Tyres are an underrated feat of engineering. They hold tonnes of weight on a cushion of air; provide traction between a vehicle and the road; and, because of their elasticity, can spring back to their original shape even after prolonged use.
The materials used in the manufacture of tyres include rubber, carbon black and other chemical compounds including sulphur and zinc oxide. The carbon black, which is manufactured via the incomplete combustion of heavy petroleum products, can be replaced with silica compounds.
So, in a novel approach to the production of this more sustainable alternative to carbon black, three chemical engineering graduates from the Indian Institute of Technology at Banaras Hindu University (BHU), Varanasi, have developed an eco-friendly process for extracting green silica from rice husk ash.