Moving towards an energy neutral WWTP – the positive impact of Exelys^TM continuous thermal hydrolysis in achieving this goal

There is an increasing need for large wastewater treatment plants to generate as much electricity as possible from biogas. This not only ensures significant operational cost savings, but also improves the environmental profile of the plant. Enhanced digestion through the use of the Exelys^TM continuous thermal hydrolysis process has the potential to help a large wastewater treatment plant move towards electrical energy neutrality. This article aims to use Csepel waste water treatment plant (WWTP) (3.5 million PE) in Budapest, Hungary as a case study to investigate the potential advantages an Exelys^TM-DLD process could provide. The results indicate that despite already having an effective and efficient digestion process, through implementation of the Exelys^TM-DLD process, Csepel has the potential to cover 65% of its total electrical needs from biogas. This is 33% more than the current situation. This also leads to a significantly improved NPV for the Exelys^TM-DLD scenario, an important factor for the operator of a large wastewater treatment plant. When looking to the future, through the optimisation of the wastewater treatment process and the application of the Exelys^TM-DLD, Csepel WWTP has the potential to be completely electrical energy neutral. This would be a significant financial advantage as electrical prices rise and carbon taxes are enforced.