Clarke Energy and Tronox have been short-listed for the Chartered Institution of Wastes Management (CIWM). The companies are finalists in the Energy Recovery category for a waste furnace gas to power project at a site in South Africa.
The CIWM Awards are taking place on the 6th of November 2014 at the Marriott Hotel, London Grosvenor Square.
The Tronox Namakwa Sands ilmenite smelter plant produces titanium oxide (TiO₂) slag and iron. The furnace gas is a waste by-product of the smelting process and is generated at the rate of >16,000Nm³/h. Investigations into the use of this smelter waste gas at Tronox Namakwa Sands to generate electricity through the use of gas engine technology commenced in 2006. In 2011 the project was approved by the Tronox Board and the plant construction started in 2012.
The plant design is based on three gas trains (each rated at 50% capacity) conditioning the gas from the existing smelter waste gas holder to supply eight (8) GE Jenbach gas engines each rated at 1.7 MWe. Most of this gas had been previously simply flared to atmosphere since the commissioning of the first furnace at Tronox Namakwa Sands in Saldanha in 1995. Commissioning of the cogeneration plant commenced in Q3 2013, and the plant reliability run was performed in December 2013.
The total rated electrical output of the plant is 13.6 MWe, with an effective net output of 12.5 MWe into the Tronox Namakwa Sands grid. All the electricity generated is used internally to reduce the power purchased from Eskom (Electricity Supply Commission of South Africa).
The project was registered with the UNFCCC as a CDM project on 18/12/2012.
The ramp up of the plant to design capacity of approximately 6 GWh per month was achieved within six months from the commencement of full operation in December 2013.
For the first six months of 2014 a total of 29.2 GWh has been exported into the Tronox Namakwa Sands smelter grid. In a full production year the output from the cogeneration plant is expected to exceed 70 GWh. The project was completed within the approved budget, although the completion of the project was delayed by three months due to design and construction delays.