The circularity of the supply chain, which allows the transformation of the current waste-sludge into END OF WASTE products, is achieved with the optimized integration of the hydrothermal carbonization process (HTC). In the last 5 years, HTC has reached full technological maturity and INGELIA has developed an industrial-scale system engineering solution for the treatment of plant-derived biomass.
The HTC process consists of a thermochemical conversion in an aqueous environment through which a biomass is transformed into a solid product rich in carbon (hydrochar), a liquid fraction rich in organic compounds and a minimum gaseous fraction. The operating conditions make the process particularly interesting for the transformation of biomass characterized by high levels of humidity such as sewage sludge, which could not be fed as such to other thermochemical conversion processes such as pyrolysis or gasification.
The resulting solid product is a peat / lignite-like fuel potentially usable in agriculture as a soil improver, soil remediation, production of materials (activated carbon, filler), while the aqueous phase maybe employed in agriculture (fertilizers) and biorefinery.
SLUDGE4.0 also faces for the first time at EU level the integration of sludge treatment systems (processes, infrastructures, controls) with HTC, with pilot and industrial validation tests that will be followed by laboratory screening: characterizations physico-chemical-bio-eco-toxicological in compliance with current regulations and validation tests on the field will demonstrate its sustainability.
In parallel, the new processes will provide the opportunity to connect the purification plants to shared computer networks in order to exploit their monitoring data and optimize the management performance of the biological sludge recovery, with environmental and economic repercussions. The processes will be integrated into a model of circular economy controlled by a management system on a regional scale that will interconnect all the Integrated Water Service purification plants through acquisition, processing and archiving of data from the various data bases of the Managers.
Through a process simulator it will therefore be possible to maintain a dynamic dialogue between the sewage treatment plants and HTC in order to identify sludge flows and quality for the targeted production of final products according to the final use with optimization of the supply chain (logistics, process, sale) and reduction of treatment, energy and transport costs.