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Client: Waste to energy plant
Context: Upgrading of pollutants control systems
Solution: A shelter gathering all analysers and dioxin samplers
The waste-to-energy plant in Evreux, which began operating in 2003, treats household residual waste and non-hazardous industrial waste from the south of the Eure, i.e. more than 200 municipalities. It belongs to the SETOM (Syndicat Etude Traitement Ordures Ménagères) of the Eure department. The site treats nearly 100,000 t of waste per year and generates steam for the production of 6.5 MW of electricity, heating and hot water which supplies about 8,000 housing equivalents in the surrounding area.
It is subject to prefectural operating authorization and ICPE regulations. This implies the need to continuously measure emissions into the atmosphere and imposes maximum thresholds for pollutant concentrations in the flue gases.
Interview with the management of Evreux’s waste-to-energy plant:
What is the context for upgrading the site in terms of emission control?
As the plant’s operating contract was expiring in 2019, a public service delegation was submitted for bidding. The selected candidate’s bid included an option for better use of the energy produced by the furnaces and the replacement of the smoke analyzers.
These are an integral part of the incineration process and contribute to the metrological monitoring of the site.
ENVEA was thus selected by the contractor to replace the analyzers located upstream and downstream of the smoke treatment process. This consists of injecting reagents (sodium bicarbonate, NH3 and lignite coke) to remove pollutants (acid gases, NOx and heavy metals) present in the flue gases emitted.
What was the solution proposed by ENVEA?
The contractor wanted a guarantee of optimum operation of the analyzers in relation to the specific environment of the plant. ENVEA proposed to rethink the installation of the equipment (smoke analyzers, dioxin samplers) in order to optimize the process, the durability of the equipment and to facilitate the daily work of the technicians. This resulted in their grouping together in a shelter, which proved to be relevant and particularly adapted to the situation.
ENVEA also anticipated regulatory changes and provided the necessary space in the shelter for future equipment.
The acquisition and handling of the data related to the measurements of the analyzers are ensured by ENVEA’s WEX platform. This platform controls, via the plant’s automated system, the shutdown of the furnace by the operator if the established thresholds are exceeded. It allows us to monitor and transmit measurement data to the stakeholders on a daily basis.
An important improvement has also been made on the communication architecture between the analyzers and the station dedicated to regulatory reporting with the implementation of a managed network loop in order to optimize the total redundancy of the systems.
Is there a particular aspect you would like to highlight?
The reliability of ENVEA equipment is appreciable and recognized in incineration. The analyzers installed give us complete satisfaction in terms of confidence in the quality of measurement.
Throughout the project we worked closely with ENVEA’s technical and commercial teams to avoid shutting down the furnace and therefore the plant. This event always has important consequences for the public service and stakeholders such as local authorities.
Plant in figures
- Continuous 24-hour operation: 25 people on site, 14 at all times
- 2 furnaces: 6.2 t of waste treated per hour per furnace
