From waste to wheels: turning rice husk ash into tyres

A new process can extract valuable silica from the ash, reducing the need for energy-intensive mining

Spotted: In some countries, such as India, rice husks – the hard shells of rice grains that are a by-product of growing the crop – are used as fuel for industrial boilers and power plants. A by-product of this process is rice husk ash (RHA), and more than 20 million tonnes of RHA is produced globally each year – most of which is sent to landfills or dumped on open ground, causing a range of negative environmental impacts.

However, RHA is high in silica – an important material used across the construction, automotive, beauty, fashion, and food industries – and Gujarat-based Brisil Technologies has developed a chemical process to extract this silica from the ash.

The patented, zero-waste chemical process uses RHA as a feedstock to generate precipitated silica, including highly dispersible silica – an advanced grade of the compound. In total, the process retrieves up to 70 per cent silica from the waste ash.

Silica has many important uses, including in tyre and rubber manufacturing, aggregates and fillers for concrete, paints, insulation, and even toothpaste. But, most silica is mined from river sand, an energy-intensive and environmentally damaging process. Extracting silica from RHA with Brisil’s method could allow manufacturers to continue using the versatile material without the enormous carbon footprint.

Brisil has received an unspecified amount of seed funding from the Centre for Innovation Incubation and Entrepreneurship at IIM Ahmedabad. The startup has also set up a commercial-scale plant in partnership with a public tyre company in Gujarat.

Rice husks are not the only biomass seeing new applications. Springwise has also spotted one company pineapple scraps into fabric and biodegradable food packaging made from waste such as banana leaves.

Written By: Lisa Magloff