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Waste treatment

Urban Nexus // Waste: Not a Burden, but an Opportunity to Make Money

By Ruth Erlbeck. Solid waste management is closely linked with water and energy and therefore an important field in which to apply the Nexus approach. In a series of case studies on Vietnam, India, Indonesia and the Philippines, GIZ‘s Urban Nexus Project looked at how solid waste management can be transformed into precious energy and water resources, as well as how other valuables can be extracted when the system is managed through a holistic Nexus perspective.

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The solid waste management studies of Nagpur/India, Da Nang/Vietnam, Tanjungpinang/Indonesia and Laguna Province/Philippines all find that the mechanical-biological treatment (MBT) with the lowest ecological footprint is much more environmentally friendly than traditional incineration. This technology recycles 95% of the disposed materials.

Why incineration does not work

The waste composition in South and South East Asia differs a great deal from the waste composition in the European countries. In these regions the waste contains much more organic substances and has a much higher content of moisture. This causes problems when it comes to incineration, as huge amounts of energy are needed to burn the waste. Incineration of this waste type is not economical.

In consequence, there are no well-functioning incineration plants in this region with exception of China. Often air filter systems of low quality are installed in order to become more economical. This is possible because the air quality of the systems is not checked regularly.

Mechanical-biological treatment (MBT)

The approach applied in these regional studies does reflect the specific waste characterisation of each city and country and departs from the wrong approach that “one size fits all”. The decision makers in the region are looking for alternative solutions and are especially interested in mechanical-biological treatment (MBT, also called maximum yield technology MYT). This technology allows for reuse of most of the waste and transforms it into energy:

  • organics to biogas from which electricity can be generated and fed into the grid or compressed biogas (CBG) is produced to run the fleet of trucks for waste collection;
  • plastic to Refused Derived Fuel (RDF) to be sold to cement plants or other industrial plants or to be used to produce energy within own power plants to be set up

Moreover, the process water can be used as service water or water for irrigation after treatment. Valuables such as minerals can be extracted and sold (resource recovery).

Making it a business case

Successful waste management of this type could be a business case. The solid waste management sector is a sector designated for private investment according to the majority of the policies makers in South and South East Asia. The prevailing business model is the public-private-partnership (PPP) in varying modes and formats.

But there are a lot of obstacles. It is difficult to successfully sell the energy gains. It needs to overcome administrative hurdles such as rules and regulations governing the feed-in tariffs and other parts of the business process. All this is complicating private investment and PPP for the MYT method and drastically reduces attractivity for investors.

Hence the private sector, but also development banks often prefer the simpler, traditional approach and choose incineration, even though its functionality and environmental consequences can be seriously questioned for South and South East Asia. The “incineration lobby group” is very strong.

Circular economy on the ground: Bangkok’s new waste treatment scheme

A breakthrough has now been reached in Bangkok, the capital of Thailand. Bangkok Metropolitan Authority and a German-Chinese private sector consortium have signed a contract to build a MYT plant to process 800 tons of waste per day.

The GIZ Urban Nexus project has been asked to develop a roadmap for solid waste management for Bangkok. The aim is to define a process of solid waste treatment that reduces the waste going to the landfills by at least 70% in 2030. To achieve this rate, it will be necessary to take a circular economy approach that puts technologies focusing on return/recycling/reuse first. Promoting MBT/MYT will be the way forward.

China is also running a pilot MBT/MYT plant in Hangzhou, established by a Chinese-German consortium, a best practice example which hopefully will be scaled up in the near future.

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