LIFE FREEDOM – Solving treatment of wastewater sewage sludge with new HTL technology to produce hydrocarbons, asphalts and fertilizers LIFE19 ENV/IT/000165
Duration of the project:
1.10. 2020. – 30.6. 2025.
EU co – financing:
Agrosistemi s.r.l. (Italy)
CAP Holding Spa, Italy; Spanish National Research Council, Spain; Impresa Caffù Costruzioni Generali S.r.l., Italy; Mondo Pulito d.o.o., Croatia; Syngen s.r.l., Italy; The University of Pavia, Hotel Italy
Web page: LIFE FREEDOM
The goal of the LIFE FREEDOM demonstration project is to prove the validity of a new technology that can solve the presented problem. This project seeks to demonstrate the widespread application of technology that follows a whole new path of sludge recovery, an alternative to current management routes. The thermochemical liquefaction process, also known as hydrothermal depolymerization or liquefaction (HTL), could be an innovative and promising solution to greatly reduce sewage sludge, recover raw materials from such waste and convert them into renewable biofuels or bituminous conglomerates. The crude oil produced, composed of a mixture of hydrocarbons, analogous to fossil fuels, can have multiple applications. One of the main goals of the HTL plant is to show the techno-economic sustainability of the production of such synthetic crude oil suitable for integration into a conventional oil refinery, in the asphalt or cement industry. Finally, another important aspect of environmental protection is phosphorus recovery. Phosphorus is a key natural resource for agriculture and other industrial sectors, but natural sources of phosphate are becoming scarce. This in turn results in rising prices and makes Europe heavily dependent on phosphate imports. The phosphorus content of sewage sludge produced in Europe could replace up to 20 or 30% of phosphate imports into the EU.
The general goal of the LIFE FREEDOM project is to apply hydrothermal liquefaction at the demonstration level as an innovative and reliable technology for sewage sludge treatment and production of useful materials of widespread industrial use by installing the HTL plant at the city WWTP. The originality of this project is the positioning of this processing system, directly related to the purifier equipment. This would allow for easy insertion into municipal treatment plants in the future, avoiding the creation of waste treatment centers, specially designed and realized, turning waste into useful raw materials. The proposed project falls under the theme of the Water Industry within the thematic priority for water. In need of finding a solution to the problem of sewage sludge disposal, and in line with the priority areas of the European Innovation Partnership on Water, this project proposes to improve wastewater treatment and a new and environmentally friendly alternative to current waste sludge management options.
- The production of waste sewage sludge (European waste code ERC 190805) will be eliminated. This means that, by considering only the CAP Holding treatment plant at the service of the municipality of Cassano d’Adda (producing sludge unsuitable for agricultural use), the landfill or the incineration of about 4,000 tons per year of biological sewage sludge will be avoided with a clear environmental advantage. More than 80% of the water contained in the purification sludge mass, currently leaving the treatment plant, will be recovered, returning to the plant head.
- Sludge transport from the purifier to the disposal site will be avoided. Assuming a minimum distance of 100 km round-trip on heavy-duty vehicles (average load 28 – 30 tons), it is equivalent to avoiding consumption of diesel fuel for the journey of more than 14,000 km per year. This is equivalent to avoiding the emission of 13,160 kg of CO2.
- In place of sludge disposal, the purifier could potentially produce: 380 tons of bio-oil and tar with similar characteristics to crude oil (about 2,700 barrels) to be used in bituminous conglomerates for the production of road surfaces. As the mixture of bituminous binders and gravel contains up to 20% of tar, by considering 10 cm as the thickness of a road surface, it could be possible to produce a road surface of 9,500 square meters per year.
- As fuel for thermal use it could be possible to obtain about 3800 MWth.
- 250 tons of mineral fraction for the production of novel binders.
- 50 tons of phosphorus (as P2O5) per year for the fertilizer industry. This quantity could be sufficient to cover the phosphorus need for a common crop such as maize, for an area between 300 and 400 hectares.