, the high-quality upcycling of glass shards is to be significantly increased: the quantity of high-quality cullet returned to float glass production is to be raised from the current 55 kilotons per year to 90 kilotons per year. In parallel, reuse is to be established in the construction sector, so that around 16.7 kilotons of reusable glass can be made available annually for insulating glazing in façades.

A further objective is to improve the data available on post-consumer glass, recycling routes and waste streams. Greater transparency is intended to lay the foundations for more efficient circular processes, robust decision-making and new business models. In the long term, the project aims to develop marketable and scalable solutions for design-for-disassembly, reuse and upcycling in the construction sector.

Approach

To achieve these objectives, the project is pursuing an integrated approach that combines technological, digital and process-related innovations. These include, on the one hand, dismantling-oriented façade designs, the standardization of pane dimensions, and life cycle assessments in accordance with ISO 14040/44, in order to systematically evaluate the environmental impacts of the solutions developed.

On the other hand, existing glass is recorded using AI-supported methods and assessed in terms of its reusability and recyclability. In addition, a mobile dismantling prototype is being further developed, and concepts for sensor technology, image processing and automatic separation are being worked on to make the dismantling and sorting processes more efficient.

Building on this, decision-making and production planning algorithms are being developed to optimize the reuse and recycling of the glass. A central data management system with standardized data formats and APIs provide the necessary digital foundation for a seamless flow of information along the process chain. This is complemented by concepts for interim storage facilities and digital marketing approaches – such as a web shop – for reusable glass containers within glass-processing plants.

The solutions developed are tested in a proof of concept and assessed in terms of their economic, logistical and environmental impact. Alongside this, publications and contributions to standardization ensure that the results are adopted in practice, on the market and within the professional community.

The "GLADIR" project is funded by the Federal Ministry for Economic Affairs and Energy (BMWE) as part of the "Application-oriented non-nuclear R&D" funding scheme under the German Government’s 8th Energy Research Programme.