WasteServ Malta - Sant'Antnin Waste Treatment - Anaerobic Digestion
Sant Antnin Waste Treatment - Anaerobic Digestion

Anaerobic digestion can be defined as a series of processes in which micro-organisms break down biodegradable material in the absence of oxygen to produce digestate (a nitrogen rich soil improver) and biogas, with an average methane content of 55-60%.

           

The organic waste from the MTP, now mixed with water and converted into pulp, passes into the anaerobic digestion tanks. Due to the various bio-kinetic processes which take place within the digesters, the pulp is broken down to further reduce the organic fraction and digestate is produced. The most important of these bio-kinetic processes is that of the methane forming bacteria. This bacteria converts the acids produced into methane and carbon dioxide. The methane is used as a fuel in a Combined Heat & Power (CHP) machine to produce heat and electricity.
           

The final process is the de-watering of the stabilized digestate, which may be used for landscaping and other projects, for example the rehabilitation of landfills.
           

In the meantime, whilst the electrical energy is fed into the national grid and contributes to Malta’s renewable energy target, the heat energy generated throughout this part of the process utilized to sustain the process itself whilst the residual is being transferred by convection through a 2km pipeline to heat the neighbouring Inspire’s indoor pool. About 800kWh of heat per week is provided for the heating of this pool. This initiative, also known as the Heat Transfer Project, was selected by the European Commission to represent Malta in the campaign ‘A world you like, with a climate you like’. This campaign brings together 27 success stories in the field of climate change from each of the EU27 countries. This project constituted a total of investment of €345,000 financed through local funds.