At Linz-Unkel (Germany) sewage treatment plant the first full scale state-of-art EloDry-Pro® plant for sewage sludge has been constructed, consisting of the PYREG® reactor and the EloDry® belt dryer. The system is characterised by small footprint, flexibility, modular design and efficient energy management.
The sludge dried using an EloDry® belt dryer undergoes staged combustion using the PYREG® module at around 6,500°C. This reduces the sludge to a fraction of its original volume while disinfecting it and removing micro-pollutants such as pharmaceutical residues. The residual ash, which has a high percentage of plant-available phosphorus, is then supplied to the fertiliser industry as a recycled raw material.
The working principle of EloDry-Pro® installation, including heat flows of the system, is presented.
The paper describes Pyreg®'s advanced emission control systems, preventing NOx formation and removing harmful substances such as mercury and sulphur.
The EloDry-Pro® technology is an innovative and cost-effective approach to decentralised thermal recycling of sewage sludge. Both sewage sludge volumes and transportation costs are reduced by up to 90%, therefore making it a low carbon cost-effective alternative to the transportation of sludge and allowing local sludge processing at plants under 100 k population.