Name
Transforming the sludge drying process with Jacobs Dune
Description
Biosolids are becoming increasingly challenging to export to land due to changing requirements of sludge quality. Concurrently, complying with Industrial Emissions Directive cannot be compromised in design, while emission control from dryer systems windrow drying is costly and fundamentally challenging. These pressures make the use of sludge cake as a fuel source more attractive. However, existing drying methods are either slow or demand high energy inputs to accelerate moisture removal. Low energy biodrying supports reduced energy consumption and improved dry solids, and enable future advanced thermal technologies. This project considers an innovative biodrying technology based on static pile composting (Dune) which seeks to minimise energy and time required to dry sludge whilst lowering greenhouse gas emissions. The system controls temperature with aeration to remove water from sludge cake and control production of greenhouse gasses far more effectively than conventional dryers and windrow piles. A partnership between Jacobs, Northumbrian Water Limited and Newcastle University, this project delivered a 12-week, 6-round Dune pilot in Summer 2026. This paper will present the results from a Dune reactor with a control sludge pile from the same source to evaluate the impact of low-power aeration and temperature control on emissions and drying performance. The trial targets increasing dry solids from 45% to 60% within two weeks, alongside detailed greenhouse gas monitoring provided by Newcastle University.
Authors
Ewan Spence, Amanda Lake, Ben Raistrick, Sam Wilson and Matt Pickersgill, Jacobs, UK