Mechanical-Biological Treatment Plant

The Mechanical-Biological Treatment Plant (PTMB) is located in the municipal district of Sant Adrià de Besòs and it treats mixed municipal solid waste from Badalona, Sant Adrià de Besòs, Santa Coloma de Gramanet and Barcelona.

Mixed municipal solid waste is composed of refuse that has not been sorted into various fractions. It is deposited in the grey street bins and on average it is composed of 30-40% organic material.

Mechanical treatment

From the reception pits, the refuse is loaded onto the feed belt for the process.

The sorting of recyclable materials and the separation of organic matter is carried out on two semi-automatic production lines that are controlled remotely from the operation room. The primary sorting equipment is made up of: trommels, balistic separators, magnetic separators, plastic film separators, secondary sorting cabins, autosorts and induction separators.

In the final stage, the refuse that remains from the entire process is sent to the energy recovery line along a conveyor belt that is located in an underground gallery that connects the two facilities.

Biological treatment

Organic material obtained in the sorting process is first subjected to a wet treatment. This produces a suspension that is then passed though a sand filter in order to extract any solids still present, both heavy and floating. It is then passed into two digesters where the organic material is subjected to fermentation processes.

This process produces methane-rich gas and digested material.

Energy production

The biogas that is produced accumulates in the upper part of the digesters from where it is extracted. One part is compressed and fed back into the tank in order to ensure constant movement and thus avoid the precipitation of materials in the deposit.

Three motors go on to produce 20.5 GWh/year, of which approximately half are for on-site consumption and the other half are fed into the electricity grid.

Energy is also generated from refuse that has not been recovered materially and that is taken to the WtE Plant for the production of electricity and steam for the heating and cooling network. These processes also reduce the volume and pollutant load of the refuse.

Technical data

  • MSW treatment capacity: 260,000 t/year
  • Constructed surface area: 1.2 Ha
  • Refuse sorting lines: 2
  • Transfer lines to the W-t-E Plant: 1
  • Direct outdoor dispatch of rejected fraction: 1 line
  • External dispatch of ROM to bio-stabilisation: 1 line
  • Bio-methanisation: 1 line
  • Biogas production: 108 million Nm3/year
  • Electrical energy production: 20.5 Gwh/year
  • Packing and expedition of by-products and recoverable waste: 4 lines

Diagram mechanical-biological treatment Plant

Echeme waste management mechanical-biological treatment Plant

Photo gallery