District Energy, Emissions Control, Energy Efficiency

New waste-to-energy plant feeds heat to western Paris: DE has the power to change our lives

Issue 5 and Volume 9.

Located only a few kilometres away from the Eiffel Tower in Paris, a substantial new waste-to-energy plant is generating both electricity and heat to supply some of the buildings of western Paris and nearby towns. Ray Burelle reports on its construction.

The SYCTOM – Isséane Recycling Centre and Energy from Waste (EFW) plant located on the Seine River in Paris, France, is a shining example of how to integrate the valorization of waste successfully into the urban community. This new EFW plant was built to replace the existing plant at Issy-les-Moulineaux, which had been in operation since 1965. Isséane processed its first waste in December 2007 and is now in full operation. Isséane is designed to service the need of more than one million people living in the surrounding communities by treating more than 460,000 tons per year of household waste while producing 52 MWh of electricity and district heating for approximately 79,000 houses and apartments.


Artist’s impression of the plant by the Seine
Click here to enlarge image

SYCTOM, the owner of Isséane, is the organization tasked with the collection, treatment and valorization of municipal solid waste for 5.5 million people in 85 communities that are part of the Paris region. The mandate of SYCTOM is first to reduce the amount of waste being produced and then to treat and valorize the waste it collects, first by recovering and recycling all materials that can be pratically reused, then by thermally treating the residual material left afterward to produce useful energy for the surrounding communities. SYCTOM is also required to carry out its operations while minimizing or eliminating any environmental impact; such as noise, air and water emissions.

UNDERGROUND ARCHITECTURE

The most striking feature of Isséane is how the plant was designed to blend into its environment and contribute to the improvement of the shore of the Seine River.

Located only a few kilometres away from the Eiffel Tower and surrounded by office and residential buildings, the site for the new plant was previously an industrial site belonging to the car and truck manufacturer Renault. To minimize the visual impact of the plant, the main building was conceived to have a maximum elevation of 21 metres by having the base 31 metres below ground level. The plant uses very short stacks that are not visible from ground level and the exhaust flue gas can be reheated, to ensure that there is no visble water vapour plume.

Having a large portion of the builing below ground also helped to reduce noise and odours significantly, as trucks that bring the waste to the centre enter the facility through an access tunnel. Soundproof materials were used in the construction of the building and the waste receiving area is maintained under negative pressure with the air being used as combustion air in the EFW furnaces.

NO MORE LANDFILLING

SYCTOM made the decision to proceed with a new EFW centre to replace the existing plant in 1998. The new facility had to comply with new regulations (Loi Royal) that forbade the landfilling of untreated waste. This new regulation included an obligation to valorize by recycling or thermally treating at least 75% of packaging material. The annual treatment capacity of Isséane is actually 20% less than the older centre it replaces, but it is still able to cope with the area’s waste and meet treatment/recycling because of a reduction in the amount of mixed waste and by improving the efficiency of recycling with the modern sorting centre that is part of Isséane. This sorting centre can handle 55,000 tonnes per year. The new centre, using best available technology (BAT), was conceived to meet the future EU norms and will significantly reduce the environmental impact compared to the existing plant it replaces.

Other beneficial impacts for the environment obtained with Isséane are:

  • Having the recycling and EFW facility in the same area where the waste is produced reduces emissions from the trucks needed to collect and transport the waste.
  • Locating the centre on the bank of the Seine provides the opportunity to ship the slag (the remaining material after combustion) by barge, eliminating the requirement for 4250 truck shipments per year, avoiding 23 tonnes of CO2 emissions.
  • By providing district heating, Isséane will also reduce fossil fuel consumption by the equivalent of 110,000 tonnes of oil that would be used for individual and community heating systems, thereby significantly reducing greenhouse gas emissions.
  • Generating electricity locally to users eliminates transmission losses com pared to power plants located some distance away from urban centres. It also improves the energy security for the local area due to grid outages as the plant is a producer of electricity close to its consumers.
  • An EFW plant is considered a ‘carbon sink’ since it eliminates potential methane emissions associated with landfilling, it displaces fossil fuel that would be used in energy generation and the CO2 emitted comes largely from biomass, a renewable fuel.

PROJECT DEVELOPMENT

The major phases of the project were:

  • Obtaining the permits to build the plant in September 2000.
  • Signing of the Environmental Quality Charter in December 2000.
  • Installation of the infrastructure for the site offices and equipment unloading facilities on the bank of the river in 2001, including a bridge over the road. These facilities were needed as the actual site did not have space directly on it for them.
  • Start of main civil construction activities on site in June 2003 to January 2005. The length of this phase was due to the very challenging aspect of needing to have most of the centre located underground next to the river. It required the installation of a water- tight enclosure around the future plant. The walls of this enclosure go to a depth of 70 metres. Site remediation work involving the removal of contaminated soil on the site was also required.
  • Equipment delivery and installation took place from late 2005 to mid-2007.
  • The second half of 2007 saw the commissioning and start-up of the equipment with the start of commercial operation in December 2007.

A bridge was built over the road to provide access between the offices and the site
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AE&E Von Roll Inova received a contract from SYCTOM in February 2000 to design, supply, erect and commission process equipment used to preform the thermal treatment of the waste and generate the high-pressure steam used to produce electricity and heat for district heating, and to provide the flue gas treatment system. One of the largest and most experienced suppliers of energy from waste equipment, the company provided its first waste treatment plant in 1939 and has since been involved in the design and installation of more than 400 plants around the world with a total processing capacity of more than 140,000 tonnes of waste daily. The company has pionnered many innovations and was at the forefront of the development and introduction of several technologies used to treat waste and remove contaminants from the combustion gases and residues.

FROM WASTE TO ENERGY

AE&E Von Roll Inova provided Isséane with two identical waste treatment lines located side by side, fed from a common waste storage pit. A side view of the equipment comprising the treatment line is shown in Figure 1.


Figure 1. Major process equipment used to treat the waste and generate energy
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Upon arriving at the plant, the trucks carrying the waste drive down a ramp to enter the waste receiving area (1). The trucks then back-up and discharge the waste into the waste storage pit (2). The waste crane (3) is then used to handle the waste and load it into the feed hopper (5) for each processing line. The waste crane is operated manually from the loader control cabin (4), but it can also be operated in a fully automated mode.

The heart of the system is the Von Roll Inova reciprocating grate (7) where the waste is combusted. Located at the bottom of the boiler, the inclined grate is divided into five sections along its length by four sections wide, for a total of 20 individually controlled sections. The reciprocating action of the grate moves the waste through the various steps of combustion until the completely combusted waste is discharged as slag at the end of the grate. The hot combustion gases rises through the furnace where some of the heat is absorbed by the water-cooled walls. The gases then reach the steam generation section (19) where they are further cooled down.

Following the steam generation equipment, the gases then enter the gas cleaning section, where the dust contained in the gas is removed by an electrostatic precipitator (20). This is followed by the injection of bicarbonate to remove gaseous contaminants (22). The bicarbonate is then removed by a fabric filter (23), which is followed by a SCR catalyst (24) used to reduce NOx. The gases then exit through the plant stack. Thermal treatment of the waste leads to a reduction in volume of the waste of approximately 90%. In addition, ferrous and non-ferrous metals are later recovered and recycled from the slag.

ENVIRONMENTAL ASPECTS

From the start, SYCTOM paid very specific attention to all environmental aspects of the new plant. At the request of the Paris neighbour city of Issy-les-Moulineaux, SYCTOM made a commitment to present an Environmental Quality Charter for the project that would cover both the construction phase and the operation of the plant. In addition to minimizing the potential impact on the immediate neighbours of the plant through odour and noise abatement measures, the plant was also designed to have no wastewater discharge into the environement and to produce air emissions of only half the current legislated norms.

Isséane, the newest Recycling and Energy from Waste facility from SYCTOM, shows the true potential of the integration of waste treatment and distributed energy production into an existing neighbourhood and how it can make a significant contribution to the environment and the quality of life of the people living there. It also shows that it is possible to derive significant value from the waste generated in our communities in the form of improved recycling with the sorting centre and local energy production.

Ray Burelle is with AE&E Von Roll Inc, Norcross, Georgia, US.
e-mail: [email protected]

Some plant data

  • Steam is sold to the district heating system at 20 bar and 220ºC in winter.
  • Thermal output of the two lines is 160 MW.
  • Steam output of the two boilers is 200 tonnes/hr at 50 bars and 400ºC.
  • Expected energy revenues from the plant are €8 million from steam sales and €3 million from electricity.
  • Slag or bottom ash represents approximately 27% of the weight of the waste. About 20 kg of ferrous and non-ferrous metal is extracted from the bottom ash while the balance is to be treated and re-used as aggregate for road construction.
  • Residues from the flue gas treatment represent 2.1% of the original weight of the waste and it is the only portion that needs to be landfilled.