Maximizing Energy Efficiency and Biogas Production: EXELYS™ – Continuous Thermal Hydrolysis

Biosolids are the largest potential energy source for a wastewater treatment facility, and therefore need to be utilized as effectively and efficiently as possible. Enhanced anaerobic digestion is now the performance benchmark for biogas production, with thermal sludge hydrolysis being recognized as the most effective pre-treatment. However, traditional batch thermal hydrolysis systems are energy and capital cost intensive. A truly continuous thermal hydrolysis system, EXELYS™ has been developed to overcome these shortcomings while maintaining a high level of effectiveness. EXELYS™ has undergone full scale pilot testing in Denmark and there is now a full scale demonstration plant operational in Denmark. Key results from the pilot testing and demonstration plant will be presented in this article. The results indicate that EXELYS™ is just as effective as batch thermal hydrolysis with regards to operational conditions, hydrolysis effect, biogas potential enhancement and sterilization effect. The results also show that EXELYS™ is much more energy efficient than batch processes. Overall, the results indicate that EXELYS™ has the potential to become the cornerstone of any energy producing wastewater treatment facility.