Glass is not biodegradable at all and it takes hundreds of years to disintegrate. When a glass bottle is thrown away, it will be around for thousands of years. If it is recycled, the process requires a tremendous amount of energy. Now there’s a third option.
A method to extract liquid silicate from waste glass has been developed by University of Queensland PhD candidate Rhys Pirie and Professor Damien Batstone. Once extracted, the material can be used to make thousands of everyday products, from concrete sealers and fertilizers to detergents and toothpaste.
Professor Batstone from UQ’s Advanced Water Management Centre specializes in converting waste into high-value products. Mr. Pirie was inspired to look into the possibilities of glass recycling after having a conversation with the professor. Amusingly enough, the pair drew inspiration together from ABC’s War on Waste series.
The pair of scientists realized that tons of glass waste are left unused because the pieces are too small to even be sorted for recycling. That’s when the idea sparked. Knowing that silicate is widely used in a variety of industries, but it is also the main component of glass, they decided to figure out a process in which to extract it from the glass. By doing so, they would be turning the unusable glass waste into a super resource!
This new process has the potential to save tens of millions of tonnes of glass from going to a landfill every year. The method also leaves behind little waste, with nearly all of the glass being turned into saleable products. Not only that, but it is cheaper to recycle the glass this way, by converting it to a silicate stockfeed, than it is to recycle it back into glass again, as new objects.
Mr. Pirie said:
“We estimate the process is more than 50 per cent cheaper than conventional ways of producing silicate. It requires less energy, raw materials and capital, and that’s before you consider the reduced social and economic costs compared to landfilling material.”
This is an exciting prospect and a catalyst for the movement towards circular economies that produce little to no waste. This is the sort of forward-thinking that is going to improve our lives in the world. It could easily be one of the building blocks to sustainable development if they find industry partners to commercialize the idea and turn it into an applicable solution.
Mr. Pirie said:
“The transition towards circular economies is a movement which is gaining momentum and something I’ve always been interested in. My PhD has highlighted how we need to make use of both the raw materials in ‘waste’ streams and the energy embodied in them during manufacture. That’s what this process does and we’re pretty confident that it will create positive, far-reaching and virtuous economic cycles.”
This new method proves that waste glass doesn’t have to just be turned into new glass or left to fill up space in landfills. They are hopeful that industry will be interested because the method frees up a lot of useful materials that can be used in a huge variety of products from construction materials to fertilizers and even cosmetics.