Rua Fernando Maia
Serra da Mira
Mina de Água
2650-262 Amadora

Occupied zone:
4 ha

Origin of Municipal Solid Waste:
Restaurants, canteens, markets, hotels.

Accepted/treated waste:
Organic waste
Products treated and valued:
Gross electricity (kWh/year): 8,000,000 - 12,000,000
Electric auto consumption (kWh/ano): 4,000,000 - 6,000,000
Compound (Mg/ano): 9,800 - 14,700

Treatment process:
Anaerobic digestion.

Maximum processing capacity:
40,000 tonnes per year in the first phase;
60,000 tonnes per year in a second phase.

Date of entry into operation:
February 3, 2005

Process Description

Process Description

The Organic Treatment and Recovery Station (ETVO) treats, through the process of Anaerobic Digestion, organic waste selectively collected in the sectors of catering, hospitality, supply and retail markets, garden cleaning, among others. It produces fertilizer for agricultural and domestic (compound) use and energy, from the use of the biogas produced in the process.
In a first phase, ETVO treats 40 thousand tons of organic matter per year, and in the future, and if justified, the increase of capacity to 60 thousand tons per year.
The treatment process consists of an Anaerobic Digestion, followed by an Aerobic Post-Treatment in a closed area. An anaerobic digestion process, wet, thermophilic, in two phases is used.
The organic waste from the different sources is delivered to the plant during two shifts: from 0h00 to 8h00 and from 16h00 to 24h00. They are deposited in a receiving and unloading area, confined and fitted with insulation doors suitable for vehicle access. This is followed by pre-treatment of the waste, for the purpose of removing undesirable materials (glass, stones, plastics, etc.).
The residues are mixed with digested material and fed to the reactor. There are two anaerobic digestion reactors in the first phase of operation. The biogas produced is stored in a reservoir with a size of 2,150 m3.
The digested and dehydrated product passes to a closed pre-compost stage, with forced aeration, followed by an open post-composting. The total retention period is 13 weeks.
All contaminated air from the facility is collected (6 air / hr changes) and treated in the biofilter, thus preventing the spread of odors in ETVO and in the vicinity.

The option of selective collection at the origin is to obtain a better quality of compost. The origins of the organic waste to be processed are distributed as follows:
Sectors Considered -% of Organic Waste processed in ETVO:

  • Restaurants (a) ˜ 35 - 50
  • Markets (b) ˜ 30 - 45
  • Canteens (c) ˜ 10 - 20
  • Gardens/Cemeteries/Parks ˜ 0 - 10
(a) Restaurants and malls, shopping centers, hotels.
(b) Supply Market of the Lisbon Region.
(c) Canteens of companies, universities, hospitals, prisons, military establishments.

The Station comprises a waste reception and preparation unit, a hydrolysis and methanization unit, a compound stabilization and tuning unit and a biogas setting unit.