By Eamonn Ryan, from the transcript
At the HFC Phase Down Workshop hosted by the Department of Forestry, Fisheries and the Environment (DFFE) on 16/17 September, Martin Botha, a project manager at A-Thermal presented on the topic of ‘Ozone depleting substances (ODS) destruction facilities in South Africa’. The following is his presentation. This is Part 1 of a five-part article.
His discussion highlighted the legislative framework, the technologies employed, and the facility’s operational practices, shedding light on how South Africa addresses the challenge of ODS disposal.
South Africa has established a comprehensive legislative framework to manage the destruction of hazardous substances, including ODS. According to Botha, the Environmental Management Act requires facilities to obtain various licenses before they can operate.
These include:
- Waste management license: Issued by the National Department of Environmental Affairs, this license is necessary for facilities that aim to destroy hazardous substances.
- Air emission license: Regulated by local municipalities, such as the City of Ekurhuleni in Botha’s case, this license ensures that emissions from the facility comply with the Minimum Emission Standards set by the South African government.
- National policy for thermal treatment: This policy outlines operational requirements for managing both general and hazardous waste, ensuring that plants adhere to best practices in waste destruction.
Destruction technologies
The facility utilises two primary technologies for ODS destruction: rotary kiln incineration and thermal oxidation. Botha explained how these technologies align with international best practices and standards outlined in the Technology and Economic Assessment Panel (TEAP) report.
- Rotary kiln incineration: This method is traditionally used for the destruction of solid waste and can also handle liquid or gaseous materials, which evaporate rapidly and are then directed to the secondary combustion chamber. Rotary kilns are known for their effectiveness in treating hazardous waste but can pose challenges with emission control due to their large size and dilution effects.
- Thermal oxidation: This involves injecting refrigerants into a high-temperature furnace where they are oxidised. The thermal oxidiser handles gaseous and liquid materials, ensuring that the ODS are broken down at temperatures above 1001°C. This method is effective in managing emissions of hydrochloric acid (HCl) and hydrofluoric acid (HF), which are byproducts of the destruction process.