Novel Process to Produce Silica-based Material from Low Quality Recycled Waste Glass

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University of South Wales


Aerospace, Aviation and Transport, Chemical, Construction and Built Environment, Creative Industries, Electronics, Sensors and Photonics, Engineering and Manufacturing, Food and Drink, Healthcare and Pharmaceuticals, Life Sciences, Materials, Agriculture

About The Opportunity:

Silica is a naturally occurring mineral composed of silicon and oxygen, the two most abundant elements in the earth's crust. It is purified and processed into either granular or beaded form.

Silica gel is a chemically inert, non-toxic material made synthetically by mixing a sodium silicate solution with a mineral acid, such as sulphuric or hydrochloric acid. Silica gel has an internal network of interconnecting microscopic pores giving a typical surface area of 700-800 square meters per gram allowing it to adsorb moisture and moisture vapour.

Commercial applications are mainly in industry sectors where the control of moisture and relative humidity are critical e.g. electronic equipment, pharmaceuticals, medical devices, food and beverage industry, aerospace and defence.

There is growing pressure in the UK for better use of resources and the development of a ‘circular economy’ where more materials are recycled and less resources are used. Defra calculates that businesses in the UK could benefit by an estimated £23 billion per year through more efficient use of resources. McKinsey calculates that globally the savings could be in the region of £3.7 trillion per year.

Current glass usage in the UK is approximately 3.6 million tonnes per year and using present technology the glass industry has the capacity to recycle over a million tonnes per year. The majority of waste glass or glass cullet (75-80%) goes to re-melting for manufacture into e.g. bottles. This represents the highest value income stream for the recycling companies. Not all glass can be recycled into the production of new glass because of the presence of contaminants or an imbalance in the colour. What remains is supplied to manufacturers to produce e.g. insulation and sound proofing materials.

However, some of the glass cannot be used in this way either and this is currently crushed and sold as low value aggregate for use e.g. in construction or as a road laying material. Both of these are low value end products. The process developed therefore could provide the materials recycling industry with the opportunity to create a higher value product from waste glass and exploit new markets. 

The University of South Wales has developed a novel process in which a silica-based desiccant can be produced from a stream of low quality waste glass thereby providing for the need to create a higher value product from waste glass. As the material is produced from a locally sourced low quality waste glass stream, the process has the potential to lessen dependence on importing silica and sourcing silica unsustainably. In addition, the process is much less energy intensive, requiring temperatures never exceeding 120°C and only requiring ambient pressures. The process is potentially lower energy and therefore more cost effective than the conventional silica production process. It has already been shown that the material produced by this process meets the British Standard as a silica gel desiccant.

Key Benefits:

  • Energy saving – temperatures used in the technical solution are much lower than in the conventional process therefore saving energy and resources, reducing carbon footprint.
  • Utilises a waste product that currently only goes into the manufacture of a low value end product.
  • The end product of the proposed technical solution is higher value and therefore more beneficial to the economy than the current end product.
  • Replaces natural resource with a waste product.
  • The end product from the technical solution has at least the same performance as silica which is currently available.
  • The end product from the process is of a similar performance level to those commercially available.
  • The moisture adsorption level meets those required by British Standards.
  • The use of waste glass in the process means it can be manufactured in the UK.


  • The main market under consideration is for silica gel as a desiccant. Commercial applications are mainly in industry sectors where the control of moisture and relative humidity are critical e.g. electronic equipment, pharmaceuticals, medical devices, food and beverage industry, aerospace and defence.

    However, other market applications have been identified if the technical solution can be developed in different ways including specialty silica, silica for chromatography and other applications such as matting agents for paints and coatings; inks and printing; digital print media; an abrasive in toothpaste; flavour carriers for perfume and oils; and as a free flow agent in powdered food.



The university is seeking licensing and collaborative research partners.