The assignment includes the project development and the basic and detailed engineering of the whole project. The separately collected organic household waste from the city of Luxembourg and the surrounding municipalities together with leftovers from supermarkets and kitchen waste are turned into green energy in the biogas plant.

These approximately 30.000 tons/year organic waste streams (annual treatment capacity of the plant) are mixed up with more or less 20.000 tons/year of different agricultural biomass.

The pre-treatment technology of the organic waste consists in a hydro-mechanical system which allows to get out all non-organic components before the anaerobic process.

To avoid any sanitary risks the pre-treated waste is pumped into the hygienisation tanks to be treated for 1 hour at 70°C. After this, the pre-treated waste is pumped into the reactors and mixed up with the agricultural biomass. The anaerobic digestion is done in several digesters and post-digesters.

This final output is partly post-treated thanks to a mechanical separator where two material flows are produced (liquid and solid). Part of the liquid output of the separator is needed as process water for the hydromechanical pre-treatment. The rest of the liquid output is stored and is used as a liquid organic fertilizer on farm land. The solid part out of the mechanical post-treatment is also used as a solid organic fertilizer on the farmland. The biogas which is produced is shortly pre-stored in 3 double membrane gas storage tanks. Before the biogas upgrading the sulfure and the water condensate are taken out. The biogas upgrading is done thanks to a water scrubber where the CO2 is washed out, so to reach natural gas quality. The biomethane is injected to the natural gas grid (± 99% CH4).