Thermal Hydrolysis Considerations for Pre-Digestion Solids Processing

Abstract

Over the last 15 years, major advances have been made in practical application of thermal hydrolysis (TH) as a pre-anaerobic digestion process to provide improved digestion performance and greater methane production, as well as to achieve better final dewatering performance and improved final biosolids cake product characteristics. Currently, there are at least two companies promoting and implementing the process, world-wide, with interest by others in examining the process for potential development and use. Several wastewater agencies in North America have examined the technology for potential use because of published successes overseas, availability of process and project information, ability to achieve Class A biosolids, and other factors including the recent decisions by the DC Water and Sewer Authority (DC Water) to construct the system at very large-scale (400 dry metric tonnes/day of capacity.)Wastewater agencies are anxious to learn about the advantages and benefits of the technology, but also about any disadvantages or operational implications that may be associated with using thermal hydrolysis pretreatment prior to anaerobic digestion.