Authors: Karla Dussan and Rory Monaghan
Summary: EPA Research 216 detailing Thermodynamic Modelling of Energy Recovery Options from Digestate at Wastewater Treatment Plants
It is vitally important to evaluate alternative means of sludge disposal in order to avoid pollution of agricultural land. Thermal conversion technologies can address the problem of surplus sludge while also providing a means to support the consolidation of a secure and indigenous energy market in Ireland. Plant scale and poor fuel properties of sludge were identified as some of the technical challenges facing the implementation of thermal conversion plants; however, a number of potential solutions, including centralised plants and waste/biomass co-processing, have also been identified which may assist in overcoming these challenges.
This techno-economic performance study offers valuable information with respect to the potential of on-site and centralised thermal conversion of sewage sludge. The information generated will inform and assist stakeholders and local and government authorities in their consideration of the establishment of these alternatives in the future. The recognised challenges with regard to implementation of gasification and combustion as waste management techniques will also inform and direct future focused research and technological development activities in areas of greatest need.
This study created inexpensive computational tools which will be available for process modelling and techno-economic evaluation of the thermal conversion of sewage sludge, and of any characterised organic waste, intended for power and heat generation. These alternatives offer sustainable means of waste management and renewable energy production that can significantly reduce the carbon footprint of waste disposal practices and improve the energy security of Ireland.
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