Why Is Continental Using Risotto Rice in Tyres?
Founded in 1871 as a rubber manufacturer, Continental is now one of the world’s largest tyre businesses.
It produces millions of tyres every year and is now focussed on the use of renewable and recycled materials inside them.
The husks of Italian risotto rice are now an ingredient, replacing silica from quartz sand in tyres.
“Innovation and sustainability go hand in hand at Continental,” says Jorge Almeida, Head of Sustainability at Continental Tires.
“Using silica from the ashes of rice husks in our tires shows that we are breaking completely new ground – without compromising on safety, quality or performance.”
What raw materials are used in tyres?
Typically, tyres are made from a mix of natural and synthetic rubbers.
Natural rubber is harvested from rubber trees that can absorb CO₂ during their growth, but unsustainable expansion of rubber plantations can contribute to deforestation and harm biodiversity.
Synthetic rubber uses petroleum and has a high carbon footprint.
Tyre wear during use can also release microplastics and nanorubber particles which may pose risks to ecosystems, wildlife and human health.
Carbon black is used to reinforce rubber and provide strength alongside the black colouring of tyres.
Silica is used to improve fuel efficiency and wet grip.
Continental’s sustainability efforts
Continents is looking to increase the use of renewable and recycled materials in its tyre production.
It achieved a 26% share of these materials in 2024 and expects this to increase to between 28-29% in 2025.
By 2030, Continental hopes to increase this share to more than 40% while maintaining consistently high safety and performance standards.
Alongside changing the materials used in its tyres, Continental is making its tyre production more sustainable.
In May 2024, the company announced it can produce CO₂ neutral tyres at its plant in Lousado, Portugal.
Natural gas was previously used as the sole energy source for steam generation at the plant, but this was swapped for self-generated solar power and renewable electricity from the power grid.
"In Lousado, we are demonstrating that even very large tire plants can achieve CO₂ neutral production,” said Dr. Bernhard Trilken, Head of Manufacturing and Logistics at Continental Tires.
“To do so, the availability of renewable energy sources at competitive prices is crucial.
"We are preparing all our plants so that they can use as much renewable energy as possible.
“The commissioning of our electric steam boiler in Lousado is the start of an exciting learning curve."
Silica from rice husks
Rice husks are an agricultural byproduct of rice production, both in the Asian agricultural industry and Italian risotto rice production.
Traditionally, silica is obtained from quartz sand and has been used in many tyre rubber components for decades.
Continental says that the use of silica has helped to reduce braking distances by nearly 50%.
It also helps to reduce rolling resistance, therefore reducing energy consumption and emissions.
Rice husks are rich in silica and when incinerated produce rice husk ash.
This is then treated to remove impurities and can be used in tyres.
Bio-based and recovered carbon black
Carbon black can account for up to 20% of the total weight of a passenger car tyre and increases the strength of rubber.
Continental uses around a dozen different types of carbon black in different parts of tyres.
Carbon black is made of elemental carbon in the form of fine black powder particles and traditionally produced by the incomplete combustion or thermal decomposition of hydrocarbons.
Bio-based carbon black is derived from organic oil instead of crude oil, like tall oil from wood pulp manufacturing.
It can also be produced using recycled raw materials, such as recycled pyrolysis oil from end of life tyres.
Continental is working to include more bio-based and recovered carbon black in its tyres and has partnered with Pyrum Innovations to optimise and expand the recycling of end of life tyres.
The thermolysis technology used extracts carbon black from end of life tyres and prepares it for reuse in new tyre production.
