From 01/01/2009, the deposit of untreated residual waste is no longer allowed in Vienna. With the new waste incineration plant in Pfaffenau, fully operational since September 2008, Vienna makes sure that 250,000 t of residual waste per year is not left unused but rather is disposed of properly according to law. The thermal recycling of the valuable raw material waste provides approx. 50,000 households with district heating as well as approx. 25,000 households with electricity.
The WKU (Vienna municipal environmental protection project group), responsible for the planning and construction of the MVA Pfaffenau, was founded in 2002 with 100% involvement of the city of Vienna.
An environmental impact assessment was conducted only 2 years after the planning began. After the commissioning of specialised companies the following year in 2005, construction work began in March 2006. In just two and a half years, one of the most modern waste incineration plants of Europe came into being in Simmering.
|Number of incineration lines:||2|
|Amount of fuel:||approx. 250,000 t/year|
|Fuel thermal rated power:||2*40 MW|
|Electric net power output:||approx. 14 MW|
|Power supply for:||aprox. 25.000 households|
|District heat extraction:||approx. 50 MW|
|Power supply for:||approx. 50,000 households|
|Commissioning (1st firing):||09/06/2008|
The following plant concept was implemented at the MVA Pfaffenau:
- Grate furnace with multi-stage flue-gas cleaning system and wastewater treatment
- Extraction-back-pressure steam turbine to generate electricity and district heating
Daily up to 200 refuse vehicles from District 48 unload their contents at the waste bunker. Two cranes lift the garbage into the feed hopper of both combustion grates. 32 tons of residual waste is burned per hour at a minimum temperature of 850 degrees.
In the heat recovery boiler, the flue gas is used to generate steam. This steam, with a pressure of 40 bar and a temperature of 400 degrees Celsius, drives a steam turbine to generate electricity. The remaining steam, after the turbine, is used for long-distance heating via heat exchangers, which is routed into the connected district-heating network. A total of 76% of the energy contained in the waste can be used effectively.
Thanks to elaborate four-stage flue-gas cleaning – consisting of electrofilter, two-stage wet scrubber, activated coke filter and a denitrification unit – the plant obtains the lowest emission levels. The cleaned flue gases are emitted into the atmosphere from an 80-metre high chimney.
Disposal / recycled waste
100% of the annual waste disposed of or recycled at the plant is delivered by the city of Vienna, District 48. Essentially, the following types of waste are used:
- Processed municipal waste
- Household waste
- Bulky refuse
After about an hour, non-combustible materials such as slag, ash, scrap and stones remain at the end of the combustion grate. The scrap is fed back into the materials cycle in the steel industry. The slag released from metals and the ash are processed to concrete at the city's own waste treatment plant in District 48 and deposited at the landfill in Rautenweg.