U.S. tire maker Goodyear Tire & Rubber Co. plans to use silica extracted from rice husk ash, which is cheaper than extracting it from sand. Silica also helps reduce the rolling resistance of tires by about 20% compared to conventional carbon black-filled tires. Nabeel A Khan recently met with Surendra Chawla, Goodyear’s global head of research and development, who has been with Goodyear for 34 years. He said Goodyear is working with NASA on airless tires. Excerpts from the interview:

How did the idea of extracting silica from rice husks come about? What are the advantages of this technology?

The concept was presented at the U.S. Small Business Innovation and Research Conference. Here we saw a small entrepreneur come up with the idea of extracting silica from rice husk ash. So our instinct was to look for these opportunities in rice-growing regions such as China, India, Brazil and even the United States. We found scientists at many research institutes working to extract silica from shellfish. What can shells do? About 20% of rice is husk. That’s a huge amount. So what they do is they burn this husk to generate electricity. When the shell is burned to generate electricity, what is left is ash.

How cost-effective is it compared to extracting silica from sand?

There are two aspects to this. Certainly, the cost is lower. However, more importantly, the energy required to extract silica from traditional sources such as sand is much higher. In order to extract silica from sand, the sand must be heated to 1400 degrees Celsius.

We don’t yet have a plant to produce silica from shellfish; it’s just a pilot plant. However, the power and temperature required to extract silica from volcanic ash is only 100 To extract silica from sand requires 1400 degrees Celsius degrees Celsius.

What are the advantages of using silica in tires compared to conventional carbon black?

Traditionally, we have used carbon black to strengthen rubber. However, silica has some unique properties over carbon black. Today, most of the material we use in the tread (the part of the tire that comes in contact with the road) is silica. Silicon dioxide provides greater strength and stiffness to the tread and reduces rolling resistance. As a result, replacing carbon black with silica can reduce rolling resistance by about 20% and improve fuel efficiency by about 3-5%. However, the high cost of silica limits its current application. Currently, carbon black is about 1/3 to 1/4 the price of silica.

Do you think there are ways to reduce costs? How do you see silica consumption increasing in tires?

It’s still in the early stages. However, over the years, it may become the most commonly used filler material in tires. Silica consumption in tires will continue to increase. Today, silica consumption as a filler is very low, about 10-15% compared to carbon black. We expect it to grow about 7-8% per year, depending on market conditions.

Is there a way to replace scarce natural rubber with synthetic rubber? To this end, Goodyear has developed a very interesting measure:-sustainability. We have our own factories producing synthetic rubber. However, we have partnered with an American biotechnology company (now owned by DuPont) to produce synthetic rubber.

What are the trends in radial and bias tires globally? What are the possible innovations in radial tires?

The world has changed dramatically from bias tires to radial tires. India and other regions are also moving in this direction, but are still in a transitional phase and will continue to grow. As India’s infrastructure improves, these changes will happen.

Another technology we are working on is non-pneumatic tires. We also have spring-loaded tires that we’re working on in collaboration with NASA. It is non-pneumatic. These tires don’t need air. But at the same time, you have to look at where the technology is. If it’s not pneumatic, it’s going to be much heavier. Will this provide enough fuel efficiency? Many studies are still in progress. Will this happen with consumer tires in the near future? I think it can be used for various purposes.