The organic fraction of solid municipal waste, commonly called "organic waste", is a significant part of the waste produced in our homes. In Trentino Alto Adige, over 145,000 tons of organic waste were collected in 2019 (Ispra Report 2019). Reducing, reusing, recycling and recovering this type of waste is good for the environment but also for the economy, because it allows to produce compost, a fertilizer useful for agriculture, but also biogas, fuel for heating and electricity.
This virtuous cycle is inspired by the concept of "circular economy": a chain that starts from the product to get to waste and back again to a product – a material or energy product - in a process in which separate waste collection and recycling make the difference.
However, C2Land, a new international research project led by entities based in Trentino, focuses on the use of organic waste in agriculture. The goal is to produce soil improvers - special fertilizers that improve the physical and biological characteristics of the soil - from organic waste. The project aims to return carbon to the earth through a hydrothermal carbonization process that transforms organic waste or wet residual biomass into a more stable material than traditional carbon-enriched compost.
The bioreactors built in the workshops of the University of Trento transform waste into material that can be used again in agriculture (as soil improver) and which has a positive impact on the release of greenhouse gases from cultivated soils.
"With this carbonization process we can achieve in a few hours what nature does in geological eras", explains Luca Fiori of the Department of Civil, Environmental and Mechanical Engineering and of the C3A of UniTrento, and scientific director of the project. "We exploit the properties of water which, if pressurized, remains liquid even at temperatures above 100 degrees, to implement a fast and economical hydrothermal carbonization process of biomass. In our reactors we treat a part of the digestate from organic waste to create an innovative soil improver, beneficial for the life of plants because it creates an optimal living environment for the development of microorganisms, while also improving soil water retention. C2Land's innovative process combines anaerobic digestion, hydrothermal carbonization and composting".
The strength of the project is that it is part of virtuous practices already in place today in the province of Trento, such as anaerobic digestion, which allows the production of biogas/biomethane, and composting, necessary to produce compost for agricultural use. There are two plants treating organic waste in the province of Trento: one in Cadino, owned by Bioenergia Trentino (anaerobic digestion and composting), and one in Rovereto, managed by the Trentino wastewater treatment agency and the IBT Group (anaerobic digestion). The C2Land project was developed from the plant configuration of the Cadino plant with a view to making it more efficient.
In addition to obtaining a new type of soil improver, the model proposed by C2Land makes it possible to intensify the process of transformation of the organic waste with advantages for plant operators. It is also effective in reducing greenhouse gas emissions from cultivated soils. The circular model of C2Land, validated in the laboratory, could now be extended to the improvement of excess sludge deriving from civil wastewater treatment plants.
The C2Land project is conducted by the University of Trento (Department of Civil, Environmental and Mechanical Engineering) with Fondazione Edmund Mach and HIT - Hub Innovation Trentino, with the involvement of the Wastewater treatment agency (Agenzia per la Depurazione) of the Autonomous Province of Trento, BioenergiaTrentino and CarboRem. The project is co-funded by EIT, the European Institute of Technology and Innovation, within the EIT Climate-KIC. The role of Fondazione Edmund Mach (FEM) in the C2Land project involved the performance of a series of biological and biochemical tests, in the laboratory and in the greenhouse, to evaluate the agronomic and environmental quality of hydrochar as it is and as a product of composting. Hub Innovazione Trentino supports the University of Trento and Fondazione Edmund Mach in defining the strategies for the enhancement and dissemination of the project results with the aim of exploiting the commercial opportunities of technological innovation.
The results of the C2Land project will be presented next Wednesday, 16 December, at 10.00, in the online conference "Digestate: from organic waste a resource for the soil".
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For further information and to register to the conference visit: https://www.unitn.it/progettoC2Land