SITA signs with anaerobic digestion technology provider

SITA Environmental Solutions (SITA) has entered into an exclusive agreement with Organic Waste Systems (OWS) in order to deliver anaerobic digestion solutions in Australia as an add-on option to its composting and recycling facilities. OWS is a world leader in the design and construction of anaerobic digestion plants and holds the patent for the Dranco anaerobic digestion process.

SITA finalised the agreement with OWS after conducting due diligence to confirm the reliability of the technology and process. The Dranco process is a proven technology for the digestion of household and commercial and industrial (C&I) organic waste streams. The first full-scale plant was put into operation in 1992 to process municipal solid waste (MSW) and is still operating. Since then, more than 20 other installations have been constructed in Europe and Asia, treating both source separated and mixed organic feedstocks. OWS installations range in capacity from 15,000 to 150,000 tonnes per annum.

The Dranco process involves a single-phase digestion in a vertical fermenter with intensive recycling of digestate. Advantages of this digestion system include:

• it produces an energy-rich biogas, which is then converted into renewable energy (electricity and heat);
• no settling of sediments or crust formation due to high solids digestion;
• no mixing equipment or moving parts in the digester, which enhances plant availability and reliability; and
• minimal or no waste water production.