PROJECT DESCRIPTION
BACKGROUND
Since January 2005, German law prohibits the land filling of waste which contains more than 5% toxic organic compounds. This threshold means that almost all domestic waste requires a treatment. In technical terms, there are two concepts considered to be state of the art: 1)thermal recycling by incineration plants and 2) mechanical/biological treatment. The ZAK-process is an advanced technology of the mechanical/biological treatment. The ZAK-process method for recovering valuable materials from domestic waste was tested on a semi-industrial scale between 1996 and 2003. A four stage development process was undertaken, involving mechanical pre-treatment of waste, biological transformation, biological drying and mechanical separation. Processing occurred to such an extent that most of the waste could be re-used or recycled as an energy or material source. The recovery of metals, minerals and combustible materials was particularly effective.
OBJECTIVES
The "ZAK-Process" project aimed to confirm the economic and environmental benefits of the ZAK-process for residual waste treatment. The process was to be upgraded into a large-scale technical operation. The benefits were to be measured during a research phase and by trialing an experimental plant. The LIFE project was embedded in a much bigger overall project, which was budgeted with € 40.000.000. The additional costs and the risk of failure for the innovative part of the overall project were to be covered by the LIFE project.
RESULTS
The project achieved all of its objectives. The ZAC process treatment plant was constructed and was in full operation at the end of the project. The results of the process showed several advantages compared to the more conventional mechanical/biological treatment of domestic waste. These were namely a high production of secondary combustible material, less amounts of waste for landfilling, high commercialisation potential of the produced recyclable wastes, low emission potential of greenhouse gases. In the site in Kahlenberg the ZAK process has meant that 50.000 t/a carbon dioxide emissions have been saved, which can be compared to the emissions generated by 32 000 averagely used cars. The project was technically challenging and its demonstration value is high. This was the first time that the SAK process was demonstrated on such a large scale. The innovation of the process is characterised by the sequence or process stages and easier maintenance and durability of units, eg. the percolator and drum sieve. Furthermore, the secondary combustible material which is produced is of a high quality and suitable for storage. This makes it easier for the plant operator to react to market mechanisms. The ZAK process system is operating in a competitive economic environment. There are several technologies, which are all competing to enter open markets, e.g. in Eastern Europe and other emerging markets. If the operability of the ZAK process is further proven successful the technology has a good chance of gaining some markets and jobs will be created in the plant constructor business.The project achieved all of its objectives. The ZAC process treatment plant was constructed and was in full operation at the end of the project. The results of the process showed several advantages compared to the more conventional mechanical/biological treatment of domestic waste. These were namely a high production of secondary combustible material, less amounts of waste for landfilling, high commercialisation potential of the produced recyclable wastes, low emission potential of greenhouse gases. In the site in Kahlenberg the ZAK process has meant that 50.000 t/a carbon dioxide emissions have been saved, which can be compared to the emissions generated by 32 000 averagely used cars. The project was technically challenging and its demonstration value is high. This was the first time that the SAK process was demonstrated on such a large scale. The innovation of the process is characterised by the sequence or process stages and easier maintenance and durability of units, eg. the percolator and drum sieve. Furthermore, the secondary combustible material which is produced is of a high quality and suitable for storage. This makes it easier for the plant operator to react to market mechanisms. The ZAK process system is operating in a competitive economic environment. There are several technologies, which are all competing to enter open markets, e.g. in Eastern Europe and other emerging markets. If the operability of the ZAK process is further proven successful the technology has a good chance of gaining some markets and jobs will be created in the plant constructor business.
