**4. Waste Tyre to Oil, Carbon, and Steel**

The recycling of waste tyres into useful products is of interest for both environmental and economic reasons. Many researchers have been working to solve the aforementioned issues and convert waste tyres into valuable products such as oil, carbon, and steel [69,92,93]. Waste-tyre oil could be used for heating by industry, refined further for use in diesel engines, or used directly as blended fuel in some stationary diesel engines. Carbon has a plethora of industrial uses, from toothpaste to electrodes and pharmaceutical goods, as well as being about 35% cleaner than coal and burning hotter, while steel can be sold as scrap metal or returned to tyre manufacturers for reuse.
