Thermodynamic modelling of energy recovery options from digestate at waste water treatment plants

Project Description

The proposed project will conduct thermodynamic modelling of the performance of thermochemical approaches to energy recovery from anaerobic digester (AD) digestate at wastewater treatment (WWT) plants. These approaches include combustion, gasification and pyrolysis. This is a highly relevant subject area due to the necessity to reduce energy consumption and greenhouse gas emissions in the WWT sector. Due to storage, food safety and public perception issues with the use of sewage sludge in agriculture, there is also a need to reduce volumes of biosolids being landspread. Energy recovery and heat integration at WWT plants can address these challenges. The objectives of the project are to: 1) conduct reviews of AD digestate properties, energy requirements at WWTs and technologies available, 2) create a physics-based model to quantify production of useful energy, valuable non-energy resources, air emissions and waste products from thermochemical, 3) use the model to compare thermodynamic performance of available technologies in order to determine the most feasible in Irish contexts, and 4) make recommendations on future research and demonstration priorities aimed at reducing energy demand and GHG emissions at WWT plants.