Ceramic industry should bring carbon reducing cold sintering process into manufacturing

As much as we want to continue to work on cutting down our personal contribution to carbon emissions into the environment, I think that the most significant difference to carbon emissions will be made by the STEM sector. It will be the discoveries of the STEM community that will ultimately drive the decarbonisation of the modern economy.

There is an understanding that the technology we need to save the planet is already there and whilst we should continue to invest in research and development, the vast amount of understanding that lies in literature needs to be brought in the public limelight and used to tackle the threat.

The technology we need to save the planet is already there

One suggestion has come from a team of researchers at the Warwick Manufacturing Group (WMG) to bring the carbon-reducing cold sintering process out of labs and into manufacturing. Let’s take this step by step. Sintering is the process of employing heat or pressure for compacting a material. Temperature and pressure are raised high enough for the particles to fuse and the material to become a solid mass yet kept low enough to prevent it from melting.

Current processes that are employed for sintering include conventional sintering, laser sintering, fast-firing sintering, liquid-phase sintering and flash sintering. Now that is a range. However, what is common amongst all these techniques is that temperatures are required within the range of 1400 to 3000°C, depending on the material and the process employed. This is where the cold sintering process (CSP) comes in. This process combines heat, pressure and makes use of water to significantly reduce the energy use of the process. Indeed, the temperatures required to produce ceramics are lowered to 300°C.

Sintering is the process of employing heat or pressure for compacting a material

The temperatures required to make ceramics are lowered from 1400°C to 300°C. Researchers made around 5 grams of ceramics in their laboratory and the manufacturers felt it safer to continue using existing methods as they can produce large amounts and rapidly produce small amounts of high-tech ceramics using existing methods.

The team of researchers in WMG at the University of Warwick have argued that manufacturers had not developed a full understanding of the potential financial and environmental benefits of using CSP in manufacturing. Researchers took a scenario-based approach to understand how the CSP may play out in the world of manufacturing rather than just research. They took three functional oxides – ZnO, PZT and BaTiO3 – which are used to produce ceramics and compared the CSP to synthesise ceramics with a range of other existing methods. They have shown that the CSP is the most economically optimal sintering process even after 15 years due to its low start-up costs. It has lower capital costs, and best return on investment and all this is in addition to the key thing we want to hear: considerable energy and emissions savings.

The Warwick Manufacturing Group is an asset to the University of Warwick where researchers work to extend the academic understanding from the labs into the real world

This makes me wonder if there are a lot of switches out there that have not been made because the processes are required to be better studied to understand their benefits. The Warwick Manufacturing Group is an asset to the University of Warwick where researchers work to extend the academic understanding from the labs into the real world.

The researchers have acknowledged that the transition from laboratory to an industry of CSP will require different facilities and instrumentation to realise its full potential, but the economic, financial and environmental benefits of the transition are huge. “The ceramic industry is an energy-intensive sector and consequently the potential to improve energy efficiency is huge”, comments Dr Taofeeq Ibn-Mohammed, who is the lead researcher on the paper, and advises that there are clear financial and environmental benefits of taking up the CSP by the manufacturing industry.