Extension of the MBT Plant VALORLIS

After a decade of successful operation, the MBT plant in Leiria is being expanded by an additional biowaste treatment line to reflect the new environmental targets of Portugal. VALORLIS - Valorização e Tratamento de Resíduos Sólidos, S.A has assigned in September 2021 the consortium between BTA International GmbH and EFACEC Sistemas e Engenharia, S.A. with the corresponding works, as it did more than 10 years ago for the construction of the MBT plant itself.

Since its start-up in 2010, the plant has treated more than 500,000 tons of unsorted household waste. But now, with the more stringent European targets for the recovery and valorisation of organic waste, VALORLIS will also receive and process biowaste that is separately collected in the households. For this reason, VALORLIS planned the expansion of the facility by a separate treatment and digestion line for an additional 25,000 tons of biowaste per year.

The biowaste processing line will also be based on the BTA® Process, just as the existing organics treatment lines at the MBT plant. In order to keep both lines (household waste and biowaste) separate, the expansion foresees a separate pre-treatment line (according to BTA® Hydromechanical Pre-Treatment), a separate digestion line (wet digestion, mesophilic) and separate process water management.

In addition to these works, the wet-mechanical pre-treatment line for household waste is to be reinforced by replacing the original light fraction removal system with the new generation one, increasing the capacity significantly.  The same system has already been in successful operation in several MBT plants for years, e.g., in Glasgow or Malta.  

The special challenge in this project is the construction of the new line under extremely tight space conditions while the plant remains in operation, although at reduced load, in order to keep the biology running to allow for a fast start-up and ramp-up of both lines. The short timeline is other major challenge.