Proceedings

Abstract

Cambi A.S. of Norway has developed thermal hydrolysis (TH) with steam explosion since the early nineties into a proven technology for the treatment of sludge. This has resulted in a track record of 26 operational plants and in the largest advanced digestion project in the world (150,000 ton DS/y) today being built in Washington DC, USA. The first TH plants were built to increase digester loading, reduce sludge volumes and to create a Class A biosolid, a fully hygienised, low-odour cake easy and safe to return to land.

Today, however, energy consumption is a major topic for WWTP operators. Next to sludge handling, energy is usually the second largest operational expense in wastewater treatment with costs continue to rise. This has sparked a strong interest in TH as a means of improving the energy balance of a WWTP.

This paper discusses how the energy balance of the TH process can be optimized to achieve maximum energy efficiency.

Keywords energy efficiency, thermal hydrolysis, sludge digestion