Abstract Waste tyre generation in South Africa is an issue for which no sustainable solution has been found. South Africa generates over 177 385 tons of waste tyres per year, and only around 25 % is recycled, the remaining 75 % accumulates in storage depots, and landfills across the country. In this work, a slurry fed IGCC system is analysed. This system does not require the use of oxygen during gasification and is designed to be self-sustaining and produces electrical power. A sensitivity analysis shows that considerable gains in thermal efficiency are made by using a turbine pressure ratio of between 20 and 30 bar. This data was then used to develop a system that processes 518 ton/day of waste tyres and operates at a gas turbine pressure ratio of 30 bar and a 1600 °C combustion temperature. The net power production from the system is 89 MW, with a thermal efficiency of 45.65 % and work efficiency of 44.97 %. However, the results from Aspen Plus were significantly less than the predicted with an overall net efficiency of 32 %. Despite the discrepancy waste tyre IGCC net-work output was found to be 10.5 GJ/ton of tyre much higher than that of conventional coal IGCC at 9.6 GJ/ton of coal.