Waste management company Interwaste is continually exploring processes and technologies to divert waste from landfills and has created a variety of methods to convert waste-to-energy.

Interwaste director for business development and marketing Kate Stubbs says the first way to get value out of waste is to understand what kind of waste is generated in your business or at home and how it can be converted into an alternative resource such as energy.

“Waste coming from industries, households and municipalities, including food, paper, cardboard, wood, textiles and plastics have to be separated accordingly so that it does not become contaminated and the most value can be extracted from the waste.”

Once separated, the waste can be converted into energy if it matches certain criteria. For example, liquid waste with an energy value into a fuel, refuse-derived-fuel (RDF) or solid waste into energy, or alternatively, a waste-to-energy plant can be used to combust waste to produce electricity or steam. Another source of energy from waste is to extract landfill gas and convert it into a biogas which could be used as vehicle fuel.

“Interwaste was the first company to start producing RDF in 2016 at its facility in Germiston. We take certain waste streams for which there is no recycling market or alternative use and we shred it into small sizes. This is then fed into production plants for power, steam or heat generation as a replacement for other fossil fuels, such as coal or gas. We are currently producing between 150 t/m and 300 t/m.”

Stubbs highlights that many companies are committed to reduce their carbon emissions and are looking at alternative sources of fuel, as well as renewable energy.

The process of collecting waste and converting it into energy can be costly, but with the changes in legislation and the carbon and landfill taxes expected to be implemented in a few years’ time, the costs of managing and disposing waste will increase, making alternative uses of waste more viable and ultimately being highly beneficial for the environment, she adds.

South Africa has stringent waste management legislation, and as more materials are banned from landfill every year, companies are compelled to look for an alternative waste solution, Stubbs explains. She believes that the introduction of stringent legislation also presents an opportunity for companies to look for new waste management solutions.

“South Africa has a relatively new waste management law, the National Environmental Management Act, which has been in place for only 20 years, and the challenge is to ensure that all people are aware of and understand it.”

Stubbs says more work is under way in South Africa to improve waste recovery and separation, and believes that, by implementing proper waste management practices, this will reduce overall costs and maintain the environment.