Glass is an essential component of modern architecture. Flooding our built spaces with daylight, it improves aesthetics and minimises artificial light sources, whilst shielding us from whatever the weather throws our way.
However, behind its apparent simplicity and versatility lies a highly energy-intensive manufacturing process. Typically, to form glass, a mixture of sand, soda ash, and limestone must be melted, and the temperatures needed for this are high. So high, in fact, that in nature glass is only formed from ultra-high energy events such as volcanic eruptions, meteorite impacts, or lightning strikes.
Given the considerable energy demands associated with traditional glass production, the industry has recognised the need to reduce its environmental footprint. Below are some of the bold innovations transforming the sector.
A Glass Act
Glass is the ultimate circular material. It is “infinitely recyclable”, which means that it can be melted and reformed into new products endlessly without a loss in quality or purity. This is in sharp contrast to plastics, where the quality reduces with each cycle due to degradation of the polymer chains.
Utilising this infinite recyclability, Saint-Gobain Glass’s Glass Forever programme is a circular-economy initiative designed to transform how sheet glass is recovered, recycled, and re-used in the construction industry. Usually, waste glass (e.g. from window units) ends up in landfill. Glass Forever tackles this by creating a closed-loop system that collects waste glass, processes it into high-quality cullet (crushed glass), and feeds it back into the production of new, high-performance products. By using recycled cullet, the consumption of virgin raw materials, and the energy needed for glass manufacture, is reduced.
Included in this process is Saint-Gobain Glass’s patented glass-crushing technology, which allows waste glass to be processed quickly and to a high specification. One example being a mobile crushing machine that is housed within a recycled shipping container for easy transportation “to significant deconstruction sites throughout the UK”.
The Glass Forever programme aims to simplify and encourage recycling within the construction industry, and it represents just one of the contributions that is reshaping the sector.
Seeing the Wood through the Trees
It may be hard to believe, but in the pursuit of glass alternatives, researchers have discovered a chemical process that increases the transparency of wood.
To understand how this process works we first need to understand the structure of wood. The main components are cellulose and lignin, and their combined structure can be compared to reinforced concrete. Cellulose provides a network of reinforcing fibres to provide strength (like the steel bars in reinforced concrete). Lignin – which gives wood its characteristic colour – fills the space between the cellulose fibres to provide rigidity and strength.
In one example, researchers at the KTH Royal Institute of Technology (KTH) in Sweden have made transparent wood by removing lignin – which strips the wood of its colour but preserves the cellulose framework – and then replacing the removed lignin with a transparent polymer to restore strength and provide a transparent composite material.
KTH have recently advanced the technology even further. Developing an entirely renewable variant with improved translucency by infusing the delignified wood with a biopolymer derived from citrus fruit.
While transparent wood is undoubtedly a fascinating and promising innovation, it remains at an early stage in terms of commercial viability. Large-scale adoption is yet to be seen, but its unique combination of sustainability and performance could pave the way for a new generation of building materials.
Fuelling the Fire
Traditional glass production is energy intensive and relies on fossil fuel furnaces. Glass Futures is trying to change that with their vision to make “a sustainable future, enabled by glass”. At their £54 million Global Centre of Excellence in St Helens, Glass Futures operates a pioneering pilot furnace uniquely designed to run on low-carbon energy sources including green electricity, hydrogen, and biofuels.
This forward-thinking initiative is not only reducing emissions associated with glass production but is also fostering collaboration across the industry. Glass Futures has partnered with leading academic institutions, such as the University of Sheffield, to advance research into low-carbon manufacturing processes and innovative materials. These partnerships are instrumental in accelerating the adoption of greener technologies, ensuring that the glass sector continues to evolve in step with the UK's broader commitment to sustainability and net-zero targets.
The Glass is Greener
Innovation is driving the glass industry towards a more sustainable future. The pioneering materials and advances in low-carbon manufacturing described above represent just a few of the examples that are paving the way to a future where sustainable construction is an integral component of our built environment.
For more on sustainable construction materials, check out my blogs on eco-friendly insulation and low-carbon cement.
Rebecca is a UK & European patent attorney specialising in the chemistry and materials fields. She works at all stages of the patent lifecycle including invention capture, drafting, prosecution, and opposition proceedings. Rebecca is passionate about advancements in green chemistry, in particular green polymer materials. She has written several articles on this topic, reflecting her keen interest in emerging technologies.
Email: rebecca.blundell@mewburn.com
