Pyrolysis of wastewater sludge - A method for conversion of low quality bio material, to renewable energy and fertilizer

The overall objective of the envisaged project is to research, develop and demonstrate a novel method for conversion of low quality biomaterial, to renewable energy and fertilizer, through a process of drying and pyrolysis of discharged wastewater sludge from Recirculated Aquaculture Systems (RAS). The purpose of this method is to utilize the energy contained in organic carbon based compounds of sludge to separate the sludge in three fractions: clean water, pyrolysis gas to provide heat for drying the sludge and to be used for heating (or chilling via absorption cooling) in the aquaculture, and a residual biochar, rich on minerals and suitable for soil treatment and as a fertilize. This project will research and integrate a new an effective Superheated Steam Drying (SHD) process combined with the pyrolysis process. In addition, we will be researching the correlation between sludge and biochar characteristic and process the design and how to reduce overall environmental impact. The proposed sludge-processing unit consisting of a combined sludge dryer utilising superheated steam and pyrolysis unit providing the thermal energy for the drying process is extremely energy efficient due to the possibility for heat recovery of hot water close to 100 degree Celsius. The process will not only contribute to a considerable contribution of thermal energy that may be used for heating or cooling purposes as required locally, but the sludge will also be reduced to a residual biochar of less than 10% of the sludge mass. Researching, developing and subsequently marketing a method for conversion of low quality biomaterial, to renewable energy and fertilizer using pyrolysis will help to remove an important growth barrier for Scandinavian suppliers of RAS technology. At the same time it will create a significant new market opportunity for a Norwegian lead supply chain selling in to the $170bn global seafood industry, of which aquaculture is responsible for half of total production.