Historically, waste treatment technologies have focused on reducing the risks associated with the disposal of both general and hazardous waste to landfill sites.
Today however, South Africa is far ahead of the global marketplace when it comes to waste management legislation, where these frameworks are setting the benchmark for innovation in the industry - driving companies to derive better, more suitable waste management solutions - solutions that focus beyond the landfill model and rather on creating alternative, commoditised products from the waste generated.
Interwaste is at the forefront of leading the technological innovation within the local waste management sector where our forward thinking initiatives stand testament to this and provide solid, sustainable and profit generating waste management opportunities - across all waste streams
The result? A ban on the landfill of any waste with a total organic carbon content in excess of 6%. In addition, the legislation introduces stringent concentration thresholds for the disposal of waste containing any, of a wide range of, organic chemicals to landfill, with immediate effect.
Interwaste has therefore developed a sound solution in deriving energy from waste, through their partnership with Lafarge - a relatively low cost, but environmentally sound solution for managing combustible waste products locally.
The Lafarge Project - Cement kiln co-processing as a solution:
Lafarge - one of the largest cement manufacturers globally - and their Lichtenburg production facility - is capable and licenced to accept hydrocarbon-sludge and waste tyre waste-derived-fuels for co-processing. As a result, through a process defined and developed by Interwaste's R&D team, the company ensures a consistent supply of high quality, alternative fuel for co-processing as well as providing excellent service to industrial waste generators as a result.
The Interwaste and Lafarge joint venture is underpinned by an alternative fuels blending platform in Kaalfontein, Johannesburg, and is the first facility to produce liquid alternative fuels for co-processing in South Africa.
The blending platform accepts various suitable waste streams from industrial generators, screens their quality and processes them to produce a consistent waste-derived-fuel product which is then transported to the Lafarge cement production facility.
The first phase was commissioned in the first quarter of 2014 and has the capacity to process heavy hydrocarbon sludges, oils and greases to produce a viscous liquid alternative fuel product that is introduced into the Lichtenburg plant, via a high pressure pump system.
This fully licensed operation, both the cement kiln in Lichtenburg and the blending platform in Kaarlfontein, are authorised to accept and process waste and have the appropriate permits from the South African Government
The type of waste suitable for such processing include: alternative fuels which have a significant calorific value (such as oil sludge wastes), alternative raw material which contain the mineral components useful in the production of clinker (some contaminated soils for example) and materials that have both a calorific value and mineral content (such as paint sludges or waste tyres).
To this end, nuclear waste, infectious medical waste, used batteries and untreated municipal waste are not permitted to be used for this purpose.
Processing combustible waste alongside coal in cement kilns has the potential to:
The original waste materials come from industries, households and sorted municipal solid waste including paper, cardboard, wood textiles, plastics etc. This RDF is meant for sole/co-feeding plants and replaces conventional fuels (e.g. coal) in production plants for power generation, steam generation, heat generation, cement kilns and other suitable combustion installations.
Interwaste is the first waste management company in Africa to develop their very own RDF plant - where waste will be processed at the Interwaste facility in Germiston. Here high calorific value wastes will be sorted, shredded in a primary shredder to reduce material size, then shredded in a secondary shredder and briquetted/densified depending on intended end use.
Benefits of RDF:
As such, Interwaste has put a lot of time and money into the landfill project to ensure not only environmental compliance, but that the landfill is a world class facility.
Key landfill innovations at the FG landfill site include:
Interwaste is involved in the generation of natural gas from its own landfill site in Midrand, and supplies organic waste to a 4MW anaerobic digestion plant in Bronkhorstspruit, Gauteng, built by Bio2watt.
Natural gas from landfill and from anaerobic digestion is produced as a by-product from bacteria eating and breaking down any organic matter. At Interwaste's landfill site in Midrand, gas is currently being flared from wells that have been sunk into the landfill, in order to determine gas yield projections for future use.
The gas currently being generated from the anaerobic digestion plant in Bronkhorstspruit is being used to generate electricity which is then "wheeled" to BMW's Rosslyn plant.
As a result, Bio2watt (and Interwaste) supply up to 30% of BMW's Rosslyn plant energy requirement from renewable sources. Interwaste also have a license for, and intend on, building an anaerobic digestion plant on its own premises in Germiston, Gauteng in the near future.
The potential uses for this gas, for the future, are;
This facility tests all new wet and dry waste streams, generated by their clients, to ascertain their suitability for different methods of waste disposal. Through this process, Interwaste analyses and monitors the leachate content of the waste, prior to recycling, reuse or disposal, to ensure that the correct method - based on the most environmentally sound solution - is applied.
No waste is accepted by Interwaste until such testing is complete and a viable solution for disposal or re-use can be attained. To aid this process and confirm the waste streams are the same as the samples taken, Interwaste has smaller testing laboratories at their various sites.
where the company offers clients a safe disposal method which is not only environmentally sound but financially viable, through the provision of a unique zero-waste to landfill solution - as part of the company's joint venture with Lafarge. This solution uses pharmaceutical waste as an alternative fossil fuel during the manufacturing of cement, ensuring that the waste can no longer be traced after going through the cement kiln process. Interwaste, to this end, also offer a full track and trace service for their pharmaceutical clients, whereby they are able to track the movements of their products as soon as it leaves their storage facility/warehouse, right to the point of destruction at the Lafarge cement kiln in Lichtenburg.